People with low HDL cholesterol alone have just as much risk of developing coronary heart disease as those with high LDL cholesterol, a meta-analysis finds.
Pooling studies of 220,000 people in the Asia-Pacific region, researchers found the risk of coronary heart disease was 57% higher in people with low HDL, but no other lipid abnormalities, compared with those who had normal HDL.
The effect was particularly pronounced among Asians, with isolated low HDL cholesterol levels linked to a 67% increased risk of heart disease compared with normal HDL.
In this population, the increased risk of coronary heart disease in patients with low HDL alone was on a par with the risk conferred by elevated LDL — about 65%.
Professor Philip Barter, director of the Heart Research Institute in Sydney, said the results provided further confirmation that low HDL cholesterol was an independent predictor of future coronary events.
“However, whereas there is a large body of robust evidence that lowering LDL cholesterol translates into a reduction in risk of having a future cardiovascular event, such information about HDL raising in humans is much less robust and is still largely circumstantial,” he said.
“The main problem with HDL is that we simply do not have HDL-raising treatments that are anywhere near as effective as the LDL-lowering effects of statins.”
The meta-analysis, which comprised 37 studies, defined low HDL cholesterol as levels less than 1.03mmol/L in men, and 1.3mmol/L in women. High LDL cholesterol levels were defined as 4.14mmol/L or greater.
The prevalence of isolated low HDL cholesterol, in the absence of other lipid abnormalities, was 22% among Asian and 15% among non-Asian populations.
This lipid pattern was, however, only associated with coronary events — there was no association between isolated low HDL and stroke.
Circulation 2011; doi: 10.1161/CIRCULATIONAHA.111.028373