The clinical utility of screening of biochemical parameters in elite athletes: analysis of 100 cases

OBJECTIVE To determine the clinical utility of screening for biochemical parameters in elite athletes. DESIGN A prospective sequential case series. SETTING The Department of Sports Medicine at the Australian Institute of Sport. PARTICIPANTS 100 elite athletes from 11 sports (56 male and 44 female athletes, mean age 19 years, range 16-27), undergoing routine medical screening. INTERVENTION Initial and follow-up assessment of the following biochemical parameters in association with clinical assessment; serum iron, ferritin, transferrin, percent transferrin saturation, sodium, potassium, chloride, calcium, magnesium, phosphate, urate, urea and creatinine, total protein, albumin, creatine kinase (CK), lactate dehydrogenase, aspartate aminotransaminase (AST), alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, total bilirubin, cholesterol and triglycerides (non-fasting), and random glucose. RESULTS 18 athletes showed no abnormalities on biochemical screening. 194 abnormal results were found in 82 athletes. 115 abnormalities were noted in 46 male and 79 in 36 female athletes. In 43 individual tests, the results did not return to normal on repeat testing. The most common abnormalities were increases in AST (27%), phosphate (13%), CK (13%), urea (12%) and bilirubin (12%). Three cases of hypercholesterolaemia and one case of haemochromatosis were identified, and one athlete, who was asymptomatic, was diagnosed with Epstein-Barr virus infection, which was suspected because of an abnormal liver function test. The other abnormalities found appeared not to be of clinical significance. CONCLUSION Most abnormalities found on routine biochemical screening in elite athletes are of no clinical significance, therefore such testing should, if used only for clinical purposes, be abandoned. When athletes are tested for iron status it would be prudent to include assessment of serum cholesterol in those with a family history of hyperlipidaemia