Low risk of overt nephropathy after 24 yr of childhood-onset type 1 diabetes mellitus (T1DM) in Norway

Abstract

Aim: To estimate the risk of diabetic nephropathy and associated risk factors in a nationwide cohort of childhood‐onset type 1 diabetes mellitus (T1DM) and 19–30 yr of diabetes duration. Methods: Patients diagnosed with childhood‐onset T1DM ( 200 μg/min, respectively] in at least two out of three consecutive overnight urine samples were defined as diabetic nephropathy. Results: Overt nephropathy was found in 7.8% [95% confidence interval (CI) 4.7–10.9] and persistent microalbuminuria in 14.9% (95% CI 10.8–19.0) of the subjects. Hemoglobin A1c (HbA1c) (p = 0.001), systolic blood pressure (BP) (p = 0.002), total cholesterol (p = 0.019), and C‐reactive protein (CRP) (p = 0.019) were associated with diabetic nephropathy. Significant predictors in 1989–1990 for the development of diabetic nephropathy in 2002–2003 were HbA1c (p < 0.001), AER (p = 0.007), and cholesterol (p = 0.022). Conclusions: In a subgroup of patients diagnosed with childhood‐onset T1DM in 1973–1982, 7.8% had overt nephropathy after 19–30 yr of diabetes duration, which is low compared with studies from other countries. HbA1c, systolic BP, total cholesterol, and CRP were each independently associated with diabetic nephropathy.