Heterozygous familial hypercholesterolemia in Hong Kong Chinese. Study of 252 cases

Earlier studies reported that Chinese subjects with heterozygous familial hypercholesterolemia (heFH) living in Mainland China or in Western countries had lower plasma low-density lipoprotein cholesterol (LDL-C) levels and lower prevalence of xanthomata or coronary heart disease (CHD) than Caucasians with heFH and a greater proportion went unrecognized. We characterized the features of Hong Kong Chinese with heFH identified by cascade screening.

Potential probands with primary hypercholesterolemia manifesting total cholesterol (TC) greater than 7.5 mmol/L or LDL-C greater than 4.9 mmol/L were selected from a lipid clinic in a public hospital in Hong Kong. After screening of 132 unrelated potential probands and their relatives, 252 subjects from 87 pedigrees were clinically diagnosed as heFH.

In 252 heFH patients (mean age 37 ± 17 years, 100 males), the plasma TC and LDL-C were 9.1 ± 1.5 mmol/L and 7.2 ± 1.5 mmol/L, respectively. In subjects aged ≥ 18 years, the prevalence of xanthomata and corneal arcus was 40.6% and 81.2% in males, and 54.8% and 66.9% in females respectively. The overall incidence of CHD was 9.9% in males and 8.5% in females in patients aged over 18 years with CHD history available. Multiple logistic regression analysis showed that advanced age and presence of xanthelasmata were significantly associated with increased risk of CHD.

This study is the first to characterize the epidemiologic features of heFH in Hong Kong Chinese, which provides new population-specific information on this genetic disorder. This may presage how this condition will manifest in China in the near future.