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Biomedical subjects

H Lithell

Publications and source records attributed to H Lithell.

At least 271 records · Page 15Linked to original sources
PubMed1982

Serum lipoprotein and apolipoprotein changes during treatment with a contraceptive vaginal ring containing levonorgestrel and estradiol.

Contraceptive vaginal rings containing estradiol and levonorgestrel were used by 22 women during 219 cycles. The estrogenicity was low and the daily dose of levonorgestrel was about 290 micrograms. The triglyceride and cholesterol concentrations decreased in whole serum and, to varying degrees, in the different lipoprotein classes. The most consistent change was a 25% (p less than 0.001) reduction in the cholesterol content of the high-density lipoprotein (HDL) fraction. The cholesterol concentration in low-density lipoprotein decreased by 11% after the first 3 months, but increased during the ensuing 9 months of treatment to regain pretreatment level. Percentage-wise, the apolipoprotein B and A-I concentrations, determined by rocket immunoelectrophoresis, were less affected than the LDL- and HDL-cholesterol concentrations. The composition of the LDL and HDL particles seemed thus to alter during the treatment. The pronounced effect on the HDL levels seen is consistent with earlier findings of a dose-dependent, androgenic effect of gestagens derived from 19-nortestosterone. However, the low basal level of LDL and its further decrement during treatment alleviate the supposedly unfavorable effect of HDL reduction from the atherogenic point of view.

Adult↗
PubMed1982

Effect of prazosin on lipoprotein metabolism in premenopausal, hypertensive women.

Eight premenopausal women with a diastolic blood pressure above 100 mm Hg were treated with prazosin (average dose, 4 mg/day) for 1 year. After 1 month and after 1 year of treatment, serum cholesterol and triglycerides did not differ significantly from pre- and post-treatment values. Nor were any statistically significant alterations found in cholesterol and triglyceride concentrations in the very low density, low density, and high density lipoproteins. The fractional catabolic rate of exogenous triglycerides and the lipoprotein lipase activity in adipose tissue and in skeletal muscle tissue were not affected by the treatment. The data support the view that prazosin therapy does not adversely affect lipoprotein metabolism in premenopausal, healthy, normolipidemic women.

Adipose Tissue↗
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↗
PubMed1982

The effects on lipid and carbohydrate metabolism of replacing some animal protein by soy-protein in a lipid-lowering diet for hypercholesterolaemic patients.

Six hypercholesterolaemic patients were fed a lipid-lowering diet during three weeks in a metabolic ward. The mean serum cholesterol decreased by 25 per cent. During the following two weeks they were given a diet with a similar composition but with half of the protein content replaced by soya bean protein. During this treatment, there was a further reduction of the serum cholesterol by 10 per cent (P less than 0.05) corresponding to a decrease of the low-density lipoprotein cholesterol by 9 per cent (P less than 0.01). The lipoprotein lipase activity in skeletal muscle increased by 38 per cent (P less than 0.05). There was no significant change of the i.v. glucose tolerance, the fasting blood glucose concentration or the serum insulin concentrations at fasting or after i.v. glucose. However, the relation between the 'peak insulin' and the fasting serum insulin expressed as the 'insulin index' increased in all patients on the soy protein diet (P less than 0.05).

Carbohydrate Metabolism↗
PubMed1981

Comparison of the metabolic effects of two hormonal contraceptive methods: an oral formulation and a vaginal ring. I. Carbohydrate metabolism and liver function.

A prospective, long-term study was undertaken to compare the metabolic effects of a contraceptive vaginal ring releasing levonorgestrel (about 290 microgram per day) and estradiol (about 180 microgram per day) and a combined oral contraceptive containing 30 microgram ethinylestradiol and 150 microgram levonorgestrel in two groups of women (n = 22 and 20, respectively). An intravenous glucose tolerance test, including determination of the insulin response to glucose, and liver function tests were performed. Both the glucose tolerance and fasting values of glucose were unaltered. The early insulin response to glucose increased by 50 percent in the contraceptive ring roup after one year of treatment, but not in the oral contraceptive group. All other insulin values were unchanged. All liver function values remained within the normal range in all subjects. There was a small significant decrease in alkaline phosphatases in both groups, which is in contrast to the effects of the early combined pills, which could cause an elevation. It is concluded that neither of these two contraceptive methods, the effects of which are predominantly gestagenic, seems to cause impairment of glucose tolerance or hepatic function.

Blood Glucose↗
PubMed1981

Comparison of the metabolic effects of two hormonal contraceptive methods: an oral formulation and a vaginal ring. II. Serum lipoproteins and apolipoproteins.

In a long-term, prospective study the effects on lipoprotein lipids and apolipoproteins (apo) of a combined oral contraceptive (OC) (30 micro gram ethinylestradiol and 150 micro gram levonorgestrel) and a contraceptive vaginal ring (CVR) releasing estradiol (about 180 micro gram per day) and levonorgestrel (about 290 micro gram per day) were compared. The two treatments induced significantly different effects. In the OC group the lipoprotein-lipid concentrations showed only minor changes, but apolipoproteins (apo) B and A-I increased by about 15%. In contrast, during treatment with the CVR there was a 25% decrement of cholesterol in high density lipoprotein (HDL) and at most 10% in low density lipoprotein (LDL) cholesterol, with only minor effects on apo B and A-I. The ratio of LDL and HDL cholesterol increased in the CVR group but not in the OC group. The results also indicate a change in the composition of the LDL and HDL particles, with an altered lipid/protein ratio, during both contraceptive treatments. Despite the impressive relative increase in LDL:HDL ratio in the contraceptive ring group, the average absolute value of this ratio did not reach the mena for healthy men.

Adolescent↗
PubMed1981

Increase of lipoprotein-lipase activity in skeletal muscle during heavy exercise. Relation to epinephrine excretion.

As part of the training programme for Swedish elite soldiers, a 10 day march is carried out with a heavy pack under active-service conditions. Six soldiers volunteered to take part in an investigation on the energy consumption with special regard to the lipid metabolism at different levels of physical effort. The degree of physical work was evaluated by continuous heart-rate recording and analysis of the excretion of epinephrine and norepinephrine in the urine. Fasting values of triglycerides and free fatty acids in blood plasma were determined and muscle biopsies (taken in the morning and in the afternoon) were analysed for lipoprotein-lipase (LPL) activity. After an overnight fast the free fatty acids were increased only in the mornings following days of heavy physical work. The plasma triglyceride concentrations were lowest in a morning proceeded by 3 days of heavy work. The muscle LPL activity in the morning was highest after a day of heavy work and lowest after days of rest. During days of heavy work this activity increased and was higher in the afternoon than in the morning. Muscle LPL activity in the afternoon was closely related to urinary excretion of epinephrine. The data indicate that LPL activity is elevated in the working skeletal muscle increasing the access of fatty acids. The degree of elevation is related to the degree of effort as described by the urinary excretion of morning. Muscle LPL activity in the afternoon was closely related to urinary excretion of epinephrine. The data indicate that LPL activity is elevated in the working skeletal muscle increasing the access of fatty acids. The degree of elevation is related to the degree of effort as described by the urinary excretion of morning. Muscle LPL activity in the afternoon was closely related to urinary excretion of epinephrine. The data indicate that LPL activity is elevated in the working skeletal muscle increasing the access of fatty acids. The degree of elevation is related to the degree of effort as described by the urinary excretion of epinephrine.

Catecholamines↗
PubMed1981

Serum lipoprotein lipid and apolipoprotein concentrations in grossly obese patients before and after jejuno-ileal shunt operation.

Fourteen grossly obese patients were studied before and 2, 6, 12 and 24 months after jejuno-ileal bypass. The major weight loss occurred during the first 6 months while there was no significant change of the mean body weight during the last 12 months of the study. During the initial period of pronounced weight loss there were significant reductions of all lipoprotein classes, e.g. at 2 months the very low density lipoprotein triglycerides had decreased by 41% (P less than 0.01), the low density lipoprotein cholesterol by 42% (P less than 0.001), the high density lipoprotein cholesterol by 27% (P less than 0.001) and the serum apolipoprotein B, A-I and A-II concentrations by 30% (P less than 0.001), 17% (P less than 0.001) and 27% (P less than 0.01) respectively. The fractional removal rate (K2) at the intravenous fat tolerance test had increased by 38% (P less than 0.01), indicating an increased removal capacity of triglyceride-rich lipoproteins. At 24 months the very low density lipoprotein triglycerides, the low density lipoprotein cholesterol and the apolipoprotein B concentration remained reduced by 28% (P less than 0.05), 48% (P less than 0.001) and 35% (P less than 0.001) respectively. The intravenous fat tolerance test K2 remained significantly increased by 44% (P less than 0.05). However, the high density lipoprotein cholesterol and the apolipoprotein A-I and A-II concentrations had successively increased again to preoperative levels. The low density lipoprotein cholesterol/high density lipoprotein cholesterol ratio was decreased by 44% (P less than 0.001) and the apolipoprotein A-I/apolipoprotein B ratio had increased by 74% (P less than 0.001), both changes presumably beneficial in regard of atherogenicity. The apolipoprotein A-I/high density lipoprotein cholesterol and apolipoprotein B/low density lipoprotein cholesterol ratios had increased by 23% (P less than 0.001) and 28% (P less than 0.001) respectively. The data indicate that the reduction of high density lipoprotein may be a transient phenomenon during the initial period of weight loss but that definite changes occur in the high density lipoprotein and low density lipoprotein composition which are apparent also 2 years after surgery.

Adolescent↗
PubMed1981

Minor dietary effects of HDL in physically active men.

In a preceding prospective study an increased high-density lipoprotein (HDL)-cholesterol and apolipoprotein (apo) A-I concentration occurred in healthy, non-obese, initially sedentary men, aged 30--44 years, after 3 months of physical training. Dietary history data revealed an increase in the absolute amount of fat-intake. In the present study we investigated whether a changed fat intake would influence the levels of lipoproteins, especially the HDL fraction, in twenty-three regularly conditioning men, aged 30--44 years, with a maximal aerobic capacity of 53.4 ml/kg x min--1 +/- 0.8, mean +/- SE. Ten subjects participated in an experimental group and thirteen in a control group. The experimental group studied before, after 4 weeks on a fat-rich diet (fifty-four energy-% fat, twenty-nine energy-% carbohydrate) and after 4 weeks on a fat-poor diet (twenty-nine energy-% fat, fifty-three energy-% carbohydrate). The data reveal that these large dietary changes did not influence HDL-cholesterol concentrations (1.71 +/- 0.10, 1.69 +/- 0.12, 1.59 +/- 0.13 mmol/l, mean +/- SE, during ordinary, fat-rich and fat-poor diet, respectively) and only influenced apo A-I levels to a minor degree after the fat-poor diet (134 +/- 6.1, 134 +/- 7.1 and 123 +/- 4.7 arbitrary units, mean values +/- SE) during ordinary, fat-rich and fat-poor diet, respectively). No changes were observed in the controls before and after 8 weeks. During the study training habits and body weight were constant. These findings show that large variations in the intake of dietary neutral fat only to a minor extent influence the level of HDL-cholesterol and apo A-I in physically active subjects.

Adult↗
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

Site differences in the basal metabolism of subcutaneous fat in obese women.

The basal capacity of femoral and abdominal fat to hydrolyze and store acylglycerols was investigated in obese women before and during 1 week of fasting. Before fasting, the lipolytic activity was lower and the lipoprotein lipase activity higher in femoral than in abdominal fat. During fasting, femoral fat lipoprotein lipase activity decreased and lipolytic activity increased to levels similar to those in abdominal fat. Acylglycerol syntheses were similar in the two fat depots before fasting, but decreased to a lower level at the abdominal than at the femoral site during fasting. Fat cell size decreased in the abdominal but not in the femoral site during fasting. Thus, regional variations in storage and mobilization of fat were found both in the fed and fasted states.

Abdomen↗
PubMed1981

Body weight, skeletal muscle morphology, and enzyme activities in relation to fasting serum insulin concentration and glucose tolerance in 48-year-old men.

Tissue samples were taken from the gastrocnemius muscle of 26 randomly selected, glucose-tolerant, 48-yr-old men. Hexokinase, phosphorylase, lactate dehydrogenase (LDH), succinate dehydrogenase, and lipoprotein lipase activity (LPLA), as well as the area per fiber type and capillary density, were determined. Mean fiber area correlated positively with relative body weight (r equals 0.53, P less than 0.01), but capillary density did not. The result is that, in cases of high body weight, each capillary supplies a larger muscle fiber area. Serum insulin concentration in the fasting state correlated positively with body weight (r equals 0.77, P less than 0.001) and with mean fiber area per capillary (r equals 0.87; P less than 0.001). Only during the latter part of an oral glucose tolerance test (OGTT) did blood glucose concentrations correlate with relative body weight and mean fiber area per capillary (r equals 0.42, r equals 0.51, P less than 0.05). A stepwise multiple regression analysis showed that the different muscle morphology measurements could account for 3/4 of the variation in the fasting serum insulin concentration, the fasting insulin/glucose ratio, and the blood glucose concentration at 120 min in the OGTT. Of the intracellular enzymes, only LDH (r equals -0.71, P less than 0.001) correlated with the mean fiber area per capillary. LPLA correlated with capillary density (r equals 0.66, P less than 0.001), and, long with the muscle morphology measurements, could account for 3/4 of the variation in serum triglyceride concentrations. The results show that a large mean muscle fiber area/capillary ratio indicates a morphologic imbalance, which is related to both glucose tolerance and various degrees of insulin sensitivity.

Blood Glucose↗
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↗
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↗