Influence of age and sex on 19 blood variables in healthy subjects.

Normal values exist for all clinical chemical tests, but it is not very clear what is normal for healthy elderly subjects. Therefore, routine blood variables were determined in 80 ambulatory, disease-free persons who had undergone rigorous health screening. The subjects were divided into the following age groups: 20 (+/- 3), 40 (+/- 3), 60 (+/- 3), and 80 (+/- 5) years, with 10 males and 10 females per age group. Blood variables were determined after an overnight fast. It was found that even with conservative statistical measures more than half of the variables were significantly affected by age or sex. Significant age differences were found for total cholesterol, triglycerides, sodium, and ASAT. Urea, creatinine, gamma-GT, phosphate, alkaline phosphatase, and albumin were characterized by both age and sex differences. No age or sex differences were found for glucose, potassium, chloride, calcium, calcium ion, iron, magnesium, total protein, and ALAT. The findings suggest that the age or sex-related changes of a number of blood variables such as cholesterol, triglycerides, and liver enzymes are not only of statistical significance, but are also of clinical relevance.