Exercise does not change high-density lipoprotein cholesterol in women after ten weeks of training

The effect of a 12-week moderate intensity interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah: a cohort study

Aim. To examine the impact of interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah unable or unwilling to quit smoking. Methods. Thirty-five participants performed an interval training (2 : 1 work : rest ratio) 3 times a week for 12 weeks at an intensity of 70% of VO₂max. All subjects were subjected to a biochemical test session before and after the training program. Results. The increase of total antioxidant status (TAS), glutathione peroxidase (GPx), and α-tocopherol, is significant only for cigarette smokers (CS) and hookah smokers (HS) groups. The decrease of malondialdehyde (MDA) and the increase of glutathione reductase (GR) are more pronounced in smokers groups compared to those of nonsmokers (NS). Superoxide dismutase (SOD) increases in NS, CS, and HS groups by 10.1%, 19.5%, and 13.3%, respectively (P < 0.001). Likewise, a significant improvement of high-density lipoprotein cholesterol (HDL-C) and TC/HDL-C ratio was observed in CS and HS groups (P < 0.05). Conclusion. Although the interval training program does not have a significant effect on blood lipid levels, it seems to be very beneficial in the defense and prevention programs of oxidative stress.

Effects of an off-site walking program on energy expenditure, serum lipids, and glucose metabolism in middle-aged women

The present study aims to identify the effects of systematic walking on exercise energy expenditure (EEE) and blood profiles in middle-aged women. Fifty-two female nurse managers, aged 32 to 57 years (42.0 +/- 6.2), were randomly assigned to an intervention group (IG) and a control group (CG) for a 12-week study of the walking program. EEE was measured using a microelectronic device. Blood profiles were assessed before and after the walking program. The mean EEE (kcal/kg/d) in the IG and CG was 4.73 +/- 1.02 and 3.88 +/- 0.81 (P = 0.01), indicating an increase of 1.17 +/- 0.98 and 0.46 +/- 0.68 from baseline (P = 0.01), respectively. The mean change in high-density lipoprotein cholesterol in the IG and CG was 1.8 +/- 8.3 mg/dL and -2.9 +/- 7.0 mg/dL (P = 0.051); that in insulin was -4.5 +/- 7.5 microU/dL and -0.6 +/- 4.3 microU/dL (P = 0.046), respectively. These results show that systematic walking increases EEE and improves blood profiles.

Blood lipid and lipoprotein adaptations to exercise: a quantitative analysis

Dose-response relationships between exercise training volume and blood lipid changes suggest that exercise can favourably alter blood lipids at low training volumes, although the effects may not be observable until certain exercise thresholds are met. The thresholds established from cross-sectional literature occur at training volumes of 24 to 32 km (15 to 20 miles) per week of brisk walking or jogging and elicit between 1200 to 2200 kcal/wk. This range of weekly energy expenditure is associated with 2 to 3 mg/dl increases in high-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) reductions of 8 to 20 mg/dl. Evidence from cross-sectional studies indicates that greater changes in HDL-C levels can be expected with additional increases in exercise training volume. HDL-C and TG changes are often observed after training regimens requiring energy expenditures similar to those characterised from cross-sectional data. Training programmes that elicit 1200 to 2200 kcal/wk in exercise are often effective at elevating HDL-C levels from 2 to 8 mg/dl, and lowering TG levels by 5 to 38 mg/dl. Exercise training seldom alters total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C). However, this range of weekly exercise energy expenditure is also associated with TC and LDL-C reductions when they are reported. The frequency and extent to which most of these lipid changes are reported are similar in both genders, with the exception of TG. Thus, for most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with weekly energy expenditures of 1200 to 2200 kcal/wk. It appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes. This amount of physical activity, performed at moderate intensities, is reasonable and attainable for most individuals and is within the American College of Sports Medicine's currently recommended range for healthy adults.

Physical activity and high density lipoprotein cholesterol levels: what is the relationship?

High density lipoprotein cholesterol (HDL-C) levels are strongly, inversely and independently associated with coronary heart disease (CHD). Increased physical activity is associated with reduced CHD mortality. This protection against CHD may partially be explained by the increase in HDL-C levels observed following aerobic exercise training. Many also agree that an exercise threshold needs to be met before such favourable changes in HDL-C metabolism can occur. Most likely, the exercise-induced changes in HDL-C are the result of the interaction amongst exercise intensity, frequency, duration of each exercise session and length of the exercise training period. Although a relative contribution of each exercise component (intensity, duration and frequency) is also likely, it has not been established. There is also substantial support for a dose-response relationship. Favourable changes in HDL-C appear to occur incrementally and reach statistical significance at approximately 7-10 miles per week or 1200 to 1600kcal. Exercise-induced changes in HDL-C may also be gender dependent. The volume of exercise required to increase HDL-C levels appears to be substantially more for women than men. This perhaps is due to higher HDL-C levels in women at baseline compared with men. However, the many other health benefits derived from increased physical activity should encourage women to participate in regular exercise regardless of the exercise effects on HDL-C levels. A practical approach in prescribing exercise for patients is to use moderate intensity exercises (70 to 80% of predicted maximal heart rate), 3 to 5 times per week, for a total of 7 to 14 miles per week. This is equivalent to approximately 1200 to 1600kcal per week. Moderate to low intensity exercise should be preferred because such exercise carries a lower risk for cardiac complications. In addition, patients are more likely to participate and sustain a lower than higher intensity exercise programme. It is also important to recognise that other modes of physical activity can also be encouraged for patients. Such activities should be associated with similar increases in HDL-C levels as long as they meet or exceed the caloric expenditure of 1200 to 1600kcal (7 to 14 miles per week of jogging).

The effects of menopausal status and exercise training on serum lipids and the activities of intravascular enzymes related to lipid transport

The study purpose was to compare the effect of exercise training on serum lipid and apolipoprotein concentrations and the activities of intravascular enzymes related to lipid transport in previously untrained eumenorrheic, premenopausal (PRM) women (n = 21; mean age, 36 +/- 3 years) and estrogen-free postmenopausal (POM) women (n = 16; mean age, 68 +/- 8 years). Subjects trained at a progressive intensity and duration (50% to 75% maximal O2 consumption [VO2max], 200 to 300 kcal/session) 4 d/wk for 12 weeks. Before and after training, VO2max, body weight, relative body fat, and fasting blood samples were obtained following 2 weeks on a standardized diet designed to maintain body weight and during the early follicular stage for the PRM group. Blood samples were analyzed for serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), the cholesterol content of the HDL3 subfraction, apolipoprotein (apo)A-I and apoB, lipoprotein(a), and the activity of lecithin:cholesterol acyltransferase (LCAT). Total and hepatic triglyceride lipase activity (HTGLA) were determined from plasma samples obtained after heparin administration. The cholesterol content of the low-density lipoprotein (LDL) and HDL2 subfractions and endothelial-bound lipoprotein lipase activity (LPLA) were calculated. A two (group) x two (time) multivariate ANOVA (MANOVA), with repeated measures for time indicated that the exercise-induced changes in physiological measurements, serum lipid or apolipoprotein concentrations, or enzyme activities did not differ between groups. Serum concentrations of TC, LDL-C, and HDL3 cholesterol, TG, and apo A-I and apoB were higher in POM women compared with the PRM group (P < .05 for all). For the combined groups, body weight and relative body fat did not change with training, but VO2max increased an average of 18.5% (P < .05). LPLA, HTGLA, and LCAT activity were unaltered with exercise training. Except for a small but significant decrease in HDL-C (-5.5%) and an elevation in apoB (4.3%; P < .05 for both), the concentrations of serum lipids and apolipoproteins did not change over the training period. We conclude that in previously untrained women, menopausal status does not influence the exercise training response of serum lipids or apolipoproteins or activities of intravascular enzymes related to lipid transport.

Body composition and serum lipids in female runners: influence of exercise level and menstrual bleeding pattern

The impact of running and menstrual disturbances on regional and total body fat distribution and serum lipids was investigated in 205 women. Body composition was measured by dual-energy X-ray absorptiometry. The total fat mass in the elite runners was approximately half of the normally active's (7.3 [0.48] kg vs. 14.3 [0.49] kg, P < 0.001) (mean [SEM]). The difference was most pronounced in the abdomen (fat percentage 9.7 [0.85]% vs. 22.0 [0.88]%, P < 0.001). The elite runners tended to have a more favourable lipid profile than the normally active (NS). A significant relation was found between lipoproteins and body fatness. In comparison with the regularly menstruating runners (n = 93), the 13 runners with amenorrhea tended to have less body fat and slightly less favourable lipid profiles (NS). In conclusion, regular exercise was associated with a low abdominal fat percentage, which may affect cardiovascular risk beneficially. Running-associated menstrual dysfunctions were not significantly related to a specific body composition or serum lipid profile.

Effect of kinesiologic recreation on plasma lipoproteins and apolipoproteins in fertile women

The effect of physical exercise on lipid and apoprotein levels was studied in 31 healthy fertile women (mean age, 39.7 +/- 2.3 years) working as civil servants and leading a mostly sedentary way of life (group 1). A control group consisted of 31 age-matched women (mean age, 39.2 +/- 2.4 years) with a comparable life-style (group 2). Group 1 performed physical exercise for at least 30 minutes three times per week. They also climbed a 500-m hill at least once per week. The study lasted 6 months, ie, from May to November 1990. Changes in maximum oxygen consumption (Vo2max), body weight, body mass index (BMI), waist to hip ratio (WHR), and levels of lipids and apolipoproteins (apos) A-1 and B were compared between the two groups of subjects. During the May-November period, the control group showed an increase in body weight (P < .02), total cholesterol, high-density lipoprotein (HDL) cholesterol, HDL3, and low-density lipoprotein (LDL) cholesterol (P < .01) and a decrease in HDL2 (P < .05). In contrast, group 1 did not show any increase in total cholesterol, and their body weight decreased (P < .01). Very-low-density lipoprotein (VLDL) cholesterol and triglyceride levels decreased (P < .02), as did LDL cholesterol and HDL2 levels (P < .05), whereas HDL cholesterol and HDL3 levels increased (P < .01). There were no statistically significant changes in WHR and apo A-1 level. The findings indicated possible seasonal variations in lipoprotein levels in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Brisk walking and serum lipid and lipoprotein variables in previously sedentary women--effect of 12 weeks of regular brisk walking followed by 12 weeks of detraining

The purpose of this study was to examine the effectiveness of brisk walking as a means of improving endurance fitness and influencing serum lipid and lipoprotein variables in previously sedentary women. Walkers (n = 10, mean (s.e.m.) age 47.3(2.0) years) followed a programme of brisk walking (mean(s.e.m.) speed 1.76(0.03) m s-1) for 12 weeks, after which the training stimulus was withdrawn. Controls (n = 10, mean(s.e.m.) age 41.6(1.2) years) maintained their habitual sedentary lifestyle throughout. Endurance fitness was determined using laboratory measures of responses to treadmill walking. Serum lipid and lipoprotein variables were determined in venous blood (12-h fasted). Body fatness was assessed by anthropometry and dietary practice using the 7-day weighed food intake technique. Measurements were repeated after 12 and 24 weeks. Brisk walking resulted in a decrease in heart rate and blood lactate concentration during exercise, while detraining was accompanied by a reversal of these changes. Changes in body mass and the ratio of circumferences at the waist and hip did not differ between groups but the sum of four skinfolds decreased with brisk walking and increased with detraining. High density lipoprotein (HDL) and HDL2 cholesterol increased with walking and decreased with detraining but no between group changes (analysis of variance, P < 0.05) were found in other lipid and lipoprotein variables. These findings suggest that regular brisk walking can improve endurance fitness and increase HDL cholesterol concentration in sedentary women.

Low-intensity endurance exercise training, plasma lipoproteins and the risk of coronary heart disease

Physically active individuals generally show a reduced risk of coronary heart disease (CHD) compared to the sedentary population. However, whether such reduction in CHD risk mainly results from the concomitant improvement in cardiorespiratory fitness or from the alterations in CHD risk factors has yet to be clearly established. Furthermore, there is still some controversy regarding the potential associations between endurance training-induced changes in metabolic variables considered as CHD risk factors (plasma glucose, insulin and lipoprotein levels) and the magnitude of improvement in cardiorespiratory fitness. From the results of several studies discussed in this article, it is proposed that prolonged endurance exercise of low intensity (approximately 50% VO2max), performed on an almost daily basis, seems to significantly improve metabolic variables considered as CHD risk factors through mechanisms that are likely to be independent from the training-related changes in cardiorespiratory fitness. The notion of 'metabolic fitness' is introduced and can be defined as the state of a ste of metabolic variables relevant to CHD risk and affected by the level of physical activity. Evidence available suggests that these metabolic variables are not closely related to the adaptation of cardiorespiratory fitness in response to exercise training. The concept of metabolic fitness has several implications for the prescription of exercise and for the primary and secondary prevention of CHD. Indeed, emphasis should not be placed on aiming at increasing VO2max through high-intensity exercise, but rather on producing a substantial increase in daily energy expenditure that will eventually lead to weight loss and related improvements in carbohydrate and lipid metabolism. Therefore, from a practical standpoint, although a 1 h daily walk may not have marked effects on cardiorespiratory fitness, it probably represents an exercise prescription that is likely to substantially improve 'metabolic fitness', thereby reducing the risk of CHD.

Plasma lipid, lipoprotein and apolipoprotein profiles in Nigerian university athletes and non-athletes

The fasting plasma lipid, lipoprotein and apolipoprotein profiles were determined in 14 healthy Nigerian male athletes and controls matched for sex and anthropometric parameters. The mean levels of total cholesterol (P < 0.05), low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) AII and E were significantly lower (P < 0.01) in the athletes than in the controls. However, there were no statistically significant differences (P > 0.05) between the mean values of the plasma triglycerides, high-density lipoprotein (HDL), very low-density lipoprotein (VLDL) cholesterol, apo AI, B, Lp(a), LpA1 and CIII:NonB respectively for the athletes and controls. A priori, the potential effect on cardiovascular disease (CVD) risk was also compared using three predictor ratios - total cholesterol: HDL cholesterol (TC:HDL), LDL cholesterol: HDL cholesterol and apo B:AI. The mean of the three ratios was lower in the athletes than in the controls; however, the differences were not statistically significant (P > 0.05). Based on our data, exercise appears to decrease the TC:HDL ratio in the athletes by lowering LDL-cholesterol, while the HDL-cholesterol is unaffected. We conclude that physical activity has salutary effects on the lipid, lipoprotein and apolipoprotein profiles of healthy Nigerian men.

Brisk walking improves endurance fitness without changing body fatness in previously sedentary women

The purpose of this study was to examine the influence of brisk walking on endurance fitness and the amount and distribution of body fat in previously sedentary women. Twenty eight women [mean age (SEM): 44.9 (1.5) years] followed the walking programme for 1 year, whilst 16 acted as controls [age 44.4 (2.3) years]. Changes in endurance fitness were evaluated by measuring the oxygen uptake (VO2) at a reference blood lactate concentration of 2 mmol.l-1. Two 1.61-km field tests of walking were completed, one at maximal speed and one at a "brisk" speed, as well as a 1.61-km walk on a motorised treadmill. The amount and distribution of body fat was determined by hydrostatic weighing and anthropometry and energy intake was evaluated using the 7-day weighed food intake method. Walkers completed an average of 157 min.week-1 of brisk walking over the year. The following were increased in walkers, relative to controls: brisk walking speed [walkers 1.73 (0.05) m.s-1 vs 1.88 (0.07) m.s-1; controls 1.69 (0.05) m.s-1 vs 1.70 (0.05) m.s-1 at baseline and 12 months respectively, P < 0.01], maximal walking speed and VO2 at 2 mmol.l-1. In addition, brisk walking reduced heart rate and blood lactate concentration during stepping as well as during standard, submaximal treadmill walking. It did not modify either the amount or the distribution of body fat, despite an unchanged energy intake.

Plasma lipid and lipoprotein profile in elderly female runners

Plasma lipid and lipoprotein profiles were compared in elderly female runners (RU: n = 15, aged 66 +/- 5 years, body fat 20 +/- 4%, training distance 35 +/- 15 km week-1, VO2max 36 +/- 4 ml kg-1 min-1, mean +/- SD) and age-matched untrained women (UT: n = 28, 66 +/- 4 years, body fat 26 +/- 6%, VO2max 26 +/- 3 ml kg-1 min-1). There were insignificant differences in total cholesterol (RU: 5.04 +/- 0.60 vs. UT: 5.48 +/- 0.85 mmol l-1), HDL-cholesterol (RU: 1.97 +/- 0.41 vs. UT: 1.91 +/- 0.36 mmol l-1) and LDL-cholesterol (RU: 2.72 +/- 0.59 vs. UT: 3.03 +/- 0.80 mmol l-1) between the two groups. Plasma triglyceride concentration of the runners was significantly lower than that of the untrained women (RU: 0.80 +/- 0.27 vs UT: 1.14 +/- 0.36 mmol l-1, P less than 0.01). No difference was observed in the LDL-cholesterol/HDL-cholesterol ratio between the two groups (RU: 1.45 +/- 0.51 vs UT: 1.64 +/- 0.53 units). These results suggest that regularly performed running of 35 km week-1 in elderly women does not further elevate their HDL-cholesterol level which is already high compared to the levels found in elderly men. However, elderly female runners appear to be protected against age-related increases in the levels of triglyceride and LDL-cholesterol.

Effect of physical training on lipids, lipoproteins, apolipoproteins, lipases, and endogenous sex hormones in men with premature myocardial infarction

In 17 men, aged 27 to 54 years, with myocardial infarction 2 to 10 months before the current exercise study, we aimed to determine whether 3 months of exercise training, at a level designed to elevate high-density lipoprotein cholesterol (HDLC), would be associated with changes in endogenous sex steroid hormones and postheparin lipoprotein and hepatic lipases, and whether the changes in sex hormones, lipids, lipoproteins, apolipoproteins, and physical activity were interrelated. Supervised bicycle ergometry, 30 minutes, 3 days per week, eliciting 75% of maximum heart rate, produced a significant training effect, with a 26% increase in the duration of the exercise test at a standardized, submaximal workload (P less than or equal to .001), and a reduction in heart rate measured at a standardized submaximal workload, P = .08. After 3 months' training, mean HDLC increased 23% (30 to 37 mg/dL), P less than or equal to .001, mean apo A2 increased 19% (43 to 51 mg/dL), P less than or equal to .001, and the ratio of total cholesterol (TC) to HDLC decreased 26% (P less than or equal to .01), while estradiol (E2) levels decreased 45% (50.1 to 27.8 pg/mL), P less than or equal to .0001. After 1 and 2 months' exercise, TC (12% [P less than or equal to .001], 11% [P less than or equal to .01]), and low-density lipoprotein cholesterol (LDLC) (13% [P less than or equal to .01], 12% [P less than or equal to .01]) were reduced. Hepatic lipase decreased 16% (P less than or equal to .01) and 16% (P less than or equal to .05) after 1 and 3 months' exercise. There were no significant changes in apo A1, lipoprotein lipase, testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), or weight. By stepwise regression analysis, after 3 months' training, 66% (P = .0025) of the variance for the increase in HDLC from baseline to day 90 was accounted for independently by a decrease in triglyceride (F = 13.2, P = .003), by reduced heart rate on a fixed submaximal load (F = 12.7, P = .0035), and by a decrease in hepatic lipase (F = 5.5, P = .036). A modest, achievable exercise program can have significant cardiovascular benefit for men after myocardial infarction by ameliorating their hyperestrogenemia, reducing TC and LDLC, improving the TC to HDLC ratio, and elevating HDLC and apo A2. The increment in HDLC was related independently to improved capacity to sustain submaximal exercise and to exercise-induced reductions in triglyceride and postheparin hepatic lipase.

Plasma lipid and lipoprotein profiles in pre- and post-menopausal middle-aged runners

Plasma lipid and lipoprotein profiles were compared in middle-aged trained and untrained women before and after menopause. Subjects were assigned to one of four groups: (1) pre-menopausal trained (Pre-T: n = 17, aged 42 +/- 5 years, body fat 19 +/- 5%, training distance 53 +/- 20 km week-1, VO2max 49 +/- 4 ml kg-1 min-1, mean +/- SD); (2) pre-menopausal untrained (Pre-UT: n = 26, 42 +/- 5 years, 24 +/- 7%, 34 +/- 6 ml kg-1 min-1); (3) post-menopausal trained (Post-T: n = 16, 54 +/- 3 years, 20 +/- 4%, 43 +/- 19 km week-1, 41 +/- 5 ml kg-1 min-1); and (4) post-menopausal untrained (Post-UT: n = 15, 55 +/- 3 years, 25 +/- 6%, 31 +/- 3 ml kg-1 min-1). There were no significant differences in total cholesterol (range 173-194 mg dl-1), triglyceride (56-72 mg dl-1), and HDL-cholesterol (HDLC: 76-85 mg dl-1) among the four groups. LDL-cholesterol (LDLC) in the post-menopausal women (Post-T: 96 +/- 32 mg dl-1; Post-UT: 104 +/- 23 mg dl-1) tended to be higher than in the premenopausal women (Pre-T: 86 +/- 25 mg dl-1, Pre-UT: 81 +/- 23 mg dl-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of exercise on cardiovascular disease risk in women with NIDDM

The effect of a 4-month exercise program on measures of cardiovascular disease (CHD) risk was observed in women (mean age = 59.2 +/- 3.9 years) of postmenopausal years with NIDDM, who demonstrated fair to normal control of blood glucose control. The women were randomly assigned to either an exercise (n = 5) or control (n = 5) group. Initially, both groups had a similar body mass index, resting heart rate and blood pressures, blood glucose and hemoglobin A1. After 4 months, the exercise group demonstrated a 32% increase (P less than 0.03) in both absolute and relative maximum oxygen uptake (VO2) while the control group remained unchanged. Significant differences were found between the exercisers and non-exercisers for absolute (F(1,8) 4.94, P = 0.057) and relative (F(1,8) 7.67, P = 0.024) maximum VO2 from pretest to posttest. Body weight (kg) and body fat (%) remained unchanged for both groups. Although total cholesterol was found to be reduced by 13% for the exercise group (P less than 0.03) and 11% for the controls (P less than 0.01), a 15% decrease (P less than 0.03) in high-density lipoprotein (HDL) was observed for the control group, only. Hence, a marked difference (P less than 0.03) in the risk ratio was observed between the exercise and control groups. These data suggest that physical exercise may play an important role in the maintenance of HDL mass and in the reduction of CHD risk factors in women of postmenopausal years with NIDDM.

Effects of exercise training on high density lipoproteins and apolipoprotein A-I in old and young men

Although exercise training has been demonstrated to improve lipid profiles in young and middle-aged subjects, the response in training in the elderly has received little attention. In this study, we assessed and compared the changes in aerobic capacity, lipid profiles, and body composition in young (Y, 31.9 +/- 5.5 years; n = 18) and older (O, 65.1 +/- 6.1 years; n = 10) subjects in response to similar 3-month exercise training programs (80% to 85% of heart rate reserve, three times per week). We hypothesized that the responses would be qualitatively similar for the two groups, although the absolute quantitative response might be somewhat less in the elderly. The two groups were quite similar at baseline for percent body fat (Y, 30.1% +/- 7.2% v O, 30.3% +/- 4.7%; P = NS) and maximal aerobic capacity (Y, 36.8 +/- 8.1 v O, 36.3 +/- 8.3 mL/kg/min; P = NS). In addition, there were no significant differences in the baseline lipid profiles between the groups. After training, the improvements in body composition were similar, with both groups losing similar amounts of fat (Y, 2.86% +/- 3.14% v O, -2.85% +/- 1.78%) and neither group significantly changing their fat-free mass. Maximal aerobic capacity improved in both groups, but the increment was greater in the young (18% v 10%, P less than .05). HDL-cholesterol (+6%, P less than .01) and apolipoprotein A-I (+6%, P less than .01) concentrations increased significantly only in the young. These increments, however, were not different from those observed in the older subjects (+7% and +4%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Levels of plasma and aortic lipids in young exercised rats with a diminished weight gain

Young exercised rats with a diminished weight gain had a decrease in high density lipoprotein (HDL) cholesterol and phospholipid levels in the plasma and augmented free cholesterol and phosphatide in the aorta. When the weight gain in the trained rats paralleled the gain in non-exercised animals, the values of these lipids were not altered. The levels of aortic free cholesterol in the non-exercised and exercised groups were inversely associated with concentrations of HDL-cholesterol, but were not related to the activities of lecithin cholesterol acyltransferase. In addition, the total cholesterol and phospholipid contents in the aorta negatively correlated with HDL-cholesterol concentrations. We propose that in young exercised rats with a diminished weight gain, the removal of aortic lipids is hampered due to a reduction in HDL-cholesterol.

A two year randomized exercise trial in older women: effects on HDL-cholesterol

Most of the research on the level of high density lipoprotein cholesterol (HDL-C) and physical activity (PA) has been cross-sectional and thus self-selection of the exercisers may occur. In the current research, 229 white postmenopausal women, mean age 57.7 years, were randomized into either a walking or a control group. Of these 229 women, 204 women had blood samples available for lipid determinations. PA was measured subjectively by the Paffenbarger Survey and objectively with activity monitors. At baseline, there were no differences in PA, total HDL-C (HDL-TC), HDL-2C or HDL-3C between the two randomized groups. After two years, the PA of the walking group was significantly higher than the PA of the control group. This increase in PA was not accompanied by changes in any of the lipids or lipoproteins. Examination of the lipid changes in the walking group by compliance status and actual activity changes revealed little difference between groups. These results suggest that it is possible to increase physical activity in older women. However, the long-term effects of the increased activity on HDL-C were not apparent despite an observed strong cross-sectional relationship between PA and HDL-C.

Alterations in lipid and protein profiles of plasma lipoproteins in middle-aged men consequent to an aerobic exercise program

Thirty-four healthy, untrained middle-aged males (mean = 58.2 years) volunteered for a longitudinal study investigating alterations in lipoprotein profiles consequent to 20 weeks of aerobic training. Twenty randomly selected experimental subjects (E) participated in a walk/run training program 3 d/wk, 48 min/d, at an intensity equal to 65% to 85% of their heart rate reserve, while 14 control subjects (C) remained in an untrained state. Blood samples were obtained in the morning after a 14-hour fast. Plasma lipoproteins were separated by ultracentrifugation and agarose-column chromatography into very low (VLDL), low (LDL), and high (HDL) density lipoprotein fractions. A training effect was evidenced in E by significant increases (P less than 0.001) in absolute VO2 max (15.2%) and relative VO2 max (16.8%). Dietary composition was monitored pretraining and posttraining with no significant change seen in either E or C. Alterations in the lipoprotein profile of E included a significant increase in HDL-cholesterol (16.6%) and significant reductions in VLDL-cholesterol (72.1%), LDL-triglyceride (26.5%), VLDL-protein (33.5%), and LDL-protein (18.7%). Furthermore, no significant changes in the level of HDL-protein and apolipoprotein AI in the HDL fraction were observed in either E or C. These data suggest that aerobic training can significantly increase HDL-cholesterol and alter lipoprotein profiles, which may subsequently reduce the risk of coronary artery disease.

Effect of alcohol intake and exercise on plasma high-density lipoprotein cholesterol subfractions and apolipoprotein A-I in women

Abstinence from alcohol consumption for 3 weeks was followed by 3 weeks of wine intake in 18 inactive and 18 physically active premenopausal women (runners). The runners weighed less and had higher plasma high-density lipoprotein (HDL) cholesterol and lower low-density lipoprotein cholesterol levels than the inactive women. There were no differences between groups in plasma total cholesterol, triglyceride and apolipoprotein A-I concentrations. Runners had higher plasma HDL2 cholesterol concentrations than inactive women (34 +/- 17 vs 19 +/- 12 mg/dl), but HDL3 cholesterol concentration did not differ between the groups (41 +/- 10 vs 39 +/- 9 mg/dl). Addition of 35 g/day of ethanol for 3 weeks did not result in a significant change in either group for any of the variables measured. The amount of exercise appears to be a more important determinant of plasma lipoproteins and apolipoprotein A-I than alcohol intake in premenopausal women.

Beta-blockers, diuretics and physical fitness as determinants of serum lipids in myocardial infarction patients

Serum lipid levels were followed in myocardial infarction patients for one year after the infarction and related to their drug use and physical performance. Serum triglyceride concentrations were significantly elevated in patients using diuretics or diuretics and beta-blockers together both 3 and 12 months after the infarction when compared to patients not having drugs. The beta-blockers alone did not change triglycerides. No differences were found in total cholesterol concentration between any of the drug groups. The HDL cholesterol levels were significantly lower in all the drug groups 12 months after the infarction in comparison with the group using no drugs, but 3 months after the infarction these differences were not present. Total work in the exercise stress test correlated negatively with serum triglycerides and total cholesterol and positively with HDL/total cholesterol ratio in the group using no drugs 12 months after the infarction. In beta-blocker users, total work correlated negatively with triglyceride and total cholesterol concentrations. In all drug groups no correlation between total work and HDL/total cholesterol ratio could be found. These data suggest that despite differences in the physical working capacity between the groups, the drugs themselves are major determinants of differences in serum lipids.

The Effects of Physical Training on Blood Lipid Profiles in Adolescents With Insulin-Dependent Diabetes Mellitus

In brief: Fourteen adolescents (eight females and six males) with insulin-dependent diabetes mellitus (IDDM) participated in a 12-week exercise program consisting of three 45-minute sessions per week. Exercise consisted of calisthenic warm-up and stretching (ten minutes), aerobic movement to music (25 minutes at 80% V o2 max), and cool-down (ten minutes). The purpose was to determine whether and to what degree such training would bring about changes in blood lipid and lipoprotein profiles in such patients. The authors found a significant decrease in low-density lipoprotein cholesterol concomitant to an increase in V o2 max with no change in glycemic control. These findings support the beneficial effects of regular exercise for individuals with IDDM.

The effects of exercise and weight loss on plasma lipids in young obese men

We studied the independent and combined effects of exercise training and weight loss on blood lipids under fixed diet and exercise conditions. Twenty-one obese sedentary men were randomly allocated to one of four treatment groups: (1) inactive and constant weight (control), (2) exercise training and constant weight, (3) inactive and weight loss, and (4) exercise training and weight loss. There were three study periods: a 3 week baseline period inactive and on an isocaloric diet, a 12 week treatment period, and a 3 week weight stabilization period. Exercise consisted of treadmill walking at an energy cost of 3500 kcal/wk for groups 2 and 4 with replacement caloric intake only in group 2. Group 3 reduced caloric intake by 3500 kcal/wk during the treatment period. Weight loss for groups 3 and 4 were 13.4 pounds and 13.7 pounds, respectively. Maximal oxygen uptake (mL/min) increased 6% in both exercise groups (2 and 4), and percent body fat decreased only in these groups. Regression analysis by group assignment on HDL cholesterol (HDL-C) showed that the inactivity-weight loss modality (group 3) and the exercise-constant weight modality (group 2) each significantly increased HDL-C, with an additive effect of exercise and weight loss (group 4). The rate of HDL-C change differed significantly between groups (P = 0.01). HDL-C increased 0.63, 0.61, and 1.89 mg/dL per 3 weeks or 2%, 2.4%, and 5.5% above baseline levels in groups 2, 3, and 4, respectively, while the control group decreased 0.11 mg/dL. Plasma triglycerides and very low-density lipoprotein (VLDL) cholesterol increased with exercise at constant weight (group 2) and decreased with exercise associated with weight loss (group 4). In conclusion, exercise and weight loss separately and independently increase HDL-C, and their effects are additive.

Response of HDL cholesterol, apoprotein A-I, and LCAT to exercise withdrawal

The effect of short-term exercise withdrawal on plasma lipoproteins, apoprotein A-I (Apo A-I), and lecithin:cholesterol acyltransferase (LCAT) was studied in moderately trained lifestyle exercisers. Eight endurance-trained men, age 18-45 years (means = 29 years), withdrew from aerobic activity for 6 weeks, while an age and fitness-matched control group (n = 9) maintained normal exercise habits. A baseline period that included two blood samplings preceded the detraining intervention. Plasma total cholesterol (TCHOL), HDL cholesterol (HDL-C) and triglyceride (TG) levels were determined weekly. Other blood variables (HDL2-C, HDL3-C, Apo A-I, and LCAT), % fat, and aerobic capacity (VO2max) were measured pre-, mid-, and post-experiment. A two-way repeated measures analysis of variance (ANOVA) indicated that the 6-week exercise withdrawal period failed to elicit significant mean changes in any blood variable, % fat, or VO2max. Therefore, a short-term layoff from aerobic activity by moderately trained, chronic exercisers generally does not adversely affect the blood lipoprotein profile or aerobic capacity.

Effect of exercise training on plasma high-density lipoprotein cholesterol level at constant weight

Previous investigations have demonstrated an increase of plasma high-density lipoprotein cholesterol (HDL-Chol) and a decrease in the ratio of low density lipoprotein (LDL)-Chol/HDL-Chol (Atherogenic Index; AI) as a result of exercise training. The question of whether elevation of HDL-Chol was a consequence of weight reduction or physical training itself was unsolved. The present study was designed to prevent the weight reduction that is associated with exercise training. Five healthy and mildly active male volunteers, aged 28-31 years, participated in a 4-week training programme. They ran on a treadmill at 140-160 m/min at 0% grade for 50 min, 5 times a week, equivalent to an energy expenditure of 9 kcal/kg body weight/day. Subjects maintained their body weights by increasing calorie intake to match increased energy expenditure. No changes were observed in mean body weight, skinfold thickness, basal metabolism, and maximal oxygen uptake after the training programme. The HDL-Chol level increased from 54 to 73 mg/dl (P less than 0.05), and the reduction of AI was 30.8% (P less than 0.05) in response to the exercise training. However, the exercise training did not induce changes in plasma total cholesterol and triglyceride (TG) levels. The results of this experiment suggested that moderate physical training itself can be a potent factor for the regulation of HDL-Chol level and improvement of the AI in the absence of alterations in body weight.