Measures of obesity and cardiovascular risk among men and women

Abstract

Objectives: This study examined associations between anthropometric measures (body mass index, waist circumference, waist-to-hip ratio, waist-to-height ratio [WHtR]) and risk of incident cardiovascular disease (CVD) (including nonfatal myocardial infarction, nonfatal ischemic stroke, and cardiovascular death).

Background: Controversy exists regarding the optimal approach to measure adiposity, and the utility of body mass index has been questioned.

Methods: Participants included 16,332 men in the Physicians' Health Study (mean age 61 years in 1991) and 32,700 women in the Women's Health Study (mean age 61 years in 1999). We used Cox proportional hazards models to determine relative risks and 95% confidence intervals (CIs) for developing CVD according to self-reported anthropometric indexes.

Results: A total of 1,505 CVD cases occurred in men and 414 occurred in women (median follow-up 14.2 and 5.5 years, respectively). Although WHtR demonstrated statistically the strongest associations with CVD and best model fit, CVD risk increased linearly and significantly with higher levels of all indexes. Adjusting for confounders, the relative risk for CVD was 0.58 (95% CI: 0.32 to 1.05) for men with the lowest WHtR (<0.45) and 2.36 (95% CI: 1.61 to 3.47) for the highest WHtR (>/=0.69; vs. WHtR 0.49 to <0.53). Among women, the relative risk was 0.65 (95% CI: 0.33 to 1.31) for those with the lowest WHtR (<0.42) and 2.33 (95% CI: 1.66 to 3.28) for the highest WHtR (>/=0.68; vs. WHtR 0.47 to <0.52).

Conclusions: The WHtR demonstrated statistically the best model fit and strongest associations with CVD. However, compared with body mass index, differences in cardiovascular risk assessment using other indexes were small and likely not clinically consequential. Our findings emphasize that higher levels of adiposity, however measured, confer increased risk of CVD.

Figure 1

Figure 1a. Relative risk (RR) of cardiovascular disease according to anthropometric indices among men Model adjusts for age, physical activity, smoking, alcohol consumption, and parental history of myocardial infarction before the age of 60. *BMI (body mass index) categories: <20.0, 20.0-22.4, 22.5-24.9, 25.0-27.4, 27.5-29.9, 30.0-34.9, ≥35.0 kg/m². WHtR (waist-to-height ratio) categories: <0.45, 0.45-<0.49, 0.49-<0.53, 0.53-<0.58, 0.58-<0.62, 0.62-<0.69, ≥0.69. WC (waist circumference) categories: 22.0-31.25, 31.5-34.25, 34.5-37.25, 37.5-40.75, 41.0-43.5, 43.75-48.0, 48.25-62.0 in. WHR (waist-to-height ratio) categories: <0.83, 0.83-<0.89, 0.89-<0.94, 0.94-<0.99, 0.99-<1.03, 1.03-<1.11, ≥1.11. Figure 1b. Relative risk (RR) of cardiovascular disease according to anthropometric indices among women Model adjusts for age, physical activity, smoking, alcohol consumption, parental history of myocardial infarction before the age of 60 years, postmenopausal hormone use, race, education, and dietary factors. *BMI (body mass index) categories: <20.0, 20.0-22.4, 22.5-24.9, 25.0-27.4, 27.5-29.9, 30.0-34.9, ≥35.0 kg/m². WHtR (waist-to-height ratio) categories: <0.42, 0.42-<0.47, 0.47-<0.52,0.52-<0.57, 0.57-<0.61, 0.61-<0.68, ≥0.68. WC (waist circumference) categories: 20.0-27.0, 27.25-30.0, 30.25-33.25, 33.5-36.5, 36.75-38.75, 39.0-43.75, 44.0-55.0 in. WHR (waist-to-height ratio) categories: <0.72, 0.72-<0.77, 0.77-<0.82, 0.82-<0.86, 0.86-<0.89, 0.89-<0.95,≥0.95.

Figure 1

Figure 1a. Relative risk (RR) of cardiovascular disease according to anthropometric indices among men Model adjusts for age, physical activity, smoking, alcohol consumption, and parental history of myocardial infarction before the age of 60. *BMI (body mass index) categories: <20.0, 20.0-22.4, 22.5-24.9, 25.0-27.4, 27.5-29.9, 30.0-34.9, ≥35.0 kg/m². WHtR (waist-to-height ratio) categories: <0.45, 0.45-<0.49, 0.49-<0.53, 0.53-<0.58, 0.58-<0.62, 0.62-<0.69, ≥0.69. WC (waist circumference) categories: 22.0-31.25, 31.5-34.25, 34.5-37.25, 37.5-40.75, 41.0-43.5, 43.75-48.0, 48.25-62.0 in. WHR (waist-to-height ratio) categories: <0.83, 0.83-<0.89, 0.89-<0.94, 0.94-<0.99, 0.99-<1.03, 1.03-<1.11, ≥1.11. Figure 1b. Relative risk (RR) of cardiovascular disease according to anthropometric indices among women Model adjusts for age, physical activity, smoking, alcohol consumption, parental history of myocardial infarction before the age of 60 years, postmenopausal hormone use, race, education, and dietary factors. *BMI (body mass index) categories: <20.0, 20.0-22.4, 22.5-24.9, 25.0-27.4, 27.5-29.9, 30.0-34.9, ≥35.0 kg/m². WHtR (waist-to-height ratio) categories: <0.42, 0.42-<0.47, 0.47-<0.52,0.52-<0.57, 0.57-<0.61, 0.61-<0.68, ≥0.68. WC (waist circumference) categories: 20.0-27.0, 27.25-30.0, 30.25-33.25, 33.5-36.5, 36.75-38.75, 39.0-43.75, 44.0-55.0 in. WHR (waist-to-height ratio) categories: <0.72, 0.72-<0.77, 0.77-<0.82, 0.82-<0.86, 0.86-<0.89, 0.89-<0.95,≥0.95.

Figure 2

Figure 2a. Relative risk (RR) of cardiovascular disease according to body mass index (BMI) and waist-to-height ratio (WHtR) among men Model adjusts for age, physical activity, smoking, alcohol consumption, and parental history of myocardial infarction before the age of 60. Figure 2b. Relative risk (RR) of cardiovascular disease according to body mass index (BMI) and waist-to-height ratio (WHtR) among women Model adjusts for age, physical activity, smoking, alcohol consumption, parental history of myocardial infarction before the age of 60 years, postmenopausal hormone use, race, education, and dietary factors.

Figure 2

Figure 2a. Relative risk (RR) of cardiovascular disease according to body mass index (BMI) and waist-to-height ratio (WHtR) among men Model adjusts for age, physical activity, smoking, alcohol consumption, and parental history of myocardial infarction before the age of 60. Figure 2b. Relative risk (RR) of cardiovascular disease according to body mass index (BMI) and waist-to-height ratio (WHtR) among women Model adjusts for age, physical activity, smoking, alcohol consumption, parental history of myocardial infarction before the age of 60 years, postmenopausal hormone use, race, education, and dietary factors.

Figure 3

Figure 3a. Relative risk (RR) of cardiovascular disease according to age and waist-to-height ratio (WHtR) among men Model adjusts for age, physical activity, smoking, alcohol consumption, and parental history of myocardial infarction before the age of 60. Figure 3b. Relative risk (RR) of cardiovascular disease according to age and waist-to-height ratio (WHtR) among women Model adjusts for age, physical activity, smoking, alcohol consumption, parental history of myocardial infarction before the age of 60 years, postmenopausal hormone use, race, education, and dietary factors.

Figure 3

Figure 3a. Relative risk (RR) of cardiovascular disease according to age and waist-to-height ratio (WHtR) among men Model adjusts for age, physical activity, smoking, alcohol consumption, and parental history of myocardial infarction before the age of 60. Figure 3b. Relative risk (RR) of cardiovascular disease according to age and waist-to-height ratio (WHtR) among women Model adjusts for age, physical activity, smoking, alcohol consumption, parental history of myocardial infarction before the age of 60 years, postmenopausal hormone use, race, education, and dietary factors.