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Biomedical subjects

A G Olsson

Publications and source records attributed to A G Olsson.

At least 19 recordsLinked to original sources

Plasma lipid and lipoprotein effects of transdermal administration of estradiol and estradiol/norethisterone acetate.

To evaluate the effect of transdermal sequential treatment with estradiol and estradiol/norethisterone acetate on lipoprotein metabolism, 25 postmenopausal women received treatment for 12 cycles of 4 weeks each (2 weeks estradiol 50 micrograms/day and 2 weeks a combined patch delivering norethisterone acetate 0.25 mg/day and estradiol 50 micrograms/day). Blood samples for lipoprotein analyses were drawn before treatment and in estrogen and combined phases in cycles 3 and 12. Plasma total cholesterol, low (LDL) and high (HDL) density lipoprotein were all significantly reduced in both estrogen and combined phases. Eighteen of the women continued the treatment for 36 cycles. In this group the HDL-cholesterol had returned to baseline values in combined phase in cycle 24. Plasma cholesterol and LDL-cholesterol values remained significantly reduced throughout the whole study compared to the pre-trial values. The present study by transdermal sequential hormonal treatment results in a lipid and lipoprotein pattern with reduced total cholesterol and LDL cholesterol in postmenopausal women.

Administration, Cutaneous

Hyperhomocyst(e)inaemia: an independent risk factor for intermittent claudication.

The aim of this study was to test the question of hyperhomocyst(e)inaemia as a risk factor for intermittent claudication (IC) independent of other important risk factors for peripheral atherosclerotic disease, such as smoking, hypertension, diabetes mellitus, hypercholesterolaemia, hypertriglyceridaemia, low levels of high-density-lipoprotein (HLD) cholesterol and age. The study population was recruited from an epidemiological study in Linköping County, Sweden, where all middle-aged men (n = 15,253, 45-69 years of age) were screened for IC. Seventy-eight subjects with verified IC and 98 healthy sex- and age-matched controls were randomly selected. Plasma levels of homocyst(e)ine (including the sum of free and bound forms of homocysteine and their disulphide oxidation products, homocystine, and homocysteine-cysteine mixed disulphide) were significantly higher (16.74 +/- 5.45 mumol l-1, mean value +/- SD, P = 0.0002) in IC subjects than in controls (13.80 +/- 3.21 mumol l-1), with 23% of the claudicants above the 95th percentile for controls. Stepwise logistic regression analysis revealed that the difference in plasma homocyst(e)ine was independent of the other above-mentioned risk factors. Moreover, the elevation of plasma homocyst(e)ine in claudicants was mainly confined to subjects with serum folate levels of less than or equal to 11.0 nmol l-1. The results suggest that folic acid supplementation should be tried in IC subjects with hyperhomocyst(e)inaemia.

Aged

Significant association between low-molecular-weight apolipoprotein(a) isoforms and intermittent claudication.

The role of lipoprotein(a) (Lp[a]) and apolipoprotein(a) (apo[a]) isoforms in symptomatic peripheral atherosclerosis was studied in 100 randomly selected middle-aged (45-69 years) men with intermittent claudication (IC) and 100 randomly selected healthy control (C) subjects. IC and C subjects were matched pairwise for sex, age, and smoking habits. Plasma Lp(a) concentrations were significantly higher in IC subjects, with a median value of 20.12 mg/dl, compared with 11.11 mg/dl in C subjects (p less than 0.0009). The elevated Lp(a) concentration was to a great extent due to a significant difference in the frequency distribution of apo(a) isoforms between IC and C subjects (p less than 0.029). Low-molecular-weight apo(a) isoforms were more prevalent in IC than C subjects. Also, IC subjects with apo(a) S2 and S3 phenotypes had higher Lp(a) concentrations than control subjects with the same phenotypes: S2:60.70 mg/dl (IC) and 48.69 mg/dl (C), p less than 0.038; and S3: 30.18 mg/dl (IC) and 12.01 mg/dl (C), p less than 0.042, so other still-unknown factors, genetic or nongenetic, may be important. Stepwise logistic regression analysis demonstrated that Lp(a) concentration contributed significantly (p less than 0.0002) to IC, independent of age, smoking, hypertension, diabetes mellitus, plasma total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, apo B, and plasma total triglycerides. Apo(a) isoforms grouped according to molecular weight were also independent of the above risk factors associated (p = 0.016) with the occurrence of IC because of their low-molecular-weight but were not independent of Lp(a) concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Plasma high density lipoprotein particle size alteration by simvastatin treatment in patients with hypercholesterolaemia.

Twenty-two patients with pronounced hypercholesterolaemia were treated with simvastatin in increasing doses, i.e. 10, 20 and 40 mg O.D. Each treatment regimen had a duration of 6 weeks. In addition to the expected low density lipoprotein (LDL)-lowering effect, simvastatin altered the plasma HDL particle size spectrum by selective elevation of the plasma HDL2b and HDL3a levels, as defined by polyacrylamide gradient gel electrophoresis (gge). While the reduction in LDL cholesterol by simvastatin was dose dependent, the effect on HDL was maximal already at 10 mg daily. On treatment with simvastatin 10 mg O.D., the plasma HDL2b and HDL3a concentrations increased by 30% (P less than 0.001) and 12% (P less than 0.01) respectively. On the corresponding treatment with simvastatin LDL cholesterol decreased by 31% (P less than 0.001). The very low density lipoprotein (VLDL) cholesterol to triglyceride ratio was significantly lowered by treatment with 10 mg simvastatin O.D. suggesting a compositional change in VLDL. Positive univariate correlations between treatment-induced decreases in plasma HDL3b/3c levels and VLDL triglyceride concentration were seen. It is suggested that inhibition of cholesterol synthesis in hypercholesterolaemic subjects by simvastatin treatment alters the composition of VLDL, which may affect the close relation between HDL and VLDL, in turn producing selective elevations of the plasma HDL2b and HDL3a levels.

Adult

Long-term efficacy and safety of simvastatin alone and in combination therapy in treatment of hypercholesterolaemia.

The 3-years efficacy and safety of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor simvastatin (S) (previously called synvinolin or MK-733) has been studied in single and combined therapy with cholestyramine (C) in 48 hypercholesterolaemic patients. Plasma lipids, lipoproteins and apolipoproteins A-I and B, and blood safety tests (haematology, liver function, creatine phosphokinase (CPK), creatinine, blood glucose and thyroid function) were determined regularly throughout the study. Extensive ophthalmological examinations with particular focus on the lens were done before initiation of therapy and at every 6 months during drug treatment. Maximal reductions of mean plasma total cholesterol concentration (34% with S; 47% with S + C) and low-density lipoprotein (LDL)-cholesterol concentration (42% with S; 56% with S + C) were achieved after 4 weeks on full-dose therapy. During continued treatment, years 1 through 3, the reduction of mean plasma total cholesterol was 26-29% with S alone, and 31-41% with S + C. Significant reductions of plasma triglycerides (15-27%) and very low density lipoprotein (VLDL) triglycerides (10-27%) were achieved in the group treated with S as single therapy. In this group there was also a significant increase (10-14%) of high-density lipoprotein (HDL)-cholesterol. In liver aspartate (AST) and alanine (ALT) aminotransferases, as well as alkaline phosphatase (ALP), minor and variable, but usually transient, increases were seen. Repeated ophthalmological examinations did not demonstrate any drug-related side effects. It is concluded that simvastatin is a safe and efficient cholesterol-lowering drug for long-term therapy, both as a single drug and in combination with cholestyramine.

Adult

Effect of different insulin regimens on plasma lipoprotein and apolipoprotein concentrations in patients with non-insulin-dependent diabetes mellitus.

The effect of insulin treatment with 2 different insulin regimens on the plasma concentrations of lipoproteins and apolipoproteins A1 and B was studied in 10 patients with non-insulin-dependent diabetes mellitus (NIDDM) and secondary failure to oral hypoglycaemic agents. The investigation was performed as a randomized crossover study with treatment periods of 8 weeks. Insulin was given either as mainly intermediate acting insulin before breakfast and dinner (2-dose insulin) or as regular insulin preprandially with intermediate acting insulin at bedtime (4-dose insulin). A similar improvement in glycaemic control was obtained with both insulin regimens. On treatment with oral agents the patients were found to have higher total plasma triglycerides and lower plasma high density lipoprotein (HDL) cholesterol than a matched non-diabetic control group. Insulin treatment almost completely normalized these lipid disturbances by reducing mean total plasma triglycerides with 36% and increasing plasma HDL cholesterol with 20% on 2-dose and 17% on 4-dose. The triglyceride concentration in the very low density lipoprotein (VLDL) fraction was reduced. Mean plasma low density lipoprotein (LDL)-cholesterol was not affected by any treatment. There was an increase of similar magnitude in both HDL2 and HDL3 concentrations but only the change in the HDL3 subfraction was statistically significant. Mean plasma apolipoprotein A1 concentration increased with 9% (P less than 0.05) while there was no significant change in the plasma apolipoprotein B concentration. The changes in the plasma concentrations of lipoproteins and apolipoproteins A1 and B were almost identical on 2- and 4-dose insulin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Effect of fish oil treatment on plasma lipoproteins in type III hyperlipoproteinaemia.

Nine patients with type III hyperlipoproteinaemia and homozygosity for the apolipoprotein E2 isoform were treated with 15 g daily of MaxEPA, a fish oil preparation rich in eicosapentaenoic acid (2.7 g daily) and docosahexaenoic acid (1.8 g daily) for 16 weeks. Plasma lipoprotein and apolipoprotein concentrations were compared with those obtained during treatment with an olive oil preparation. MaxEPA treatment decreased plasma median total cholesterol, triglyceride and apolipoprotein B concentrations by 16, 53 and 19%, respectively. Plasma median very low density lipoprotein (VLDL)-cholesterol, triglyceride and apolipoprotein B concentrations were reduced by 45, 62 and 75% respectively, while the abnormal VLDL-cholesterol/triglyceride ratio remained unchanged. Individual reductions of VLDL concentrations varied considerably, for VLDL-cholesterol between 10 and 75%. In the majority of cases the abnormal late pre beta-bands on agarose electrophoresis, typical for type III hyperlipoproteinaemia normalized to pre beta-mobility on MaxEPA treatment. LDL-cholesterol and apolipoprotein B tended to increase after 8 weeks on MaxEPA but decreased again after 16 weeks. Median plasma high density lipoprotein cholesterol and apolipoprotein A-I did not change during MaxEPA treatment. It is concluded that MaxEPA have decreasing effects on plasma VLDL lipid and apolipoprotein concentrations in apolipoprotein E2 homozygous type III hyperlipoproteinaemia but that this effect is variable and unpredictable.

Adult

Decreased mitogenic activity in hypercholesterolaemic plasma.

The mitogenic activity on rat aortic smooth muscle cells of plasma from patients with hypercholesterolaemia was compared to that of plasma from a normocholesterolaemic control group and to that obtained after lowering plasma cholesterol levels in the hypercholesterolaemic groups with simvastatin. Mean plasma total and low density lipoprotein cholesterol and apolipoprotein B concentrations in the two groups were 8.62 +/- 0.62 mmol l-1, 7.03 +/- 0.56 mmol l-1 and 1.96 +/- 0.14 g l-1, respectively, and 5.05 +/- 0.20 mmol l-1, 3.42 +/- 0.18 mmol l-1 and 0.80 +/- 0.04 g l-1, respectively, all differences significant at P less than 0.001. During simvastatin treatment these parameters decreased to 5.70 +/- 0.35, 4.15 +/- 0.33 mmol l-1 and 1.33 +/- 0.08 g l-1, all changes being significantly (P less than 0.001) lower than before treatment. Hyperlipidaemic plasma in untreated patients had a significantly lower mitogenic activity than normolipidaemic control plasma as measured by autoradiographic labelling of DNA after 3H-thymidine incorporation, 25.7 +/- 1.8% vs. 32.0 +/- 1.9%, P less than 0.05. Lowering plasma cholesterol levels in the hyperlipidaemic patients 'normalized' the mitogenic activity to 32.3 +/- 1.6%, P less than 0.05. The reason for this unexpected finding is not known.

Adult

The effect of serum lipid regulation on the development of femoral atherosclerosis in hyperlipidaemia: a non-randomized controlled study.

The development of femoral atheroma after 1 year of treatment with diet and nicotinic acid plus fenofibrate was studied in 45 asymptomatic, hyperlipidaemic, middle-aged male subjects in a non-randomized controlled study. The median serum very low density lipoprotein (VLDL) cholesterol concentration and the low density lipoprotein (LDL) cholesterol concentration were lowered by 67% and 36%, respectively, in the treatment group. The median serum high density lipoprotein (HDL) cholesterol concentration was increased by 23%. Femoral atheroma was estimated by overall atherosclerosis score (OAS). Changes in femoral atherosclerosis were estimated by intrapair comparison of angiograms. Progression was found in 24% and 40% in the treatment and control groups, respectively. Regression occurred in 29% and 0%, respectively. The OAS decrease correlated with reductions in VLDL cholesterol and systolic blood pressure.

Adult

Effects of nicotinic acid on serum cholesterol concentrations of high density lipoprotein subfractions HDL2 and HDL3 in hyperlipoproteinaemia.

Nicotinic acid was given in a 4-g daily dose for 6 weeks to 41 weight-stable patients of mean age (+/- SD) 52 +/- 9 years, with type IIa, type IIb or type IV hyperlipoproteinaemia (HLP), in order to study its effects on serum cholesterol concentrations of high density lipoprotein (HDL) subfractions HDL2 and HDL3. The triglyceride and cholesterol levels of serum very low density (VLDL) and low density (LDL) lipoproteins decreased during treatment (P less than 0.001). Serum HDL and HDL2 cholesterol levels increased by 37% and 135%, respectively. These changes were positively correlated (r = 0.93; P less than 0.001). There was no significant change in mean serum HDL3 cholesterol concentration. A negative correlation existed between changes in HDL3 and HDL2 cholesterol levels (r = -0.54; P less than 0.001). Multiple stepwise linear regression analyses revealed that the initial HDL3 cholesterol predicted more than 30% of the increase in HDL2 cholesterol. Changes in the concentrations of HDL2 and HDL3 cholesterol after 6 weeks of drug treatment were not related to the type of HLP, neither were these effects of nicotinic acid correlated with changes in VLDL or LDL lipid levels. The concept has previously been proposed, on the basis of in vitro data, that HDL2 is formed from HDL3 particles in the blood. Our results suggest that, in man, this reaction is stimulated in vivo by prolonged nicotinic acid therapy.

Adult

Comparative effects of simvastatin and cholestyramine in treatment of patients with hypercholesterolaemia.

The efficacy and safety of 20 mg simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor) and of 16 g cholestyramine daily in the treatment of 34 hypercholesterolaemic patients have been compared after dietary treatment and stratified randomization. The effect of combined treatment with the two drugs was studied in 5 patients with severe hypercholesterolaemia. After 6 weeks of treatment the simvastatin group showed a significantly greater (p less than 0.05) decrease in the mean total plasma cholesterol concentration from 7.88 to 5.48 mmol/l than in the cholestyramine group in whom there was a fall from 7.82 to 6.73 mmol/l. Simvastatin decreased the mean plasma LDL cholesterol concentration from 6.07 to 3.76 mml/l and cholestyramine decreased it from 6.16 to 4.46 mmol/l. Simvastatin also reduced the mean plasma total triglycerides by 24%, VLDL triglycerides by 20% and VLDL cholesterol by 36%, while cholestyramine led to increases in these parameters by 64%, 85% and 63%, respectively. Mean plasma HDL cholesterol concentration and the subfractions HDL2 and HDL3 cholesterol were significantly increased by simvastatin. Simvastatin and cholestyramine reduced the mean plasma apolipoprotein B concentration by 28% and 13%, respectively. The mean plasma apolipoprotein A-I concentration was significantly higher only on simvastatin treatment. Simvastatin did not cause any subjective or objective side effects, while cholestyramine caused gastrointestinal problems in 31% of patients. Small increases in serum alanine aminotransferase (S-ALT) activity were seen with both drugs. Cholestyramine significantly raised the serum alkaline phosphatase (S-ALP) although to a level still within the normal range. It is concluded that 20 mg simvastatin was more effective than 16 g cholestyramine in the treatment of hypercholesterolaemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Prevalence of femoral atherosclerosis in asymptomatic men with hyperlipoproteinaemia.

Sixty-two male subjects with primary hyperlipoproteinaemia of type IIA (n = 18), type IIB (n = 18) or type IV (n = 24) underwent femoral arteriography to investigate the degree of atherosclerosis. All except two were free from symptoms of peripheral arterial disease. The presence of atheroma was determined according to a standardized consensus procedure based on visual interpretation. Atherosclerosis were graded by means of a scoring system, whereby an overall atherosclerosis score (OAS) was calculated for each patient, based on four consecutive segments of the femoral artery. Thirteen type IIA (72%), 14 type IIB (78%) and 18 type IV (75%) patients had femoral atherosclerosis, and the mean OAS in the patients with hyperlipoproteinaemia of these types were 0.58, 0.75 and 0.49, respectively, all with a standard error of the mean about 0.05. The atherosclerosis score increased the more distal the arterial segment, being most prevalent in the lower inferior segment. The OAS was higher in patients of above median age, in those with systolic or diastolic blood pressure above the median and in smokers. Multiple stepwise regression analysis showed that low density lipoproteins cholesterol was highly significantly related to OAS among smokers. In conclusion, femoral atherosclerosis is a prevalent finding in asymptomatic subjects with hyperlipoproteinaemia and could serve as a basis for intervention studies.

Adult