Insulin has an exacerbating effect on endogenous hypertriglyceridemia. Experiments were carried out in order to study the acute effects of insulin in 6 patients with endogenous hypertriglyceridemia and 6 controls. 0.1 Unit insulin/kg body weight was injected into the portal vein. Blood samples were taken from the portal and hepatic veins and analysed for FFA, glycerol, VLDL-triglycerides (VLDL-TG) and insulin. Liver blood flow was measured with cardiogreen. This technique allowed a study of the acute effect of insulin on the hepatic extraction of substrates and on the hepatic production of VLDL-TG. Under basal conditions the production of VLDL-TG in patients with endogenous hypertriglyceridemia was not statistically different from the production in controls. The results did not provide statistical proof of a correlation between the production and the hepatic uptake of VLDL-TG precursors; however, the production was negatively correlated to the hepatic clearance rate of insulin. During a one-hour observation period after the application of insulin, the production of VLDL-TG was decreased in controls and increased in patients with endogenous hypertriglyceridemia. The application of insulin was also followed by a decreased uptake of free fatty acids and glycerol, this change being similar in controls and in patients with endogenous hypertriglyceridemia. There was no correlation between the effect of insulin on the production of VLDL-TG and on the uptake of substrates by the liver. It is concluded that insulin has a direct effect on the production of VLDL-TG which is independent of substrate supply. The adverse effect of insulin in endogenous hypertriglyceridemia may reflect some type of impaired hepatic responsiveness to insulin.

Forty-eight patients (20 diabetic, 28 nondiabetic) with angiographically confirmed peripheral vascular disease (PVD) were examined to discover whether the measurement of pulse reappearance time (PRT) during reactive hyperemia is a more useful method than the measurement of peripheral systolic blood pressure (ankle pressure index; API) for making a specific diagnosis of PVD. Specific diagnosis refers to the degree and localization of occlusive atherosclerosis determined by Doppler ultrasound techniques for both measurements. We found that PRT and API both provided accurate qualitative proof of a peripheral blood flow deficit in diabetic and nondiabetic subjects. However, in relation to the angiographically defined degree and localization of sclerotic lesions, there were significant differences. The sclerotic degree of occlusive PVD in diabetic subjects was correlated with the results of the PRT (P less than .001), whereas the API was not (P greater than .05). The occlusion localization could only be distinguished by PRT measurements in both diabetic and nondiabetic subjects. Compared with control subjects (4.1 s) the half-maximum PRT of blood flow velocity was delayed in stenotic PVD to 5.7 s, in occlusive PVD of the upper leg to 14.3 s, in occlusive PVD of the lower leg to 29.6 s, and in multilevel disease to 45.0 s (P less than .0005 vs. control). The results show that Doppler sonographic measurement of the peripheral systolic blood pressure is only useful for an overall diagnosis of PVD in diabetic subjects, whereas PRT measurement, by quantifying the degree and localization of sclerotic lesions, can be used additionally either to confirm or to specify this diagnosis.

The apoprotein composition of the main lipoprotein fractions (VLDL, LDL‐1, LDL‐2 and HDL) was studied initially in 15 patients with Broad‐β disease. Analytical isoelectric focusing of urea‐soluble apo‐VLDL and apo LDL‐1 demonstrated a variant pattern of the polymorphic Apoprotein E with a deficient Apo E‐III band in all patients. The Apo E‐III deficiency pattern was seen in only six out of 304 hyperlipidaemic controls. These six Apo E‐III deficient controls had characteristic signs of Broad+ disease, and thus represented patients not previously recognized as having the disorder. The Apo E focusing patterns were constant on repeated examinations and were stable under different metabolic conditions. The data show that Apo E‐III deficiency in VLDL is a specific qualitative marker for Broad‐β disease, allowing an unequivocal diagnosis that had not been possible previously. Indirect evidence suggests that Apo E‐III deficiency is the basic lipoprotein abnormality underlying the familial dyslipoproteinaemia.

Necrotic ulcers of the feet are a dangerous complication of the diabetic foot syndrome. Besides peripheral vascular disease (PVD) peripheral neuropathy is an important factor in the pathogenesis of necroses. We examined whether the reserve of circulation during reactive hyperemia at the feet of patients with type I diabetes mellitus with abnormal blood flow (n = 17) is decreased compared with diabetic (n = 14) and nondiabetic (n = 20) controls. Further we analyzed whether there is a correlation with the oxygen supply of the foot. PVD was excluded by clinical check-up, oscillography, and Doppler ultrasound. The reserve of circulation of the foot was measured during reactive hyperemia and oxygen supply of the foot by oximetry. Abnormal blood flow of the foot was diagnosed by the pulsation index. On examination it was found that the reserve of circulation of diabetic feet with abnormal blood flow is about 52% less than in diabetic and about 50% less than in nondiabetic controls (P < or = 0.005). The decreased reserve of circulation correlates with the oxygen supply of the feet; this is about 21% less compared to diabetic feet with normal blood flow and about 16% less in comparison to nondiabetic feet. The present study shows that diabetic feet suffer from disturbed circulation although there is no evidence of PVD. This disturbed circulation is correlated with a decreased oxygen supply of the feet. Hypoxia during strain could be of great importance in the pathogenesis and treatment of necrotic ulcers of diabetic feet.