Optimal Blood Lipid Levels: An International Report

Ernst Wynder of the American Health Foundation of New York City, was an intense investigator and free-ranging entrepreneur in modern medicine and public health. His academic credentials were established by a pioneering 1951 publication with surgeon Ewarts Graham in St. Louis about a case-control study of cigarette-smoking and death due to bronchial carcinoma.

Wynder in the 1970s became concerned with professional views of what was the “normal” blood cholesterol level. Most clinical laboratory forms of the time used the cut-point of 300 mg/dl to flag abnormal. Below that level, attention was rarely called to cholesterol. Wynder decided to gather representatives of each major medical discipline and charge them with defining “optimal” blood cholesterol levels, insisting on their independent deliberations. He enlisted Barry Lewis of London to summarize clinical data, Bob Wissler, the pathological data, and Henry Blackburn, the epidemiological data. Each group of experts arrived at Wynder’s elegant quarters at the Ford Foundation in Manhattan in the Fall of 1979 and deliberated separately, presenting their conclusions in a final plenary session.

It turned out that experts from each discipline had arrived at virtually identical conclusions on what were ideal levels of blood total cholesterol for a population, and what levels they thought were feasible to achieve in Western industrialized populations. At the time, data on lipoprotein subfractions from representative populations were not available. The ideal mean value of 160 mg/dl was illustrated in a curtotic distribution with few population values above 200. It was thought feasible in a decade or so to arrive at a mean of 190, with a standard deviation of +/-30, compared to the existing mean of 210 with a standard deviation of 35. Wynder went on to develop similar recommendations for ideal blood lipid values for youth.

Following the success of the LRC Primary Prevention Trial in 1984, a consensus conference of the NHLBI formalized recommendations for a National Cholesterol Education Project (NCEN) in the medical and public health community, where 200 mg/dl was the upper limit of “normal” for the individual and 130 as the upper limit for LDL. The NCEN have since modified these recommended values as a result of extensive subsequent trial data indicating the lower LDL and the higher HDL the better.

Official recommendations have not considered the setting of separate population goals to complement these individual goals for intervention on blood lipid levels, reflecting the general orientation of science toward medical rather than public health strategies of prevention. (Henry Blackburn)

Reference

Wynder, E.L., H.Blackburn, B.Lewis, R.Wissler 1980. Plasma Lipids: Optimal Levels for Health. Academic Press, New York.