The Association Between Diet and Physical Activity on Insulin Resistance in the Women's Interagency HIV Study

OBJECTIVES: To evaluate the association of diet and physical activity with insulin resistance (IR) in HIV-infected and HIV-uninfected women. METHODS: Cross-sectional analyses of summary dietary measures and physical activity intensity scores obtained from women enrolled in the San Francisco (n = 113) and Chicago (n = 65) Women's Interagency HIV Study (WIHS) sites. IR was estimated using the homeostasis model assessment (HOMA-IR). Stepwise regression models assessed the association of diet and physical activity with HOMA-IR after adjustment for demographic, behavioral, and clinical factors. RESULTS: Compared with HIV-uninfected women, HIV-infected women were older and more likely to have health insurance. In multivariable analysis including all women, being from San Francisco ( P = 0.005), having a higher mean body mass index (BMI, P < 0.001), and having a higher percent kilocalories from sweets (P = 0.025) were associated with greater HOMA-IR; heavy intensity physical activity (P = 0.006) and annual household income more than $36,000 ( P = 0.02) was associated with a lower HOMA-IR. In analysis limited to HIV-infected women, having a higher body mass index (P < 0.001) and a history of protease inhibitor use (P = 0.002) were significantly associated with higher HOMA-IR; heavy intensity activity (P = 0.06) was marginally associated with lower HOMA-IR and being menopausal (P = 0.05) was marginally associated with higher HOMA-IR. CONCLUSIONS: Among urban women with or at risk for HIV-infection, heavy intensity physical activity was associated with lower HOMA-IR, whereas higher percent kilocalories from sweets were associated with higher HOMA-IR. Given the overall health benefits of physical activity and a diet low on sugar, these behaviors should be encouraged whenever possible.