Obesity largely explained a higher prevalence of diabetes and hypertension in black women with HIV than in white men with HIV, according to a 1,800-person cross-sectional study at the University of Alabama at Birmingham (UAB). But obesity did not explain racial and sexual differences in rates of other cardiometabolic diseases, including dyslipidemia, cardiovascular disorders and chronic kidney disease (CKD).
Research in people with HIV infection reveals that risks and rates of cardiometabolic disease differ by race and sex. Because obesity could exacerbate these differences, UAB researchers assessed rates of five cardiometabolic comorbidities -- dyslipidemia, hypertension, cardiovascular disorders, diabetes and CKD -- in 1,800 HIV-positive people in care at some point between July 2010 and June 2011.
The 1,800 study participants included 655 black men (37% of 1,800), 308 black women (17%), 725 white men (40%) and 112 white women (6%). Across those four groups, age averaged 41.5, 46.1, 46.0 and 45.5 years respectively. Almost half of black women (49%) were obese, compared with 24% of black men, 15% of white men and 24% of white women. More than 90% in all four groups had started antiretroviral therapy.
The UAB team assessed odds of each cardiometabolic disease in the four groups by two logistic regression models. The first model adjusted for race/sex, age, CD4+ count, insurance status, history of tobacco use and time on antiretroviral therapy. The second model adjusted for all those risk factors plus obesity status.
With white men as the reference group, black men, black women and white women all had significantly lower odds of dyslipidemia in model 1. Adjusting for obesity in model 2 had little impact on those associations. Compared with white men, the other three groups also had lower odds of cardiovascular disease, and again obesity had little impact on those associations. CKD proved more than twice as likely in black men as white men (adjusted odds ratio [aOR] 2.36, 95% confidence interval [CI] 1.51 to 3.70) in model 1. But adjusting for obesity in model 2 had no impact on that association.
Both black women and black men had nearly twice higher odds of hypertension than white men in model 1. Adjusting for obesity in model 2 had only a modest impact on chances of hypertension in black men versus white men. But adjusting for obesity made the higher odds of hypertension in black women than white men nonsignificant (from aOR 1.85, 95% CI 1.37 to 2.49, to aOR 1.28, 95% CI 0.94 to 1.76). Compared with white men, black women (but not black men or white women) had independently higher odds of diabetes (aOR 1.82, 95% CI 1.18 to 2.80) in model 1. Adjusting for obesity in model 2 sharply attenuated that association (aOR 1.36, 95% CI 0.86 to 2.14).
Logistic regression determined that obesity alone independently almost doubled the odds of dyslipidemia (aOR 1.72, 95% CI 1.31 to 2.27), more than doubled the odds of diabetes (aOR 2.52, 95% CI 1.74 to 3.66) and tripled the odds of hypertension (aOR 2.98, 95% CI 2.32 to 3.84).
Stressing that half of the black women in this population were obese, the authors note that "[o]verall diet quality is reported to be poorer among black compared to white populations, and black women may be more sensitive to the effects of dietary factors on blood pressure and glycemic control."
The UAB investigators believe "research among HIV-uninfected populations combined with our study findings suggests that weight maintenance or planned weight loss could play a crucial role in diabetes and blood pressure control and prevention among HIV-infected black women who present with high obesity prevalence." At the same time, they underline the findings that white men with HIV had higher rates of dyslipidemia and cardiovascular disease than other groups, even though they had a lower obesity prevalence.
In a nationally representative U.S. sample of people in care for HIV, the Centers for Disease Control and Prevention found that almost half of HIV-positive women under 40 years old (48.5%) were obese, and obesity prevalence was higher in black women with HIV (45.8%) than in white (35.6%) or Hispanic (36.3%) women with HIV. Among all women, obesity prevalence was 17% higher in women with HIV than in the general population.
Mark Mascolini is a freelance writer focused on HIV infection.