Body Mass Index and Vascular Disease in Men Aged 65 Years and Over: HIMS (Health In Men Study).

BACKGROUND: Understanding the relationship between body mass index (BMI) and vascular disease at older age has become increasingly important in the many countries where both average age and BMI are rising.

METHODS AND RESULTS: In this prospective cohort study, 12 203 men (aged ≥65) were recruited in 1996-1999 from the general population in Perth, Australia. To limit reverse causality, analyses excluded those with past vascular disease and the first 4 years of follow-up. During a further 8 (SD3) years of follow-up, there were 1136 first-ever major vascular events (nonfatal myocardial infarction, nonfatal stroke, or death from any vascular cause). Cox regression (adjusted for age, education, and smoking) related BMI at recruitment to incidence of major vascular events. At ages 65 to 94, the lowest risk of major vascular events was at ≈ 22.5 to 25 kg/m2 . In the higher BMI range (≥25 kg/m2 ), 5 kg/m2 higher BMI was associated with 33% higher risk of major vascular events (hazard ratio, 1.33 [95% confidence interval, 1.18-1.49]): 24% higher risk of ischemic heart disease (1.24 [1.06-1.46]); 34% higher risk of stroke (1.34 [1.11-1.63]); and 78% higher risk of other vascular death (1.78 [1.32-2.41]). In the lower BMI range, there were fewer events and no strong evidence of an association (hazard ratio per 5 kg/m2 higher BMI, 0.82 [95% confidence interval, 0.61-1.12]).

CONCLUSIONS: In this population of older men, risk of major vascular events was lowest at ≈ 22.5 to 25 kg/m2 . Above this range, BMI was strongly related to incidence of major vascular events, with each 5 kg/m2 higher BMI associated with ≈30% higher risk.