Hypercholesterolaemia and risk of coronary heart disease in the elderly: impact of age: the Copenhagen City Heart Study.
BACKGROUND
Population and interventional studies have shown that high plasma-cholesterol is a risk factor of coronary heart disease (CHD). However, in most of the studies elderly people were excluded.


OBJECTIVE
This paper assesses whether the effect of total plasma-cholesterol on the risk of incident CHD decreases with age in a healthy population.


METHODS
Within the Copenhagen City Heart Study in 1981-1983, 4647 men and 5829 women, aged 40-93 years, underwent a cardiovascular health examination including measurement of plasma-cholesterol. The cohort was followed with respect to incident CHD until 1994, i.e. before statins were introduced in Denmark.


RESULTS
In people below 60 years of age plasma-cholesterol levels on 5-6; 6-8; and >8 mmol/L were associated with relative risks of CHD on 2.0 (95% confidence interval (CI) 1.2-3.2, P=0.004); 3.1 (CI 2.0-5.0, P<0.001); and 5.1 (CI 2.8-9.3, P<0.001), respectively (reference group: plasma-cholesterol <5 mmol/L). In people aged 60-70 years a plasma-cholesterol level on 5-6 mmol/L was not associated with increased risk, whereas plasma-cholesterol on 6-8 mmol/L and >8 mmol/L was associated with relative risks on 1.3 (CI 1.0-1.8, P=0.03), and 2.3 (CI 1.6-3.4, P<0.001), respectively. In people aged 70-80 years only plasma-cholesterol >8 mmol/L conferred increased relative risk on 1.6 (CI 1.2-2.4, P=0.007). In people above 80 years of age increased plasma-cholesterol was not associated with increased risk of incident CHD.


CONCLUSIONS
The risk of incident CHD associated with high plasma-cholesterol declines with age. This finding should be considered in future recommendations of plasma-cholesterol levels in elderly people without atherosclerotic cardiovascular disease.
Iversen
Allan
A
The Copenhagen City Heart Study, Bispebjerg University Hospital, Denmark. aiversen@dadlnet.dk
Jensen
Jan Skov
JS
Scharling
Henrik
H
Schnohr
Peter
P