Changes of albumin concentrations in the first morning urine according to age and sex in 2990 healthy children and adults

Abstract

This study was performed to clarify the changes in urinary albumin excretion according to age and sex in healthy subjects, for the appropriate judgment of microalbuminuria in insulin-dependent diabetes mellitus (IDDM). Concentrations of albumin in the first morning urine from 2990 healthy individuals (1713 males, 1277 females) aged from 6 to 39 years were measured by turbidimetry immunoassay. Reference values of the concentrations for each age group were obtained from the 95% confidence limits from the distribution simulated by the x 2-test ( k = 1). Reference values were 1.3–2.2 mg/dl in children aged 6–11 years. Values for 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 gradually from 1.7 mg/dl at age 11 years to 3.9 mg/dl at age 16 years. There 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 years, the values decreased from 3.9 mg/dl to 3.3 mg/dl in females, and to 2.9 mg/dl in males. We conclude that reference values of urinary albumin excretion change according to age and sex, which should be taken into consideration in the assessment of diabetic nephropathy in IDDM.