People with high levels of ‘good cholesterol’ have a higher mortality rate than people with normal levels, according to new research by the University of Copenhagen.
In men with extremely high HDL levels, the mortality rate was 106 per cent higher than for the normal group. For women with extremely high levels, the mortality rate was 68 per cent higher.
Børge Nordestgaard, one of the study’s authors, said: ‘These results radically change the way we understand ‘good’ cholesterol. Doctors like myself have been used to congratulating patients who had a very high level of HDL in their blood. But we should no longer do so, as this study shows a dramatically higher mortality rate.’
The researchers analysed data from 116,000 subjects from the Copenhagen City Heart Study and the Copenhagen General Population Study, in combination with mortality data from the Danish Civil Registration System. They have followed the subjects for an average of 6 years, and based the study on just over 10,500 deaths.
They calculated the mortality rate based on these deaths and medical information on the subjects. Just 0.4 per cent of the men and 0.3 per cent of the women covered by the study had an extremely high level of HDL in their blood.
The study also found excessive mortality for people with extremely low levels of HDL in the blood. The people with medium levels of HDL in the blood had the lowest mortality.
This is the first study to demonstrate excessive mortality rates associated with high levels of HDL in the general population.
Nordestgaard said: ‘It appears that we need to remove the focus from HDL as an important health indicator in research, at hospitals and at the general practitioner. These are the smallest lipoproteins in the blood, and perhaps we ought to examine some of the larger ones instead. For example, looking at blood levels of triglyceride and LDL, the ‘bad’ cholesterol, are probably better health indicators.’