PubMed Health⌕ Search

Biomedical subjects

H Lithell

Publications and source records attributed to H Lithell.

297 records · Page 17Linked to original sources
PubMed1977

Supplementation with vitamin E in hyperlipidemic patients treated with diet and clofibrate. Effects on serum lipoprotein concentrations, plasma fatty acid composition and adipose tissue lipoprotein lipase activity.

Twelve hyperlipidemic patients on long term treatment with a lipid lowering diet enriched in polyunsaturated fatty acids and with clofibrate were supplemented with vitamin E (400 mg/day). The effect on serum lipoprotein concentration, plasma lipid fatty acid composition, and adipose tissue lipoprotein lipase activity was studied. No additional lipid-lowering effect was registered during a treatment period of 4 months. A slight increase in total serum cholesterol concentration and in high density lipoprotein concentration was probably attributable to seasonal variations in serum lipoprotein concentrations. No major changes of fatty acid composition in plasma cholesteryl esters or triglycerides were recorded. However, an increased relative amount of arachidonic acid and a reduced amount of palmitic acid in the plasma phospholipids after 2 months was possibly caused by the vitamin E therapy.

Adipose Tissue↗
PubMed1977

A method of determining lipoprotein-lipase activity in human adipose tissue.

A method of determining lipoprotein-lipase activity (LPLA) in human adipose tissue specimens (weighting 5-50 mg) is described. The specimens were incubated at 37 degrees C in a reaction medium based on a glycine buffer (pH 8.3, ionic strength 0.08), in which the enzyme was stablized and the velocity of release of fatty acids was constant during the incubation. The enzyme activity was increased, as is characteristic of lipoprotein-lipase (LPL), three to four-fold by the addition of serum. The inhibitions by NaCl, protamine sulphate and apolipoprotein C-III were as for LPL, when analysed in both a serum-activated and non-activated reaction medium. The apparent LPLA was about six times greater when analysed in a reaction medium based on a glycine buffer in the presence of heparin (1 g/l) than when analysed in a reaction medium based on a Tris buffer. An analysis of the influence of a high (1 g/l) and a low (0.05 g/l) concentration of heparin on the properties of the enzyme activity was carried out, using LPL of bovine skim milk as a reference enzyme. A phospholipid/soybean-oil emulsion was used as substrate, with [3H]triolein as a trace substance. The emulsion was stable for 5 months. The adipose tissue specimens were stored in liquid nitrogen. The analytical error was 15%, which was reduced to 11% (=within-day variation) when intra-individual comparisons were made.

Adipose Tissue↗
PubMed1976

Gemfibrozil as a lipid lowering compound in hyperlipoproteinaemia. A placebo-controlled cross-over trial.

The efficacy of gemfibrozil in lowering increased serum lipoprotein concentrations was tested in a placebo-controlled cross-over trial on 30 patients. Administered in a dose of 1200 mg daily, gemfibrozil reduced increased serum triglyceride levels by approximately 50% and reduced increased serum cholesterol concentrations by about 20%. Elevated VLDL triglyceride levels were reduced by 60%, and increased LDL cholesterol concentrations were reduced by approximately 20%. The mean HDL cholesterol concentration increased during gemfibrozil treatment. No adverse reactions attributable to gemfibrozil were recorded during the trial.

Adipose Tissue↗
PubMed1975

The smoking habits of men with intermittent claudication.

Smoking habits among 54 male patients with intermittent claudication (IC) and 200 healthy 50-year-old men from the same county have been studied. The prevalence of smokers at the age of 50 was 98% among the IC patients against 46% among the healthy controls. The percentage of heavy smokers and the total tobacco consumptiion were not significantly different in the two groups. However, the percentage of smokers who began to smoke before the age of 15 was significantly higher in IC patients than in the healthy group, 28% to 7%.

Adult↗
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

Skeletal muscle lipoprotein-lipase activity in insulin-dependent diabetic patients with and without albuminuria.

In patients with insulin-dependent diabetes mellitus (IDDM), albuminuria reflects widespread vascular dysfunction. Albuminuria has been associated to defects of heparan sulfate proteoglycan (HSPG) within the extracellular matrix. Our hypothesis is that loss of HSPG in vascular walls reduces the HSPG-bound lipoprotein-lipase activity (LPLA), thereby causing elevated levels of plasma triglyceride (TG) seen in IDDM patients with albuminuria. The aim of the present study was to evaluate whether LPLA in muscle capillaries could be related to TG in IDDM patients with and without albuminuria. This is a cross-sectional study including ten healthy control subjects (group C), nine patients with IDDM and urinary albumin excretion rate (AER) of 30 mg/24 h or less (group D0) and 20 patients with IDDM and AER greater than 30 mg/24 h (group DA). Muscle LPLA, plasma TG, total cholesterol, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and very-low-density lipoprotein cholesterol (VLDL) were measured. Between groups no difference in total cholesterol, TG, VLDL, and LDL was found. In patients with albuminuria, LPLA was reduced compared to controls, however, the difference between the groups was not statistically significant [median (range)] 35.9 mU/g (20.4-103) versus 44.6 mU/g (28.2-57.2) and 40.9 mU/g (21.7-53.5) in group DA, C, and D0, respectively, p = 0.76. AER was not correlated to LPLA. An overall negative correlation between TG and LPLA was found; r = -0.33, p = 0.04, supported by an overall significant positive correlation between LPLA and HDL; r = 0.32, p = 0.045. We conclude that, in insulin-dependent diabetes mellitus, skeletal muscle lipoprotein-lipase activity is associated with plasma triglyceride, while an association between lipoprotein-lipase activity and urinary albumin excretion is questionable.

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↗