A cross-sectional study was conducted in 192 type 2 diabetic patients. Plasma basal
C-peptide and stimulated
C-peptide were measured before and 6 minutes after
intravenous injection of 1 mg
glucagon. The relationship between
C-peptide and microvascular complications was statistically analyzed.
RESULTS: In patients with retinopathy, basal
C-peptide was 1.9±1.2 ng/mL, and stimulated
C-peptide was 2.7±1.6 ng/mL; values were significantly lower compared with patients without retinopathy (P=0.031 and P=0.002, respectively). In patients with nephropathy, basal
C-peptide was 1.6±0.9 ng/mL, and stimulated
C-peptide was 2.8±1.6 ng/mL; values were significantly lower than those recorded in patients without nephropathy (P=0.020 and P=0.026, respectively). Stimulated
C-peptide level was associated with increased prevalence of microvascular complications. Age-, DM duration-, and
hemoglobin A1c-adjusted odds ratios for retinopathy in stimulated
C-peptide value were 4.18 (95% confidence interval [CI], 1.40 to 12.51) and 3.35 (95% CI, 1.09 to 10.25), respectively. The multiple regression analysis between nephropathy and
C-peptide showed that stimulated
C-peptide was statistically correlated with nephropathy (P=0.03).
CONCLUSION: