URINARY CREATININE ADJUSTED REFERENCE RANGES FOR HOMOVANILLIC AND VANILLYLMANDELIC ACID IN CHILDREN AND ADULTS

The relationship between urinary homovanillic acid (HVA), vanillylmand elic acid (VMA) and creatinine is investigated and reference ranges ar e constructed for HVA and VMA. A total of 769 urine samples were obtai ned from children and adults. The ratios HVA/creatinine and VMA/creati nine were highly correlated with creatinine concentration; hence, refe rence to creatinine was found to be an inappropriate adjustment for ur inary dilution. An alternative method based upon linear regression is proposed. After allowing for differing levels of creatinine, HVA and V MA were found to be significantly correlated with age, height and weig ht for individuals aged less than 20 years. In those aged over 20 year s, HVA was significantly correlated with weight and VMA with age. Diff erences between sexes were found in the levels of HVA and VMA, the exc eption being VMA in the over 20 age group. Reference ranges were const ructed for HVA and VMA which are variously dependent upon creatinine, age, sex and weight.