Body mass index in middle age and health-related quality of life in older age: the Chicago heart association detection project in industry study.

BACKGROUND: Overweight and obesity are associated with higher morbidity and shorter life expectancy, but the effect of body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) ascertained during middle age on subsequent quality of life among older survivors is unknown. This study evaluates whether BMI in middle age is related to health-related quality of life in older age.
METHODS: This prospective cohort of adults from the Chicago Heart Association Detection Project in Industry included 6766 middle-aged men and women, aged 36 to 64 years, without diabetes mellitus or myocardial infarction at baseline (November 7, 1967-January 8, 1973), who completed a 26-year follow-up questionnaire in 1996 when they were 65 years and older. Relationships of baseline BMI (categories: normal weight, overweight, and obese) to mean 26-year follow-up Health Status Questionnaire 12 scores (measuring physical, mental, and social well-being) were assessed.
RESULTS: For men and women, BMI had significant inverse-graded associations with all Health Status Questionnaire 12 scores (P<.01 for trend for all). Scores (adjusted for baseline cardiovascular disease risk factors and 1996 age) were highest (best) in normal-weight individuals (BMI, 18.5-<25.0) and decreased significantly (P range,.006-<.001 for trend) with higher BMI, with worst outcomes for obese persons (BMI, >or=30.0). A higher multivariate-adjusted percentage of normal-weight persons reported excellent or very good health compared with overweight and obese persons: for women, 46.8% vs 37.9% and 24.3%; and for men, 53.8% vs 49.1% and 36.5% (P<.001 for trend).
CONCLUSIONS: A higher BMI in middle age is associated with a poorer quality of life in older age. Preventive measures may lessen the burden of disease and impaired quality of life associated with excess weight.