Search PubMed⌕ Search

Biomedical subjects

J Boberg

Publications and source records attributed to J Boberg.

At least 37 records · Page 2Linked to original sources
PubMed1982

Reduction of low density and high density lipoprotein cholesterol by fat-modified diets. A survey of recent findings.

The aim of this review is to summarize recent findings concerning the effects of fat-modified diets on serum lipoproteins, especially on high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol concentrations. Generally, both HDL and LD cholesterol are reduced in subjects on diets enriched in polyunsaturated fatty acids (PUFA diets). The only exceptions to this rule are hypertriglyceridaemic patients with low HDL or LDL concentrations. The changes in HDL and LDL cholesterol are inversely related to the respective HDL and LDL concentrations before dietary treatment. Increasing HDL cholesterol concentrations are seen only during simultaneous body weight reduction. Low HDL cholesterol concentrations are not normalized on PUFA diets. The ratio of LDL cholesterol to HDL cholesterol shows only marginal changes during treatment with a PUFA diet. Thus we cannot clearly state how a lipid-lowering diet might contribute to the anti-atherogenic effect which seems to be characteristic of this type of diet, on the basis not of the change in fasting serum lipoprotein concentrations, but of epidemiological and experimental data.

Adolescent↗
PubMed1981

Treatment of hyperlipoproteinemia with 'type-specific' diets under metabolic ward conditions. Effects on serum lipoproteins and serum lipid esters.

Three lipid lowering diets for treatment of different types of hyperlipoproteinemia were prepared based on ordinary Swedish food. Seven different daily menus were planned with an identical composition at all energy levels. The fat and protein content provided 34-35% and 20% of the energy, respectively. The ratios between polyunsaturated and saturated fatty acids varied in the three diets between 1.3 and 2.0. The cholesterol content was 0.14 g per 6.7 MJ. The effects of the diets were evaluated under isoenergetic conditions in 45 hyperlipoproteinemic patients during 2 weeks. The concentration of the very low density lipoprotein triglycerides decreased by 27-33%, the low density lipoprotein by 16-19% and the high density lipoprotein cholesterol by 5-13% compared with the concentrations during a preceding 2-week period on a control diet. No changes of the lipoprotein removal capacity indicated that the effects were mainly due to a reduced production of serum lipoproteins.

Adipose Tissue↗
PubMed1981

Will serum lipid lowering treatment reduce the incidence of coronary heart disease?

The question whether serum lipid lowering treatment will reduce the incidence of coronary heart disease (CHD) has been a matter of intense debate during the last few years. When analysing the results from the major preventive trials, it can be concluded that there is no unequivocal evidence that lipid lowering treatment will reduce the death rate in CHD. However, the great majority of the trials performed have shown a reduced number of CHD deaths in the treatment group, compared with the control group. There is strong evidence that lipid lowering treatment of hyperlipidaemic patients will reduce the incidence of non-fatal myocardial infarctions. This reduction is directly proportional to the degree of cholesterol lowering achieved.

Adult↗
PubMed1981

Lipoprotein lipase activity in adipose tissue of spontaneously hyperlipidemic rats.

The lipoprotein lipase activity in adipose tissue of Sprague-Dawley rats 1, 4, 9 and 15 months of age, was investigated. The study revealed that a significant inverse relationship exists between serum triglyceride level and lipoprotein lipase activity in epididymal fat pad. Thus, the lipoprotein lipase activity in 1 and 15 months old rats are on the average 5.3 and 1.1 nkat/g wet weight, respectively, simultaneously as serum triglyceride level increase from 0.74 mmol/l to 3.51 mmol/l, respectively. It is suggested that impaired removal of very low density lipoproteins is one possible explanation of the enhanced levels of this lipoproteins in the old rat. The lipase activity investigated had the characteristic properties of lipoprotein lipase, i.e. it was activated by the addition of serum, inhibited by high ionic strength and varied with the nutritional state. However, it could not be exclude that monoacylglycerol lipase present in epididymal fat pad also decreased with age. The possible connection between the age-related reduction of lipoprotein lipase activity in epididymal fat pad and the age-related gomerulonephritis found in these rats is discussed.

Adipose Tissue↗
PubMed1980

The effects of colestipol when combined with clofibrate in the treatment of severe hyperlipidemia. Short-term and long-term studies.

Twenty-two patients suffering from hyperlipidemia and receiving therapy consisting of a lipid-lowering diet and clofibrate (1 g X 2) were in addition given colestipol hydrochloride (5 g X 3) (Colestid, Upjohn) in a randomized, cross-over study for 2 periods of 6 weeks. Both the cholesterol and the triglyceride concentrations in very low density lipoproteins remained unchanged during the colestipol treatment. The cholesterol concentration in low density lipoproteins decreased by 23% (P < 0.001) and increased in high density lipoproteins by 4% (P < 0.01). In a second part of the project, the effects on the lipoprotein lipids of 15 g of colestipol divided into 1, 2 or 3 daily doses were studied when added to ongoing therapy with clofibrate (1 g X 2) and lipid-lowering diet. When the colespitol was divided into 2 or 3 daily doses, the effects were manifested equally but were less pronounced when 1 dose per day was given. In a third study, 14 patients who were treated with a combination of lipid-lowering diet, clofibrate (1 g X 2) and colestipol hydrochloride (15 g daily) were followed over a 2-year period, during which time the serum cholesterol and triglyceride concentrations were maintained at a reduced level. The fasting blood glucose and serum insulin concentrations were increased during colestipol treatment. Such treatment should therefore not be given to patients with impaired glucose tolerance.

Alkaline Phosphatase↗
PubMed1980

Reduction of high density lipoprotein cholesterol and apoliproprotein A-I concentrations by a lipid-lowering diet.

Nine hyperlipoproteinaemic patients were treated with a serum lipid-lowering diet during 4 weeks in a metabolic ward. The diet contained 35% energy from fat and the ratio between polyunsaturated and saturated fats (the P/S ratio) was 2.0. This treatment caused a reduction of the serum concentrations of the low density lipoprotein cholesterol (Chol) by 17% (P less than 0.01), of the apolipoprotein (apo) B by 27% (P less than 0.01), of high density lipoprotein (HDL) Chol by 15% (P less than 0.05) and of the apo A-I by 9% (P less than 0.02). The apo B/apo A-I ratio decreased by 19% (P less than 0.01). It is suggested that the reduced HLD Chol and apo A-I concentrations may be due to both the qualitative change to more polyunsaturated fats in the diet and to the reduction of the total dietary fat intake.

Adult↗
PubMed1980

Changes in the fatty acid composition of the plasma lipid esters during lipid-lowering treatment with diet, clofibrate and niceritrol. Reduction of the proportion of linoleate by clofibrate but not by niceritrol.

The fatty acid composition of the plasma lipid esters has been studied during lipid-lowering treatment of 95 patients with atherosclerotic disease. During the first two months of the trial only a diet was prescribed. During the ensuing two months either clofibrate or niceritrol, a nicotinic acid ester, was added in a randomized order. During the last two months the second drug was added. The combined treatment with diet, clofibrate and niceritrol caused highly significant serum lipid reductions. The fatty acid composition in the plasma lipid esters was determined in samples from each trial period to measure the degree of dietary adherence. During dietary treatment the relative content of saturated and monounsaturated fatty acids secreased and the polyunsaturated fatty acids increased with an increasing ratio between pulyunsaturated and saturated fatty acids (P/S ratio) in the cholesterol esters and triglycerides. Only minor changes were seen in the phospholipids. The changes caused by the diet were partly reversed by clofibrate while niceritrol did not cause any major changes of the fatty acid composition. Clofibrate treatment coincided with increasing amounts of monounsaturated fatty acids, especially oleate (18 : 1), in the cholesterol esters, triglycerides and phospholipids while there were significant reductions of the content of linoleic (18 : 2) acid in both the cholesterol esters and triglycerides. The 18 : 2/18 : 1 ratio decreased significantly in all the lipid esters analyzed. However, the P/S ratio was not significantly affected, partly because the relative content of saturated fatty acids also tended to decrease during clofibrate treatment. It is concluded that addition of clofibrate treatment to patients who are on a diet enriched with polyunsaturated fats is associated with a change from polyunsaturated to monounsaturated fatty acids in the plasma lipid esters but does not significantly effect the ratio between polyunsaturated and saturated fatty acids. The fatty acid changes caused by clofibrate treatment and counteracted by an increased amount of polyunsaturated fat in the diet.

Aged↗
PubMed1979

Comparison of glucose tolerance, serum insulin, serum lipids and skinfold thickness between 50- and 60-year-old men.

Two apparently healthy male groups, one 60 (n = 67) and one 50 (n = 367) years of age were compared with respect to blood glucose, serum lipid and serum insulin concentration and intravenous glucose tolerance. These groups were recruited from two health surveys performed on male populations of these ages in the municipality of Uppsala. The prevalence of diabetes mellitus in the two health survey populations were 4.5% and 0.9%, respectively. No significant differences in serum triglycerides, serum cholestrol and fasting serum insulin concentrations were found between the two age groups. Significantly higher k-values and higher early serum insulin response to i.v. glucose were found in the younger than in the older age group. The older age group was more obese, than the younger group. It is concluded that the prevalence of diabetes increases considerably in males between 50 and 60 years of age. In parallel, the prevalence of decreased glucose tolerance is increasing, which might partly be explained by increased body weight and partly by an impaired pancreatic beta-cell function.

Adipose Tissue↗
PubMed1979

Hepatic triglyceride and lipoprotein lipase activities of post-heparin plasma in normals and hypertriglyceridemics.

Post-heparin plasma hepatic triglyceride lipase (H-TGL) and lipoprotein lipase (LPL) activities were 8-34 and 3.5-21 (range) mu mol/ml/hr respectively in males with normal serum lipid concentrations. In females the corresponding values were 4-25 and 4-16 mu mol/ml/hr. No significant differences were observed between ages or between the two sexes. Male patients with hypertriglyceridaemia had similar activities of H-TGL but significantly lower values for LPL activities than the control males. Significant linear correlations were found between serum triglyceride concentrations and LPL activities both for males (coefficient of correlation = r = -0.64) and for females (r = -0.62).

Adolescent↗
PubMed1978

Determination of lipoprotein-lipase activity in human skeletal muscle tissue.

An in vitro assay system was developed for the determination of lipoprotein-lipase activity in 10--30-mg specimens of human skeletal muscle tissue. The reaction medium of the assay was based on a glycine buffer of pH 8.3 (at 37 degrees C) with a heparin concentration of 1.5 g/l (about 180 IU/ml). The enzyme activity was measured as the release of [3H]oleic acid from a serum-activated, triglyceride emulsion, in which [3H]trioleate was used as trace substance. The enzyme activity studied had the characteristic properties of lipoprotein-lipase activity, i.e. it was activated by the addition of serum or apolipoprotein C-II and inhibited in the presence of high ionic strength, protamine sulphate or apolipoprotein C-III. A mean Km of 0.40 +/- 0.13 (S.D.) mmol/l for triglyceride substrate was found in tissue samples that had very different concentrations of lipoprotein-lipase activity. This Km was similar to the low fasting concentrations of very low density lipoprotein triglycerides often found in healthy individuals. The lipoprotein-lipase activity was not decreased freezing and storing the tissue specimens in liquid nitrogen. The within-day variation of the method was 16 percent and the between-day variation 8 percent. Muscle tissue from the vastus lateralis muscle had, on the average, a 60 percent higher concentration of lipoprotein-lipase activity than the rectus abdominis muscle in the same subject.

Adipose Tissue↗