Biomedical subjects

Erkki Wuolijoki

Publications and source records attributed to Erkki Wuolijoki.

6 recordsLinked to original sources

PubMed2006

Plasma asymmetric dimethylarginine (ADMA), nitrate and the indices of low-density lipoprotein oxidation.

BACKGROUND: Oxidative modification of low-density lipoprotein (LDL) is an important contributor to atherosclerosis. Also, oxidized LDL is suspected to cause accumulation of asymmetric dimethylarginine (ADMA), an endogenous competitive nitric oxide synthase inhibitor, which is suggested to be an independent risk factor for atherosclerosis. This study was performed to evaluate how plasma ADMA is related to plasma nitric oxide production, oxidized LDL and ex vivo susceptibility of LDL to oxidation in mildly hypercholesterolemic otherwise healthy subjects. METHODS: Plasma ADMA was determined using high performance liquid chromatography tandem mass spectrometry. LDL oxidation was estimated by the lag time and rate of copper-induced LDL oxidation. The nitric oxide production in plasma was estimated based on nitrate (NO(3)(-)) determination and plasma oxidized LDL was determined by a capture ELISA. RESULTS: Low ADMA was a significant determinant for high LDL oxidation rate and concentration of plasma ADMA was associated with nitrate levels. CONCLUSIONS: There may be an interplay between LDL fatty acid oxidation rate and plasma ADMA and nitrate. We hypothesize that plasma ADMA has a bivalent role: high ADMA may have a protective role in decelerating LDL fatty acid oxidation and also a risk factor for endothelial dysfunction by decreasing availability of nitric oxide.

Adult↗

PubMed2005

Interleukin-6 modulates plasma cholesterol and C-reactive protein concentrations in nonagenarians.

OBJECTIVES: To establish whether the relationship between interleukin-6 (IL-6) and plasma lipid and C-reactive protein (CRP) concentrations is different in Finnish nonagenarians than in middle-aged subjects with lower inflammatory status. DESIGN: Cross-sectional. SETTING: Observational cohort study concentrating on the oldest old. PARTICIPANTS: Nonagenarians (n=291, mean age+/-standard deviation 90+/-1; 68 men, 223 women) who lived in the Tampere municipality in southern Finland and a middle-aged control population from the same area (n=227, aged 44+/-8). MEASUREMENTS: Plasma high sensitive CRP and lipid concentrations were analyzed using an automatic analyzer and IL-6 levels using enzyme-linked immunosorbent assay. RESULTS: Plasma concentrations of IL-6 (4.39+/-5.25 vs 1.88+/-1.98 pg/mL) and CRP (3.54+/-4.98 vs 1.53+/-1.91 mg/L) were significantly higher in nonagenarians than in middle-aged subjects (P<.001). In nonagenarians, plasma CRP levels increased (P<.001) and plasma total cholesterol (P=.006), low-density lipoprotein cholesterol (P=.02), and high-density lipoprotein cholesterol (P=.002) levels decreased according to IL-6 quartiles. In middle-aged subjects, similar associations were not found. CONCLUSION: The relationship between IL-6 and plasma CRP and cholesterol levels in nonagenarians with enhanced systemic inflammation differs from that of middle-aged subjects.

Adult↗

PubMed2005

Microcrystalline chitosan is ineffective to decrease plasma lipids in both apolipoprotein E epsilon 4 carriers and non-carriers: a long-term placebo-controlled trial in hypercholesterolaemic volunteers.

Chitosan is a deacetylated product of chitin. Microcrystalline form of chitosan has a large adsorption area claimed to decrease gastrointestinal absorption of cholesterol. However, the long-term effect of chitosan on plasma lipids is variable, the averaged influence being negligible or lacking in mildly-to-moderately hypercholesterolaemic (4.8-6.8 mmol/l) subjects. We evaluated whether this variation and inefficacy depend on apolipoprotein E genotype. 130 middle-aged, otherwise healthy men (n=55) and women (n=75) were randomized into two treatment groups for a 7 month trial. During a 1 month run-in period all participants received placebo. Subsequently, one half first took placebo twice daily for 3 months and then 1.2 g chitosan twice daily for 3 months, and the other half vice versa in a cross-over way. Altogether 84 participants completed the study. Plasma lipids and glucose were determined at the end of each phase of the study, and all subjects undergone to the cross-over phases were apolipoprotein E genotyped. Chitosan altered plasma total, low- and high density cholesterol, triglycerides, and blood glucose in neither apolipoprotein E epsilon 4 allele carriers (n=29) nor non-carriers (n=55), compared to placebo. In conclusions, chitosan is ineffective to decrease plasma lipids in apolipoprotein E epsilon 4 carrier and non-carrier phenotypes with mildly-to-moderately increased plasma cholesterol.

Adolescent↗

PubMed2004

Dietary composition as a determinant of plasma asymmetric dimethylarginine in subjects with mild hypercholesterolemia.

Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide synthase inhibitor that participates in the regulation of vasodilatory function and is also linked to hypertension, whereas its stereoisomere, symmetric dimethylarginine (SDMA), is biologically inactive. Dietary components influence vascular functions and a high-fat meal seems to increase postprandial plasma ADMA levels. However, it has not been published whether diet influences plasma ADMA levels. In this study, we investigated the impact of diet on plasma ADMA and SDMA levels. Thirty-four mildly hypercholesterolemic, otherwise healthy women (n = 14) and men (n = 20) with a mean age of 46.2 years (range, 35 to 62 years) participated in the study. The subjects were examined twice at intervals of 2 months. Seven-day food records were used to analyze diet and alcohol intake. ADMA was measured by using high-performance liquid chromatography (HPLC)-tandem mass spectrometry. In a multivariate analysis (R2 = 0.20, P < .002), low amount of energy received from carbohydrates (r = -0.31, P = .009) and high plasma triglycerides (r = 0.30, P = .01) were predictors of high ADMA plasma levels. Alcohol drinkers had higher plasma ADMA concentrations than abstainers (0.50 +/- 0.13 v 0.42 +/- 0.11 micromol/L, P = .04). Plasma ADMA correlated with systolic (r = 0.60, P = .005) and diastolic blood pressure (r = 0.53, P = .02) in abstainers but not in alcohol drinkers. Plasma SDMA was not associated with any dietary components or with blood pressure. In conclusion, a high amount of dietary carbohydrates is strongly associated with low levels of plasma ADMA. Concentration of ADMA in plasma seems to be higher in alcohol drinkers than in abstainers.

Adult↗

PubMed2003

The effect of long-term microcrystalline chitosan therapy on plasma lipids and glucose concentrations in subjects with increased plasma total cholesterol: a randomised placebo-controlled double-blind crossover trial in healthy men and women.

OBJECTIVE: To evaluate the long-term effect of microcrystalline chitosan (MCC) on plasma lipids, especially the concentration of low-density lipoprotein (LDL) cholesterol, in subjects with a moderately increased concentration of plasma total cholesterol. METHODS: A total of 130 middle-aged men and women without severe disease and with a total cholesterol of 4.8-6.8 mmol/l and triglycerides below 3.0 mmol/l were randomised into two treatment groups. At the beginning of the 10-month trial, all participants received placebo 1.2 g twice daily during a 1-month run-in period. Subsequently, group 1 first received 1.2 g placebo twice daily for 3 months and then 1.2 g MCC twice daily for 3 months. Correspondingly, group 2 received 1.2 g MCC twice daily during the first and 1.2 g placebo twice daily during the second 3-month period. During the final 3-month follow-up period, both groups received MCC. Altogether, 83 participants completed the study. RESULTS: No difference was detected in the change in the LDL-cholesterol concentration between the treatments during the crossover trial ( P=0.98 for interaction between time period and treatment group, repeated-measures analysis of variance for crossover design). In an otherwise similar analysis, no differences were detected between the treatments in the concentrations of total cholesterol, high-density lipoprotein cholesterol, triglycerides and glucose. CONCLUSIONS: Treatment with MCC had no effect on the concentrations of plasma lipids or glucose in healthy middle-aged men and women with moderately increased plasma cholesterol concentrations.

Adjuvants, Pharmaceutic↗

PubMed2002

Cholesterol-lowering properties and safety of chitosan.

Chitosan (CAS 9012-76-4) is derived by alkaline deacetylation from chitin, an abundant polymeric product of natural biosynthesis especially in crustaceans. It is available in a primary, unorganised structure, but also in a microcrystalline form. As a dietary supplement, chitosan has been claimed to control obesity and to lower serum cholesterol. A variety of chitosan products have been freely available worldwide in health stores and pharmacies. This review summarises the current knowledge about cholesterol-lowering and safety properties of chitosan and focuses its possible application for the treatment of hypercholesterolaemia. Chitosan behaves as a polycationic(+) cellulose-like fibrillar biopolymer that forms films with negatively charged surfaces. It is not specifically hydrolysed by digestive enzymes in man, but limited digestion of chitosan due to bacterial flora and to the unspecific enzymes might occur. Negatively charged molecules in stomach attach strongly to the positive charged tertiary amino group (-NH3+) of chitosan. Therefore, chitosan reduces fat absorption from gastrointestinal tract by binding with anionic carboxyl groups of fatty and bile acids, and it interferes with emulsification of neutral lipids (i.e., cholesterol, other sterols) by binding them with hydrophobic bonds. In short-term animal studies the safety of chitosan has been good. There are only few studies with chitosan in humans. In man, dietary chitosan has been reported to reduce serum total cholesterol levels by 5.8-42.6% and low-density lipoprotein levels by 15.1-35.1%. In short-term trials up to 12 weeks, no clinically significant symptoms have been observed with chitosan compared to placebo. Mild and transitory nausea and constipation have been reported in 2.6-5.4% of subjects. Although chitosan has been clinically well tolerated, it cannot be recommended to people allergic to crustaceans.

Animals↗