Diabetes prediction, lipid accumulation product, and adiposity measures; 6-year follow-up: Tehran lipid and glucose study

Abstract

Background: The body mass index (BMI) is the most commonly used marker for evaluating obesity related risks, however, central obesity measures have been proposed to be more informative. Lipid accumulation product (LAP) is an alternative continuous index of lipid accumulation, which is computed from waist circumference (WC, cm) and triglycerides (TGs, mmol/l): (WC-65) xTG (men) and (WC-58) xTG (women). We sought in this study to assess if LAP can outperform BMI, waist-to-height-ratio (WHtR), or waist-to-hip-ratio (WHpR) in identifying prevalent and predicting incident diabetes.

Results: The cross-sectional analyses were performed on a sample included 3,682 men and 4,989 women who were not pregnant, aged > or = 20 years. According to the age (> or = 50 and <50 years) - and sex-specific analyses, odds ratios (ORs) of LAP for prevalent diabetes were higher than those of BMI, WHpR, or WHtR among women, after adjustment for mean arterial pressure and family history of diabetes. The OR of LAP in old men was lower than those of other adiposity measures; in young men, however, LAP was superior to BMI but identical to WHpR and WHtR in identifying prevalent diabetes. Except in young men, LAP showed highest area under the receiver operating characteristic curves (AROC) for prevalent diabetes (P for trend < or = 0.005). For longitudinal analyses, a total of 5,018 non-diabetic subjects were followed for approximately 6 years. The ORs of BMI, WHpR, and WHtR were the same as those of LAP in both sexes and across age groups; except in young men where LAP was superior to the BMI. AROCs of LAP were relatively the same as anthropometric adiposity measures.

Conclusions: LAP was a strong predictor of diabetes and in young individuals had better predictability than did BMI; it was, however, similar to WHpR and WHtR in prediction of incident diabetes.

Figure 1

Study population: included, excluded, lost to the follow-up and events, and censored individuals. Starting point is black text-box with upward, for cross sectional study; downward, for longitudinal study.

Figure 2

Fourth vs. first quartiles of LAP versus BMI, WHpR, and WHtR, for identification of prevalent DM, IFG, and IGT, and prediction of incident DM. BMI, body mass index; DM, diabetes mellitus; IFG, impaired fasting plasma glucose; IGT, impaired glucose tolerance; LAP, lipid accumulation product; WHpR, waist to hip ratio; WHtR, waist to height ratio.