Obesity, insulin resistance and isolated low high-density-lipoprotein cholesterol in Chinese subjects

Aim Recent studies have shown that the risk of developing coronary heart di sease in subjects with 'isolated low high-density-lipoprotein cholesterol ( HDL-C)' (defined as HDL-C <0.9 mmol/l and total cholesterol (TC) < 5.2 mmol /l) was similar to those with hypercholesterolaemia. We examined the preval ence of isolated low HDL-C in Hong Kong Chinese and its relationship with i nsulin resistance and triglyceride (TG) level. Methods Hong Kong Chinese subjects (n = 1493) recruited in a population-bas ed prevalence survey for cardiovascular risk factors were examined. Insulin resistance was calculated using a computer-solved homeostasis model assess ment method. Results Of the 1493 subjects, 72 (4.8%) had isolated low HDL-C, in whom hal f (n = 36) had TG greater than or equal to 1.7 mmol/l and half (n = 36) had TG < 1.7 mmol/l. Compared with the 'controls' (subjects with TC <5.2 mmol/ l and HDL-C greater than or equal to 0.9 mmol/l; TC greater than or equal t o 5.2 mmol/l and HDL-C < 0.9 mmol/l; or TC <greater than or equal to> 5.2 m mol/l and HDL-C 0.9 mmol/l, n = 1421), subjects with isolated low HDLC and high TG were more obese, had higher plasma glucose, fasting and 2 h plasma insulin concentrations and insulin resistance. Subjects with isolated low H DL-C and TG < 1.7 mmol/l had similar insulin concentrations and insulin res istance, but were more obese than the 'controls'. Subjects with isolated lo w HDL-C and high TG also had higher fasting PG, insulin and insulin resista nce than those with isolated low HDL-C and low TG. Conclusions In this population-based study, 4.8% of Hong Kong Chinese had i solated low HDL-C, which was closely associated with obesity. The coexisten ce of high TG suggests an insulin-resistant state.