Objectives: To assess the relationship of body weight and anthropometry to all-cause mortality in older men.
Design: A prospective cohort study of 3741 elderly Japanese-American men, enrolled in the Honolulu Heart Program. For this report, the follow-up began at baseline examinations (1991-1993), when the men were aged 71-93 y.
Measurements: Variables of interest were body mass index (BMI), waist-to-hip ratio (WHR), and the sum of the subscapular and triceps skinfold thickness. Possible confounders included age, education, physical activity index, smoking, alcohol consumption, systolic and diastolic blood pressure, cholesterol, glucose and insulin concentrations.
Results: After an average of 4.5 y of follow-up, 766 men (21%) had died. Higher BMI was associated with lower adjusted mortality risks (relative risk (RR)) highest vs lowest quintile-based category = 0.5, 95% confidence interval (CI): 0.4-0.6, P-trend < 0.001). Results were independent of WHR, and did not change after excluding current and former smokers or those who died within one year of follow-up. The relation between WHR and mortality appeared to be U-shaped, but after adjustment for BMI, a higher WHR steadily increased the risk of dying (RR highest vs lowest category = 1.5, 95%CI: 1.1-2.0, P-trend=0.004). Especially in subjects with a high BMI, there was a positive association between WHR and mortality. The results for skinfold thickness were similar to the results for BMI, but less strong.
Conclusions: In older men, BMI and skinfold thickness showed a consistent inverse association with mortality, even after accounting for early mortality. The WHR, on the other hand, was positively related to mortality, especially when BMI was high. Thus, excess abdominal fat mass (FM) warrants closer concern than being overweight, in terms of affecting mortality in the elderly.