Waist Circumference vs. Waist-to-Hip Ratio in Rural Mexico
MK Dougherty, ES Clausen, K Bailey, TJ Brooks, HE Gaskins, AP Starling, BD Skinner PhD, E Ashkin MD, P Sloane MD, MG Cohen MD
1. S Barquera, RA Durazo-Arvizu, A Luke, G Cao and RS Cooper. Hypertension in Mexico and among Mexican Americans: prevalence and treatment
patterns. Journal of Human Hypertension (2008) 22, 617–626.
2. World Health Organization. Definition, Diagnosis and Classification of Diabetes Mellitus and Its Complications: Report of a WHO Consultation.
Geneva: World Health Organization, 1999
The 15 rural communities
we screened were located
near Juventino Rosas, in
the central state of
Guanajuato, Mexico.
86% of the participants were women. Immigration, cultural norms, and the arrival of
the planting season all contributed to this gender discrepancy.
Mexican youth are among
those at highest risk for HIV
infection
Methods
Cross-sectional study design
The fifteen communities around Juventino Rosas were
selected by local officials based on two criteria:
High rate of economic migration to the US.
Limited access to health care.
During June-July 2008, a convenience sample of 431
participants from these pueblos were:
Convenience sample from 15 communities
Recruitment: church announcements and
introductions, loud speaker announcements, flyers
Participants recruited during health fairs
Circumferences were measured over clothes at the waist
at the level of the umbilicus, and at the hip at the widest
point of the buttocks.
Total cholesterol, HDL cholesterol, and blood glucose
were measured with the Cholestech® LDX testing system,
a small point-of-care analyzer test and cassette system.
Blood pressure was taken on both arms using an aneroid
sphygmomanometer after each subject had been seated
for five minutes. The arm with the highest systolic blood
pressure was the measurement accepted.
To determine the relation of each measurement of
abdominal obesity to cardiovascular risk, we assessed the
value of each measurement as a diagnostic test for five
categories of CV risk:
High total cholesterol: >200 mg/dL
Hypertension: >130 mmHg systolic or > 85 mmHg
diastolic pressure
Low HDL-C: <40 mg/dL for men, <50 mg/dL for women
Glucose intolerance: >100 mg/dL fasting blood glucose
Metabolic syndrome: Any 3 of the previous 4 categories
Post-test risk reduction counseling was conducted by
medical students and/or physicians.
Oral consent was obtained from all subjects according to
IRB-approved consent form.
Diagnosis
Sensitivity 95% CI
LR +
Variable
Count
%
Diagnoses
Hypercholesterolemia
59
16.5
Hypertension
168
39.1
Low HDL-C
309
89.1
Glucose intolerance
84
19.6
Metabolic syndrome
67
15.6
Waist hip ratio
High
379
88.5
Low
49
11.5
Waist circumference
High
259
60.4
Low
170
39.6
Fig 1. Distribution of diagnoses in total sample (n= 431)
LR -
Cardiovascular disease is the leading cause of death among
both Mexicans and Mexican-Americans1, and abdominal
obesity is a known risk factor for cardiovascular events,
being one of five components collectively known as the
"metabolic syndrome.“
ATPIII guidelines define abdominal obesity using waist
circumference (>102 cm for males, >88 cm for females).
ATPIII guidelines, while addressing ethnic differences in
cardiovascular risk between non-Hispanic whites and MexicanAmericans, were not developed from studies of populations in
Mexico, thus their recommendation may not be as strongly
validated in these populations.
We questioned if abdominal obesity’s effect on cardiovascular
risk is more accurately measured using abdominal
circumference or waist-to-hip ratio (>0.85 women, >0.9
males)2 in a rural Mexican population.
The state of Guanajuato, Mexico provides a large source of
immigration to North Carolina, thus an investigation in this
region may also inform recommendations for the immigrant
population of North Carolina.
Implications:
This research will better inform cardiovascular screening
procedures, in both rural Mexico and in genetically similar
populations such as the migrant worker populations of
North Carolina.
The necessary research for this project has also augmented
previous research done in this population on the prevalence
of cardiovascular risk factors, demonstrating the need while
providing recommendations for future screening efforts, and
improving preventative health in Mexican populations.
Results
B
A
Introduction
Specificity 95% CI
High Total
Cholesterol
0.90 (0.79, 0.96)
0.10 (0.07, 0.14)
Hypertension
0.94 (0.89, 0.97)
0.15 (0.11, 0.20)
Low HDL-C
0.92 (0.88, 0.95)
0.16 (0.06, 0.31)
Waist-to-hip ratio is uniformly more sensitive a marker for every
cardiovascular risk factor.
Glucose intolerance
0.92 (0.83, 0.97)
0.12 (0.09, 0.16)
Waist circumference was uniformly more specific a marker for every
cardiovascular risk factor.
Metabolic
syndrome
0.95 (0.87, 0.99)
0.13 (0.09, 0.17)
Figure 4: Measures of abdominal obesity as predictors of
other cardiovascular risk factors
All participants were over 30 years old, with a mean age of 45.9 (SD 17.0).
Sample contained 369 women and 62 men, for a total or 431.
Combining sensitivities and specificities, waist circumference shows more
favorable likelihood ratios for the categories of glucose intolerance and
metabolic syndrome, while waist-to-hip ratio has favorable likelihood ratios
for low HDL-C. .
Fig 2. Sensitivities and specificities of waist/hip ratio
for conditions of cardiovascular risk
Diagnosis
Sensitivity 95% CI
Specificity 95% CI
0.35 (0.29, 0.41)
Conclusions
The study does not suggest a significantly closer association with other
cardiovascular risk factors for waist-to-hip ratio than for waist
circumference. Therefore we advise adherence to ATP III guidelines in
diagnosing metabolic syndrome in rural Mexican populations.
High Total
Cholesterol
Hypertension
0.68 (0.54, 0.79)
0.70 (0.62, 0.77)
0.45 (0.39, 0.52)
Waist-to-hip ratio is perhaps a better screening tool for lifestyle
modification counseling among rural Mexicans, as the higher prevalence
of elevated waist-to-hip ratio make this a more sensitive marker of
abdominal obesity.
Low HDL-C
0.67 (0.62, 0.73)
0.34 (0.20, 0.51)
Limitations/Caveats:
Glucose intolerance
0.76 (0.65, 0.85)
0.43 (0.38, 0.49)
Metabolic syndrome
0.82 (0.70, 0.90)
0.44 (0.38, 0.49)
Fig 3. Sensitivities and specificities of high waist
circumference for conditions of CV risk
Acknowledgements to Maria Ferris, MD, Bradley Layton, UNC Family Medicine Department, AOA Kuckein Research Grant, Medical Student Research Program, UNC SOM International Fellowship, Rotary Club, UNC Global Initiatives, Robertson Collaboration Fund, and CAMPOS
The study was a convenience sample, the sample size was small, and
males were underrepresented.
The study uses measures of abdominal obesity as diagnostic tests for
other CV risk factors only to quantify these measures’ association with
CV risk. Abdominal obesity is not a sufficient indicator of these other
risk factors to eliminate the need for separate screening based on
positive or negative findings of abdominal obesity.
The study did not measure the association of measures of abdominal
obesity with mortality of any cause.