Oxidized LDL and thickness of carotid intima-media are associated with coronary atherosclerosis in middle-aged men: lower levels of oxidized LDL with statin therapy

We investigated the relation between serum lipids including oxidized LDL and the severity of coronary atherosclerosis. Serum lipids and oxidized LDL was measured in 62 men (33-66 years), who underwent diagnostic coronary angiography and sonography to measure the carotid intima-media thickness. LDL oxidation was found in chemical analyses to be due to conjugated fatty acids in cholesteryl esters and triglycerides. Regression analysis indicated that the carotid intima-media thickness and the ratio of LDL diene conjugation to LDL cholesterol (the ox-LDL:LDL ratio) were the only factors associated independently with the severity of coronary atherosclerosis. The patients with multi-vessel disease who did not use lipid lowering therapy had a 50% thicker carotid intima media (P = 0.030) and a 41% higher ox-LDL:LDL ratio (P = 0.020) than patients with normal vessels. Further, patients with multi-vessel disease on statin therapy had a 24% lower ox-LDL:LDL ratio than the subjects with multi-vessel disease who did not use lipid lowering drugs (P = 0.027), although the concentration of LDL cholesterol did not differ between the groups. This study supports the hypothesis that lipid oxidation plays a role in the development of atherosclerosis.

The effect of chiropractic care on jet lag of Finnish junior elite athletes

OBJECTIVE

To determine the effect of chiropractic care on jet lag in Finnish junior elite athletes.

SUBJECTS

Fifteen Finnish junior elite athletes.

METHODS

Through use of a table of random numbers, each athlete was assigned by sex to one of 3 groups: chiropractic adjustment, sham adjustment, or control. As needed, the chiropractic adjustment group athletes (n = 5) were adjusted on a daily basis by licensed chiropractors using a toggle/recoil procedure. The sham adjustment group athletes (n = 5) received sham adjustments on a daily basis by licensed chiropractors. The control group athletes (n = 5) were not adjusted or sham-adjusted but participated in all test protocols. Sleep, jet lag, chiropractic, and mood data (the last acquired through use of the Profile of Mood States) were collected on a daily basis for 18 consecutive days.

RESULTS

Repeated-measures analyses of variance (3 x 2) of total mood disturbance scores and heart rate variables indicated that there were no significant (.05 level) between-group differences. Sleep data were analyzed through use of a 3 x 2, repeated-measures multivariate analysis of variance. Pillai's trace indicated that there were no between-group differences. Self-assessment of jet lag by participants after traveling to Georgia and after returning to Finland showed no between-group differences.

CONCLUSIONS

It was concluded that chiropractic care did not reduce the effects of jet lag.

Reduced oxidized low-density lipoprotein after weight reduction in obese premenopausal women

BACKGROUND

Several studies support the hypothesis that oxidation of low-density lipoprotein (LDL) promotes atherogenesis. Obesity is one of the risk factors of atherosclerosis, but it is not known whether obesity is related to LDL oxidation.

OBJECTIVE AND DESIGN

We investigated the effect of weight reduction and subsequent weight maintenance program on LDL oxidation in 77 obese premenopausal women (BMI 29-46 kg/m(2)). Another group of seven obese women served as a control group. Oxidized LDL was measured as baseline concentration of conjugated dienes in LDL lipids (ox-LDL). The weight reduction was performed in 12 weeks, using a very-low-energy diet.

RESULTS

The mean weight loss was 13 kg (92 vs 79 kg). During weight reduction, the concentration of LDL cholesterol decreased by 11%, the concentration of ox-LDL decreased by 40%, and the ratio of ox-LDL to LDL by 33%. The concentration of LDL antioxidant capacity (LDL-TRAP) decreased by 8%, but the decrease was caused by the decrease in LDL. The concentration of LDL, ox-LDL or LDL-TRAP did not change in the control group. The weight reduction correlated with the decrease of ox-LDL. During the subsequent 9 month weight maintenance programme, the concentrations of serum LDL (10%), ox-LDL (11%), LDL-TRAP (29%), and the ratio of LDL-TRAP to LDL (21%) decreased.

CONCLUSION

This study strengthens the evidence that the risk of atherogenesis is influenced favourably by weight reduction in obese women. This risk reduction is associated with a reduced oxidation of LDL.

Reduced mildly oxidized LDL in young female athletes

We investigated the effect of physical activity and sports participation on LDL oxidation in vivo and on lipid risk factors in 183 teenage girls (9-15 years): 64 gymnasts, 61 runners, and 58 controls. Oxidized LDL was measured as baseline levels of conjugated dienes in LDL lipids (ox-LDL). The gymnasts had a 15% lower ratio of LDL conjugated dienes to LDL cholesterol (ox-LDL:LDL ratio, P = 0.0052) compared to controls, and the difference persisted when the body mass index was included as a covariate (ANCOVA, P = 0.013). Also, the gymnasts had a 12% higher ratio of HDL cholesterol to total cholesterol than the controls (ANCOVA, P = 0.046). There were no differences in the other common lipid risk factors between the groups. The ox-LDL:LDL ratio correlated negatively with HDL cholesterol (r = -0.23, P=0.0021) and with physical activity METs (multiples of resting metabolic rate) (r = -0.21, P=0.0040). Our study strengthens the evidence that the atherogenic risk is influenced favourably by physical exercise and sporting activities as early as in adolescents. This risk reduction is associated with lower mildly oxidized LDL in adolescent girls.

Evaluation of autoantibodies against oxidized LDL and antioxidant status in top soccer and basketball players after 4 months of competition

Antioxidant status and titers of autoantibodies against oxidized low-density lipoproteins (ox-LDL-Ab) were investigated in top soccer (S; n = 21, age 24.6 +/- 4.3 years) and basketball (B; n 3,000 mIU/ml) in ox-LDL-Ab were found in half the players (12S and 4B) with a maximum reaching 6000 mIU/ml (normal range: 200-600 mIU/ml), showing an in vivo LDL oxidation. There was no correlation between ox-LDL-Ab titers and chlolesterol, LDL cholesterol, or antioxidant levels. Nevertheless, plasma vitamin C concentration was lower in athletes having high levels of ox-LDL-Ab when compared with those with normal levels (8.49 +/- 3.14 mirogram/ml vs. 10.39 +/- 2.55 microgram/ml), but this difference was not statistically significant. In conclusion, our data suggest that potential atherogenic and cardiovascular risks as reflected by high titers in ox-LDL-Ab may exist in some top athletes despite a nonaltered antioxidant status.

Comparison of physiological strain and muscular performance of athletes during two intermittent running exercises at the velocity associated with VO2max

The purpose of this study was to examine physiological strain and muscular performance responses of well trained athletes during two intermittent running exercise protocols at the velocity associated with VO2max. Ten national level middle-distance runners (VO2max 69.4+/-5.1; mean+/-SD) performed in random order two 28 min treadmill running exercises: 14 bouts of 60 s runs with 60 s rest (IR60) and 7 bouts of 120 s runs with 120 s rest between each run (IR120). During IR120 peak oxygen uptake (12%), peak heart rate (3%) and peak blood lactate (79%) were significantly higher than during IR60 (P< 0.001) and almost the same as in the VO2max test. In IR120 the relative aerobic energy release calculated on the basis of the accumulated oxygen deficit during the running bouts was significantly higher than in IR60 (81.5+/-2.7 vs. 70.2+/-2.6%, P<0.001) likewise the sum oxygen consumption during the 14 min running (P< 0.001), while during the 14 min recovery it was as much lower (P < 0.001). There were no changes either during or between the IR60 and IR120 protocols with regard to the muscular performance parameters, stride length or height of maximal vertical jumps. In conclusion, during intermittent running at the velocity associated with VO2max doubling the duration of work and rest bouts from 60 s to 120s increased the physiological strain of well trained athletes to the same level as at exhaustion in the VO2max test but the muscular performance variables were not influenced.

HMG CoA reductase inhibitors are related to improved systemic endothelial function in coronary artery disease

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase (statins) may enhance vascular endothelial function independent of their cholesterol lowering effect. To test this hypothesis, we surveyed two groups of patients (age 55+/-7, mean+/-SD) with coronary artery disease that were matched for age, blood pressure and serum lipid levels. Group 1 comprised 23 men without lipid-lowering medication and Group 2 included 22 patients with ongoing HMG CoA reductase inhibitor medication. Flow-mediated (endothelium-dependent) arterial dilatation (FMD) and nitrate-mediated (smooth muscle dependent) dilatation (NMD) were measured in the brachial artery using high resolution ultrasound. FMD was considerably higher in group 2 (4.3+/-2.6 vs. 2.6+/-2.8%; P<0.05). In multivariate regression model, statin use was the only significant (P<0.05) predictor of FMD. In all subjects, FMD correlated with statin dose (P<0.05 for trend). NMD was non-significantly higher in group 2 (11.4+/-5.0 vs. 9.0+/-4.2%, P=0. 08). We conclude that patients with established coronary artery disease on HMG CoA reductase inhibitor therapy have better vascular endothelial function than similar patients without the medication. These data provide further support for the idea that HMG CoA reductase inhibitors enhance endothelial function independent of their lipid-lowering effects. This may suggest that these drugs could be beneficial in secondary prevention of coronary artery disease regardless of the serum cholesterol concentration.

Serum hormone and myocellular protein recovery after intermittent runs at the velocity associated with VO(2max)

The responses of serum myocellular proteins and hormones to exercise were studied in ten well-trained middle-distance runners [maximal oxygen consumption (VO(2max)) = 69.4 (5.1) ml x kg(-1) x min(-1)] during 3 recovery days and compared to various measures of physical performance. The purpose was to establish the duration of recovery from typical intermittent middle-distance running exercises. The subjects performed, in random, order two 28-min treadmill running exercises at a velocity associated with VO(2max): 14 bouts of 60-s runs with 60 s of rest between each run (IR(60)) and 7 bouts of 120-s runs with 120 s of rest between each run (IR(120)). Before the exercises (pre- exercise), 2 h after, and 1, 2 and 3 days after the exercises, the same series of measurements were performed, including those for serum levels of the myocellular proteins creatine kinase, myoglobin and carbonic anhydrase III (S-CK, S-Mb and S-CA III, respectively), serum hormones testosterone, Luteinizing hormone, follicle-stimulating hormone and cortisol (S-testosterone, S-LH, S-FSH and S-cortisol, respectively) and various performance parameters: maximal vertical jump height (CMJ) and stride length, heart rate and ratings of perceived exertion during an 8-min run at 15 km x h(-1) (SL(15 km x h(-1)), HR(15 km x h(-1)) and RPE(15 km x h(-1)), respectively). Two hours after the end of both exercise bouts the concentration of each measured serum protein had increased significantly (P < 0.001) compared to the pre-exercise level, but there were no changes in SL(15 km x h(-1)) or CMJ. During the recovery days only S-CK was significantly raised (P < 0.01), concomitant with a decrease in CMJ (P < 0.01) and an increase in RPE(15 km x h(-1)) (P < 0.01). Hormone levels remained unchanged compared to the pre-exercise levels during the recovery days and there were no significant differences between the two exercise bouts in any of the observed post-exercise day-to-day responses. With the exception of S-CK, after IR(120) the post-exercise responses returned to their pre-exercise levels within the 3 days of recovery. The present findings suggest that a single 28-min intermittent middle-distance running exercise does not induce changes in serum hormones of well-trained runners during recovery over 3 days, while changes in S-CK, CMJ and RPE(15 km x h(-1)) indicate that 2-3 days of light training may be needed before the recovery at muscle level is complete.

Effects of ascorbic acid and carbohydrate ingestion on exercise induced oxidative stress

BACKGROUND

We studied the effects of supplementation of vitamin C and carbohydrate on acute exercise-induced lipid peroxidation.

METHODS

EXPERIMENTAL DESIGN

two randomized controlled trials.

PARTICIPANTS

17 endurance athletes.

INTERVENTIONS

in study I, nine athletes repeated twice a 10.5-km maximal run and ingested in a randomized single-blind order either 2.0 g vitamin C or placebo. In study II, eight athletes repeated twice a 27-km maximal run and ingested in randomly either 105 g carbohydrate or placebo. Venous blood samples were taken before the exercise, immediately after the exercise, and after a recovery period of 90 min (study I) or 120 min (study II).

MEASURE

serum diene conjugation, lipid peroxidation.

RESULTS

In study I, there was no difference in serum diene conjugation between the trials during exercise (pre- vs post-exercise). However, during the recovery period (post-exercise vs recovery sample) serum diene conjugation concentration decreased by 11% in the vitamin C trial but not in placebo (p = 0.028). In study II, there was no difference between the carbohydrate and placebo trials.

CONCLUSIONS

Vitamin C and carbohydrate do not prevent exercise-induced increase in oxidative stress, but vitamin C, being a potent aqueous antioxidant, seems to decrease the levels of diene conjugation during recovery after exercise. The clinical significance of this phenomenon needs further evaluation.

Baseline diene conjugation in LDL lipids as a direct measure of in vivo LDL oxidation

OBJECTIVES

To additionally test validity of the recently developed method (LDL baseline diene conjugation, LDL-BDC) for determination of circulating oxidized LDL.

DESIGN AND METHODS

A detailed comparison between the ultracentrifugation and heparin precipitation methods for LDL isolation was performed to test suitability of the fast precipitation method. Validity of LDL-BDC as an indicator of circulating oxidized LDL was tested by comparing LDL-BDC to results obtained by the immunological autoantibody method.

RESULTS

BDC values in LDL isolated by heparin precipitation did not differ from those isolated by sequential ultracentrifugation. While highest amount of diene conjugation was found in LDL (40% of that in serum), substantial amounts were also found in VLDL (31%) and HDL (25%). When analyzed in the same samples, assays for the titer of autoantibodies against oxidized LDL and LDL-BDC were found to show good correlation (r = 0.57, p = 0.001, n = 29).

CONCLUSIONS

These results, together with thus far conducted studies on clinical applicability of the method, indicate that LDL-BDC is a promising candidate in search for a method for estimation of LDL oxidation in vivo.

Low LDL oxidation in veteran endurance athletes

The 'oxidation hypothesis' states that oxidative modification of low-density lipoprotein (LDL) is important in the pathogenesis of the atherosclerotic lesion. Physical exercise has been reported to reduce clinical manifestations of atherosclerosis. We compared the effects of aerobic physical exercise history on oxidation characteristics of plasma LDL at rest in non-smoking male veteran endurance athletes (n= 15) and control subjects (n= 16). As an indicator of LDL oxidation we used a method which provides an estimate of LDL diene conjugation in vivo. The athletes had lower plasma LDL cholesterol diene conjugation (P=0.003). They also had lower cholesterol, lower LDL and higher high-density lipoprotein (HDL) cholesterol. Intensive physical exercise energy expenditure correlated inversely with LDL diene conjugation (r=-0.41, P= 0.021). We conclude that participation in intensive physical exercise training is associated with reduced plasma LDL fraction oxidation as reflected by LDL diene conjugation. This finding may have relevance for studies aiming to explain the variation in occurrence of ischemic heart disease.

Effects of a long acting somatostatin analog on pituitary, adrenal, and testicular function during rest and acute exercise: unexpected stimulation of testosterone secretion

The purpose of this study was to delineate the possible endocrine effects of exercise-induced GH secretion. Twelve healthy adult males were studied during short (20 min) and subsequent prolonged (2 h) physical exercise and recovery period (2 h), both after injection of a long acting somatostatin analog [Sandostatin (ST); 0.1 or 0.05 mg, sc] and after a control saline injection. Additional subjects were studied during rest with similar injections of ST (0.1 mg) and saline (n = 7) or using a lower ST dose (0.01 mg; n = 6). Several venous blood samples were taken during the trials and analyzed for selected hormones, monitoring pituitary, testicular, and adrenal functions. ST injection blocked the serum GH response to short term maximal bicycle ergometer exercise, but not to the following prolonged bicycle exercise. No relationship of the exercise-associated GH increase to the concomitant endocrine responses of the adrenals and testes was observed. Unexpectedly, the higher ST doses (0.1 and 0.05 mg) increased the mean levels of serum testosterone by 18-25% in both exercise (P = 0.0017) and rest trials (P < 0.0001), respectively. ST did not affect the levels of LH, FSH, or cortisol. ST slightly increased serum sex hormone-binding globulin (3%; P = 0.021) and albumin (4%; P = 0.017) concentrations, but not that of free testosterone. Because the testosterone response to somatostatin was fast and without a simultaneous increase in LH, it was consistent with a direct testicular response. The explanation for this novel ST effect remains obscure, but it may be due to modulation of some paracrine mechanisms inhibiting testicular steroidogenesis.

Measurement of serum lipid peroxidation during exercise using three different methods: diene conjugation, thiobarbituric acid reactive material and fluorescent chromolipids

Serum lipid peroxidation was measured by three different methods (diene conjugation, DC; thiobarbituric acid reactive material, TBARM; and fluorescent chromolipids, FC) during physical exercise of different duration. The aim of the study was to investigate which of the three methods is the most representative in measuring oxidative stress after physiological stimulus (physical exercise) in man. In general, diene conjugation is a measure of early events of lipid peroxidation reactions, TBARM measures end products of lipid peroxidation and FC are products formed by reaction of end products of lipid peroxidation with the amino groups. In trial I, 8 subjects ran 1 km with maximal speed; in trial II, 7 subjects ran 10 km with maximal speed; in trial III, 9 subjects ran 27 km with maximal speed, and in trial IV, 5 subjects cycled 8 days in competition, altogether 1061 km biking. In each trial venous blood samples were taken before and immediately after the exercise. In trials II, III, and IV serum DC concentration increased by 14% (P < 0.05), 11% (P < 0.01), and 25% (P < 0.05), respectively, during the exercise. FC or TBARM did not change in the trials. We conclude that DC as a measure of the early phase of lipid peroxidation may be less affected by protective antioxidant functions than FC and TBARM methods, which both measure end products of lipid peroxidation. Therefore, DC may be the most sensitive of the three methods to estimate serum lipid peroxidation induced by exercise in man.(ABSTRACT TRUNCATED AT 250 WORDS)