Low serum cholesterol increases the risk of noncardiovascular events: an antagonist viewpoint.

Considerable debate concerning the apparent association of low serum cholesterol levels with enhanced noncardiovascular disease mortality has been aired in both scientific and lay publications within the past year. This debate has resulted in some medical experts calling for a moratorium on efforts to reduce serum cholesterol, particularly with drugs, and for a more conservative approach to screening and modifying cholesterol levels for the primary prevention of coronary heart disease (CHD). Observational studies, including the Framingham Heart Study, the Multiple Risk Factor Intervention Trial, the Whitehall Study, and the International Collaborative Group, have not substantiated a cause and effect relationship between "naturally" occurring low serum cholesterol and noncardiovascular disease mortality, such as cancer. Intervention trials designed to lower high serum cholesterol levels by diet and drugs have also not been conclusively shown to produce excess harm that offsets the benefit of reduced CHD events. Several primary and secondary CHD prevention trials, with sufficient numbers of subjects to provide the statistical power to detect potential detrimental effects of lowering cholesterol levels, are currently in progress and will be very helpful in resolving the concern about noncardiovascular disease mortality.