Increased Waist-to-height Ratio May Contribute to Age-related Increase in Cardiovascular Risk Factors

BACKGROUND: The risk of cardiovascular diseases (CVDs) increases with age. The objective was to determine whether lifestyle and dietary behaviors and anthropometric measures, which are affected by these behaviors, contribute to the increase of CVD risk factors across age categories of 20–50-year-old. METHODS: In a cross-sectional design, 437 adults aged 20–50-year-old were selected from households living in Shiraz. Risk factors of CVD, including body mass index (BMI), waist-to-height ratio (WHtR), blood pressure, fasting blood glucose (FBG), serum triglycerides, total cholesterol, and low- and high-density lipoprotein cholesterol (LDL-C and HDL-C, respectively) as well as lifestyle behaviors (physical activity and smoking), dietary habits, and food intakes were assessed across the age categories of 20–29, 30–39, and 40–50 years. Linear regression was used to examine the contribution of different variables to the age-related increase of CVD risk factors. RESULTS: All CVD risk factors, except for HDL-C, significantly increased across age categories. Older subjects had healthier dietary habits and food intakes, but they possessed nonsignificantly lower physical activity and higher smoking rate compared to younger adults. Adjusting for physical activity, smoking, and BMI did not change the significant positive association between age and CVD risk factors but adjusting for WHtR disappeared associations for blood pressure, triglycerides, and metabolic syndrome although significant associations remained for FBG and total and LDL-C. CONCLUSIONS: Age-related increase of CVD risk factors occurred independent of lifestyle habits. WHtR, but not BMI, may partially contribute to the age-related increase in CVD risk factors.