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Biomedical subjects

B Vessby

Publications and source records attributed to B Vessby.

At least 199 records · Page 11Linked to original sources
PubMed1980

Increased plasma HDL-cholesterol and apo A-1 in sedentary middle-aged men after physical conditioning.

Previous studies have demonstrated an inverse relationship between plasma high density lipoproteins (HDL) cholesterol and coronary heart disease risk. In the present study we investigated prospectively the effect of a moderate physical conditioning programme on plasma lipids and lipoproteins, especially HDL-cholesterol and apolipoprotein A-I (apo A-I), the major apoprotein of HDL. Healthy, sedentary, middle-aged men were randomly selected and assigned either to a training group (n = 24, age 40 +/- 3.4, mean +/- SD) or to a control group (n = 13, age 39 +/- 5.0). Training consisted of various indoor and outdoor sports activities 45 min/day, 3 times/week for 12 weeks at an intensity of approximately 80% of measured maximal oxygen uptake (VO2 max). The trained subjects were studied at 4, 8 and 12 weeks. The training increased VO2 max by 12% (P less than 0.01). Increases were observed in both apo A-I (10%, P less than 0.02) and HDL-cholesterol (8%, P less than 0.02) after training, with significant increases already after 4 and 8 weeks, respectively. Furthermore, decreases in total plasma cholesterol (5%, P less than 0.004) and plasma triglycerides (26%, P less than 0.003) were found without changes in body weight, body composition, cigarette smoking, alcohol consumption or the percentage composition of dietary intake. Fasting serum-insulin concentrations decreased significantly during training. No changes were noted in the control group. The present study demonstrates prospectively that moderate physical training can increase HDL.

Adult↗
PubMed1979

Pronounced lipoprotein lipid reduction obtained by combined lipid-lowering treatment in patients with atherosclerotic disease.

The feasibility of reducing serum lipoprotein levels in patients with atherosclerotic disease by combining diet, clofibrate and nicotinic acid (niceritrol) has been investigated. An additive lipid-lowering effect of diet and the two drugs was demonstrated. It was possible to reduce the serum triglycerides (TG) in hypertriglyceridaemic patients by 50-60%. This corresponded to a reduction of very low density lipoprotein (VLDL) TG by 73 and 66% in patients with hyperlipoproteinaemia (HLP) type IIB and IV, respectively. In normotriglyceridaemic patients the serum TG concentration decreased by 30-40%. The serum cholesterol (Chol) concentration was reduced by 33% and the low density lipoprotein (LDL) Chol by 37% in HLP type IIA and IIB. The LDL Chol decreased by 32% in normolipoproteinaemic patients and by 21% in HLP type IV. The mean value for serum cholesterol after therapy was in all groups close to 200 mg/100 ml. In hypertriglyceridaemic patients high density lipoprotein (HDL) Chol increased by 18%. Clofibrate and niceritrol differed with regard to the effect on serum lipoprotein concentrations as well as on other metabolic parameters. Niceritrol was significantly more effective than clofibrate in lowering LDL Chol and in increasing HDL Chol. Niceritrol treatment significantly reduced the Chol/TG ratio in VLDL while no such effect was seen during clofibrate administration. The two drugs also showed significantly different effects on the fractional removal rate (K2) of triglyceride-rich lipoproteins as measured by the intravenous fat tolerance test (IVFTT). The K2 was significantly increased by clofibrate but was not affected by niceritrol treatment. The two drugs differed also with regard to the effects on serum uric acid concentration and the liver function tests. The plasma fibrinogen levels and the erythrocyte sedimentation rates were reduced during treatment with both niceritrol and clofibrate. The present study demonstrates that it is possible to obtain substantial reductions of serum lipoprotein concentrations by combining lipid-lowering diet, clofibrate and niceritrol treatment. There was an additive lipid-lowering effect of this treatment and the combination of the two drugs seemed beneficial in regard to certain possible side effects. The impact of a lipid reduction within this range on cardiovascular morbidity and mortality remains to be evaluated.

Adult↗
PubMed1978

Para-aminosalicylic acid as a lipid-lowering agent.

The capacity of para-aminosalicylic acid (PAS) to lower initially high serum lipoprotein lipid concentrations was tested in a double-blind crossover study. Thirty patients who were on a lipid-lowering diet were treated with PAS (6 gm daily) for 4 wk. There was an average reduction of the serum triglyceride concentration of 28% (p less than 0.001) and of 12% of the serum cholesterol concentration (p less than 0.001) corresponding to a reduction of very low density lipoprotein (VLDL) triglycerides of 40% (p less than 0.001) and low density lipoprotein (LDL) cholesterol of 6% (p less than 0.05). In hypercholesterolemic patients, the LDL cholesterol reduction was 14% (p less than 0.001). In patients with hypertriglyceridemia type IV, the mean reduction of the VLDL triglyceride concentration was 47% (p less than 0.01), corresponding to a serum triglyceride reduction by 37% (p less than 0.01). In spite of the decrease of VLDL concentration, there was an unexpected reduction of the lipoprotein lipase activity in adipose tissue of 16% (p less than 0.02). The glucose tolerance and the serum insulin concentrations at fasting and after glucose injection were not changed.

Adipose Tissue↗
PubMed1978

Lipoprotein-lipase activity in human skeletal muscle and adipose tissue in the fasting and the fed states.

Sixteen healthy subjects, 7 females and 9 males, with a mean age of 25 years (range 22--29 years), were studied in the fasting state in the morning and 8 h later after partaking of breakfast, lunch and two small meals. The lipoprotein-lipase activity in the adipose tissue increased significantly from 80 +/- 32 to 117 +/- 61 nmol fatty acid released per gram and minute (nmol FA/g/min), whereas in skeletal-muscle tissue it decreased significantly from 25 +/- 11 to 17 +/- 9 nmol FA/g/min. The concentration of serum triglycerides increased significantly from 0.93 +/- 0.18 mmol/l (mean +/- SD) in the fasting state to 1.57 +/- 0.64 mmol/l in the fed state. In the fasting state the lipoprotein-lipase activity of skeletal muscle was inversely related to the ratio between the concentrations of insulin and glucagon.

Adipose Tissue↗
PubMed1978

Lipolytic activities in post-heparin plasma in man measured with different substrate emulsions.

1. Post-heparin lipolytic activity in man has been studied by using a triglyceride substrate emulsion containing different emulsifiers. 2. The lipolytic activity measured was profoundly influenced by the type of emulsifier used in the substrate. Substrate stabilized by synthetic emulsifiers give higher lipolytic activity than Intralipid, which contains egg phospholipids as emulsifiers. This difference was solely explained by higher salt-resistant lipase activities found with emulsions containing synthetic emulsifiers. The salt-inhibited lipase activity, which has properties as a lipoprotein lipase, was not influenced by the type of emulsifier. 3. When used under specified conditions Intralipid seems to be virtually specific for extrahepatic post-heparin lipolytic activity.

Emulsions↗
PubMed1978

Increase of the lipoprotein-lipase activity in human skeletal muscle during clofibrate administration.

Lipoprotein-lipase activity was determined in tissue from the skeletal muscle of the leg and the subcutaneous adipose tissue of the abdomen in fourteen patients before and after 1 month of clofibrate administration. The concentrations of serum triglycerides decreased by, on the average, 37% in a group of thirteen patients which mainly consisted of subjects with type-IV hyperlipoproteinaemia. Clofibrate administration was associated with an average increase of the skeletal muscle-tissue lipoprotein-lipase activity of 50% (P less than 0.005). There was a significant correlation between the percentage changes in skeletal muscle-tissue lipoprotein-lipase activity and those of the triglycerides concentrations and the K2-values in an intravenous fat tolerance test during clofibrate treatment. Adipose-tissue lipoprotein-lipase activity did not change significantly. One patient with type-I hyperlipoproteinaemia had very low values of skeletal muscle-tissue lipoprotein-lipase activity and moderately low adipose-tissue lipoprotein-lipase activity. In this patient, neither the tissue lipoprotein-lipase activity nor the triglycerides concentration changed during clofibrate therapy. Fasting serum insulin concentrations decreased significantly during clofibrate administration and the percentage decrease was significantly correlated to the percentage increase of skeletal-muscle lipoprotein-lipase activity. It is suggested that the lowering of insulin levels is a possible mechanism through which glucagon activity is enhanced and this may increase skeletal muscle-tissue lipoprotein-lipase activity.

Adipose Tissue↗
PubMed1977

Inheritance of type-III hyperlipoproteinemia. Lipoprotein patterns in first-degree relatives.

The lipoprotein (LP) patterns were studied in the families of 19 index cases with type-III hyperlipoproteinemia (HLP). Seventy adult first-degree relatives (93% ascertainment) to the 19 probands were analyzed. The diagnosis of HLP type III among the first-degree relatives was based on three criteria, all of which had to be fulfilled to make the diagnosis: (1) presence of a slow-moving band in very-low-density LP (VLDL) on agarose gel electrophoresis migrating in beta or close to beta position; (2) A cholesterol/triglyceride ratio (mg/100 ml: mmoles/liter) in VLDL greater than 29.0; and (3) A "III-index" [cholesterol/triglycerides in VLDL x 10 divided by cholesterol/triglycerides in low-density LP (LDL)] greater than 1.30. When defined according to these criteria there was a marked over-representation of HLP type III among the relatives (27%). There was also an increased frequency of hypertriglyceridemia (28% against expected 15%), mainly because of a high prevalence of HLP type IV (24%). On agarose gel electrophoresis a "late pre-beta" band, probably indicative of an increased amount of intermediary LP particles, was frequently present (47%) among relatives not classified as HLP type III. Type-III patients with hypertriglyceridemia were characterized by a significantly higher body weight than those with normotriglyceridemic type III. However, there was no qualitative difference in the composition of the lipoproteins in normotriglyceridemic and hypertriglyceridemic type-III patients. A genetic analysis of the LP patterns within the families showed several examples of vertical transmission of HLP type III. There was no sex linkage. Six of thirteen analyzed parents showed LP patterns classified as HLP type III. Another two parents were most probably carriers of the gene. Of the siblings to the probands, 23% showed a type-III pattern and another four (7%) showed LP patterns very similar to type III, fulfilling two of three criteria for HLP type III. The data support the concept that HLP type III is inherited as an autosomal dominant gene. It was indicated that HLP type IV with a late pre-beta band in VLDL may represent another expression of the gene for HLP type III. It is suggested that HLP type III may be a pathogenetically heterogenous group of lipid disorders. A separation of type III into two subgroups with low or normal and high LDL cholesterol concentration, respectively, may facilitate the understanding of the inheritance of type III as well as of the pathogenesis behind this LP abnormality.

Adult↗
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

Fat emulsions with added free cholesterol or fatty acid cholesteryl esters. Studies on removal mechanisms in vivo and hydrolysis by lipoprotein lipase in vitro.

The fractional elimination rate of fat emulsions of soybean oil, emulsified with egg yolk phosphatides with 1% addition of cholesterol or various cholesteryl fatty acid esters, was studied in rabbits. The fractional removal rate k2%/min was the same after addition of free cholesterol or esters with fatty acids up to eight carbon esters. The k2 values were twice as high for emulsions with cholesteryl-stearate, three times higher with added cholesteryl-palmitate and four times higher when cholesteryl-linoleate was added. The triglyceride (TG) lipase activity was determined with human or rabbit post-heparin plasma and with purified bovine lipoprotein lipase. All these enzyme sources gave similar results. Addition of saturated cholesteryl esters did not affect the lipase activity, but addition of 1% cholesterol markedly decreased the lipase activity. Furthermore, addition of cholesteryl-linoleate and linolenate reduced post-heparin TG lipase activity.

Animals↗
PubMed1976

Studies on the serum lipoprotein composition in 50-year-old men. A suggestion of chemical criteria for diagnosis of hyperlipoproteinaemia type III (Broad-beta disease).

The serum lipoprotein (LP) composition in hyperlipoproteinaemia (HLP) type III, when studied in a population of 50-year-old men, was characterized by a high cholesterol/triglyceride ratio in the very low density lipoprotien (VLDL) fraction, a high low density lipoprotein (LDL) triglyceride concentration and a low LDL cholesterol/triglyceride ratio. No one of these three variables, however, was found to be a suitable single parameter for diagnosis for HLP type III because of an overlap between HLP type III and other LP patterns with regard to the studied variables. In an effort to find a parameter with a better discriminative capacity a "III-index" was invented.

Cholesterol↗
PubMed1976

Serum lipoprotein concentration and composition in healthy 50-year-old men.

The classification of hyperlipoproteinaemias (HLP) is based on arbitrary limits between "normolipidaemia" and "hyperlipidaemia". 92 randomly selected healthy 50-year-old men were studied regarding serum lipoprotein (LP) lipid composition to define limits for "normality". Cholesterol and triglyceride concentrations were determined and the individual ratios between cholesterol and triglycerides were calculated in the ultracentrifugally isolated LP density classes. A significant linear correlation between cholesterol and triglyceride concentrations was found in the very low density lipoproteins (VLDL) and low density lipoproteins (LDL) but not in the high density lipoproteins (HDL). When different percentile limits for LDL cholesterol and VLDL triglycerides were used as cut-off points for "normality" not only the absolute prevalence but also the relative frequency of different types of HLP was influenced. 26 overweight men studied separately showed significantly increased VLDL cholesterol and triglyceride levels with maintenance of the normal ratio cholesterol/triglycerides of this LP class compared with non-obese subjects. Three different kinds of "extra bands" were occasionally seen on agarose electrophoresis: a "double pre-beta" band in whole serum (3%), a "sinking pre-beta" band with density greater than 1.006 (17%) and a "late pre-beta" band in VLDL (22%). While "sinking pre-beta" is identical with Lp (a) LP the "late pre-beta" band probably represents a certain accumulation of "intermediary particles".

Cholesterol↗
PubMed1976

Lipoprotein composition and lipoprotein interrelations in 50-year-old men with hyperlipoproteinaemia.

The serum lipoprotein (LP) composition and LP lipid interrelations were studied in 50-year-old men with different types of hyperlipoproteinaemia (HLP) and in randomly sampled health controls from the same population. The ratio cholesterol/triglycerides in very low density lipoproteins (VLDL)was high in HLP type III. The other types of HLP showed ratios not significantly different from the controls. The low density lipoprotein (LDL) cholesterol concentration was similar in controls, type III and type IV while, by definition, higher values were seen in type II A and II B. All types of HLP showed statistically significantly higher LDL triglycerides than the controls. HLP type II A and II B showed cholesterol/triglyceride ratios in LDL similar to the controls. The corresponding ratio in type IV was lower than in the control subjects but the lowest ratio was seen in type III with a mean value below the 5th percentile of healthy controls. The high density lipoprotein (HDL) cholesterol concentration was decreased in HLP type IV. Apparently elevated HDL triglyceride levels were seen in all types of HLP with the highest mean value in type III. The LP lipid interclass relationships were analysed in the random sample of health men and compared to corresponding relationships in the different types of HLP. Apart from HLP type III and HLP type IV with low LDL cholesterol levels all other types of LP interconversions. Intype IV a significant negative correlation between VLDL concentration and LDL cholesterol concentration and the cholesterol/triglyceride ratio in VLDL. There were no significant correlations between LDL cholesterol concentration and VLDL lipid variables in other types of HLP and normolipidaemia.

Age Factors↗
PubMed1976

Detection and characterization of hyperlipoproteinaemia in middle-aged men.

Serum lipoprotein (LP) concentrations were determined and LP patterns were classified in 261 middle-aged men, recruited from a health examination survey, with serum lipid values above the 80th percentile of the same population. Individuals with hyperlipoproteinaemia (HLP) and normolipidaemic controls were characterized also regarding family history of cardiovascular disease, socio-economic factors and clinical and laboratory variables. Subjects with HLP type IV-V and IIB were overweight and showed hyperuricaemia and hyperinsulinaemia compared with normolipidaemic controls and subjects with HLP type IIA. The latter showed elevated erythrocyte sedimentation rate. In spite of being overweight, subjects with HLP type III showed normal fasting values of insulin and uric acid in serum and normal early insulin response to intravenous glucose. The glucose tolerance did not differ significantly between the groups. Men with HLP types IV-V had predominantly sedentary occupations, in contrast to those with type IIA. There were significantly more smokers in the groups with HLP type IIB and IV-V than in the control group. Thus, individuals with different types of HLP tend to show different metabolic profiles but also different socioeconomic and clinical patterns, suggesting that exogenous factors are of importance in the expression of the LP abnormalities.

Age Factors↗
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

Conversion of type III hyperlipoproteinaemia to type IV hyperlipoproteinaemia by a fat-free, carbohydrate rich diet.

Hyperlipoproteinaemia type III has been considered a clear cut clinical entity characterized by the presence of cholesterol rich "floating" beta very low density lipoproteins (VLDL) after ultracentrifugation. Carbohydrate inducibility is pronounced in type III. This study was undertaken to elucidate the effect of a high carbohydrate diet in type III as an effort to clarify a suggested association between type III and IV hyperlipoproteinaemia. On an isocaloric fat free carbohydrate rich diet the lipoprotein pattern changed as the VLDL triglycerides increased 31 per cent on average and LDL and HDL cholesterol decreased by 40 and 22 per cent. The high ratio cholesterol/triglycerides in VLDL was normalized. The lipoprotein levels in serum after carbohydrate induction showed all characteristics of a type IV with high VLDL triglycerides, normal cholesterol/triglyceride ratio in VLDL, subnormal cholesterol levels in LDL and HDL with changed relation between LDL1 and LDL2. On electrophoresis the floating beta band disappeared. It is probable that depending on the nutritional situation, the metabolic defect in type III may be expressed either as a type III or a type IV. An explanation of the effects of the carbohydrate rich diet on the lipoprotein pattern is suggested.

Cholesterol↗
PubMed1975

Serum levels of thyroid-stimulating hormone in hyperlipoproteinemia.

Similar serum lipoprotein abnormalities have been demonstrated in hyperlipoproteinemia type III and hypothyroidism. In this study the levels of thyroid-stimulating hormone in serum were determined in clinically euthyroid patients with different types of hyperlipoproteinemias and in subjects with a normal lipoprotein pattern. The mean value for thyroid-stimulating hormone was significantly higher in the group with hyperlipoproteinemia type III than in normal controls (p smaller than 0.01) and in the group with hyperlipoproteinemia type II A (p smaller than 0.02). The levels of thyroid-stimulating hormone were positively correlated to the triglyceride and cholesterol concentration in the very low density lipoprotein fraction and the ""III-index''.

Cholesterol↗