Ari Palomäki

Enhanced oxidizability of ubiquinol and α‐tocopherol during lovastatin treatment

A double‐blinded, placebo‐controlled cross‐over trial was carried out with 27 hypercholesterolemic men with coronary heart disease. During the 6‐week treatment period lovastatin (60 mg/day) decreased fasting serum LDL cholesterol by 45%, LDL phosphorus by 38% and apoB by 33%. Ubiquinol content diminished by 13% as measured per LDL phosphorus. When LDL was oxidized ex vivo with AMVN both LDL ubiquinol and α‐tocopherol were exhausted faster after lovastatin treatment compared to placebo, by 24% (P<0.005) and 36% (P<0.0001), respectively. Lag time in copper‐induced oxidation of LDL decreased by 7% (P<0.01). This suggests diminished antioxidant‐dependent resistance of LDL to the early phase of oxidative stress.

Apolipoprotein A-IFIN (Leu159-->Arg) mutation affects lecithin cholesterol acyltransferase activation and subclass distribution of HDL but not cholesterol efflux from fibroblasts.

We showed earlier that the apolipoprotein A-I Leu159-->Arg mutation (apoA-IFin) results in dominantly inherited hypoalphalipoproteinemia. In the present study we investigated the effect of the apoA-IFin mutation on lipoprotein profile, apoA-I kinetics, lecithin:cholesterol acyltransferase (LCAT) activation, and cholesterol efflux in vitro. Carriers (n = 9) of the apoA-IFin mutation exhibited several lipoprotein abnormalities. The serum HDL cholesterol level was diminished to 20% of normal, and nondenaturing gradient gel electrophoresis of HDL showed disappearance of particles at the 9.0- to 12-nm size range (HDL2-type) and the presence of small 7.8- to 8.9-nm (mostly HDL3-type) particles only. HDL3-type particles from both the mutation carriers and nonaffected family members were similarly converted to large, HDL2-type particles by phospholipid transfer protein in vitro. Studies on apoA-I kinetics in four affected subjects favored accelerated catabolism of apoA-I. Experiments with reconstituted proteoliposomes showed that the capacity of apoA-IFin protein to activate LCAT was reduced to 40% of that of the wild-type apoA-I. The impact of the apoA-IFin protein on cholesterol efflux was examined in vitro using [3H]cholesterol-loaded human fibroblasts and three different cholesterol acceptors: (1) total HDL, (2) total apoA-I combined with phospholipid, and (3) apoA-I isoform (apoA-IFin or wild-type apoA-I isoform 1) combined with phospholipid. ApoA-IFin did not impair phospholipid binding or cholesterol efflux from fibroblasts to any of the acceptors used. Only one of the nine apoA-IFin carriers appears to have evidence of clinically manifested atherosclerosis. In conclusion, although the apoA-IFin mutation does not alter the properties of apoA-I involved in promotion of cholesterol efflux, its ability to activate LCAT in vitro is defective. In vivo, apoA-IFin was found to be associated with several lipoprotein composition rearrangements and increased catabolism of apoA-I.

Erectile dysfunction, physical activity and metabolic syndrome: differences in markers of atherosclerosis

BackgroundErectile dysfunction (ED), impaired arterial elasticity, elevated resting heart rate as well as increased levels of oxidized LDL and fibrinogen associate with future cardiovascular events. Physical activity is crucial in the prevention of cardiovascular diseases (CVD), while metabolic syndrome (MetS) comprises an increased risk for CVD events. The aim of this study was to assess whether markers of subclinical atherosclerosis are associated with the presence of ED and MetS, and whether physical activity is protective of ED.Methods57 MetS (51.3 ± 8.0 years) and 48 physically active (PhA) (51.1 ± 8.1 years) subjects participated in the study. ED was assessed by the International Index of Erectile Function (IIEF) questionnaire, arterial elasticity by a radial artery tonometer (HDI/PulseWave™ CR-2000) and circulating oxLDL by a capture ELISA immunoassay. Fibrinogen and lipids were assessed by validated methods. The calculation of mean daily energy expenditure of physical exercise was based on a structured questionnaire.ResultsED was more often present among MetS compared to PhA subjects, 63.2% and 27.1%, respectively (p < 0.001). Regular physical exercise at the level of > 400 kcal/day was protective of ED (OR 0.12, 95% CI 0.017-0.778, p = 0.027), whereas increased fibrinogen (OR 4.67, 95% CI 1.171-18.627, p = 0.029) and elevated resting heart rate (OR 1.07, 95% CI 1.003-1.138, p = 0.04) were independently associated with the presence of ED. In addition, large arterial elasticity (ml/mmHgx10) was lower among MetS compared to PhA subjects (16.6 ± 4.0 vs. 19.6 ± 4.2, p < 0.001), as well as among ED compared to non-ED subjects (16.7 ± 4.6 vs. 19.0 ± 3.9, p = 0.008). Fibrinogen and resting heart rate were highest and large arterial elasticity lowest among subjects with both MetS and ED.ConclusionsMarkers of subclinical atherosclerosis associated with the presence of ED and were most evident among subjects with both MetS and ED. Thus, especially MetS patients presenting with ED should be considered at high risk for CVD events. Physical activity, on its part, seems to be protective of ED.Trial registrationClinicalTrials.gov NCT01119404

Circulating oxidized low-density lipoproteins and arterial elasticity: comparison between men with metabolic syndrome and physically active counterparts

BackgroundAccumulation of oxidized low-density lipoproteins in the intimae of arteries and endothelial dysfunction are key events in the development of atherosclerosis. Patients with metabolic syndrome are at high risk for cardiovascular diseases but the linkage between metabolic syndrome and atherosclerosis is incompletely understood. We studied whether the levels of oxidized LDL and arterial elasticity differ between metabolic syndrome patients and physically active controls.Methods40 men with metabolic syndrome and 40 physically active controls participated in this cross-sectional study. None of the study subjects had been diagnosed with cardiovascular disease. Levels of oxidized LDL were assessed by a two-site ELISA immunoassay. Arterial elasticity was assessed non-invasively by the HDI/PulseWave™ CR-2000 arterial tonometer.ResultsLevels of oxidized LDL were 89.6 ± 33.1 U/L for metabolic syndrome subjects and 68.5 ± 23.6 U/L for controls (p = 0.007). The difference remained significant after adjustment for LDL cholesterol. Large artery elasticity index (C1) was 16.2 ± 4.1 mL/mmHgx10 for metabolic syndrome subjects and 19.4 ± 3.7 mL/mmHgx10 for controls (p = 0.001), small artery indices (C2) were 7.0 ± 3.2 mL/mmHgx100 and 6.5 ± 2.9 mL/mmHgx100 (NS), respectively.ConclusionsSubjects with metabolic syndrome had elevated levels of oxidized LDL and reduced large arterial elasticity compared to controls. This finding may partly explain the increased risk for cardiovascular diseases among metabolic syndrome patients.Trial registrationClinicalTrials.gov NCT01114763

Effects of dietary cold-pressed turnip rapeseed oil and butter on serum lipids, oxidized LDL and arterial elasticity in men with metabolic syndrome

BackgroundRapeseed oil is the principal dietary source of monounsaturated and n-3 polyunsaturated fatty acids in the Northern Europe. However, the effect of rapeseed oil on the markers of subclinical atherosclerosis is not known. The purpose of this study was to compare the effects of dietary intake of cold-pressed turnip rapeseed oil (CPTRO) and butter on serum lipids, oxidized LDL and arterial elasticity in men with metabolic syndrome.MethodsThirty-seven men with metabolic syndrome completed an open and balanced crossover study. Treatment periods lasted for 6 to 8 weeks and they were separated from each other with an eight-week washout period. Subjects maintained their normal dietary habits and physical activity without major variations. The daily fat adjunct consisted either of 37.5 grams of butter or 35 mL of VirginoR CPTRO. Participants were asked to spread butter on bread on the butter period and to drink CPTRO on the oil period. The fat adjunct was used as such without heating or frying.ResultsCompared to butter, administration of CPTRO was followed by a reduction of total cholesterol by 8% (p < 0.001) and LDL cholesterol by 11% (p < 0.001). The level of oxidized LDL was 16% lower after oil period (p = 0.024). Minimal differences in arterial elasticity were not statistically significant.ConclusionCold-pressed turnip rapeseed oil had favourable effects on circulating LDL cholesterol and oxidized LDL, which may be important in the management of patients at high cardiovascular risk.Trial registrationClinicalTrial.gov NCT01119690

Effects of Lovastatin Therapy on Susceptibility of LDL to Oxidation During α-Tocopherol Supplementation

A randomized, double-masked, crossover clinical trial was carried out to evaluate whether lovastatin therapy (60 mg daily) affects the initiation of oxidation of low density lipoprotein (LDL) in cardiac patients on alpha-tocopherol supplementation therapy (450 IU daily). Twenty-eight men with verified coronary heart disease and hypercholesterolemia received alpha-tocopherol with lovastatin or with dummy tablets in random order. The two 6-week, active-treatment periods were preceded by a washout period of at least 8 weeks. The oxidizability of LDL was determined by 2 methods ex vivo. The depletion times for LDL ubiquinol and LDL alpha-tocopherol were determined in timed samples taken during oxidation induced by 2, 2-azobis(2,4-dimethylvaleronitrile). Copper-mediated oxidation of LDL isolated by rapid density-gradient ultracentrifugation was used to measure the lag time to the propagation phase of conjugated-diene formation. alpha-Tocopherol supplementation led to a 1.9-fold concentration of reduced alpha-tocopherol in LDL (P<0.0001) and to a 2.0-fold longer depletion time (P<0.0001) of alpha-tocopherol compared with determinations after the washout period. A 43% prolongation (P<0.0001) was seen in the lag time of conjugated-diene formation. Lovastatin decreased the depletion time of reduced alpha-tocopherol in metal ion-independent oxidation by 44% and shortened the lag time of conjugated-diene formation in metal ion-dependent oxidation by 7%. In conclusion, alpha-tocopherol supplementation significantly increased the antioxidative capacity of LDL when measured ex vivo, which was partially abolished by concomitant lovastatin therapy.

Return to work after coronary artery bypass surgery. A 10-year follow-up study

Objectives. To establish which factors influence patients’ return to work and how well they remain at work after coronary artery bypass grafting (CABG). Design. Five hundred and sixty nine consecutive CABG patients aged less than 65 years were followed for 10 years. Data were collected from patient records and by questionnaires supplemented with information from Finnish national archives. Results. Multivariate analysis showed the best predictors for return to work to be younger age, preoperative working, as well as absence of diabetes or perioperative cardiac damage. Almost half of the patients aged less than 60 and preoperatively not retired were working one year after CABG. Five years postoperatively, 85% of patients younger than 60 years and once returned to work were still working. Correspondingly, of subjects remaining under 60 years during a 10-year follow-up, 75% continued working. Conclusions. Younger age and preoperative employment were the most important predictors of successful return to work. Once returned after CABG, patients’ staying at work was comparable with that in the general population.

Associations of metabolic syndrome and diabetes mellitus with 16-year survival after CABG

BackgroundThe associations of metabolic syndrome (MetS) or diabetes mellitus (DM) on long-term survival after coronary artery bypass grafting (CABG) have not been extensively evaluated. The aim of the present study was to assess the impact of MetS and DM on the 16-year survival after CABG.MethodsDiabetic and metabolic status together with relevant cardiovascular data was established in 910 CABG patients operated in 1993-94. They were divided in three groups as follows: neither DM nor MetS (375 patients), MetS alone (279 patients) and DM with or without MetS (256 patients). The 16-year follow-up of patient survival was carried out using national health databases. The relative survival rates were analyzed using the Life Table method comparing the observed survival rates of three patient groups to the rates based on age-, sex- and time-specific life tables for the whole population in Finland. To study the independent significance of MetS and DM for clinical outcome, multivariate analysis was made using an optimizing stepwise procedure based on the Bayesian approach.ResultsBayesian multivariate analysis revealed together six variables to predict clinical outcome (2 months to 16 years) in relation to the national background population, i.e. age, diabetes, left ventricular ejection fraction, BMI, perfusion time during the CABG and peripheral arterial disease. Our principal finding was that after postoperative period the 16-year prognosis of patients with neither DM nor MetS was better than that of the age-, sex-and time-matched background population (relative survival against background population 1.037, p < 0.0001). The overall survival of MetS patients resembled that of the matched background population (relative survival 0.998, NS). DM was associated with significantly increased mortality (relative survival 0.86, p < 0.0001). Additionally, mortality was even higher in patients receiving insulin treatment than in those without. Excess death rate of DM patients was predominantly caused by cardiovascular causes.ConclusionIn this long-term follow-up study patient groups without diabetes had at least equal 16 years’ survival after CABG than their matched background populations. Survival of DM patients started to deteriorate already few years after the operation.

Comparison of LDL trap assay to other tests of antioxidant capacity; effect of vitamin E and lovastatin treatment.

Oxidized low density lipoprotein (LDL) has a major impact in the development of atherosclerosis. Risk for oxidative modification of LDL is usually determined indirectly by measuring the capability of LDL to resist radical insult. We compared three different methods quantifying the antioxidative capacity of LDL ex vivo in dyslipidemic patients with coronary heart disease. Plasma samples were obtained from two double-blinded cross-over trials. The duration of all interventions (placebo, lovastatin 60 mg/day, RRR-α-tocopherol 300 mg/day and lovastatin + RRR-α-tocopherol combined) was 6 weeks. The total radical capturing capacity of LDL (TRAP) in plasma was determined using 2,2-azobis(2,4-dimethyl-valeronitrile) (AMVN)-induced oxidation, and measuring the extinction time of chemiluminescence. TRAP was compared to the variables characterizing formation of conjugated dienes in copper-induced oxidation. Also the initial concentrations and consumption times of reduced α-tocopherol (α-TOH) and ubiquinol in AMVN-induced oxidation were determined. Repeatability of TRAP was comparable to that of the lag time in conjugated diene formation. Coefficient of variation within TRAP assay was 4.4% and between TRAP assays 5.9%. Tocopherol supplementation produced statistically significant changes in all antioxidant variables except those related to LDL ubiquinol. TRAP increased by 57%, the lag time in conjugated diene formation by 34% and consumption time of α-TOH by 88%. When data of all interventions were included in the analyses, TRAP correlated with the lag time (r = 0.75, p < 10-6), with LDL α -TOH (r = 0.50, p < 0.001) and with the consumption time of α-TOH (r = 0.58, p < 0.0001). In the baseline data, the associations between different antioxidant variables were weaker. TRAP correlated with the lag time (r = 0.55, p < 0.001) and α-TOH consumption time (r = 0.48, p < 0.05), and inversely with apolipoprotein Al (r = -0.51, p < 0.05). Lag time at the baseline did not correlate with ubiquinol or tocopherol parameters, or with any plasma lipid or lipoprotein levels analyzed. Lovastatin treatment did not significantly affect the antioxidant capacity of LDL. In conclusion, TRAP reflects slightly different properties of LDL compared to the lag time. Thus, LDL TRAP assay may complement the other methods used to quantify the antioxidant capacity of LDL. However, TRAP and the lag time react similarly to vitamin E supplementation.

The risk of metabolic syndrome after gestational diabetes mellitus - a hospital-based cohort study

BackgroundWomen with gestational diabetes mellitus (GDM) are at an increased risk of developing metabolic syndrome (MetS) after delivery. Recently, the prevalence of both GDM and MetS has increased worldwide, in parallel with obesity. We investigated whether the presentation of MetS and its clinical features among women with previous GDM differs from that among those with normal glucose tolerance during pregnancy, and whether excess body weight affects the results.MethodsThis hospital-based study of two cohorts was performed in Kanta-Häme Central Hospital, Finland. 120 women with a history of GDM and 120 women with a history of normal glucose metabolism during pregnancy, all aged between 25 and 46 were enrolled. They all underwent physical examination and had baseline blood samples taken. All 240 women were also included in subgroup analyses to study the effect of excess body weight on the results.ResultsAlthough the groups did not differ in body mass index (BMI; p = 0.069), the risk of developing MetS after pregnancy complicated by GDM was significantly higher than after normal pregnancy, 19 vs. 8 cases (p  =  0.039). Fasting glucose (p < 0.001) and triglyceride levels (p < 0.001) were significantly higher in women affected. In subgroup analysis, cardiovascular risk factors were more common in participants with high BMI than in those with previous gestational diabetes.ConclusionsThe risk of MetS was 2.4-fold higher after GDM than after normal pregnancy. Cardiovascular risk factors were more common in participants with high BMI than in those with previous GDM. Multivariate analysis supported the main findings. Weight control is important in preventing MetS after delivery.