Relationship among age, serum cholesterol level and population percentile in adults.

The data of the National Health and Nutrition Examination Survey comprehensively have shown that distributions of serum cholesterol levels in the US adult population are age and sex dependent. General formulas were constructed and published by the author on the basis of the data of the National Health and Nutrition Examination Survey to predict the population percentile for serum cholesterol levels by age. A mathematical model and a computer program previously published by the author were employed in the study. Analysis of the computer-assisted predicted and the National Health and Nutrition Examination Survey-reported percentiles indicated that the designed program for calculating the formulas was accurate and reliable. The formula could determine the relationship among adult age, serum cholesterol level and population percentile. A comprehensive table and nomograms that show the relationship among age, serum cholesterol level and population percentile in men and women for each year group between 20 and 79 years of age are obtained in this study, using the previously published formulas. The population percentiles predicted by the formula may reflect the relative degrees of risk for coronary heart disease. The population percentile, simultaneously expressed as 'risk percentile', may be used as a parameter of risk assessment for coronary heart disease for all adult ages and sexes. Seventy-five population percentile of serum cholesterol level is suggested as a cutoff point of high 'risk percentile' for coronary heart disease. This information on the percentile may have a preventive diagnostic value for detection, evaluation and treatment of patients with high cholesterol levels. The comprehensive table and nomograms showing the relationship among age, serum cholesterol level and population percentile may be hopefully available to clinicians and useful in their medical practice and may also be helpful in future clinical investigation.