Influence of Demographic Factors on Serum Concentrations of Seven Chemical Constituents in Healthy Human Subjects
Abstract Serum from 519 subjects attending a screening clinic and from the laboratory staff was used to study the influence of age, sex, body weight, social class, blood pressure, and smoking habit upon the concentration in serum of urea, uric acid, cholesterol, inorganic phosphate, total protein, calcium, and magnesium. Values for urea, uric acid, calcium, and magnesium were significantly higher in males. Age was a positive determinant of urea and cholesterol in both sexes, and of magnesium in females only. The correlation of uric acid with age was positive in females and negative in males, but in both sexes the correlation between uric acid and weight was strongly positive. Regression equations were developed to express the demographic and nondemographic contributions to the individual's blood chemistry values. From these, a set of demographically-corrected reference values were derived. When applied to a selected group of female hospital outpatients, these seemed to discriminate more accurately between subjects with and without disease than did conventional parametric limits.