A comparative study of microvascular complications in patients with secondary and type 1 diabetes.

The prevalence of retinopathy, albuminuria, and neuropathy were assessed in 25 patients with insulin-requiring diabetes secondary to chronic pancreatitis and in 25 patients with Type 1 (insulin-dependent) diabetes, matched for age at diabetes onset (secondary, 39 +/- 11 (+/- SD) years vs Type 1, 38 +/- 11 years) and duration of diabetes (10 +/- 6 vs 10 +/- 7 years). The prevalence of retinopathy was significantly higher in Type 1 diabetic patients (52%) than those with secondary diabetes (20%) (p less than 0.02). Median urinary excretion of albumin was 9 (range 1-206) mg 24-h-1 in patients with Type 1 diabetes and 7 (1-90) mg 24-h-1 in patients with secondary diabetes (NS). One secondary diabetic patient and five Type 1 diabetic patients had microalbuminuria (NS). Vibration perception threshold (measured at the big toe) was identical in the two groups of patients, and no patient had a threshold indicating somatic neuropathy (biothesiometry greater than 20 V). Retinopathy is more frequent in patients with Type 1 diabetes than in patients with insulin-requiring diabetes secondary to chronic pancreatitis. Retinopathy is so frequent in the latter group, however, that regular ophthalmoscopic examination is still required.