Extrapolation shows that acarbose is an efficient and acceptable drug for the treatment of NIDDM with poor metabolic control by diet alone. It has beneficial effects on postprandial hyperinsulinemia and postprandial hypertriglyceridemia.

In obese people, an increase of plasma leptin levels is well-known and is seen as a consequence of the increased body fat mass. Moreover, a relationship between fasting concentrations of leptin and insulin has been described. Hyperinsulinemia is considered to be indicative of insulin resistance. We aimed at elucidating the interrelations between leptin, insulin and insulin resistance in type 2 diabetic patients. Under metabolic ward conditions, we investigated 21 moderately overweight men with type 2 diabetes. The patients had a mean age of 49.1 years, a mean body mass index (BMI) of 26.8 kg/m(2), and a mean diabetes duration of 82.5 months. All patients were treated with diet alone. We measured fasting leptin and insulin levels, body composition by determination of total body water, and insulin resistance by euglycemic hyperinsulinemic clamp technique. At univariate analysis, fasting leptin level significantly and positively correlated with BMI (r=0.49, p=0.02) and with fasting insulin (r=0.69, p=0.001), while it negatively correlated with the glucose disposal rate (r=-0.62, p=0.002). Furthermore, leptin was inversely correlated with HDL-cholesterol (r=-0.45, p=0.04). When excluding the influence of body fat mass or of BMI in partial correlation analysis, the correlations between leptin and insulin or insulin sensitivity remained significant. The relationship between insulin resistance (as measured directly in the clamp experiments) and leptin concentrations was also shown by subdividing the diabetic patients according to tertiles of insulin sensitivity. The highest fasting leptin levels were observed in those patients with the most expressed insulin resistance. Our data point to a functional relationship between insulin resistance and leptin concentrations in insulin-resistant type 2 diabetic men, independently of body composition. This relationship is believed to be mediated by insulin.

The influence of hGH and IGF-I levels on lipid-, lipoprotein metabolism and fibrinolysis were studied in 23 patients with active acromegaly (14 women and 9 men, mean age 49.8 +/- 2.1 years) compared to a sex, BMI and age-matched control group. Mean Lp(a) levels were significantly higher in acromegalics than in controls (469.8 +/- 140.1; n = 23 vs. 162.7 +/- 64.9 mg/l; n = 111; p < 0.01). We found elevated apolipoprotein A-I and Apo E-concentrations in acromegalic patients compared to controls (apo A-I: 1.79 +/- 0.06 vs. 1.46 +/- 0.04 g/l; p < 0.01; apo E: 98.35 +/- 6.4 vs. 72.53 +/- 3.38 mg/l; p < 0.05). 30% of the acromegalics showed increased plasminogen activator inhibitor activity (PAI) while 66% had increased tissue-type plasminogen activator (t-PA) concentrations. There was a correlation between hGH and Lp(a) (r = 0.414; p = 0.05), between hGH and PAI (r = -0.59; p < 0.005) and IGF-I and t-PA activity (r = -0.44; p < 0.05). In a subgroup of nine acromegalics Lp(a) was reduced by 32.2 +/- 6.7% (p < 0.05) after a six-month octreotide therapy and HDL2-cholesterol-concentration increased from 0.17 +/- 0.04 to 0.24 +/- 0.04 mmol/l (p < 0.05). In conclusion, our results demonstrate that elevated Lp(a)-concentrations and changes in fibrinolysis contribute to the cardiovascular complications and should therefore be controlled in acromegalic patients.

Glibenclamide increases circadian leptin and insulin concentrations, whereas acarbose does not. This observation may help to explain weight gain in subjects treated with glibenclamide and stable weight in those treated with acarbose in the long run.

In 43 normolipidemic postmenopausal women we studied fasting and postprandial (oral fat load with 50 g fat per square meter; blood sampling for 5 h) lipoprotein components and lipoprotein(a) levels before and with the administration of conjugated equine estrogens opposed by medrogestone (on days 11-21). Data was compared intraindividually; the second testing was performed during the last 5 days of the combined estrogen/progestogen phase of the third cycle. Fasting low-density lipoprotein (LDL) and total cholesterol concentrations decreased significantly; high-density lipoprotein (HDL) cholesterol, including subfractions HDL2 and HDL3, was not changed. Fasting triglyceride concentrations increased. All lipoprotein fractions measured showed a postprandial elevation with the exception of chylomicron cholesterol concentrations. There was a significant effect of hormone replacement therapy on the postprandial course of total cholesterol (decrease; P < 0.001), VLDL cholesterol (increase; P = 0.025), and the triglyceride proportion in the LDL plus HDL fraction (increase; P < 0.001). With hormone replacement therapy the postprandial curve of total triglycerides was increased only 1 h after the fat load while chylomicron triglyceride concentrations were lowered after 5 h. VLDL triglycerides were not influenced. In all patients with lipoprotein(a) levels above 10 mg/dl, this parameter decreased (about 25%). Although increasing fasting triglyceride concentrations, hormone replacement therapy does not bring about an exaggerated postprandial increase in triglycerides. Postprandial chylomicron clearance is evidently promoted. Hormone replacement therapy leads to a small increase in triglycerides in the LDL plus HDL fraction by inhibiting hepatic lipase activity. Moreover, the decrease in lipoprotein(a) levels may contribute to the antiatherosclerotic effect.