Sensitivity and specificity of body mass index and main risk factors for cardiovascular disease in middle-income urban participants in Guanajuato, Mexico

Abstract

Introduction: several studies have questioned body mass index (BMI) as an accurate diagnostic tool for obesity and therefore a predictor of cardiovascular risk. But BMI is widely used currently. Objective: we analyzed the sensitivity and specificity of BMI and compared cardiovascular risk factors in middle-income urban participants in Guanajuato, Mexico, at different ages. Design: an analytical and cross-sectional study was carried out in 385 apparently healthy subjects, stratified by age ranges (20 to 59 years old). A high global CVD risk was obtained with the Framingham risk score (Framingham Risk Score > 20 %). The odds ratio was used to assess the association between high global CVD risk and the dietetic and anthropometric variables. Sensitivity, specificity, and correlation statistical analyses were carried out between BMI and other anthropometric variables with high cardiovascular risk, and this was integrated to derive recommendations to improve risk factor detection (p < 0.05 and power of 80 %). Results: a high global CVD risk was found in 4 % of the sample. BMI ≥ 30 kg/m2 had a sensitivity of 77 % for the detection of high cardiovascular risk; waist circumference ≥ 90 cm (men) or ≥ 80 cm (women) and body fat percentage ≥ 25% (men) or ≥ 35 % (women) had a sensitivity of 100 %. BMI showed a significant association with high global CVD risk (OR = 6.1; 95 % CI, 1.6-22.6, p < 0.01), but was not able to predict high global CVD risk in at least 30 % of the cases. There was not significative difference by age group for waist circumference, body fat percentage, total cholesterol, and low-density lipoprotein. Regarding the comparison of dietary intake of the stratified population by age group, intake of cholesterol, added sugars, fiber, sodium were highest in the 20 years group. Conclusions: a higher intake of cholesterol, simple sugars, and sodium was observed in the 20-year-old age group. The use of BMI with waist circumference and percentage of body fat used together allow a better assessment of cardiovascular risk. We need to integrate this new recom-mendation to increase early detection of main risk factors for cardiovascular disease.