CHANGES OF ALBUMIN CONCENTRATIONS IN THE 1ST MORNING URINE ACCORDING TO AGE AND SEX IN 2990 HEALTHY-CHILDREN AND ADULTS

This study was performed to clarify the changes in urinary albumin exc retion according to age and sex in healthy subjects, for the appropria te judgment of microalbuminuria in insulin-dependent diabetes mellitus (IDDM). Concentrations of albumin in the first morning urine from 299 0 healthy individuals (1713 males, 1277 females) aged from 6 to 39 yea rs were measured by turbidimetry immunoassay. Reference values of the concentrations for each age group were obtained from the 95% confidenc e limits from the distribution simulated by the chi(2)-test (k=1). Ref erence values were 1.3-2.2 mg/dl in children aged 6-11 years. Values f or females increased significantly from 22 mg/dl at age 11 years to 3. 9 mg/dl at age 12 years (P < 0.0001) and those of males increased grad ually from 1.7 mg/dl at age 11 years to 3.9 mg/dl at age 16 years. The re were significant differences between males and females at the ages of 12 (P < 0.0001), 13 (P < 0.0001), and 14 (P < 0.0007). After 17 yea rs, the values decreased from 3.9 mg/dl to 3.3 mg/dl in females, and t o 2.9 mg/dl in males. We conclude that reference values of urinary alb umin excretion change according to age and sex, which should be taken into consideration in the assessment of diabetic nephropathy in IDDM.