Chapter 2 - Effect of Age, Gender, Diet, Exercise, and Ethnicity on Laboratory Test Results

Abstract

Many factors, such as age, gender, diet, exercise, and ethnicity/race, have an impact on clinical laboratory test results. Other factors, such as fasting, special diets, and nutraceuticals, can also significantly alter the results of clinical laboratory tests. These factors can be classified into two categories: nonmodifiable (age, gender, and ethnicity/race) and modifiable (diet and exercise, fasting, special diets, and nutraceuticals). Current reference intervals partially account for the age and gender effects on laboratory results. Diet has a marked effect on laboratory test results, as noted by changes in lipid profiles and glucose measurements. These changes reflect the metabolic and endocrine processes associated with food composition, amount, and intake intervals. However, ethnicity/race is a surrogate marker for environmental, socioeconomic/demographic, and/or genetic factors. With the exception of the estimated glomerular filtration rate calculation, few tests have widely used ethnic-specific reference intervals.