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Biomedical subjects

B Vessby

Publications and source records attributed to B Vessby.

203 records · Page 12Linked to original sources
PubMed1975

Effects of dietary treatment on lipoprotein levels in hyperlipoproteinaemia.

Diet constitutes the basis of all lipid lowering therapy. The mechanisms responsible for the effects of the different dietary measures are not yet fully understood. Dietary treatment 'normalized' the lipid levels in over 50% of the mild to moderate hyperlipoproteinaemic states encountered in a middle-aged population with clinical manifestations of atherosclerotic cardiovascular disease. Triglyceride and cholesterol determinations in isolated lipoprotein fractions supplied additional information on the character and extent of the lipoprotein changes induced by diet.

Cholesterol↗
PubMedDate not supplied

Relationships between endothelium-dependent vasodilation, serum vitamin E and plasma isoprostane 8-iso-PGF(2alpha) levels in healthy subjects.

Due to the reported associations between a low intake of vitamin E and atherosclerosis on one hand, and between endothelial dysfunction and atherosclerosis on the other hand, we investigated the relationship between endothelium-dependent vasodilation and serum levels of vitamin E (alpha- and gamma-tocopherol) as well as the lipid peroxidation markers malondialdehyde and 8-iso-PGF(2alpha) in a healthy population. Healthy subjects (31 men and 25 women), aged between 20 and 69 years, underwent measurements of forearm blood flow (FBF) at rest and during local infusion of 2 and 4 microg/min of methacholine (Mch, to evaluate endothelium-dependent vasodilation) and 5 and 10 microg/min of sodium nitroprusside (SNP, to evaluate endothelium-independent vasodilation, and during reactive hyperemia using venous occlusion plethysmography. Serum alpha-tocopherol concentration was significantly related to the index of endothelial function (r = 0.46, p < 0.01), defined as the ratio between the maximal dilatations during Mch and SNP infusions. Serum gamma-tocopherol levels were positively related to the maximal FBF during reactive hyperemia (r = 0.54, p < 0.01) in women only. Furthermore, in women only, plasma 8-iso-PGF(2alpha) levels were inversely related to the relative increases in FBF during both Mch and SNP infusions (r = -0.58 and r = -0.59, p < 0.01 for both). The results show a relationship between the levels of alpha-tocopherol and endothelial vasodilatory function, suggesting a beneficial role for this potent lipid-soluble antioxidant also in a population sample of apparently healthy subjects. Furthermore, in women, the accumulation of lipid peroxidation products such as 8-iso-PGF(2alpha) seems to be associated with an impaired vasodilation in general.

Adult↗
PubMedDate not supplied

Lipoprotein lipase activity in skeletal muscle is related to insulin sensitivity.

The relative effects of obesity, alone or in combination with insulin resistance and hyperinsulinemia (with or without diabetes), on lipoprotein concentrations, blood pressure, and other risk factors for cardiovascular disease were investigated in 28 men (mean age, 63 years). Special attention was given to lipoprotein lipase (LPL) activity in tissues and to postheparin plasma LPL activity and hepatic lipase activity and their relation to insulin resistance. The 28 men fulfilled the entrance criteria of the study so that they could be allocated to one of the four groups (seven in each group): 1) normal body weight, normal fasting insulin level, and normal glucose tolerance (controls); 2) the same as in group 1 but with moderate obesity; 3) the same as in group 2 but with fasting hyperinsulinemia; 4) the same as in group 3 but with non-insulin-dependent diabetes mellitus. Glucose infusion rate for the control group was 8.1 +/- 2.1 mg/kg body wt/min (mean +/- SD) at an insulin infusion rate of 56 milliunits/m2/min. The average values in groups 2, 3, and 4 were 6.0 +/- 0.7, 3.2 +/- 0.5, and 1.9 +/- 1.0 mg/kg body wt/min, respectively. Concentrations of very low density lipoproteins as well as blood pressure and urate concentrations were highest and those of high density lipoproteins were lowest in the two hyperinsulinemic groups (groups 3 and 4). Skeletal muscle LPL activity was 46 +/- 23, 41 +/- 25, 23 +/- 6, and 31 +/- 13 milliunits/g wet wt (mean +/- SD) in the four groups, respectively. There was a positive correlation between glucose infusion rate and muscle LPL activity (r = 0.58, p less than 0.0001). The hepatic lipase activity was positively correlated with the insulin area under the curve of the intravenous glucose tolerance test (r = 0.35, p = 0.02). Furthermore, blood pressure, free fatty acid concentration, liver enzymes, and urate concentrations were significantly correlated with glucose infusion rate at the clamp test. These data give further support for insulin resistance as an important factor behind the observed lipoprotein abnormalities and blood pressure elevations as part of the insulin resistance syndrome characteristic for obese and diabetic patients.

Adipose Tissue↗
PubMedDate not supplied

Serum lipoprotein and lipoprotein lipase in overweight, type II diabetics during and after supplemented fasting.

Poorly controlled, obese, Type II diabetics were studied before, during, and 3 months after a weight reduction program that used supplemented fasting (200 kcal or 0.9 MJ/day). During fasting, the very low density lipoprotein (VLDL) triglycerides (TG) decreased, as did the adipose tissue lipoprotein lipase (AT-LPLA) and skeletal muscle lipoprotein lipase (SM-LPLA) activities. Three months later VLDL TG remained low (-59%), while high density lipoprotein cholesterol was higher (+11%) and blood glucose control improved compared with values on admission. The fractional removal rate (K2) at the i.v. fat tolerance test (IVFTT) and the SM-LPLA were unchanged, while AT-LPLA (expressed per gram of wet weight, but not as whole-body AT-LPLA) increased by 25%. There were no significant correlations between AT-LPLA and the lipoprotein TG concentrations or K2-IVFTT, although there were significant positive correlations between SM-LPLA and K2-IVFtt, both on admission and after body weight stabilization. This may indicate that SM-LPLA is more directly related to the capacity to remove lipoprotein TG, at least in obese diabetic patients. K2-IVFTT was inversely correlated to the VLDL TG and cholesterol concentrations both before and 3 months after fasting. Because both SM-LPLA and K2-IVFTT were unchanged after body weight reduction, the change in VLDL TG may be mainly due to a reduced rate of lipoprotein synthesis.

Adipose Tissue↗