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Biomedical subjects

B Vessby

Publications and source records attributed to B Vessby.

At least 109 records · Page 6Linked to original sources
PubMed1992

Effects of lipid-lowering diets enriched with monounsaturated and polyunsaturated fatty acids on serum lipoprotein composition in patients with hyperlipoproteinaemia.

Controlled comparisons of the effects of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) as a part of lipid-lowering diets in persons with hyperlipoproteinaemia are sparse. The present study was carried out at a metabolic ward. Forty hyperlipidaemic patients (25 hypercholesterolaemic and 15 hypertriglyceridaemic) were given a 3-week diet rich in either MUFA (saturated fatty acids 7.3 energy% (E%), MUFA 14.6 E%, PUFA 4.8 E%) or PUFA (saturated fatty acids 7.8 E%, MUFA 8.4 E%, PUFA 10.4 E%), but otherwise with an identical composition. The mean serum cholesterol reduction on the MUFA diet was 12% (P < 0.001), with a low density lipoprotein cholesterol reduction of 11% (P < 0.001). The corresponding reductions on the PUFA diet were 15% (P < 0.001) and 16% (P < 0.001). The serum apolipoprotein B and A-I concentrations decreased highly significantly by 13% and 11% on the MUFA diet and by 14% and 11% on the PUFA diet. None of these changes differed between the two diets. Neither were there any differences between the diets regarding the effects on blood glucose, serum insulin and plasma fibrinogen, but there was a significant decrease in serum insulin with a significant reduction of the insulin/glucose ratio after the MUFA diet. The results of this study indicate that MUFA and PUFA are interchangeable within the given frames in lipid lowering diets even in patients with hyperlipidaemia.

Adult↗
PubMed1992

Supplementation with n-3 fatty acids reduces triglycerides but increases PAI-1 in non-insulin-dependent diabetes mellitus.

The effects of dietary supplementation with n-3 fatty acids on lipid and glucose metabolism and on fibrinolysis were evaluated in 14 non-insulin-dependent diabetic patients who were given 10 g of MaxEPA (3 g n-3 fatty acids) or placebo (olive oil) per day in a randomized double-blind cross-over study during two consecutive 8-week periods. The serum triglyceride (TG) concentrations decreased by 27% (P < 0.01) after addition of MaxEPA with a reduction of VLDL TG by 36% (P < 0.05) while LDL cholesterol increased by 6% (P = 0.05). The fasting blood sugar and HbA1c concentrations increased significantly after addition of MaxEPA but the changes were not significantly different from those during the placebo period. The highest glucose concentrations at fasting and after an i.v. glucose injection were seen after MaxEPA while the serum insulin concentrations were unchanged. The peripheral insulin sensitivity, as measured by a euglycaemic, hyperinsulinaemic clamp technique, did not change during the study. The mean plasminogen inhibitor-1 (PAI-1) activity of the patients was elevated compared with healthy controls. In spite of the reduction of the triglyceride concentrations and unchanged insulin levels, there was a significant increase of the activity of PAI-1 (+21%, P < 0.01) after MaxEPA suggesting a possible impairment of the fibrinolytic capacity. In many situations there seems to be a reduction of PAI-1 when the triglycerides are lowered. In the diabetic patients given n-3 fatty acids this was not the case.

Aged↗
PubMed1992

Polyunsaturated fatty acids may impair blood glucose control in type 2 diabetic patients.

Fifteen patients with Type 2 diabetes were given two diets rich in either saturated fat or polyunsaturated fat in alternate order over two consecutive 3-week periods on a metabolic ward. Both diets contained the same amount of fat, protein, carbohydrates, dietary fibre, and cholesterol. The proportions of saturated, monounsaturated and polyunsaturated fatty acids in the saturated fat diet were 16, 10, and 5%-energy and in the polyunsaturated fat diet (PUFA) 9, 10, and 12%-energy. The PUFA diet contained a high proportion of n-3 fatty acids. Metabolic control improved significantly in both dietary periods, due to both qualitative dietary changes and a negative energy balance. The serum lipoprotein concentrations decreased on both diets but the serum lipids were significantly lower after the PUFA diet (serum triglycerides -20%, p = 0.001; serum cholesterol -5%, p = 0.03; VLDL-triglycerides -29%, p less than 0.001; and VLDL-cholesterol -31%, p = 0.001) than after the saturated fat diet. Average blood glucose concentrations during the third week were significantly higher fasting (+15%, p less than 0.01), and during the day at 1100 h (+18%, p less than 0.001) and 1500 h (+17%, p = 0.002) on PUFA than on the saturated fat diet. Significantly higher blood glucose levels were also recorded with a standard breakfast, while the sum of the insulin values was lower (-19%, p = 0.01). HbA1c did not differ significantly between the two dietary periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗
PubMed1992

Metabolic effects of pindolol and propranolol in a double-blind cross-over study in hypertensive patients.

Metabolic effects of pindolol and propranolol were investigated in a randomised study of double-blind, double-dummy design in 39 Caucasians with newly detected hypertension. Each active treatment period was 6 months long. A euglycaemic hyperinsulinaemic clamp test was done to measure insulin sensitivity, and i.v. glucose tolerance was investigated with insulin determinations. Lipoprotein concentrations were quantified and lipoprotein lipase activities were determined in muscle and adipose tissue and in plasma after heparin injection. The blood pressure was significantly reduced by both regimes. The insulin sensitivity index was decreased by 34% during propranolol treatment and by 17% during pindolol treatment. The insulin concentrations in plasma were elevated at the end of the i.v. glucose tolerance test but were not high enough to compensate for the insulin resistance, so HbA1c and glucose concentrations were increased. A significant reduction of lipoprotein lipase activity in skeletal muscle during propranolol treatment probably explains the pronounced increase in serum triglyceride concentration during propranolol treatment despite lower free fatty acids and higher lipoprotein lipase activity in adipose tissue. These changes of lipoprotein lipase activity were not correlated to the changes in insulin sensitivity. In summary, the metabolic effects were significantly less pronounced with pindolol than with propranolol, which probably can be ascribed to the agonistic effect of pindolol on beta 2 adrenoceptors.

Aged↗
PubMed1990

Interruption of long-term lipid-lowering treatment with bezafibrate in hypertriglyceridaemic patients. Effects on lipoprotein composition, lipase activities and the plasma lipid fatty acid spectrum.

When bezafibrate therapy was interrupted in patients who had been on continuous treatment for hyperlipoproteinemia for 4-10 years, there were significant increases in the serum cholesterol, triglyceride and apolipoprotein B concentrations corresponding to an increase of the very low density lipoprotein (VLDL) levels by approximately 50%. This increase of VLDL was accompanied by reduced levels of the post-heparin lipoprotein lipase activity (LPLA) (P = 0.07) and hepatic lipase (P = 0.05) activity with a significant reduction of the skeletal muscle LPLA (P less than 0.05), but not the adipose tissue LPLA, and a retarded removal of an i v injected fat emulsion (P less than 0.01). There were no significant changes of the low or high density lipoprotein cholesterol or the apolipoprotein A-I or A-II concentrations. Three months after bezafibrate treatment the content of linoleic and gammalinoleic acid in the plasma cholesterol ester had increased significantly, while the palmitoleic and oleic acids were reduced in spite of unchanged dietary treatment. Taken together, the data indicate that a lipid-lowering effect of bezafibrate, particularly on the VLDL lipids, is maintained throughout long treatment periods. One mechanism for the reduced level of the triglyceride-rich lipoproteins is an increased activity of the lipoprotein-lipase activity in the skeletal muscle, which decreased when the treatment was interrupted. The significance of the changes of the plasma lipid fatty acid spectrum during bezafibrate treatment remains unclear.

Aged↗
PubMed1990

Dietary supplementation with n-3 fatty acids may impair glucose homeostasis in patients with non-insulin-dependent diabetes mellitus.

The effects on lipoprotein and glucose metabolism of addition of n-3 fatty acids were studied in 14 non-insulin-dependent diabetic patients who were given 10 g of MaxEPA (3 g n-3 fatty acids) or placebo (olive oil) per day in a randomized double-blind cross-over study during two consecutive 8-week periods. After MaxEPA treatment, there was a marked increase in long-chain polyunsaturated fatty acids of the n-3 series in the plasma lipid esters and in the platelet phospholipids, while the n-6 fatty acid content decreased. The very low density lipoprotein (VLDL) triglyceride concentrations decreased significantly (by 22%) on MaxEPA treatment. However, these changes were not significantly different from those observed during the placebo period. The blood glucose concentration tended to increase during MaxEPA treatment, and to decrease during the placebo period, the changes under the two regimes being significantly different (P less than 0.01). In addition, the rate constant for glucose disappearance (k value) for the intravenous insulin-tolerance test, which reflected the peripheral insulin sensitivity, tended to decrease during MaxEPA treatment and increase during administration of the placebo, there being a significant difference (P less than 0.03) between the changes during the two treatments. The reason for the observed changes in blood glucose concentration and peripheral insulin sensitivity is still unclear.

Adult↗
PubMed1989

n-3 fatty acids and blood glucose control in diabetes mellitus.

Our knowledge of the effects of n-3 fatty acids on the glucose homeostasis in diabetes mellitus is at present incomplete. The results are in certain respects conflicting. Several studies have shown that addition of n-3 fatty acids, especially in type-2 diabetes, may increase blood glucose concentrations without a concomitant increase of insulin or C-peptide concentrations. The glucose/insulin ratio is increased in fasting as well as after meals. On the other hand, some data indicate that, in spite of increased or unchanged glucose concentrations, there may be an improved peripheral insulin sensitivity. The stimulated insulin response may be reduced after mixed meals, although there are no indications of significant impairments of the response to intravenous glucose. The reasons for the observed changes are still obscure. More controlled studies, during prolonged periods of time, are needed. At present it would seem important to closely follow diabetic patients with respect to glucose and lipid metabolism if treated with n-3 fatty acids. As for now, diabetic patients are recommended to increase their intake of fish in the diet. The use of pharmacological doses of n-3 fatty acids remains investigational.

Blood Glucose↗
PubMed1989

Dietary habits in renal stone patients compared with healthy subjects.

The dietary habits of renal calcium stone patients were investigated both by dietary history and by 4-day food records and compared with the dietary habits of control subjects, matched on the basis of age, sex, social and professional status. The method using 4-day records seemed to be more precise, judged by the correlation to the urinary output of nutrients. There was no difference in the daily intake of major nutrients between stone formers and controls, but a higher ingestion of vitamin C in controls and a larger consumption of alcohol among stone formers. In contrast to some epidemiological evidence, there were no significant differences in consumption of animal protein when stone formers were matched for social class. Despite a similar total intake of calcium, the stone formers excreted more calcium in the urine, probably reflecting a higher intestinal absorption of calcium. There seem to be only marginally different dietary habits between stone formers and carefully matched control subjects. Differences in the urinary output of minerals and electrolytes are mainly due to variations in gastrointestinal uptake.

Adult↗
PubMed1989

Dietary habits and effects of dietary advice in patients with type 2 diabetes. Results from a one-year intervention study.

The diets of 22 patients with type 2 diabetes were evaluated by a dietary-history interview. Sixteen of the patients were also interviewed after a 1-year intervention period, to find out whether continuous contact with a dietitian at a health centre could influence the food habits and thereby improve the metabolic control. In most participants the diabetes was fairly well controlled on entry into the study. Another 24 patients took part in the same intervention programme but did not agree to participate in the dietary-history interview. These subjects had, in general, a poorer metabolic control on admission. According to the study design, the patients were to make four visits to the dietitian during the first 6 months, and one visit at the end of the year. The patients were advised to eat a fat-modified, fibre-enriched diet. Among the patients who completed both the intervention programme and the dietary-history interviews there were significant reductions in mean body weight, haemoglobin A1c and serum triglycerides during the first half of the study. After 12 months, however, only the mean body weight and serum triglycerides remained lower than before the intervention period. A study of the fatty acid composition of the plasma cholesterol esters showed a significant reduction of the content of oleic acid (18:1 n-9). The dietary interviews indicated only minor changes (not significant) in the intake of energy and different nutrients, including dietary fibre, after 1 year. However, the effects of the intervention were better in the patients who did not participate in the dietary interview with significant reductions in the mean body weight, fasting blood glucose, haemoglobin A1c and serum triglycerides also after 1 year.

Aged↗
PubMed1989

C-peptide but not insulin concentrations are related to the serum lipoprotein levels during insulin treatment of non-insulin-dependent diabetes mellitus (NIDDM) patients.

In 21 non-insulin-dependent diabetic patients with secondary drug failure, once-daily long-acting insulin lead to a moderately improved metabolic control. At the conclusion of the study (eight months) the fasting blood glucose and HbA1c concentrations were significantly decreased, but the postprandial blood glucose concentrations in the afternoon were unaltered. The peripheral insulin sensitivity, as measured by the intravenous insulin tolerance test, and the lipoprotein lipase activity in adipose and skeletal muscle tissue had increased. After initiation of insulin therapy there was a transient decrease of the fasting and glucagon-stimulated C-peptide concentrations. The very low density lipoprotein lipids and apolipoprotein B, A-I and A-II were also reduced transiently. The only significant difference in lipoprotein composition at eight months compared with on admission, was an increased cholesterol and decreased triglyceride concentration in the high density lipoproteins. There were significant relationships between the C-peptide, but not the peripheral insulin, concentrations and the serum lipid concentrations. This may indicate that high peripheral insulin concentrations after administration of exogenous insulin may affect the hepatic lipoprotein production less than the portal insulin concentrations mainly derived from endogenous production.

Biomarkers↗
PubMed1988

Apolipoprotein-E-binding proteins of rat liver endothelial cells.

In an attempt to characterise the apolipoprotein-E-binding proteins of rat liver endothelial cells, we prepared membranes from monolayer cultures of liver endothelial cells as an enriched source of membrane receptors. The membranes could specifically bind iodinated very-low-density lipoproteins (VLDL) and the binding could be inhibited effectively by unlabelled VLDL and high-density lipoproteins, but only moderately by low-density lipoproteins. To identify the binding proteins, we performed immunoprecipitation studies of solubilised iodinated liver endothelial cells and cell membranes, respectively, using purified apolipoprotein E and monospecific polyclonal IgG directed towards this apolipoprotein. The antibodies together with the bound apolipoprotein E and iodinated liver endothelial cell proteins were harvested with staphylococcal protein A-Sepharose. The immunoprecipitates were subjected to sodium dodecyl sulphate-polyacrylamide gel electrophoresis, and after autoradiography of the dried gel, the Mr of the liver endothelial cell proteins bound to apolipoprotein E could be determined. Two protein bands with molecular masses of 55-60 and 110, and a weak band of 170 kDa could be detected from intact cells. These proteins were specifically precipitated only in the presence of divalent cations, and might represent cell-surface receptors for apolipoprotein-E-containing lipoproteins. Additional bands were seen when cell membranes were used, the most prominent ones having molecular masses of 32 and 35 kDa. These proteins could be of intracellular origin, or they may be degradation products of the other apolipoprotein-E-binding proteins.

Actin Cytoskeleton↗
PubMed1988

Serum lipids and apolipoproteins in children with type 1 (insulin-dependent) diabetes during the first two years of the disease.

Serum lipoproteins and apolipoproteins were studied at diagnosis and 6, 12 and 24 months later in 30 consecutive children aged 3-15 years with newly detected Type 1 (insulin-dependent) diabetes mellitus (December 1982-October 1984) and in 44 healthy control children. Serum triglycerides at diagnosis were significantly higher than after 6-24 months and also higher than in the control group (p less than 0.001). At follow-up, triglycerides in the very low density lipoproteins and low density lipoproteins were restored to normal, while high density lipoprotein triglycerides remained high. Serum cholesterol at onset of diabetes was significantly higher than in the control children (p less than 0.01), mainly because of increased very low density lipoprotein cholesterol (p less than 0.001). Cholesterol in serum and in the serum lipoprotein fractions was similar to that in the control children at follow-up, except that high density lipoprotein cholesterol was higher in the diabetic children after 6 months. The concentrations of the serum apolipoproteins A-I, A-II and B were higher at onset of diabetes than in the control children (p less than 0.001, p less than 0.01, p less than 0.05 respectively), with a significantly increased ratio of apolipoprotein A-I to A-II in the diabetic children (p less than 0.001). The serum apolipoprotein concentrations were normalised during treatment. The ratio of apolipoprotein A-I to B did not differ from that in control children. On admission, there were strong positive correlations between HbA1c and the concentrations of the very low density lipoproteins and the low density and high density lipoprotein triglycerides.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗