(1/5144) Serum triglyceride: a possible risk factor for ruptured abdominal aortic aneurysm.
BACKGROUND: We aimed to determine the relationship between ruptured abdominal aortic aneurysm (AAA) and serum concentrations of lipids and apolipoproteins. METHODS: A cohort of 21 520 men, aged 35-64 years, was recruited from men attending the British United Provident Association (BUPA) clinic in London for a routine medical examination in 1975-1982. Smoking habits, weight, height and blood pressure were recorded at entry. Lipids and apolipoproteins were measured in stored serum samples from the 30 men who subsequently died of ruptured AAA and 150 matched controls. RESULTS: Triglyceride was strongly related to risk of ruptured AAA. In univariate analyses the risk in men on the 90th centile of the distribution relative to the risk in men on the 10th (RO10-90) was 12 (95% confidence interval [CI] : 3.8-37) for triglyceride, 5.5 (95% CI: 1.8-17) for apolipoprotein B (apoB) (the protein component of low density lipoprotein [LDL]), 0.15 (95% CI : 0.04-0.56) for apo A1 (the protein component of high density lipoprotein [HDL]), 3.7 (95% CI: 1.4-9.4) for body mass index and 3.0 (95% CI: 1.1-8.5) for systolic blood pressure. Lipoprotein (a) (Lp(a)) was not a significant risk factor (RO10-90 = 1.6, 95% CI: 0.6-3.0). In multivariate analysis triglyceride retained its strong association. CONCLUSION: Triglyceride appears to be a strong risk factor for ruptured AAA, although further studies are required to clarify this. If this and other associations are cause and effect, then changing the distribution of risk factors in the population (by many people stopping smoking and adopting a lower saturated fat diet and by lowering blood pressure) could achieve an important reduction in mortality from ruptured AAA. (+info)
(2/5144) Association of the inflammatory state in active juvenile rheumatoid arthritis with hypo-high-density lipoproteinemia and reduced lipoprotein-associated platelet-activating factor acetylhydrolase activity.
OBJECTIVE: To investigate the relationship between the quantitative and qualitative abnormalities of apolipoprotein B (Apo B)- and Apo A-I-containing lipoproteins and between lipoprotein-associated platelet-activating factor acetylhydrolase (PAF-AH) activity in patients with juvenile rheumatoid arthritis (JRA) as a function of the inflammatory state. METHODS: Twenty-six JRA patients and 22 age- and sex-matched control subjects with normal lipid levels participated in the study. Fourteen patients had active disease, and 12 had inactive disease. Plasma lipoproteins were fractionated by gradient ultracentrifugation into 9 subfractions, and their chemical composition and mass were determined. The PAF-AH activity associated with lipoprotein subfractions and the activity in plasma were also measured. RESULTS: Patients with active JRA had significantly lower plasma total cholesterol and high-density lipoprotein (HDL) cholesterol levels as compared with controls, due to the decrease in the mass of both the HDL2 and HDL3 subfractions. Patients with active JRA also had higher plasma triglyceride levels, mainly due to the higher triglyceride content of the very low-density lipoprotein plus the intermediate-density lipoprotein subfraction. The plasma PAF-AH activity in patients with active JRA was lower than that in controls, mainly due to the decrease in PAF-AH activity associated with the intermediate and dense low-density lipoprotein subclasses. The lipid abnormalities and the reduction in plasma PAF-AH activity were significantly correlated with plasma C-reactive protein levels and were not observed in patients with inactive JRA. CONCLUSION: This is the first study to show that patients with active JRA exhibit low levels of HDL2 and HDL3 and are deficient in plasma PAF-AH activity. These alterations suggest that active JRA is associated with partial loss of the antiinflammatory activity of plasma Apo B- and Apo A-I-containing lipoproteins. (+info)
(3/5144) Chlamydia pneumoniae antibodies are associated with an atherogenic lipid profile.
OBJECTIVE: To determine, within a representative population group of men and women, whether alteration of the lipid profile might underlie the reported association between Chlamydia pneumoniae and ischaemic heart disease. DESIGN AND SETTING: Cross sectional survey in an area with a high incidence of ischaemic heart disease. SUBJECTS: 400 randomly selected participants in the World Health Organisation MONICA project's third population survey in Northern Ireland. MAIN OUTCOME MEASURES: Stored sera were examined by microimmunofluorescence for IgG antibodies to C pneumoniae at a dilution of 1 in 64. Mean total and high density lipoprotein (HDL) cholesterol were compared between seropositive and seronegative individuals with adjustment for age, measures of socioeconomic status, smoking habit, alcohol consumption, body mass index, and the season during which blood had been taken. RESULTS: In seropositive men, adjusted mean serum total cholesterol and HDL cholesterol were 0.5 mmol/l (9.2%) higher and 0.11 mmol/l (9.3%) lower, respectively, than in seronegative men. Differences in women did not achieve statistical significance, but both total cholesterol and HDL cholesterol were higher (3.6% and 5.8%, respectively) in seropositive than in seronegative individuals. CONCLUSIONS: There is serological evidence that C pneumoniae infection is associated with an atherogenic lipid profile in men. Altered lipid levels may underlie the association between C pneumoniae and ischaemic heart disease. (+info)
(4/5144) Effect of fasting on temporal variation in the nephrotoxicity of amphotericin B in rats.
Evidence for temporal variation in the nephrotoxicity of amphotericin B was recently reported in experimental animals. The role of food in these variations was determined by studying the effect of a short fasting period on the temporal variation in the renal toxicity of amphotericin B. Twenty-eight normally fed and 28 fasted female Sprague-Dawley rats were used. Food was available ad libitum to the fed rats, while the fasted animals were fasted 12 h before and 24 h after amphotericin B injection to minimize stress for the animals. Water was available ad libitum to both groups of rats, which were maintained on a 14-h light, 10-h dark regimen (light on at 0600 h). Renal toxicity was determined by comparing the levels of excretion of renal enzyme and the serum creatinine and blood urea nitrogen (BUN) levels at the time of the maximal (0700 h) or the minimal (1900 h) nephrotoxicity after the intraperitoneal administration of a single dose of dextrose (5%; control group) or amphotericin B (50 mg/kg of body weight; treated group) to the rats. The nephrotoxicities obtained after amphotericin B administration at both times of day were compared to the nephrotoxicities observed for time-matched controls. In fed animals, the 24-h urinary excretion of N-acetyl-beta-D-glucosaminidase and beta-galactosidase was significantly higher when amphotericin B was injected at 0700 and 1900 h. The excretion of these two enzymes was reduced significantly (P < 0.05) in fasting rats, and this effect was larger at 0700 h (P < 0.05) than at 1900 h. The serum creatinine level was also significantly higher (P < 0.05) in fed animals treated at 0700 h than in fed animals treated at 1900 h. Fasting reduced significantly (P < 0.05) the increase in the serum creatinine level, and this effect was larger in the animals treated at 0700 h. Similar data were obtained for BUN levels. Amphotericin B accumulation was significantly higher (P < 0.05) in the renal cortexes of fed rats than in those of fasted animals, but there was no difference according to the time of injection. These results demonstrated that fasting reduces the nephrotoxicity of amphotericin B and that food availability is of crucial importance in the temporal variation in the renal toxicity of amphotericin B in rats. (+info)
(5/5144) The impact of an amino acid-based peritoneal dialysis fluid on plasma total homocysteine levels, lipid profile and body fat mass.
BACKGROUND: The caloric load from glucose-based peritoneal dialysis (PD) fluids contributes to hypertriglyceridaemia, adiposity and, as result of anorexia, protein malnutrition in PD patients. It has been suggested that replacement of a glucose-based by an amino acids-based PD fluid (AA-PDF) for one exchange per day might improve the nutritional status and lipid profile. Due to the uptake of methionine from the dialysate, however, exposure to AA-PDF might aggravate hyperhomocysteinaemia, a frequently occurring risk factor for atherosclerosis in uraemic patients. METHODS: We studied the impact of a once daily exchange with 1.1% AA-PDF instead of glucose-based PD fluid for 2 months on plasma methionine and total homocysteine (tHcy) levels, lipid profile, butyrylcholinesterase (BChE) and body fat mass of seven stable PD patients. Results are expressed as mean+/-SEM. RESULTS: Methionine levels did not increase significantly during therapy, but tHcy levels increased substantially from 60+/-12 to 84+/-19 micromol/l after 1 month (P=0.039), and to 85+/-22 micromol/l after 2 months of AA-PDF treatment. Serum triglyceride concentration decreased from 3.0+/-0.4 mmol/l at entry to 2.6+/-0.5 mmol/l (at 1 month, P=0.041 vs baseline). Serum BChE also decreased from 6.9+/-0.4 U/ml at entry to 6.3+/-0.4 U/ml after 2 months (P=0.014). Total cholesterol concentration and cholesterol fractions did not change. The reduced exposure to glucose-based PD fluid for 2 months resulted in a 0.5 kg reduction in fat mass which was due mainly to a reduction in fat mass of the trunk region (0.3 kg, P=0.031). CONCLUSIONS: It is concluded that methionine-containing AA-PDF induces an increase in the plasma tHcy level. This might, potentially, offset the beneficial effects of an improved serum lipid profile and reduced fat mass on the risk of cardiovascular disease in PD patients. Lowering the methionine content of the fluid, therefore, may be required to overcome this adverse effect. (+info)
(6/5144) Survey of total error of precipitation and homogeneous HDL-cholesterol methods and simultaneous evaluation of lyophilized saccharose-containing candidate reference materials for HDL-cholesterol.
BACKGROUND: Standardization of HDL-cholesterol is needed for risk assessment. We assessed for the first time the accuracy of HDL-cholesterol testing in The Netherlands and evaluated 11 candidate reference materials (CRMs). METHODS: The total error (TE) of HDL-cholesterol measurements was assessed in native human sera by 25 Dutch clinical chemistry laboratories. Concomitantly, the suitability of lyophilized, saccharose-containing CRMs (n = 11) for HDL-cholesterol was evaluated. RESULTS: In the precipitation method group, which included 25 laboratories and four methods, the mean (minimum-maximum) TE was 11.5% (2.7-25.2%), signifying that 18 of 25 laboratories satisfied the TE goal of +info)
(7/5144) Elevated hepatic lipase activity and low levels of high density lipoprotein in a normotriglyceridemic, nonobese Turkish population.
Low levels of high density lipoprotein cholesterol (HDL-C) are associated with increased risk of coronary heart disease and, in the United States, are often associated with hypertriglyceridemia and obesity. In Turkey, low HDL-C levels are highly prevalent, 53% of men and 26% of women having HDL-C levels <35 mg/dl, in the absence of hypertriglyceridemia and obesity. In this study to investigate the cause of low HDL-C levels in Turks, various factors affecting HDL metabolism were assessed in normotriglyceridemic Turkish men and women living in Istanbul and in non-Turkish men and women living in San Francisco. Turkish men and women had significantly lower HDL-C levels than the San Francisco men and women, as well as markedly lower apolipoprotein A-I levels (25 and 39 mg/dl lower, respectively). In both Turkish and non-Turkish subjects, the mean body mass index was <27 kg/m2, the mean triglyceride level was <120 mg/dl, and the mean total cholesterol was 170-180 mg/dl. The mean hepatic triglyceride lipase activity was 21% and 31% higher in Turkish men and women, respectively, than in non-Turkish men and women, and remained higher even after subjects with a body mass index >50th percentile for men and women in the United States were excluded from the analysis. As no dietary or behavioral factors have been identified in the Turkish population that account for increased hepatic triglyceride lipase activity, the elevation most likely has a genetic basis. high density lipoprotein in a normotriglyceridemic, nonobese Turkish population. (+info)
(8/5144) Comparison of synthetic saponin cholesterol absorption inhibitors in rabbits: evidence for a non-stoichiometric, intestinal mechanism of action.
The hypocholesterolemic activities of pamaqueside and tiqueside, two structurally similar saponins, were evaluated in cholesterol-fed rabbits. The pharmacological profiles of the saponins were virtually identical: both dose-dependently decreased the intestinal absorption of labeled cholesterol 25-75%, increased fecal neutral sterol excretion up to 2.5-fold, and decreased hepatic cholesterol content 10-55%. High doses of pamaqueside (>5 mg/kg) or tiqueside (>125 mg/kg) completely prevented hypercholesterolemia. Decreases in plasma and hepatic cholesterol levels were strongly correlated with increased neutral sterol excretion. Ratios of neutral sterol excreted to pamaqueside administered were greater than 1:1 at all doses, in opposition to the formation of a stoichiometric complex previously suggested for tiqueside and other saponins. Ratios in tiqueside-treated rabbits were less than unity, a reflection of its lower potency. Pamaqueside-treated rabbits exhibited a more rapid decline in plasma cholesterol concentrations than control animals fed a cholesterol-free diet, indicating that the compound also inhibited the absorption of biliary cholesterol. Intravenous administration of pamaqueside had no effect on plasma cholesterol levels despite plasma levels twice those observed in rabbits given pamaqueside orally. These data indicate that pamaqueside and tiqueside induce hypocholesterolemia by blocking lumenal cholesterol absorption via a mechanism that apparently differs from the stoichiometric complexation of cholesterol hypothesized for other saponins. (+info)