Nozomu Sasaki

C-Peptide/Creatinine Ratio in Early Morning Urine as an Indicator of Residual B-Cell Function in Insulin-Dependent Diabetes

The C‐peptide/creatinine (Cr) ratio in early morning urine was evaluated to assess B‐cell function. The subjects were 12 boys and 36 girls with insulin‐dependent diabetes mellitus (IDDM). The controls were 130 boys and 137 girls aged 4–15 years. There was a significant inverse correlation of this ratio with the duration of insulin therapy (r = ‐0.5807, P<0.01). The daily insulin dose in U/kg was significantly different among the following groups: 1.22 ± 0.31 U/kg in group 1 with undetectable C‐peptide, 0.94 ± 0.37 in group 2 with a decreased ratio and 0.45 ± 0.28 in group 3 with a normal ratio. HbAl levels were 11.3 ±1.6% in group 1 and 9.2 ± 1.1% in group 3. The difference was significant. The result shows that the C‐peptide/ Cr ratio in early morning urine is useful for assessing B‐cell function in diabetic children.