Hypertriglyceridaemic waist phenotype as a simple predictive marker of incident diabetes in Asian-Indian men with prediabetes.

ABSTRACT

AIM: To determine prospectively the association of baseline hypertriglyceridaemic waist phenotype with incident diabetes in Asian-Indian men with impaired glucose tolerance. METHODS: In a randomized 2-year diabetes prevention trial in 517 men with impaired glucose tolerance, 123 (23.8%) developed diabetes. Baseline anthropometric, metabolic and clinical variables were estimated. Associations of hypertriglyceridaemic waist phenotype (waist circumference ≥ 90cm and a serum triglyceride level of ≥ 1.7 mmol/l) with insulin resistance and incident diabetes were assessed using multiple linear regression and Cox's proportional hazard models, respectively. RESULTS: Men with an isolated enlarged waistline and hypertriglyceridaemic waist phenotype had significantly higher BMI and percentage of total body fat compared with the group with normal waistline and triglyceride levels and the group with isolated hypertriglyceridaemia. The men with hypertriglyceridaemic waist phenotype had higher insulin resistance (mean ± sd homeostasis model assessment of insulin resistance value 3.6 ± 1.5) compared with those in the isolated enlarged waistline, the isolated hypertriglyceridaemia or the normal waistline and triglyceride level groups (3.1 ± 1.4, 2.7 ± 1.0 and 2.5 ± 1.1, respectively, all P < 0.05 compared with hypertriglyceridaemic waist phenotype). Multiple linear regression analyses showed that hypertriglyceridaemic waist phenotype was significantly associated with insulin resistance after adjusting for age, BMI, family history, percentage of total body fat, smoking, alcohol intake, 2-h plasma glucose and HDL cholesterol level. Hypertriglyceridaemic waist phenotype was independently associated with incident diabetes after adjusting for the above confounders and gamma-glutamyl transferase (hazard ratio 1.49, 95% CI 1.01-2.21; P = 0.047). The association of hypertriglyceridaemic waist phenotype with incident diabetes was abolished when insulin resistance was introduced into the model (hazard ratio 1.39, 95% CI 0.092-2.10; P=0.12). CONCLUSIONS: Hypertriglyceridaemic waist phenotype is a simple clinical proxy measurement for insulin resistance and is strongly associated with incident diabetes in Asian-Indian men with impaired glucose tolerance.