Ilkka Penttilä

Serum fatty acids, apolipoproteins, selenium and vitamin antioxidants and the risk of death from coronary artery disease.

The independent association of serum concentrations of saturated and polyunsaturated fatty acids, apolipoproteins AI and B, selenium and vitamins A and E with the risk of death from coronary artery disease (CAD) was studied in 92 persons with no previous myocardial infarction, who died from CAD during a 5-year follow-up, and their 92 1-to-1 matched controls. Case-control pairs came from a randomly drawn population sample of approximately 12,000 persons aged 30 to 64 years from 2 provinces of eastern Finland, an area with exceptionally high CAD mortality. Control subjects were matched for sex, age, serum cholesterol, mean arterial pressure, tobacco consumption and history of cardiovascular diseases. The persons who died of CAD had lower serum esterified arachidonic acid concentrations before follow-up than the control subjects (41 vs 48 mg/liter, p = 0.05), and this difference was greater for pairs with no chest pain on effort (36 vs 50 mg/liter, p less than 0.05). The adjusted risk of CAD death in persons with a serum polyunsaturated to saturated (P/S) fatty acid ratio of 0.28 or less (in the lowest tertile) was 3.5-fold (95% confidence interval [CI], 1.5 to 8.2) compared with those with higher serum P/s ratios in a multivariate logistic model and 5.6-fold (95% CI 1.6 to 19.8) for pairs with no chest pain on effort. A low serum apolipoprotein AI concentration (1.25 g/liter or less, in the lowest tertile) was associated with a 2.5-fold (95% CI 1.1 to 5.7) adjusted risk of CAD death among the chest pain-free persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Stromelysin-1 and Interleukin-6 Gene Promoter Polymorphisms Are Determinants of Asymptomatic Carotid Artery Atherosclerosis

The functional 5A/6A polymorphism of the stromelysin-1 promoter has been implicated as a potential genetic marker for the progression of angiographically determined atherosclerosis in patients with coronary artery disease. Recently, a novel interleukin-6 (IL-6) gene functional G/C polymorphism at −174 in the promoter has also been reported. In this study, we analyzed the relation of these two polymorphisms with carotid artery atherosclerosis in 109 randomly selected, middle-aged men without exercise-induced ischemia. Atherosclerosis was quantified as intima-media thickness (IMT) by high-resolution ultrasonography. Univariately, stromelysin genotype was significantly (P =0.015) associated with IMT, and this relation remained (P =0.033) after adjustments for age, cardiorespiratory fitness, body mass index, smoking, LDL cholesterol, and systolic blood pressure and for sonographers. The 5A/6A polymorphism independently explained 7% of the variance in carotid bifurcation IMT. The IL-6 polymorphism was also significantly associated (P =0.036) with increased IMT, with men homozygous for the G allele having IMT that was 11% greater than men homozygous for the C allele. Men who were homozygous for both the 6A and G alleles had an covariate adjusted IMT that was 36% greater than men who were homozygous for neither allele (P <0.003). These data suggest that genetic factors that predispose to reduced matrix remodeling (stromelysin 6A allele) and to increased inflammation (IL-6 G allele) combine to increase susceptibility for intima-media thickening in the carotid bifurcation, a predilection site for atherosclerosis.

Effects of Aerobic Physical Exercise on Inflammation and Atherosclerosis in Men: The DNASCO Study: A Six-Year Randomized, Controlled Trial

Context Few data address whether exercise slows progression of atherosclerosis. Contribution In this 6-year trial, middle-aged Finnish men were randomly assigned to progressive aerobic exercise or usual activity. Progressive exercise targeted 45- to 60-minute sessions 5 times weekly of activities such as walking, jogging, or cycling. Exercisers improved their ventilatory aerobic threshold and decreased their resting heart rate. However, intimamedia thickness of the carotid artery measured by ultrasonography did not differ between groups, except in a subgroup of men not taking statins. Implications Aerobic exercise did not slow progression of atherosclerosis in middle-aged men, except for those not taking statins. The Editors Observational studies suggest that physical inactivity and low cardiorespiratory fitness predict atherosclerotic cardiovascular disease (CVD) (1-6) and that an increase in habitual physical activity (7) and cardiorespiratory fitness (8) are associated with decreased mortality. These findings are the basis for a general public health message recommending a minimum of 30 minutes of regular moderate exercise per day (9). While exercise training at a weekly energy expenditure of 1500 kcal or more attenuates the progression of angiographically established coronary atherosclerosis (10), there are no data from randomized, controlled trials on the antiatherosclerotic effects of regular physical exercise in a general population. Moreover, studies using CVD mortality as an end point would require enormous sample sizes, and ethical issues limit the use of intracoronary arteriography in asymptomatic persons. Ultrasonographically assessed intimamedia thickness of the carotid arteries allows noninvasive investigation of preclinical stages of atherosclerosis in unselected human populations (11). Intimamedia thickness has been used as a surrogate end point for clinical coronary events (12) and in clinical trials (13). We previously reported an inverse association of cardiorespiratory fitness to carotid artery intimamedia thickness (14) and its progression rate (15). Clinical trials have revealed several plausible antiatherogenic mechanisms of exercise, such as favorable changes in plasma lipid levels, blood pressure, body adiposity, plasma glucose levels, insulin levels, and hemostatic factors (9). However, these effects only partially explain the inverse association between physical activity and CVD. Inflammation plays a major role in the pathogenesis of atherosclerosis (16). High-sensitivity C-reactive protein (CRP) levels are a marker of inflammation, and even slightly elevated serum levels of CRP predict clinical manifestations of atherosclerotic CVD (17). Short-term uncontrolled studies suggest that physical activity has a beneficial impact on the inflammatory reaction (18). In the DNASCO (DNA Polymorphism and Carotid Atherosclerosis) Study, a 6-year randomized, controlled trial in a population-based sample of middle-aged men, we investigated the effect of regular long-term physical exercise on chronic low-grade inflammation and the progression of atherosclerosis, as assessed by noninvasive repeated measurements of carotid artery intimamedia thickness. Methods Study Design The primary end point was progression of the mean intimamedia thickness of the carotid artery in a 6-year randomized, controlled trial of an exercise intervention. The Research Ethics Committee of the Kuopio University Hospital approved the protocol. Figure 1 shows the flow of patients through the study during recruitment, intervention allocation, and follow-up to data analysis. Participants were a random sample obtained from the population registry. Men were sent a letter inviting them to participate, and all participants provided signed informed consent. Forty-eight men did not respond to the invitation, and another 40 men did not present to the laboratory for the baseline examinations; no data are available on the characteristics of these 88 men. Figure 1. Flow of participants through the study. In 1994 to 1995, 140 men were randomly assigned to the exercise group (n= 70) or the control group (n= 70) by selecting a sealed, opaque envelope that contained the group assignment. The envelopes appeared identical, and an equal number was reserved for both study groups. Exclusion criteria were diseases or physical conditions restricting participation in regular exercise and malignant diseases or mental states restricting cooperation. During the 6-year intervention, 20 men (9 in the exercise group and 11 in the control group) dropped out because of death (2 in the exercise group and 4 in the control group), severe diseases (4 in the control group), relocation (1 in the exercise group), or loss of motivation (6 in the exercise group and 3 in the control group). For statistical analyses, multiple imputation methods were applied to replace missing end-point values. The first dropouts, all due to death, did not take place until the third year. Table 1 shows the number of patients with common chronic diseases as well as the number of patients who received drug treatment during the intervention. Table 1. Patients with Chronic Diseases and Those Who Received Drug Treatment during the Intervention Primary End Point Carotid artery atherosclerosis was measured ultrasonographically as the mean intimamedia thickness. The same certified sonographer performed all biannual scannings during the 6 years, and we report results from 6 study visits (at baseline and at years 2 through 6). An ultrasound device with a high-resolution 10-MHz transducer was used, following a standardized and pretested protocol, and the scannings were recorded on super VHS videotape. The calibration of the ultrasound unit was routinely checked. Another certified sonographer measured intimamedia thickness of the far wall of the right carotid artery. Both sonographers were blinded to the randomization status of the study participants. The measurement of intimamedia thickness extended to the longest wall region where the lumenintimal and mediaadventitial boundaries could be clearly identified by an automated edge-detection program on the basis of active contour (19). The mean intimamedia thickness of the traced region was used for the statistical analysis. Cardiorespiratory Performance, Exercise Electrocardiography, and Blood Pressure To allow assessment of changes in cardiorespiratory fitness and to monitor exercise habits more objectively, all participants annually performed a bicycle ergospirometry test. The patients electrocardiograms were continuously monitored and recorded every minute during the test and up to 7 minutes after exercise. An exercise physiologist visually defined ventilatory aerobic threshold as the first nonlinear increase of ventilation in the ergospirometry test. A trained nurse measured blood pressure annually. After the men had been lying on an examination bed for 45 minutes, blood pressure was measured by a random-zero mercury sphygmomanometer, according to the MONICA (MONItoring CArdiovascular disease) protocol (20). Exercise Intervention The men in the exercise group were prescribed walking, jogging, cross-country skiing, swimming, and cycling as the main methods of aerobic exercise. The program was progressive: During the first 3 months, the men were advised to exercise 3 times per week for 30 to 45 minutes per session. Thereafter, they were asked to exercise 5 times per week for 45 to 60 minutes per session. Exercise intensity was determined individually, and modified when necessary, to correspond to ventilatory threshold level, that is, 40% to 60% of maximal oxygen uptake. The men in the exercise group were given heart rate monitors to help them adhere to the prescribed training heart rate. The participants performed the program on their own and were asked to report each exercise session in a diary, which was checked in a face-to-face meeting with an exercise physiologist at 6-month intervals. In accordance with the regulations of the Ethics Committee, men in the control group were allowed to choose whether to engage in physical exercise, but no efforts were made to change their habitual activity. Accordingly, the participants in the control group were not asked to report their exercise habits in a diary. Biochemical Analyses Blood sampling and serum assays for fasting cholesterol and its subfractions have been described elsewhere (21). Serum high-sensitivity CRP levels were measured by a commercial immunoassay (IMMULITE 2000 High-Sensitivity CRP, Diagnostic Products Corp., Los Angeles, California) using the IMMULITE 2000 Analyzer (Diagnostic Products Corp.). Other Methods Participants were asked about smoking habits and were classified as smokers or nonsmokers on the basis of current smoking status. Dietary energy and fat intake were assessed annually with 4-day food records (3 weekdays and Sunday). Portion sizes were estimated by using a picture booklet or household measurement units. Records were analyzed by using MicroNutrica software (The Social Insurance Institution, Turku, Finland), based on nutrient files from Finnish food analyses (22). Statistical Analysis An estimate of the sample size (2n= 114) was based on assumptions about the reduction (25%) in the rate of progression of intimamedia thickness between the exercise and control groups, the duration of the trial (6 years), the number of equally spaced end-point measurements (7), variability due to participants and measurement error (0.4 mm), and dropout rate (25%). The significance level was 5%, with a power of 90% (23). Statistical analyses were based primarily on an intention-to-treat approach with 140 participants. For secondary analyses, patients treated with cholesterol synthesis inhibitors, which are known to have a powerful antiatherosclerotic effect (24), were excluded (6 in the exercise group and 9 in the control group) (Figure 1). Multiple imputation methods available in S-PLUS

Relationship between serum lipids, lipoproteins and pseudocholinesterase during organophosphate poisoning in rabbits

The activities of serum pseudocholinesterase, lecithin: cholesterol acyltransferase (LCAT) and gamma-glutamyltransferase in rabbits were investigated before and after dichlorvos administration in vivo. The effects of this organophosphate on some serum lipids and lipoprotein fractions were also determined. LCAT activity remained almost unaffected after organophosphate administration. However, serum gamma-glutamyltransferase and pseudocholinesterase activities markedly decreased. Dichlorvos markedly lowered both serum low density lipoprotein (LDL) and cholesterol contents, whereas high density lipoprotein (HDL) concentration increased and very low density lipoprotein (VLDL) remained unaffected. Triglycerides as well as esterified fatty acids increased significantly but the statistical changes in free fatty acid concentrations were not significant, because individual variations in fatty acid concentrations were high.

A Method for Routine Assay of Plasma Ascorbic Acid Using High-Performance Liquid Chromatography

Abstract A description is given of a specific and simple liquid chromatographic method for the determination of vitamin C (ascorbic acid) in protein-free plasma. The analysis time per sample is only 4 min, the retention time of ascorbic acid being 2.4 min. A detection limit of 0.3 mg/l (1.7 μmol/l) was achieved using the routine attenuation of the detector. The day-to-day coefficient of variation is less than 7.2% at a physiological level and the within-day variation is less than 4.7%. The method recovered 101% (mean) of ascorbic acid supplemented to plasma. Mean plasma ascorbic acid concentration was 11.1 mg/l (63 μmol/l) in healthy adult volunteers, whereas considerably lower values were found in a group of randomly selected 54-year-old-men.

Abnormal hematologic profiles in elite cross-country skiers: blood doping or?

ObjectiveThere is widespread public concern about fairness in sports. Blood doping undermines fairness and places athletes health at risk. The purpose of this study was to examine the prevalence of abnormal hematologic profiles in elite cross-country skiers, which may indicate a high probability of blood doping. Setting and ParticipantsSamples were obtained as part of routine International Ski Federation blood testing procedures from participants at the World Ski Championships. Sixty-eight percent of all skiers and 92% of those finishing in the top 10 places were tested. Main Outcome MeasuresUsing flow cytometry, we analyzed erythrocyte and reticulocyte indices. Reference values were from the 1989 Nordic Ski World Championships data set and the International Olympic Committee Erythropoietin 2000 project. ResultsOf the skiers tested and finishing within the top 50 places in the competitions, 17% had “highly abnormal” hematologic profiles, 19% had “abnormal” values, and 64% were normal. Fifty percent of medal winners and 33% of those finishing from 4th to 10th place had highly abnormal hematologic profiles. In contrast, only 3% of skiers finishing from 41st to 50th place had highly abnormal values. ConclusionsThese data suggest that blood doping is both prevalent and effective in cross-country ski racing, and current testing programs for blood doping are ineffective. It is unlikely that blood doping is less common in other endurance sports. Ramifications of doping affect not only elite athletes who may feel compelled to risk their health but also the general population, particularly young people.

Relationship Between Lipid Peroxidation and Plasma Fibrinogen in Middle-Aged Men

The relationship between lipid peroxidation (plasma malondialdehyde [MDA] concentration) and plasma fibrinogen level was analyzed in 144 men, aged 53-62 years. MDA was measured colorimetrically and fibrinogen with the thrombin method. Mean plasma MDA concentration was 12.6 (SD 1.2) micromol/L, plasma fibrinogen level 2.91 (0.47) g/L, and body mass index 27.1 (3.5) kg/m(2). Prevalence of smoking was 17%. MDA correlated moderately with fibrinogen. Both MDA and fibrinogen correlated positively with waist hip ratio (WHR) and blood leukocyte count, but inversely with VO(2)max. Both MDA and fibrinogen levels were higher in smokers than in non-smokers (p<0. 01). In multiple stepwise regression analysis, plasma MDA, VO(2)max, smoking, and leukocyte count explained 38.1% of the variance in plasma fibrinogen level, with the individual contributions reaching 20.6%, 9.7%, 5.5%, and 2.3%, respectively. WHR, serum triglycerides, and age did not enter the model. These data suggest that increased lipid peroxidation is associated with elevated plasma fibrinogen level in middle-aged men.

Dose-Response Relationships in Blood Lipids during Moderate Freshwater Fish Diet

Fish and fish oils are known to counteract coronary heart disease risk factors. We have previously showed that eating moderate amounts of freshwater fish modifies lipid and prostanoid metabolism in healthy students. In this study, the dose response relationship was clarified. One hundred male students took part and were randomly divided into control and four fish diet groups with different fish diets. Hematological, serum lipid and vitamin E and A analyses were performed. Already 1.5 fish containing meals per week increased n-3 to n-6 ratio of fatty acids in erythrocyte ghost phosphatidylethanolamine. The serum triglyceride and apolipoprotein B concentration fell significantly in the group eating 3.8 fish containing meals a week for 12 weeks. At two lower doses (1.5 and 2.3 meals/week) the tendency to lower values was already seen. No significant changes were observed in the serum cholesterol, apolipoprotein A1 and vitamin E and A concentrations. The hematological variables also remained unchanged. The results show that moderate amounts of fish as a constituent of normal diet have beneficial effects on lipid metabolism.

Separation of the apoprotein components of human serum high density lipoprotein: chromatofocusing, a new simple technique

The high-density lipoproteins (HDL) are a heterogeneous group of particles operationally defined as those lipoproteins isolated between the densities of 1.063 and 1.210 g/ml. About 50% of HDL mass is protein, 30% is phospholipid, and 20% is cholesterol [l]. Of the several apolipoproteins present, apo A-I and apo A-II are major components; minor polypeptides include apo C-I, apo C-II, apo C-III, apo D and apo E [2-41. Apoprotein A-I and apoprotein A-II constitute about 90% of total HDL protein, with a ratio of apo A-I to APO-II of 3 : 1 in both HDL, and HDL, [5]. Apoprotein C is present in the HDL density range of humans in small amounts, and comprises 5-10% of HDL, protein, and l-2% of HDL, protein [6]. The most used methods to separate different apoproteins from HDL are gel filtration combined with DEAE cellulose ion-exchange chromatography [7,8]. In this study, chromatofocusing of human serum apoHDL with and without urea has been employed to fractionate different apoproteins, and slab gel electrophoresis has been performed to study the purity of fractions.

Lipids and apolipoproteins A-I, B and C-II and different rapid weight loss programs (weight lifters, wrestlers boxers and judokas)

Apolipoproteins A-I, B, C-II and lipids were studied before and after rapid weight loss schedules. The compared groups were all athletic. Apolipoproteins were determined by electroimmunoassay methods using apoproteins purified by chromatofocusing column method. Dextran T10 was shown to increase rocket height in ApoB assay. Over 1% Dextran concentrations gave poor response. The linearity during calibration was from 0.3 to 3.0 g ApoB/l. Baseline values of ApoA-I in wrestlers, weightlifters, boxers and judokas were slightly higher as compared to normal population; ApoB was clearly reduced (mean value of 690 mg/l). Weight-loss was significant in each experimental group; mean value of 4.1% in active exercise, sauna and diuretic groups together. Compared as the whole sportsmen group in passive weight loss (or sauna) and diuretic groups the most pronounced changes were seen to be elevated apoprotein concentrations, whereas weight-loss by active rapid exercise resulted no apoprotein changes, but instead an increment in HDL cholesterol and decrement in triglycerides, respectively. The present study was the first to evaluate baseline values of apoproteins A-I, B and C-II in first class athletes and also the possible changes in these and lipid values in rapid weight-loss practices.