Retinopathy in newly presenting non-insulin-dependent (type 2) diabetic patients

One hundred and twenty-nine (97 M, 32 F) previously untreated non-insulin-dependent diabetic patients were studied. Meal and glucose (75 g) tolerance tests were performed on two separate days with glucose, C-peptide and insulin levels estimated during each with the inclusion of growth hormone during the meal test. In addition glycosylated haemoglobin (HbA1) and plasma creatinine levels were determined. Clinical evaluation included detailed ophthalmological examination following mydriasis. Differences between retinopaths (n = 21) and non-retinopaths (n = 108) were FPG 13.7 vs 11.6 (mmol/l) (p less than 0.01); HbA1: 12.9 vs 11.3 (%) (p less than 0.01); BMI: 25.2 vs 29.4 (kg/m2) (p less than 0.001); age 56.8 vs 52.4 (yr) (ns); creatinine: 91.2 vs 88.4 (mumol/l) (ns); systolic blood pressure: 152.4 vs 143.9 mmHg (ns); diastolic blood pressure 87.9 vs 87.7 mmHg (ns); fasting growth hormone: 4.6 +/- 0.9 vs 2.4 +/- 0.3 (mU/1) (p less than 0.01). Multivariate logistic analysis however revealed that systolic blood pressure in conjunction with the insulin response gave the most significant correlation with retinopathy. No significant correlation was observed with age, sex, diastolic blood pressure, creatinine, family history or smoking. The effect of disease duration could not be evaluated. B-cell function appears central to microvascular complications in non-insulin dependent diabetes mellitus.