Impact of overweight and obesity on hospitalization: race and gender differences

Objective: To examine associations between weight status and number of all-cause and cause-specific hospitalizations overall, and by race and gender. Design: Longitudinal cohort study. Subjects: White and black adults (n = 15 355) from the Atherosclerosis Risk in Communities Study who were normal weight (body mass index: >= 18.5 to <25.0 kgm(-2); n = 4997), overweight (>= 25.0 to <30.0 kgm(-2); n = 6100), or obese (>= 30.0 kgm(-2); n = 4258) at baseline. Measurements: Information on hospitalizations was collected using community and cohort surveillance methods. Negative binomial models adjusted for race, gender, field center, age, physical activity, education level, smoking status, alcoholic beverage consumption and health insurance at baseline. Adjusted numbers of hospitalizations were calculated after setting covariates to the mean value (for continuous variables) or to the average distribution (for categorical variables) observed in the entire cohort and are expressed as the number of hospitalizations per 1000 adults followed over a period of 13 years. Results: The covariate-adjusted average number of all-cause hospitalizations was 1316 per 1000 normal weight, 1543 per 1000 overweight and 2025 per 1000 obese. Normal weight women had significantly fewer hospitalizations than normal weight men (1173 versus 1515 per 1000), but the increase associated with being obese on the number of all-cause hospitalizations was larger in women than men (791 versus 589 per 1000). There was no significant difference detected between the number of hospitalizations in normal weight whites and blacks, and the increase in hospitalizations with overweight or obesity was also not different. Effects of weight status on several primary causes of hospitalization differed by gender and race group. Conclusion: Our work suggests that obesity prevention may reduce hospitalizations, a major component of rising healthcare costs. The impact of successful obesity prevention is likely to be larger in women than in men, and similar in blacks and whites.