Diagnostic biochemical tests in Aboriginals.

Commonly used diagnostic biochemical tests were performed on blood samples from a small group of Aboriginal Australians. Reference ranges derived from a white urban population appear to be applicable to the study group for the correct interpretation of plasma electrolyte, urea, creatinine, urate, albumin and calcium levels. Care should be exercised in the use of the plasma urea level alone as a screening test for renal function. Results for the plasma enzyme activities of both aspartate and alanine aminotransferases suggest that the reference ranges currently used by laboratories may be inappropriate for correct diagnostic interpretation. Thyroid function tests showed that plasma levels of total thyroxine, total triiodothyronine, and thyroxine-binding globulin were lower than normal white values in this group of tribal Aboriginals; this suggests that the reference ranges derived from a white population are misleading for diagnostic purposes.