Its long been known that high cholesterol levels are linked to an increased risk of a heart attack (myocardial infarction, MI) or sudden death from cardiac causes. However, a report in 1994 encouraged the idea that there was no use in tackling cholesterol in persons over 70. It became almost exceptional to measure cholesterol levels in these "older-old" people. Now that the results of some large studies involving the use of cholesterol-lowering drugs called statins are available, it's necessary to revise this thinking.

The statin drugs (which belong to the class of drugs called HMG-CoA reductase inhibitors) have become the most widely used medication for raised cholesterol levels in most people. The article summarized here reviews the 5 major statin studies reported over the last 6 years, proving the value of statins in aggressively treating raised cholesterol levels at any age.

Two of these 5 studies concern the use of statins in persons who haven't had a serious cardiovascular incident (such as a heart attack). These are called primary prevention studies, as they measure the effect of a drug in preventing a first occurrence of an undesirable event.

The first primary prevention study was done in over 6,500 people (85% were men) who had normal cholesterol levels and no obvious arterial disease. A fifth of the subjects were over 65. Statin treatment (lovastatin) decreased the numbers of fatal and non-fatal MIs by 40%. With lovastatin, the chances of having an MI were about the same in the older as in the younger subjects - in other words, lovastatin counteracted the expected increase in MIs normally seen as one ages.

The second study also included over 6,500 subjects, who were between 45 and 65, and had high cholesterol levels. Statin treatment (in this case, pravastatin) reduced the chances of having a MI by 40% in the subjects 45 to 55, and by 27% in those 55 to 65.

Three studies done in persons who had already had a heart attack were reviewed; these are known as secondary prevention studies. The first included over 4,000 patients with raised cholesterol levels. Treatment with the statin simvastatin reduced the chances of dying from a heart attack by 42%. Although the reduction was a bit less in persons over 60 compared with the rest of subjects, the benefit of simvastatin was still quite significant in the older patients.

The next study analyzed results from over 4,000 patients (mostly men) with a history of heart attack but normal cholesterol levels (i.e. below 240 mg/dL, or 6.2 mmol/L). The statin used here, pravastatin, reduced the chances of an MI by 27% in patients over 60, compared with a 20% reduction in those under 60.

The final study reviewed was done in over 9,000 patients with a history of MI or angina, and a wide range of cholesterol levels. Treatment with pravastatin produced an overall 24% reduction in the chances of dying or having a non-fatal MI. In people over 70 the reduction was less, but still important - 15%.

The statins work by reducing the formation of low-density lipoprotein (LDL) cholesterol in the liver (the "bad" cholesterol), leading to reduced total and LDL-cholesterol levels in the blood. However, the statins seem to have effects beyond just lowering cholesterol levels. These include improved functioning of the artery wall cells, stopping the break-off of parts of atherosclerosis deposits, antioxidant properties, and anti-inflammatory effects. There is no reason to think these actions are any less in older persons.

Two new reports have shown that statins, in addition to their beneficial effects on cardiac conditions, may also improve bone mineral density (BMD) and prevent fractures in older women who are at risk of osteoporosis.

All statins are effective in lowering LDL-cholesterol levels, although they may differ in the strength of their activity. Their side-effect patterns are quite similar. Perhaps future studies will show differences in the way different statins show their additional effects (e.g. anti-inflammatory or antioxidant activity). Until then, there is no good reason to prefer one statin to another.

There is no doubt that older people with raised cholesterol levels are not getting the treatment they deserve. A US report in 1998 found that only 5% of people above 60 who had raised cholesterol levels and had had an MI were actually receiving lipid-lowering drugs. A change in approach is clearly needed, in view of the obvious benefits of treatment with statin drugs.

Source

Hypercholesterolemia: is lipid-lowering worthwhile for older patients?
PC. Deedwania, Geriatrics, 2000, vol. 55, pp. 22--28