Identifying subgroups of obesity using the product of triglycerides and glucose: the Korea National Health and Nutrition Examination Survey, 2008-2010.

Abstract

To determine whether the TyG index, a product of the levels of triglycerides and glucose, may be a valuable marker for identifying metabolically obese but normal weight (MONW) or metabolically healthy but obese (MHO) individuals. A total of 17 029 nondiabetic subjects (7185 men and 9844 women) were selected from the Korea National Health and Nutrition Examination Survey conducted in 2008-2010. Individuals with a normal body mass index (BMI) (≥18·5 and <23 kg/m(2) ) and the highest quartile of the homoeostasis model assessment of insulin resistance (HOMA-IR) were classified as MONW. Individuals with obesity (BMI ≥25 kg/m(2) ) and the lowest quartile of HOMA-IR were classified as MHO. The TyG index was calculated as ln[fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2]. The levels of the TyG index paralleled with various metabolic risk parameters. The index was significantly higher in the MONW group and lower in the MHO group when compared with the non-MONW group and the non-MHO group, respectively. The odds ratios (ORs) of being categorized into the MONW group were approximately fourfold higher in the highest vs lowest quartiles of the TyG index (3·999: 95% CI, 2·508-6·376 in men; 4·737: 95% CI, 3·418-6·565 in women) among normal weight subjects. Conversely, there was a stepwise decrease in the OR of being categorized into the MHO group across the TyG index quartiles among obese subjects. These data highlight the value of the TyG index in discriminating those subjects with higher risks of metabolic diseases.