Effect of a controlled exercise program on serum lipoprotein levels in women on oral contraceptives

Effects of Exercise on the Resting Heart Rate: A Systematic Review and Meta-Analysis of Interventional Studies

Resting heart rate (RHR) is positively related with mortality. Regular exercise causes a reduction in RHR. The aim of the systematic review was to assess whether regular exercise or sports have an impact on the RHR in healthy subjects by taking different types of sports into account. A systematic literature research was conducted in six databases for the identification of controlled trials dealing with the effects of exercise or sports on the RHR in healthy subjects was performed. The studies were summarized by meta-analyses. The literature search analyzed 191 studies presenting 215 samples fitting the eligibility criteria. 121 trials examined the effects of endurance training, 43 strength training, 15 combined endurance and strength training, 5 additional school sport programs. 21 yoga, 5 tai chi, 3 qigong, and 2 unspecified types of sports. All types of sports decreased the RHR. However, only endurance training and yoga significantly decreased the RHR in both sexes. The exercise-induced decreases of RHR were positively related with the pre-interventional RHR and negatively with the average age of the participants. From this, we can conclude that exercise-especially endurance training and yoga-decreases RHR. This effect may contribute to a reduction in all-cause mortality due to regular exercise or sports.

Nine months aerobic fitness induced changes on blood lipids and lipoproteins in untrained subjects versus controls

Regular endurance exercise has favorable effects on cardiovascular risk factors. However, the impact of an exercise-induced change in aerobic fitness on blood lipids is often inconsistent. The purpose of this study was to investigate the effect of nine consecutive months of training on aerobic fitness and blood lipids in untrained adults. Thirty subjects 35-55 years of age (wt: 73.1 +/- 13.6 kg, height 171.1 +/- 9.0 cm, %body fat 24.6 +/- 6.3%, 14 males and 16 females) were randomly assigned to an exercise (EG) (N = 20) and control (CG) (N = 10) group. All subjects completed an incremental treadmill test, anthropometric measurements, and venous blood sample collection before and after the 9 months of exercise. Participants in the exercise group were supervised and adjusted for improvements in running performance, whereas no change was administered for the control group. One-way and multivariate ANOVA was conducted to determine significant differences in means for time and group in selected variables [body mass, % body fat, BMI; VO(2peak), km/h at 2.0 (v-LA2) and 4.0 (v-LA4) mmol l(-1) blood lactate (LA) concentration, km/h of the last load (v-max); TC, LDL-C, HDL-C, TG, Apo B, Apo A-1, and Lp (a)]. Correlation coefficients and multivariate regression analysis was used to determine the association between aerobic fitness and blood lipids. The exercise group improved significantly (P < 0.0001) in VO(2peak), v-LA2, v-LA4, v-max and exhibited a significant decrease in Apo B (P < 0.04) compared to the control group (NS). In 9 months, E achieved 24% increase in VO(2peak) and 18% reduction in Apo B, denoting the impact of cardiovascular fitness on cardiovascular risk.

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.

Effects of exercise and estrogen therapy on lipid profiles of postmenopausal women

PURPOSE

We compared the effects of aerobic exercise training on lipid and lipoprotein levels in 18 postmenopausal women who were (N = 8) or were not (N = 10) receiving estrogen replacement therapy (ERT).

METHODS

Each group was tested for lipids, diet recall and VO2max before and after a 12 wk exercise program, consisting of 30-50 min of an aerobic activity at 75-85% of VO2max, 3-4 sessions per week.

RESULTS

Both groups increased VO2max by 8% and neither group changed their diet. The ERT group had higher levels of triglycerides and lower levels of low density lipoprotein (LDL-C) (P < 0.01) before training. There were no mean group changes in any of the lipid variables with training. However, individual changes in LDL-C and Total Cholesterol (TC) were strongly related to baseline weight in the nonestrogen group (r = 109.91, r = -0.82) but not in ERT (r = -0.30, r = -0.51). Subsequently, all subjects were redivided into two groups based on BMI (< or = 27 or > or = 27) regardless of ERT status. TC decreased significantly (P < 0.05) in the < or = 27 BMI group.

CONCLUSIONS

Exercise training had little effect on the lipid profiles of the ERT and the nonestrogen groups, but body weight seems to be a modulating factor. Heavier subjects did not respond as favorably to 12 wk of exercise training as postmenopausal women with less body mass, regardless of the presence of exogenous estrogen.

Interaction of oral contraceptive use with the effects of age, exercise habits and other cardiovascular risk modifiers on metabolic risk markers

An analysis was undertaken to determine whether combined oral contraceptive (OC) use interacts with the effects of potential cardiovascular risk modifiers (age, body mass index, cigarette smoking, alcohol intake, exercise habit, family histories of heart disease or diabetes, number of pregnancies and duration of OC use) on blood pressure and lipid, lipoprotein, glucose and insulin risk markers for cardiovascular disease. Relationships between risk modifiers and risk markers were compared between non-users (n = 418) and users of low-estrogen dose OC (n = 925, categorised according to progestin content as monophasic levonorgestrel, triphasic levonorgestrel, norethindrone or desogestrel). OC use diminished the adverse effects of age on glucose tolerance. Aerobic exercise had a particularly beneficial effect on triglyceride levels and OGTT insulin response in OC users. The rise in HDL and HDL2 cholesterol concentrations with alcohol intake seen in non-users was diminished in OC users. Increasing duration of use of a desogestrel combination was associated with increasing HDL cholesterol concentrations. No adverse effects of risk modifiers on metabolic risk markers and blood pressure were augmented by OC use, and some were even diminished.

Effects of exercise training on cardiovascular function and plasma lipid, lipoprotein, and apolipoprotein concentrations in premenopausal and postmenopausal women

This study examined the effects of aerobic exercise on lipid levels in premenopausal and postmenopausal women. Fifty healthy middle-aged women (mean age, 50 years) were randomly assigned to 12 weeks of either aerobic exercise (walking and jogging) or nonaerobic strength exercise (circuit Nautilus training). Concentrations of total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, and very low density lipoprotein cholesterol were assessed, along with apolipoprotein (apo) A-I, apo A-II, apo B, and triglycerides. To document changes in aerobic capacity, maximum treadmill testing was performed with expired-gas analysis before and after the exercise program. Aerobic exercise was associated with an 18% improvement in peak VO2. Women in the aerobic group had an increased VO2, from 26.7 to 31.4 ml/kg/min (p less than 0.0001), while the VO2 of the women in the strength training group did not change (25.8 ml/kg/min before and after). There were no differential changes in lipid levels because all subjects experienced slight reductions in high density lipoprotein cholesterol and total cholesterol and increases in apo A-I and the apo A-I to apo B ratio. There was a tendency for the aerobic group to exhibit lower levels of apo A-II and a greater apo A-I to apo A-II ratio, however. We conclude that premenopausal and postmenopausal women experience similar changes in aerobic capacity and lipid levels with exercise and that the short-term effects of aerobic and nonaerobic exercise on lipid profiles are generally comparable.

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)

The influence of oral contraceptives and habitual physical activity on serum lipids in black adolescents and young women

The effects of oral contraceptive use and habitual physical activity on serum cholesterol and lipoproteins were studied in 37 black females ages 16 to 28 years over a 3-month period. By the third month of oral contraceptive use, high-density lipoprotein (HDL) levels were lower and the low-density lipoprotein (LDL) to HDL ratio and total serum cholesterol (T Chol) to HDL ratio were significantly higher in those receiving oral contraceptive with norgestrel. The level of physical activity had no significant effect on HDL levels. The active subjects had lower T Chol and HDL levels and a lower T Chol to HDL ratio at the end of 3 months. Subjects in the active-norethindrone group had lower T Chol to HDL ratios than those taking norgestrel. The nonactive norgestrel group had a continuous increase in their T Chol to HDL ratio over the 3-month period. These effects should be considered when counseling sexually active teenagers and when recommending an oral contraceptive.

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.

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.

Relationship of exercise, oral contraceptive use, and body fat to concentrations of plasma lipids and lipoprotein cholesterol in young women

To investigate the relationship of exercise and oral contraceptive use to plasma lipids and lipoproteins, a cross-sectional study was designed to compare lipid levels in 96 exercising and non-exercising women who used or did not use oral contraceptives. Exercisers had significantly lower plasma triglyceride concentrations and low-density/high-density lipoprotein ratios than non-exercisers after adjustment for differences in pill type distribution between groups. Women using progestin-dominant pills had significantly lower plasma triglyceride and high-density lipoprotein concentrations and significantly higher low-density/high-density lipoprotein ratios compared with women using estrogen/progestin-balanced pills. As body fat was significantly associated with both pill type and physical activity, it is unclear how much of these lipoprotein differences were due to body fat, exercise, or pill use. Regular physical activity together with reduced body fat partially compensated for plasma lipoprotein differences associated with oral contraceptive use.

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.

Relationship of menopausal status and exercise level to HDL-cholesterol in women

The relationship between exercise habits, menopausal status and HDL cholesterol (HDL-C) was studied in 44 long-distance runners, 47 joggers, and 45 relatively inactive females. In each group, some women were post-menopausal (Post-M) and some pre-menopausal (Pre-M). HDL-C level was higher in runners (77.6 mg/dl) and joggers (70.4 mg/dl) than in the inactive group (62.1 mg/dl), but was not different Pre-M vs Post-M. Total cholesterol (TC) and LDL-C were higher in Post-M than in Pre-M subjects, but did not differ among exercise groups. Body weight and % fat were lower in Pre-M vs Post-M groups and were lower in the runners vs inactive subjects. The HDL-C/TC ratio was higher in the runners vs inactive subjects and there was a significant exercise-menopausal interaction indicating a beneficial exercise effect. Adjustment of lipoprotein values for possible confounding variables did not alter these results. Endurance exercise by Post-M females may help prevent adverse lipid and lipoprotein changes which might predispose them to coronary heart disease.

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

Effects of a 10 wk, three times per wk individualized bicycle ergometer training program were investigated in 16 healthy sedentary women 19-29 yr-old who were not taking oral contraceptives or other medications. Twelve women were in an interval type program, 6 in a continuous program, all performing 30 min exercise per session at 70% maximum heart rate reserve. Conditioning responses did not differ between the training regimens. Training produced increases in maximum oxygen uptake and physical work capacity. Percent body fat determined by underwater weighing was significantly reduced as was resting heart rate, after the training program. Maximum heart rate was unchanged. Despite changes in "fitness" variables, post-training values of high density lipoprotein cholesterol and triglycerides did not differ from pretraining. High-density lipoprotein cholesterol was significantly reduced at 2 and 5 wk of training and returned to control levels at 10 wk. Exercise conditioning leading to improved physical fitness in healthy women may not be associated with increments in high density lipoprotein cholesterol levels.

Cradle-to-grave atherosclerosis: high density lipoprotein cholesterol

This presentation reviews environmental and genetic factors that relate to high density lipoprotein cholesterol, the most potent independent lipoprotein risk factor for coronary heart disease. Although at least three decades of work have focused upon the primary atherogenic lipoprotein, low density lipoprotein cholesterol (C-LDL), which has a strong positive association with coronary heart disease (CHD), it has only been in the past decade that detailed epidemiologic and biochemical studies have revealed that high density lipoprotein cholesterol (C-HDL) is the most potent lipoprotein cholesterol related to coronary heart disease; this relationship is, however, inverse.