Body Mass Index as a Predictor of Mortality in Older People in Taiwan

Abstract

Background: Obesity is associated with diverse health risks, but its role as a risk factor for death remains controversial in the elderly. This study estimated the association of body mass index (BMI) with the risk of death from any cause and from specific diseases in elderly Taiwanese. Methods: The Six-Community Hypertension Intervention Project Study, a nationwide population-based cohort, was conducted in 1982 and followed up for 23 years. Cause of death was ascertained by review of death certificate files. Proportional hazards models were used to evaluate the association between the baseline BMI and risk of death. Results: Of 1,568 participants aged 65 years (range, 60–75 years) at study entry, 1,085 (69%) died during follow-up. The relationship between death from any cause and BMI follows a J-shaped pattern. Increasing BMI categories were associated with increased risk of all-cause mortality (BMI, 25–26.9: hazard ratio, HR, 1.36; 95% confidence interval, CI, 1.11–1.67; BMI ≥ 27: HR, 1.46; 95% CI, 1.15–1.85). Death from diabetes, cardiovascular diseases or cancer increased progressively with increasing categories of BMI, and HRs were significantly increased at BMI levels > 23.0kg/m2 (BMI, 23–24.9: HR, 1.29; 95% CI, 1.05–1.60; BMI, 25–26.9: HR, 1.58; 95% CI, 1.21–2.05; BMI ≥ 27: HR, 1.74; 95% CI, 1.29–2.35). These associations were more obvious in men than in women. Conclusion: This study found that BMI > 25kg/m2 was a significant independent predictor of all-cause mortality, especially among older men. BMI > 23kg/m2 also increased risk of mortality from cancer, cardiovascular diseases and diabetes. The relationship was J-shaped in older Taiwanese.

Keywords

• body mass index
• elderly
• mortality
• obesity
• Taiwan