Morbidity and mortality risk associated with an overweight BMI in older men and women

There is controversy as to whether older adults with a BMI in the overweight range (25 to 29.9 kg/m2) are at increased health risk and whether they should be encouraged to lose weight. The purpose of this study was to determine whether older adults with a BMI in the overweight range are at increased morbidity and mortality risk.

Participants consisted of 4968 older (>or=65 years) men and women from the Cardiovascular Health Study limited access dataset. Based on BMI (kg/m2), participants were grouped into normal-weight (20 to 24.9 kg/m2), overweight (25 to 29.9 kg/m2), and obese (>or=30 kg/m2) categories. Participants were followed for up to 9 years to determine if they developed 10 weight-related health outcomes that are pertinent to older adults. Cox proportional hazards models were used to estimate the hazards ratios of morbidity and mortality after adjusting for age, sex, income, smoking, and physical activity.

Compared with the normal-weight group, the risks of myocardial infarction, stroke, sleep apnea, urinary incontinence, cancer, and osteoporosis were not different in the overweight group (p>0.05). The risks for arthritis and physical disability were modestly increased in the overweight group (p<0.05), whereas the risk for type 2 diabetes was increased by 78% in the overweight group (p<0.01). After adjusting for all relevant covariates, all-cause mortality risk was 11% lower in the overweight group (p<0.05).

A BMI in the overweight range was associated with some modest disease risks but a slightly lower overall mortality rate. These findings suggest that a BMI cut-off point of 25 kg/m2 may be overly restrictive for the elderly.