INCREASED COMPLICATIONS IN NONINSULIN-DEPENDENT DIABETIC-PATIENTS TREATED WITH INSULIN VERSUS ORAL HYPOGLYCEMIC AGENTS - A POPULATION STUDY

A cross-sectional population study was performed in a cohort of 890 no n-insulin-dependent diabetes mellitus (NIDDM) patients residing in the greater Denver metropolitan region. Its purpose was to evaluate the r elationship between insulin and oral hypoglycemic agents (OHAs) with r egard to metabolic control and diabetic complications. The mean glycos ylated hemoglobin for patients treated with insulin was 12.0 +/- 0.15% versus 11.4 +/- 0.14% (p <.03) for OHA. The difference in fasting blo od sugar for the insulin-treated group (195.0 +/- 3.5 mg/dl) versus th e OHA-treated group (194.0 +/- 2.9 mg/dl) was not statistically signif icant. Categorical increases in urinary albumin excretion were associa ted positively with insulin versus OHA therapy (p <.0001). Patients tr eated with insulin therapy had a higher frequency of peripheral vascul ar disease (insulin therapy, 14%; OHA therapy, 10%; p <.05); neuropath y (insulin therapy, 55%; OHA therapy, 37%; p <.0001); and retinopathy (insulin therapy, 71%; OHA therapy, 45%; p <.0001). The frequency of c ardiovascular disease was equivalent in the two groups (17% versus 13% ). In protocols correcting for diabetes duration, glycosylated hemoglo bin, and gender in a multivariate model, the use of insulin still was related significantly to increases in urinary albumin excretion (p <.0 1), retinopathy (p <.0001), and neuropathy (p <.0008). In a subgroup o f individuals with diabetes duration > 10 years (n = 211 for insulin t reatment, n = 118 for OHA treatment), the frequency of neuropathy stil l was significantly higher in the insulin group (63% vs 49%; p <.016) as was retinopathy (85% vs 58%; p <.0001). Overt albuminuria also was more significant in the insulin-treated patients (p <.04). In summary, the NIDDM patients treated with insulin had more nephropathy, retinop athy, and neuropathy than did NIDDM patients treated with OHA, indepen dent of duration of diabetes, fasting blood glucose, glycosylated hemo globin, age, and blood pressure level. These results in NIDDM patients may be due to contributions from worse blood glucose control at an ea rlier stage in the patients' diabetes and/or the mitogenic, atherogeni c, thrombogenic, and vascular permeability effects of insulin.