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OBJECTIVE To compare the effects of tolrestat and placebo in patients with subclinical diabetic neuropathy. RESEARCH DESIGN AND METHODS Non-insulin-dependent diabetes mellitus (NIDDM) patients with early involvement of the autonomic nervous system were identified by only one pathological (outside the 99% confidence interval of the normal population) squatting test (vagal or sympathetic). Fifty-seven patients entered a randomized, placebo-controlled, double-blind, parallel 52-week study of tolrestat at a dose of 200 mg/day. Cardiovascular reflex tests (squatting vagal and sympathetic tests, pressure gain, deep breathing, lying-to-standing, Valsalva maneuver, and orthostatic hypertension), vibration thresholds, tendon reflexes, and muscle strength were assessed throughout the study. RESULTS At 12 months, nerve function significantly improved in patients receiving tolrestat and deteriorated in patients taking placebo. At baseline, the squatting vagal test was normal in 16 patients in the tolrestat group and in 15 patients in the placebo group. At 12 months, 25 patients taking tolrestat had a normalized squatting test, but only 6 patients taking placebo did (P = 0.02). Vibration perception threshold improved by a value of 6 ± 3 V in the tolrestat group (P < 0.001) and deteriorated by a value of 3 ± 1.8 V (P < 0.001) in the placebo group. CONCLUSIONS Tolrestat may be useful in the primary prevention of diabetic neuropathy.

OBJECTIVE To determine the effects of metformin on blood pressure, left ventricular mass, and some metabolic and endocrine parameters in nondiabetic, obese, hypertensive women. RESEARCH DESIGN AND METHODS Twelve obese, nondiabetic, hypertensive women received 850 mg metformin 2 times/day for 12 wk and placebo for another 12 wk, according to a double-blind, cross-over, randomized design. All patients were hospitalized 4 times, i.e., before randomization and after each treatment (metformin or placebo), to conduct metabolic and cardiovascular investigations (oral glucose tolerance test, euglycemic clamp associated with indirect calorimetry, and echocardiography). RESULTS Fasting glucose, HbA1c, fasting and glucose-stimulated insulin, blood pressure and left ventricular mass, cholesterol, triglycerides, and fibrinogen decreased significantly after metformin treatment, whereas high-density lipoprotein cholesterol increased. The improvement in glucose metabolism resulted from increased sensitivity to insulin. CONCLUSIONS These findings suggest that metformin treatment in obese, nondiabetic, hypertensive women produces a more favorable cardiovascular risk profile.