Urinary laminin P1 as an index of glycemic control in children with insulin-dependent diabetes mellitus.

OBJECTIVE

To evaluate the clinical meanings of urinary laminin P1, urinary laminin P1 concentrations in children with insulin-dependent diabetes mellitus (IDDM) were measured and compared with urinary levels of albumin, kappa light chain (kappa-LC), alpha 1-microglobulin (alpha 1-MG), beta 2-microglobulin (beta 2-MG), and n-acetyl-b-D-glucosaminidase (NAG).

RESEARCH DESIGN AND METHODS

Forty-six children with IDDM and 31 age-matched controls were studied. The first urine in the morning was collected for three days and stored at -20 degrees C until assayed. The mean values were used for the study. Radioimmunoassay (RIA) was used to measure of laminin P1, kappa-LC, alpha 1-MG, and beta 2-MG. NAG and haemoglobin Aic (HbA1c) concentrations were measured by a colorimetric method and high-performance liquid chromatography, respectively.

RESULTS

Urinary laminin P1 levels in IDDM were 54.2 + 3.4 (SE) mU/microM.Cr, significantly higher than those in control subjects (40.7 +/- 2.3 mU/microM.Cr, p < 0.01). In 10 out of 46 patients (21.7 percent), the values were higher than the mean +/- 2 SD of controls. Urinary albumin, kappa-LC, alpha 1-MG, beta 2-MG, and NAG in IDDM were higher than those in control subjects (p < 0.01). There were significant correlations between urinary laminin P1 levels and urinary albumin, kappa-LC, NAG, alpha 1-MG, and beta 2-MG. A significant correlation was also shown between urinary laminin P1 and HbA1c concentrations (p < 0.01).

CONCLUSIONS

From the above results, we conclude that urinary laminin P1 concentrations could be one of the clinical indexes for glycemic control and damage of the glomerulus in IDDM.