Insulin Resistance, Low Cardiorespiratory Fitness, and Increased Exercise Blood Pressure Contribution of Abdominal Obesity Maxime Huot, Benoit J. Arsenault, Valérie Gaudreault, Paul Poirier, Louis Pérusse, Angelo Tremblay, Claude Bouchard, Jean-Pierre Després, Caroline Rhéaume Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 Abstract—Individuals with insulin resistance and low cardiorespiratory fitness are frequently found to have an increased waist circumference and high exercise blood pressure. We tested the hypothesis that the relationships among insulin resistance, low cardiorespiratory fitness, and increased exercise blood pressure may be mediated by an elevated waist circumference. This study included 317 apparently healthy men and women (mean age: 34.8⫾12.8 years; mean body mass index: 26.1⫾5.2 kg/m2). Exercise blood pressure values were measured using a submaximal ergometer test evaluating physical working capacity. Plasma insulin and glucose levels were measured during a 3-hour oral glucose tolerance test. Multivariate regression analyses showed that waist circumference accounted for 32.8% (P⬍0.0001) and 45.1% (P⬍0.0001) of the variance in exercise systolic blood pressure in men and women, respectively. Participants were classified into tertiles according to either insulin response, measured during the oral glucose tolerance test, or fitness levels and then further subdivided into 2 subgroups using sex-specific waist circumference thresholds. Individuals with an increased waist circumference (ⱖ94 cm and ⱖ80 cm for men and women, respectively) had higher exercise systolic blood pressure compared with individuals with low waist circumference, irrespective of their level of insulin resistance (10.6 versus 6.8, 12.2 versus 7.7, and 13.2 versus 8.7 mm Hg/metabolic equivalent, respectively, for the low, intermediate, and high tertiles; P⬍0.05) or fitness levels (13.1 versus 8.2, 12.0 versus 7.9, and 10.6 versus 7.1 mm Hg/metabolic equivalent, respectively, for the low, intermediate, and high tertiles; P⬍0.05). Individuals with a higher waist circumference have elevated exercise systolic blood pressure, regardless of their insulin sensitivity or level of cardiorespiratory fitness. (Hypertension. 2011;58:1036-1042.) ● Online Data Supplement Key Words: insulin resistance 䡲 cardiorespiratory fitness 䡲 abdominal obesity 䡲 exercise blood pressure I had higher resting systolic BP (SBP) and diastolic BP (DBP) than individuals with low levels of visceral adipose tissue.10 Moreover, other investigators observed in women that there is an association between low CRF and higher exercise SBP (ExSBP) response during submaximal exercise, even after adjustment for resting SBP, heart rate, body mass index (BMI), age, and time to exhaustion.11 However, the specific contribution of abdominal adiposity to exercise BP (after control for relevant covariates, including CRF) remains unclear, but some authors have suggested that this relationship could be related to arterial stiffness, a phenomenon caused by inflammation.12–14 Although some studies have suggested an association between insulin resistance (IR) and an increase in BP during exercise,15 discordant findings have been reported in the literature. For instance, some have observed a strong relationship between IR and exercise BP,12,16 and others have t is well-documented that normotensive individuals with an elevated blood pressure (BP) response to exercise are at a higher risk of developing future systemic hypertension (HT).1– 4 It has been reported that individuals characterized by elevated exercise BP may account for 5%2 to 40%5 of individuals at risk of developing cardiovascular disease. Because an abnormal BP response to exercise increases mortality risk from myocardial infarction and increases the risk of developing cardiovascular disease,6 – 8 identifying and understanding the key determinants of exercise-induced BP response is clinically relevant. Recently, Carnethon et al9 suggested that low cardiorespiratory fitness (CRF) is associated with incident HT and that improvement in CRF could prevent 34% of new HT cases. A previous report from our laboratory showed that, independent of CRF, individuals with greater visceral adipose tissue accumulation (measured directly by computed tomography) Received July 28, 2011; first decision August 22, 2011; revision accepted September 27, 2011. From the Division of Kinesiology, Department of Social and Preventive Medicine (M.H., L.P., A.T., J.-P.D.) and Department of Family Medicine and Emergency Medicine (C.R.), Faculty of Medicine, and Faculty of Pharmacy (P.P.), Université Laval, Québec, Québec, Canada; Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec (M.H., B.J.A., V.G., P.P., A.T., J.-P.D., C.R.), Québec, Québec, Canada; Human Genomics Laboratory (C.B.), Pennington Biomedical Research Center, Baton Rouge, LA. Correspondence to Caroline Rhéaume, Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 Chemin Ste-Foy, Québec, Québec G1V 4G5, Canada. E-mail [email protected] © 2011 American Heart Association, Inc. Hypertension is available at http://hyper.ahajournals.org DOI: 10.1161/HYPERTENSIONAHA.111.180349 1036 Huot et al reported modest increases in exercise DBP with increases in IR.13 One study has, however, observed a relationship among IR, CRF, and obesity (evaluated with BMI and waist:hip ratio) in men with type 2 diabetes mellitus and found an independent association between IR and SBP response to exercise.17 To the best of our knowledge, no study has yet simultaneously examined the relationship among abdominal obesity, IR, CRF, and BP response to exercise in apparently healthy adults. The aim of this study was to investigate whether the relationship between IR and exercise BP, as well as the relationship between CRF and exercise BP, could be explained by the fact that individuals with IR and/or poor CRF have greater abdominal fat accumulation. Methods Study Population Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 Study participants were apparently healthy men and women who participated in the Québec Family Study. Included in this analysis were 317 participants without diabetes mellitus and without HT at rest for whom we had body composition measurements, position measurements, and data on waist circumference (WC), resting and submaximal exercise BP, CRF, glucose homeostasis measurement, lipid profile, and dietary/physical journals. The study sample included participants from whom we obtained data on body composition, CRF, and glucose homeostasis. The Québec Family Study is a population-based study of French-Canadian families living in and around the Québec City area. The Québec Family Study was approved by the medical ethics committee of Université Laval. Participants were recruited through the media and gave their written informed consent to participate in the study. Only men and women, 18 to 65 years of age, who were not receiving medication for cardiovascular disease, diabetes mellitus, HT, dyslipidemias, or endocrine disorders were considered for the present analyses. The 79 smokers (24.9%) in our cohort were asked to refrain from smoking before their evaluation. Additional details about the Québec Family Study have been reported previously.18 Exercise, Blood Pressure, and Abdominal Obesity 1037 last stage. This allowed for the PWC at a heart rate of 150 bpm to be interpolated.22 The PWC150, defined as the power output at 150 bpm, was then calculated from the linear relationship between heart rate and power output and expressed as kilopound per minute per kilogram (kpm/kg) to take individual differences in body weight into account. Expired air was analyzed with a Beckman Measurement Metabolic Cart to obtain oxygen consumption (V̇O2) corrected for standard conditions and computed in liters of O2 per minute.23 To consider the individual differences in workloads attained at the final stage and body weight, the V̇O2 was converted to metabolic equivalents (METs; 1 MET⫽3.5 mL O2*kg⫺1*min⫺1) using the following formula: (V̇O2 (L/min)*1000)/(weight (kg)*3.5). Resting Hemodynamic Measurement Resting BP measurements were taken using standard procedures: in the morning, in the fasting state, and in a semi-inclined position after a 45-minute rest (after an assessment of resting metabolic rate) using a mercury sphygmomanometer (Propper) and an appropriately sizedcuff (Welch Allyn Tycos). Resting BP measurements were taken on the same day as the exercise test. Participants were asked not to smoke for 2 hours before the measurement of their BP. The mean of 2 valid BP measurements was retained. Exercise Hemodynamic Measurement We used levels of BP attained at the last stage of the submaximal exercise test. As the workload reached during the final stage of the PWC150 differed from one individual to another, we used the method described previously by Zanettini et al24 to quantify the increase in BP adjusted for each individual’s working capacity. Hence, we computed the difference between the SBP and DBP from rest to exercise divided by the intensity reached at the end of the last stage of the PWC150 (Figure S1, available in the online Data Supplement at http://hyper.ahajournals.org). The ExSBP and exercise DBP were expressed as SBP or DBP variation per 1-MET increment (in millimeters of mercury per MET). Analysis of Dietary Intake Height and body weight were measured following standardized procedures. WC was measured using graduated tape while in a standing position. WC was measured as the narrowest circumference of the abdomen, between the iliac crest and the twelfth ribs.19 Dietary intake was assessed through the use of a 3-day dietary journal, which was completed for 2 weekdays and 1 weekend day. Subjects were asked to record all of the foods and beverages ingested (except water) with the use of a balance and measuring cups and spoons. Subjects received instructions from a nutritionist on the procedures needed to complete the dietary record and to measure food portions. After completion, the record was verified by a nutritionist. Macronutrient and micronutrient intakes were estimated through the use of a computerized version of the Canadian Nutrient File. Macronutrient intakes were expressed in absolute values (in grams) and also as percentages of total energy intake. Glucose Homeostasis Measurement Physical Activity Measurement A 3-hour 75-g oral glucose tolerance test was performed in the morning after an overnight fast. Blood samples were obtained in EDTA-containing tubes through a venous catheter placed in an antecubital vein to determine fasting plasma glucose and insulin levels. Plasma glucose levels were measured enzymatically, and plasma insulin levels were measured by radioimmunoassay with polyethylene glycol separation20 at ⫺15, 0, 15, 30, 45, 60, 90, 120, 150, and 180 minutes. Areas under the curve for insulin during the oral glucose tolerance test were calculated using the trapezoid method.21 Daily physical activity level and patterns were evaluated through the use of a 3-day physical activity diary. Subjects recorded the energy expenditure level for each 15-minute period over 24 hours based on activities classified on a 1 to 9 scale, with 1 corresponding with activities of very low energy expenditure, such as sleeping, and 9 to activities of very high energy expenditure, such as running. Based on this information, we estimated energy expenditure with daily physical activities and expressed them as kilocalories per kilogram of body weight to take into account individual differences in body weight. CRF Measurement Statistical Analysis The CRF of each participant was assessed using a progressive submaximal physical working capacity (PWC) test performed on a modified Monark cycle ergometer (Stockholm, Sweden). Heart rate was measured through an ECG derivation and was recorded during 3 consecutive 6-minute stages with increasing workloads, each separated by 1 minute of free pedalling at the minimal workload of 25 W. The protocol was designed to ensure that each subject would reach a target heart rate between 150 and 170 bpm at the end of the Data are presented as mean⫾SD in Tables and as mean⫾SEM in Figures. Baseline characteristics of participants are presented separately for men and women. BP was compared between participants classified on the basis of WC using the most recent cutoffs established by the International Diabetes Federation (⬍ or ⱖ94 cm and ⬍ or ⱖ80 cm for white men and women, respectively)25 and sex-specific tertiles of insulin area under the curve (AUC) or sex-specific tertiles of CRF. Differences among groups were evalu- Anthropometric and Body Composition Measurements 1038 Hypertension December 2011 Table 1. Characteristics of the 171 Men and 146 Women of the Study Variables men and women analyzed separately. In this model, we included age, smoking, salt intake, alcohol intake, energy expenditure by kilograms, BMI, WC, insulin AUC, SBP, DPB, and CRF. Statistical analyses were performed using SAS version 9.2 (SAS Institute, Cary, NC). Men (n⫽171) Women (n⫽146) Age, y 36.3⫾13.9 33.1⫾11.1 Waist circumference, cm 89.3⫾12.2 80.7⫾14.5 Body mass index, kg/m2 Results 25.9⫾4.2 26.3⫾6.1 Resting SBP, mm Hg 113⫾10 108⫾9 Resting DBP, mm Hg 70⫾8 67⫾8 6.92⫾1.40 5.90⫾1.38 Total cholesterol, mmol/L 4.8⫾1.0 4.6⫾0.9 HDL cholesterol, mmol/L 1.1⫾0.3 1.3⫾0.3 LDL cholesterol, mmol/L 3.0⫾0.8 2.7⫾0.8 Cholesterol/HDL cholesterol 4.6⫾1.4 3.7⫾1.0 Triglycerides, mmol/L 1.5⫾1.0 1.2⫾0.5 The study sample included 171 apparently healthy men and 146 apparently healthy women. A total of 71 participants were classified as prehypertensive according to American guidelines on HT.26 Table 1 presents baseline anthropometric and metabolic characteristics of study participants, as well as resting SBP and DBP and exercise BP at 150 bpm. Mean CRF levels for men and women derived from the PWC150 test are also shown. Pearson correlation coefficients for the associations among WC, insulin AUC, CRF, and BP indices before and after adjustment for cardiometabolic risk markers are presented in Table 2. Table 3 presents the partial and total contributions of the combination of BMI, WC, insulin AUC, age, smoking, salt intake, alcohol intake, energy expenditure, SBP, DBP, and PWC150 to the variance of ExSBP for the entire cohort and for men and women examined separately. Thus, WC made significant a contribution to the variance of ExSBP in both sexes. Because WC is a crude clinical marker of intra-abdominal obesity, we have repeated all of the above analyses by replacing WC with a direct measurement of visceral adiposity measured by computed tomography. Essentially similar results were observed using either WC or visceral adipose tissue as the abdominal adiposity variable (data not shown). PWC150/kg, METs Glucose, mmol/L Insulin, pmol/L 5.2⫾0.5 5.0⫾0.4 61.2⫾43.1 64.2⫾48.2 Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 PWC150/kg indicates physical working capacity at 150 bpm; SBP, systolic blood pressure; DBP, diastolic blood pressure; HDL, high-density lipoprotein; LDL, low-density lipoprotein; MET, metabolic equivalent. Data are presented as mean⫾SD. ated with a 1-way ANOVA. Pearson correlation coefficients, adjusted for age, smoking, physical activity, and diet, or for a combination of these previous variables and 2 of the 3 cardiometabolic risk markers considered in the present study, were performed to assess the sex-specific relationships between WC, insulin AUC or CRF with BP indices. Stepwise multiple regression analyses were computed to quantify the contribution of cardiometabolic risk markers to the variance in BP indices for the entire sample and for Table 2. Correlation Coefficients (R) Among Waist Circumference, Insulin Area Under The Curve Measured During a 75-g Oral Glucose Tolerance Test, Cardiorespiratory Fitness, and Blood Pressure Indices Before and After Adjustment for Insulin Area Under the Curve, Cardiorespiratory Fitness, or Waist Circumference WC Variable Adjusted for Age, Smoking, Physical Activity, and Diet Insulin AUC Adjusted for Insulin AUC and CRF CRF Adjusted for Age, Smoking, Physical Activity, and Diet Adjusted for WC and CRF Adjusted for Age, Smoking, Physical Activity, and Diet Adjusted for WC and Insulin AUC ⫺0.02 Total (n⫽300) SBP 0.27† 0.24† 0.12* 0.01 ⫺0.06 DBP 0.30† 0.24† 0.19* 0.08 ⫺0.04 ExSBP 0.58† 0.48† 0.45† 0.26† ⫺0.20* ⫺0.13* 0.07 0.13* 0.01 0.03 ExDBP ⫺0.09 0.02 ⫺0.07 Men (n⫽163) SBP 0.21* 0.17* 0.13 0.04 ⫺0.07 ⫺0.00 DBP 0.25* 0.17* 0.23* 0.14 ⫺0.07 0.03 0.40† ExSBP ExDBP 0.48† ⫺0.03 0.28* 0.02 ⫺0.29* ⫺0.18* ⫺0.05 0.02 0.02 ⫺0.05 ⫺0.05 Women (n⫽137) SBP 0.28* 0.16 0.12 ⫺0.02 ⫺0.30* ⫺0.20* DBP 0.27* 0.18* 0.12 0.00 ⫺0.21* ⫺0.10 ExSBP 0.63† 0.50† 0.57† 0.42† ⫺0.31* 0.02 ExDBP ⫺0.17* 0.13 0.22* 0.11 0.07 ⫺0.16 WC indicates waist circumference; insulin AUC, insulin area under the curve measured during a 75-g oral glucose tolerance test; CRF, cardiorespiratory fitness; SBP, systolic blood pressure; DBP, diastolic blood pressure; ExSBP, exercise systolic blood pressure; ExDBP, exercise diastolic blood pressure. *Pⱕ0.05. †P⬍0.0001. Exercise, Blood Pressure, and Abdominal Obesity R2, % Dependent Variables Independent Variables Partial Total P WC 40.1 40.1 ⬍0.0001 ⫹Insulin AUC ⫹4.3 44.4 ⬍0.0001 ⫹Age ⫹4.0 48.4 ⬍0.0001 ⫹DBP ⫹1.2 49.7 0.0075 ⫹BMI ⫹0.7 Total (n⫽300) ExSBP 50.4 0.0432 ⫹SBP ⫹PWC150/kg Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 ⫹Smoking ⫹Salt intake ⫹Alcohol intake ⫹Energy expenditure Men (n⫽163) ExSBP WC 32.8 32.8 ⬍0.0001 ⫹Age ⫹6.0 38.8 0.0001 ⫹DBP ⫹4.0 42.8 0.001 ⫹PWC150/kg ⫹1.9 44.7 0.0216 ⫹BMI 16 14 Low WC High WC 12 1 1,2,3,5 1,3 1,2,4 10 2 8 6 4 2 0 B 1039 (1) (2) Low (3) (4) Intermediate (5) (6) High Insulin AUC Tertiles 1.6 1.4 Low WC High WC 1,2 1.2 1.0 0.8 0.6 0.4 0.2 0 (1) (2) Low (3) (4) Intermediate (5) (6) High Insulin AUC Tertiles Figure 1. Mean variation values of systolic blood pressure (SBP; A) and diastolic blood pressure (DBP; B) induced by exercise corrected for intensity (⌬SBP and ⌬DBP per 1-metabolic equivalent [MET] increment) classified on the basis of sex-specific tertiles of insulin area under the curve (AUC; lowest: ⬍40 785; intermediate: ⱖ40 785 and ⬍70 230; or highest: ⱖ70 230 pmol/L for men and lowest: ⬍46 931; intermediate: ⱖ46 931 and ⬍69 701; or highest: ⱖ69 701 pmol/L for women) and waist circumference (WC; ⬍ or ⱖ94 cm and ⬍ or ⱖ80 cm for men and women, respectively). 1, 2, 3, 4, and 5 are significantly different from corresponding subgroup. P⬍0.05. ⫹Insulin AUC ⫹SBP ⫹Smoking ⫹Salt intake ⫹Alcohol intake ⫹Energy expenditure Women (n⫽137) ExSBP A Δ SBP per 1-MET increment (mm Hg / MET) Table 3. Multivariate Regression Analyses Showing the Contribution of Age, Smoking, Salt Intake, Alcohol Intake, Energy Expenditure, Body Mass Index, Waist Circumference, Insulin Area Under the Curve, Systolic Blood Pressure, Diastolic Blood Pressure, and Cardiorespiratory Fitness to the Variance in Exercise Systolic Blood Pressure Δ DBP per 1-MET increment (mm Hg / MET) Huot et al WC 45.1 45.1 ⬍0.0001 ⫹Insulin AUC ⫹9.1 54.2 ⬍0.0001 ⫹Age ⫹3.9 58.1 0.0006 ⫹BMI ⫹SBP ⫹DBP ⫹PWC150/kg ⫹Smoking ⫹Salt intake ⫹Alcohol intake ⫹Energy expenditure Variables included in the multivariate model were age, smoking, salt intake, alcohol intake, energy expenditure per kilogram, BMI, WC, insulin AUC, SBP, DBP, PWC150/kg, and ExSBP. WC indicates waist circumference; insulin AUC, insulin area under the curve measured during a 75-g oral glucose tolerance test; CRF, cardiorespiratory fitness; SBP, systolic blood pressure; DBP, diastolic blood pressure; ExSBP, exercise systolic blood pressure; BMI, body mass index; PWC150/kg, physical working capacity at 150 bpm; salt intake, average No. of salted foods recorded in each participant’s dietary journal; alcohol intake, average grams per day of alcohol recorded in each participant’s dietary journal; energy expenditure, expressed as kilocalories per kilogram of body weight (kcal/kg). To determine whether IR is associated with higher exercise BP, we classified men and women on the basis of sex-specific tertiles of insulin AUC and sex-specific WC (⬍ or ⱖ94 cm and ⬍ or ⱖ80 cm for men and women, respectively). Figure 1A shows that individuals with elevated WC had higher values of ⌬SBP per 1-MET increment compared with individuals with low WC, independent of insulin levels. There was no relationship between groups of insulin AUC and WC for ⌬DBP per 1-MET increment (Figure 1B). Finally, to determine whether poor CRF is associated with higher exercise BP, men and women were classified on the basis of sex-specific tertiles of CRF and sex-specific WC (⬍ or ⱖ94 cm and ⬍ or ⱖ80 cm for men and women, respectively). Figure 2A shows that individuals with elevated WC had higher values of ⌬SBP per 1-MET increment compared with individuals with low WC, independent of CRF. However, individuals with high CRF had lower ⌬SBP per 1-MET increment compared with those with low CRF for similar WC. There was no difference between groups of CRF and WC for ⌬DBP per 1-MET increment (Figure 2B). 1040 Δ SBP per 1-MET increment (mm Hg / MET) A Hypertension 16 14 Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 Δ DBP per 1-MET increment (mm Hg / MET) Low WC High WC 1 1,3 1,2,3,5 12 10 2 8 1,2,4 6 4 2 0 B December 2011 (1) (2) Low (3) (4) Intermediate (5) (6) High CRF Tertiles 1.8 1.6 Low WC High WC 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 (1) (2) Low (3) (4) Intermediate (5) (6) High CRF Tertiles Figure 2. Mean variation values of systolic blood pressure (SBP; A) and diastolic blood pressure (DBP; B) induced by exercise corrected for intensity (⌬SBP and ⌬DBP per 1-metabolic equivalent [MET] increment) classified on the basis of sex-specific tertiles of CRF (lowest: ⬍9.63; intermediate: ⱖ9.63 and ⬍12.07; highest: ⱖ12.07 kpm/kg for men and lowest: ⬍6.93; intermediate: ⱖ6.93 and ⬍8.65; highest: ⱖ8.65 kpm/kg for women) and waist circumference (WC; ⬍ or ⱖ94 cm and ⬍ or ⱖ80 cm for men and women, respectively). 1, 2, 3, 4, and 5 are significantly different from corresponding subgroup. P⬍0.05. Discussion The most important finding of our study is that, irrespective of IR and/or CRF levels, apparently healthy men and women with elevated WC had a more pronounced increase in exercise BP than subjects with a lower WC. Although we did notice that IR and CRF levels were associated with BP indices (especially ExSBP) measured during a submaximal test, our results suggest that such an association could be explained to a large extent by the fact that individuals with IR and/or low CRF levels were also characterized by abdominal obesity. This finding suggests that an increased WC may capture a fair amount of metabolically active visceral fat, which may represent a key “mediating factor” linking low CRF and/or IR to higher ExSBP. The rationale for identifying another potential mediating factor in the relationship between low CRF and incident HT using an intermediate risk marker for HT is that the evaluation of exercise BP combined with abdominal obesity could enable the clinician to identify, at an earlier stage, individuals at increased risk of cardiovascular events. Previous studies have also examined the relationship between IR and exercise BP. In a sample of treated nondiabetic hypertensive individuals, Park et al27 showed that individuals with an elevated homeostasis model assessment index were also likely to have an exaggerated BP response to exercise, a finding that suggests the contribution of IR to the regulation of exercise BP.27 This association was also found to be independent of resting BP.27 Other authors who previously studied IR and exercise BP in normotensive insulin resistant HT-prone subjects,28 active asymptomatic men,29 and uncomplicated type 2 diabetic men,29 observed an increase in exercise DBP with increases in IR. The hypothesis put forward to explain these variations is that there is a close relationship between DBP and peripheral vascular resistance28 or there is an impaired vascular reactivity combined to higher serum cholesterol concentrations.29 However, our study only showed a difference in the ExSBP of abdominally obese individuals who were in the highest insulin tertiles. Thus, our study provides evidence that the previously reported association between IR and exercise BP could be explained by the concomitant presence of abdominal obesity. In addition, Brett et al29 have also suggested that IR was influenced by CRF and that it could partly explain the association between exercise DBP and IR. In a large population of 1411 normotensive and hypertensive women, Kokkinos et al11 showed that the most important determinants of BP response to exercise were resting SBP and effort duration.11 After 6 minutes of exercise, SBP was significantly more elevated in women with low CRF, even after adjustment for age, BMI, and resting BP,11 compared with women with high CRF. Results obtained by Brett et al29 are similar to our results in that low CRF seemed to be associated with higher ExSBP compared with individuals with high levels of CRF. Kumagai et al17 studied the relationship of SBP during exercise with IR, obesity, and CRF in men with type 2 diabetes mellitus. Their results showed that changes in SBP during exercise were significantly and negatively associated with glucose tolerance and IR. These findings suggested an independent association between IR and SBP response to exercise.17 However, they did not find any relationship between ExSBP and markers of adiposity, such as waist:hip ratio, BMI, body fat percentage, and either visceral fat area or subcutaneous fat area.17 However, this study included only 63 men, all of whom had type 2 diabetes mellitus. It is also possible that the more pronounced impairments in the plasma glucose-insulin homeostasis, such as those observed in patients with type 2 diabetes mellitus, may contribute to deteriorations in hemodynamic parameters, irrespective of adiposity indices. Several pathophysiological mechanisms linking IR, CRF, abdominal obesity, and exercise BP may contribute to an increased BP response to exercise. Previous studies have shown that arterial stiffness is associated with an exaggerated BP response to exercise, obesity, IR,30 and poor CRF.12,31 One factor typically observed in individuals with IR and/or abdominal fat accumulation is a decrease in NO bioavailability, which could be the result of increased blood glucose and free fatty acid concentrations and an increased superoxide production by adipocytes.32 This impairment could also be related to inflammation with visceral fat producing several proinflammatory cytokines14 or the result of an inappropriately elevated cyclic GMP stimulated by NO, therefore impairing Huot et al Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 vasodilation.13 It is also plausible that renin-angiotensin-aldosterone system could be involved, because visceral fat secretes renin-angiotensin-aldosterone system mediators, such as angiotensinogen,14 which is associated with vascular inflammation. Angiotensin also mediates negative cardiovascular effects through the signaling pathways of reactive oxygen species, which amplifies oxidative stress provoked by other agents33 and has been linked to increases in exercise BP.34 According to previous work35–38 showing the stronger predictive value of WC for incident HT, our results indicate that WC seems to be more closely associated with BP indices than any other obesity indices, such as BMI (Table 3). Such a conclusion is also consistent with findings from our previous longitudinal study, which indicated that maintaining low levels of visceral adiposity and high levels of CRF were both important targets for the maintenance of a healthy cardiometabolic risk profile (including BP) in apparently healthy individuals.39 It is important to note that our study population was limited to middle-aged white participants with a relatively low prevalence of HT. This may limit the generalization of our findings to other populations with various ethnicities and with broader age ranges or diseases.40 In addition, considering that there was no replication sample available, the unique size and characteristics of our cohort may have had an impact on which variables were retained in our model. Also, the possibility of a measurement bias in the assessment of resting BP (only office BP) should be taken into consideration, because ambulatory BP monitoring has been shown to provide more accurate assessment of BP. In conclusion, these results suggest that abdominally obese individuals are characterized by an elevated SBP response to exercise, irrespective of IR and CRF levels. The evaluation of exercise BP combined with abdominal obesity could enable the clinician to identify, at an earlier state, individuals at increased risk of cardiovascular events. Perspectives Based on our findings, we believe that longitudinal and/or intervention studies with specific measurements of IR, CRF, exercise BP, and abdominal obesity are required to properly investigate risk factors of HT and the extent to which the relationship between these parameters is explained by abdominal obesity. Of course, we recognize that the BP response to exercise is not routinely performed in clinical practice for abdominally obese patients, but we hope that our study will raise interest in future studies looking further at this potentially useful marker. Moreover, because of the lack of studies investigating the impact of physical activity and/or CRF levels and other lifestyle interventions, further interventional studies are needed to investigate whether increasing CRF levels and decreasing abdominal obesity will lead to improvements in BP at exercise and, consequently, will decrease cardiovascular disease risk. Identifying cardiometabolic risk factors of HT and the extent to which these risk factors contribute to BP are key to the development of successful BP managing strategies. Exercise, Blood Pressure, and Abdominal Obesity 1041 Acknowledgments We express our gratitude to the Québec Family Study subjects for their excellent collaboration and the staff of Centre Hospitalier de l’Université Laval. We especially thank Guy Fournier and Lucie Allard of the Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec; Dr Germain Thériault of Université Laval; and Claude Leblanc of the Physical Activity Sciences Laboratory for their help with data collection and for their contribution to the study. Sources of Funding B.J.A. is supported by a postdoctoral fellowship from the Fonds de la Recherche en Santé du Québec and the Fondation de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec. C.B. is partly funded by the John W. Barton, Sr, Chair in Genetics and Nutrition. A.T. is partly funded by the Canada Research Chair in Environment and Energy Balance. J.-P.D. is the scientific director of the International Chair on Cardiometabolic Risk, which is based at Université Laval. P.P. is a clinical scholar from the Fonds de la Recherche en Santé du Québec. The Québec Family Study was supported by multiple grants from the Medical Research Council of Canada (now the Canadian Institutes of Health Research), the Canadian Diabetes Association, and other agencies in Québec and elsewhere in Canada. Disclosures None. References 1. Manolio TA, Burke GL, Savage PJ, Sidney S, Gardin JM, Oberman A. Exercise blood pressure response and 5-year risk of elevated blood pressure in a cohort of young adults: the CARDIA Study. Am J Hypertens. 1994;7:234 –241. 2. Singh JP, Larson MG, Manolio TA, O’Donnell CJ, Lauer M, Evans JC, Levy D. Blood pressure response during treadmill testing as a risk factor for new-onset hypertension: the Framingham Heart Study. Circulation. 1999;99:1831–1836. 3. Miyai N, Arita M, Morioka I, Miyashita K, Nishio I, Takeda S. Exercise BP response in subjects with high-normal BP: exaggerated blood pressure response to exercise and risk of future hypertension in subjects with high-normal blood pressure. J Am Coll Cardiol. 2000;36:1626 –1631. 4. Matthews CE, Pate RR, Jackson KL, Ward DS, Macera CA, Kohl HW, Blair SN. Exaggerated blood pressure response to dynamic exercise and risk of future hypertension. J Clin Epidemiol. 1998;51:29 –35. 5. Laukkanen JA, Kurl S, Rauramaa R, Lakka TA, Venalainen JM, Salonen JT. Systolic blood pressure response to exercise testing is related to the risk of acute myocardial infarction in middle-aged men. Eur J Cardiovasc Prev Rehabil. 2006;13:421– 428. 6. Mundal R, Kjeldsen SE, Sandvik L, Erikssen G, Thaulow E, Erikssen J. Exercise blood pressure predicts mortality from myocardial infarction. Hypertension. 1996;27:324 –329. 7. Filipovsky J, Simon J, Chrastek J, Rosolova H, Haman P, Petrikova V. Changes of blood pressure and lipid pattern during a physical training course in hypertensive subjects. Cardiology. 1991;78:31–38. 8. Kurl S, Laukkanen JA, Rauramaa R, Lakka TA, Sivenius J, Salonen JT. Systolic blood pressure response to exercise stress test and risk of stroke. Stroke. 2001;32:2036 –2041. 9. Carnethon MR, Evans NS, Church TS, Lewis CE, Schreiner PJ, Jacobs DR Jr, Sternfeld B, Sidney S. Joint associations of physical activity and aerobic fitness on the development of incident hypertension: coronary artery risk development in young adults. Hypertension. 56:49 –55. 10. Rheaume C, Arsenault BJ, Belanger S, Perusse L, Tremblay A, Bouchard C, Poirier P, Despres JP. Low cardiorespiratory fitness levels and elevated blood pressure: what is the contribution of visceral adiposity? Hypertension. 2009;54:91–97. 11. Kokkinos PF, Andreas PE, Coutoulakis E, Colleran JA, Narayan P, Dotson CO, Choucair W, Farmer C, Fernhall B. Determinants of exercise blood pressure response in normotensive and hypertensive women: role of cardiorespiratory fitness. J Cardiopulm Rehabil. 2002;22:178 –183. 12. Tsiachris D, Tsioufis C, Dimitriadis K, Kokkinos P, Faselis C, Tousoulis D, Michaelides A, Papademetriou V, Stefanadis C. Relationship of ambu- 1042 13. 14. 15. 16. 17. 18. Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 19. 20. 21. 22. 23. 24. 25. Hypertension December 2011 latory arterial stiffness index with blood pressure response to exercise in the early stages of hypertension. Blood Press Monit. 15:132–138. Chang HJ, Chung JH, Choi BJ, Choi TY, Choi SY, Yoon MH, Hwang GS, Shin JH, Tahk SJ, Choi BI. Endothelial dysfunction and alteration of nitric oxide/cyclic GMP pathway in patients with exercise-induced hypertension. Yonsei Med J. 2003;44:1014 –1020. Hutley L, Prins JB. Fat as an endocrine organ: relationship to the metabolic syndrome. Am J Med Sci. 2005;330:280 –289. Sironi AM, Gastaldelli A, Mari A, Ciociaro D, Positano V, Buzzigoli E, Ghione S, Turchi S, Lombardi M, Ferrannini E. Visceral fat in hypertension: influence on insulin resistance and -cell function. Hypertension. 2004;44:127–133. Tzemos N, Lim PO, MacDonald TM. Exercise blood pressure and endothelial dysfunction in hypertension. Int J Clin Pract. 2009;63:202–206. Kumagai S, Kai Y, Hanada H, Uezono K, Sasaki H. Relationships of the systolic blood pressure response during exercise with insulin resistance, obesity, and endurance fitness in men with type 2 diabetes mellitus. Metabolism. 2002;51:1247–1252. Bouchard C. Genetic epidemiology, association, and sib-pair linkage: Results from the Québec Family Study. In: Bray GA, Ryan DH, eds. Molecular and Genetic Aspects of Obesity. Pennington Center Nutrition Series. Baton Rouge, LA: Louisiana State University Press; 1996;5: 470 – 481. Lohman TG, Roche AF, Martorell R. Chapter 4: circumferences. In: Book HK, ed. Anthropometric Standardization Reference Manual. Champaign, IL: Human Kinetics Books; 1988:39 – 80. Richterich R, Dauwalder H. Determination of plasma glucose by hexokinase-glucose-6-phosphate dehydrogenase method [in German]. Schweiz Med Wochenschr. 1971;101:615– 618. Arsenault BJ, Lachance D, Lemieux I, Alméras N, Tremblay A, Bouchard C, Pérusse L, Després JP. Visceral adipose tissue accumulation, cardiorespiratory fitness, and features of the metabolic syndrome. Arch Intern Med. 2007;167:1518 –1525. Bouchard C, Lortie G, Simoneau JA, Leblanc C, Theriault G, Tremblay A. Submaximal power output in adopted and biological siblings. Ann Hum Biol. 1984;11:303–309. Lortie G, Bouchard C, Leblanc C, Tremblay A, Simoneau JA, Theriault G, Savoie JP. Familial similarity in aerobic power. Hum Biol. 1982;54: 801– 812. Zanettini JO, Pisani Zanettini J, Zanettini MT, Fuchs FD. Correction of the hypertensive response in the treadmill testing by the work performance improves the prediction of hypertension by ambulatory blood pressure monitoring and incidence of cardiac abnormalities by echocardiography: results of an eight year follow-up study. Int J Cardiol. 141: 243–249. Alberti KG, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, Donato KA, Fruchart JC, James WP, Loria CM, Smith SC Jr. Harmonizing the metabolic syndrome: a joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity. Circulation. 2009;120: 1640 –1645. 26. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, Jones DW, Materson BJ, Oparil S, Wright JT Jr, Roccella EJ. The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. Hypertension. 2003;42:1206 –1252. 27. Park S, Shim J, Kim JB, Ko YG, Choi D, Ha JW, Rim SJ, Jang Y, Chung N. Insulin resistance is associated with hypertensive response to exercise in non-diabetic hypertensive patients. Diabetes Res Clin Pract. 2006;73: 65– 69. 28. Andersen UB, Olsen MH, Dige-Petersen H, Ibsen H. Exercise blood pressure is related to insulin resistance in subjects with two hypertensive parents. Blood Press. 2003;12:314 –318. 29. Brett SE, Ritter JM, Chowienczyk PJ. Diastolic blood pressure changes during exercise positively correlate with serum cholesterol and insulin resistance. Circulation. 2000;101:611– 615. 30. Webb DR, Khunti K, Silverman R, Gray LJ, Srinivasan B, Lacy PS, Williams B, Davies MJ. Impact of metabolic indices on central artery stiffness: independent association of insulin resistance and glucose with aortic pulse wave velocity. Diabetologia. 53:1190 –1198. 31. Tsioufis C, Dimitriadis K, Thomopoulos C, Tsiachris D, Selima M, Stefanadi E, Tousoulis D, Kallikazaros I, Stefanadis C. Exercise blood pressure response, albuminuria, and arterial stiffness in hypertension. Am J Med. 2008;121:894 –902. 32. Seifalian AM, Filippatos TD, Joshi J, Mikhailidis DP. Obesity and arterial compliance alterations. Curr Vasc Pharmacol. 8:155–168. 33. Nashar K, Nguyen JP, Jesri A, Morrow JD, Egan BM. Angiotensin receptor blockade improves arterial distensibility and reduces exerciseinduced pressor responses in obese hypertensive patients with the metabolic syndrome. Am J Hypertens. 2004;17:477– 482. 34. Shim CY, Ha JW, Park S, Choi EY, Choi D, Rim SJ, Chung N. Exaggerated blood pressure response to exercise is associated with augmented rise of angiotensin II during exercise. J Am Coll Cardiol. 2008;52: 287–292. 35. Chuang SY, Chou P, Hsu PF, Cheng HM, Tsai ST, Lin IF, Chen CH. Presence and progression of abdominal obesity are predictors of future high blood pressure and hypertension. Am J Hypertens. 2006;19: 788 –795. 36. Poirier P, Lemieux I, Mauriège P, Dewailly E, Blanchet C, Bergeron J, Despres JP. Impact of waist circumference on the relationship between blood pressure and insulin: the Quebec Health Survey. Hypertension. 2005;45:363–367. 37. Yanai H, Tomono Y, Ito K, Furutani N, Yoshida H, Tada N. The underlying mechanisms for development of hypertension in the metabolic syndrome. Nutr J. 2008;7:10. 38. Kanai H, Matsuzawa Y, Kotani K, Keno Y, Kobatake T, Nagai Y, Fujioka S, Tokunaga K, Tarui S. Close correlation of intra-abdominal fat accumulation to hypertension in obese women. Hypertension. 1990;16: 484 – 490. 39. Rheaume C, Arsenault BJ, Dumas MP, Perusse L, Tremblay A, Bouchard C, Poirier P, Despres JP. Contributions of cardiorespiratory fitness and visceral adiposity to six-year changes in cardiometabolic risk markers in apparently healthy men and women. J Clin Endocrinol Metab. 2011;96: 1462–1468. 40. Poirier P. Obesity, adiposity indices, and blood pressure; ethnicity does matter. Am J Hypertens. 2008;21:244. Insulin Resistance, Low Cardiorespiratory Fitness, and Increased Exercise Blood Pressure: Contribution of Abdominal Obesity Maxime Huot, Benoit J. Arsenault, Valérie Gaudreault, Paul Poirier, Louis Pérusse, Angelo Tremblay, Claude Bouchard, Jean-Pierre Després and Caroline Rhéaume Downloaded from http://hyper.ahajournals.org/ by guest on June 15, 2017 Hypertension. 2011;58:1036-1042; originally published online October 24, 2011; doi: 10.1161/HYPERTENSIONAHA.111.180349 Hypertension is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 2011 American Heart Association, Inc. All rights reserved. Print ISSN: 0194-911X. Online ISSN: 1524-4563 The online version of this article, along with updated information and services, is located on the World Wide Web at: http://hyper.ahajournals.org/content/58/6/1036 Data Supplement (unedited) at: http://hyper.ahajournals.org/content/suppl/2011/10/25/HYPERTENSIONAHA.111.180349.DC1 Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Hypertension can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Hypertension is online at: http://hyper.ahajournals.org//subscriptions/ Online Supplement INSULIN RESISTANCE, LOW CARDIORESPIRATORY FITNESS AND INCREASED EXERCISE BLOOD PRESSURE: CONTRIBUTION OF ABDOMINAL OBESITY Short title: Exercise, blood pressure and abdominal obesity Maxime Huot, BSc1,2, Benoit J. Arsenault, PhD2, Valérie Gaudreault, MD², Paul Poirier, MD, PhD, FRCPC, FACC, FAHA2,3, Louis Pérusse, PhD1, Angelo Tremblay, PhD1,2, Claude Bouchard, PhD4, Jean-Pierre Després, PhD, FAHA1,2, Caroline Rhéaume, MD, PhD, CFPC2,5 1) Division of Kinesiology, Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec, Canada 2) Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada 3) Faculty of Pharmacy, Université Laval, Québec, Canada 4) Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA, United States. 5) Department of Family Medicine and Emergency Medicine, Faculty of Medicine, Université Laval, Québec, Canada Address for correspondence: Caroline Rhéaume, MD, PhD, CFPC Centre de recherche de l’Institut universitaire de cardiologie et de pneumologie de Québec 2725 Chemin Ste-Foy Québec, Québec G1V 4G5, Canada TEL: (418) 656-8711 x 3717 Examples of the correction of peak exercise blood pressure by intensity in MET Figure S1. Example A shows the blood pressure response of 2 individuals who reached the same intensity (7 METs, an average response for our cohort) at the last stage of the PWC150. However, the high responder with a peak SBP of 210 mm Hg had an increase of 12,86 mm Hg/MET compared to the low responder who only increased his SBP by 5 mm Hg/MET, reaching 155 mm Hg. Example B shows the blood pressure response of 2 individuals who reached the same SBP (210 mm Hg) but at different intensities for the last stage of the PWC150. Even though both had an elevated SBP increase at exercise, the high SBP responder, who only reached 7 METs(,) had an increase of 12,86 mm Hg/MET compared to the low SBP responder, who reached 12 METs with a 7,5 mm Hg/MET increase.
© Copyright 2026 Paperzz