Elevated high-density lipoprotein cholesterol levels in older endurance athletes

Associations between Plasma Branched Chain Amino Acids and Health Biomarkers in Response to Resistance Exercise Training Across Age

Leucine, isoleucine and valine (i.e., the branched chain amino acids, BCAA) play a key role in the support and regulation of tissue protein regulation and also as energy substrates. However, positive relationships exist between elevated levels of BCAA and insulin resistance (IR). Thus, we sought to investigate the links between fasting plasma BCAA following a progressive resistance exercise training (RET) programme, an intervention known to improve metabolic health. Fasting plasma BCAA were quantified in adults (young: 18-28 y, n = 8; middle-aged: 45-55 y, n = 9; older: 65-75 y, n = 15; BMI: 23-28 kg/m², both males and females (~50:50), in a cross-sectional, intervention study. Participants underwent 20-weeks whole-body RET. Measurements of body composition, muscle strength (1-RM) and metabolic health biomarkers (e.g., HOMA-IR) were made pre- and post-RET. BCAA concentrations were determined by gas-chromatography mass spectrometry (GC-MS). No associations were observed across age with BCAA; however, RET elicited (p < 0.05) increases in plasma BCAA (all age-groups), while HOMA-IR scores reduced (p < 0.05) following RET. After RET, positive correlations in lean body mass (p = 0.007) and strength gains (p = 0.001) with fasting BCAA levels were observed. Elevated BCAA are not a robust marker of ageing nor IR in those with a healthy BMI; rather, despite decreasing IR, RET was associated with increased BCAA.

Exercise and Cardiovascular Progenitor Cells

Autologous stem/progenitor cell-based methods to restore blood flow and function to ischemic tissues are clinically appealing for the substantial proportion of the population with cardiovascular diseases. Early preclinical and case studies established the therapeutic potential of autologous cell therapies for neovascularization in ischemic tissues. However, trials over the past ∼15 years reveal the benefits of such therapies to be much smaller than originally estimated and a definitive clinical benefit is yet to be established. Recently, there has been an emphasis on improving the number and function of cells [herein generally referred to as circulating angiogenic cells (CACs)] used for autologous cell therapies. CACs include of several subsets of circulating cells, including endothelial progenitor cells, with proangiogenic potential that is largely exerted through paracrine functions. As exercise is known to improve CV outcomes such as angiogenesis and endothelial function, much attention is being given to exercise to improve the number and function of CACs. Accordingly, there is a growing body of evidence that acute, short-term, and chronic exercise have beneficial effects on the number and function of different subsets of CACs. In particular, recent studies show that aerobic exercise training can increase the number of CACs in circulation and enhance the function of isolated CACs as assessed in ex vivo assays. This review summarizes the roles of different subsets of CACs and the effects of acute and chronic exercise on CAC number and function, with a focus on the number and paracrine function of circulating CD34+ cells, CD31+ cells, and CD62E+ cells. © 2019 American Physiological Society. Compr Physiol 9:767-797, 2019.

Dyslipidaemia in the elderly: to treat or not to treat?

INTRODUCTION

The elderly population (i.e. aged ≥ 65 years) is increasing worldwide. Ageing is associated with a higher incidence and prevalence of cardiovascular disease (CVD). Areas covered: The prevalence of CVD risk factors including type 2 diabetes mellitus, hypertension and dyslipidaemia also increases with advancing age, contributing to the higher absolute CVD risk observed in the elderly. The present narrative review comments on the associations of dyslipidaemia with CVD as well as the effects of lifestyle measures and lipid-lowering drugs on lipids and CVD risk with a special focus on the elderly population. Individual treatment goals and therapeutic options according to current guidelines are also reviewed. Finally, we discuss special characteristics of the elderly that may influence the efficacy and safety of drug therapy and should be considered before selection of hypolipidaemic pharmacotherapy. Expert commentary: There may be a greater CVD benefit in older patients following drug therapy compared with younger ones. Treatment goals and therapeutic options should be individualized according to current guidelines. Specific characteristics that may influence the efficacy and safety of drug therapy in the elderly should be considered in relation to dyslipidaemia treatment.

A cross-sectional examination of the physical fitness and selected health attributes of recreational all-terrain vehicle riders and off-road motorcyclists

The aims of this study were: (1) to characterize selected fitness and health attributes of two types of habitual recreational off-road vehicle riders - off-road motorcyclists and all-terrain vehicle riders; (2) to explore differences among riders in terms of vehicle type, age, and gender; and (3) to compare the fitness and health of riders to population norms and clinical health standards. Canadian off-road riders (n = 141) of both sexes aged 16 years and over were recruited through local and national off-road riding organizations. Anthropometry, fitness, and health measures of off-road motorcycle and all-terrain vehicle riders were compared with population norms, health standards, and physical activity guidelines. Off-road motorcycle riders had above average aerobic fitness (79th percentile), while all-terrain vehicle riders were lower than average (40th percentile). All riders had a healthy blood lipid profile and a low incidence of the metabolic syndrome (12.9%) compared with members of the general population. Off-road motorcycle riders had healthier body composition and fitness than all-terrain vehicle riders; however, the body composition of off-road motorcycle riders was no healthier than that of the general population and all-terrain vehicle riders were worse than the general population. Off-road motorcycle riders had healthier anthropometry and fitness than all-terrain vehicle riders and thus fewer health risk factors for future disease, demonstrating that the physiological profiles of off-road riders are dependent on vehicle type.

Cardiorespiratory fitness and metabolic risk factors in obesity

PURPOSE OF REVIEW

An increase in cardiorespiratory fitness (CRF) through exercise training appears to partly ameliorate the health hazards of obesity and a number of mechanisms might explain the potential benefits. We review recent evidence about the relationships between CRF, exercise training and metabolic risk factors in obesity.

RECENT FINDINGS

Epidemiological data have shown that the anti-inflammatory effects of exercise could be an important mechanism in explaining cardio-protective effects of physical activity. Emerging evidence suggests that exercise training reduces markers of inflammation and improves glucose control in obesity, independent of weight loss. Novel mechanisms appear to involve exercise-induced changes in CD14+CD16+ cell populations, expression of toll-like receptors, and key changes in the metabolic regulation of visceral white adipose tissue. Other promising recent research has focused on exercise-induced signalling pathways governing glucose metabolism, such as insulin receptor substrate and Akt substrate. Using novel imaging techniques, studies have demonstrated exercise-induced improvements in lipoprotein subfraction particle size, and reduction in visceral adipose tissue and liver fat, independent of weight loss. These effects appear to be mostly restricted to interventions consisting of relatively high doses of exercise or exercise combined with calorie restriction, although further work is required to elucidate the dose-response relationships.

SUMMARY

Physical activity and the pursuit of physical fitness are important in the treatment of obesity because exercise training can improve a number of metabolic risk factors independent of weight loss. Thus exercise can provide important health benefits irrespective of weight loss in obese and overweight individuals.

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.

What Can We Learn About Diet and Physical Activity From Master Athletes?

Only 13% of those 65 years and older engage in vigorous physical activity 3 or more days a week and obesity rates are increasing by 45% in adults over the age of 60. Physical activity helps prevent chronic disease and improves quality of life, yet few adults of any age are active. One exception is master athletes who participate in competitive sports during the middle and later years. The aerobic fitness of master athletes, as measured by maximal oxygen consumption, shows some decline, but not nearly as much as in sedentary controls. Master athletes have lipid profiles similar to those of young adults, which decreases their risk of heart disease. Master athletes also have better glucose tolerance and lower waist-to-hip ratios than sedentary adults, decreasing their risk for metabolic syndrome and type 2 diabetes. In the few dietary studies that have been conducted, master athletes consume more food energy while maintaining lower body weights than sedentary adults. Learning what motivates master athletes to stay highly active may help health professionals develop strategies to encourage exercise in the sedentary population of older adults.

Cardiovascular disease risk factors in habitual exercisers, lean sedentary men and abdominally obese sedentary men

OBJECTIVE

To investigate whether the favourable cardiovascular disease (CVD) risk factor profile of habitual exercisers is attributable to exercise or leanness.

DESIGN

Cross-sectional study of 113 nonsmoking men aged 30-45 y. CVD risk factors were compared in exercisers (n=39) and sedentary men (n=74), and in subgroups of lean exercisers (n=37), lean sedentary men (n=46) and obese sedentary men (n=28). Waist girth was used to identify lean (<100 cm) and abdominally obese (> or =100 cm) subgroups.

MEASUREMENTS

Blood pressure, physical activity (7-day recall), physical fitness (maximum oxygen consumption) and fasted lipoproteins, apolipoprotein (apo) B, triglycerides, glucose and fibrinogen.

RESULTS

Exercisers were fitter and leaner than sedentary men and had a better CVD risk factor profile. Total cholesterol, LDL-cholesterol and apo B concentrations were lower in lean exercisers than in lean sedentary men, suggesting that exercise influences these risk factors. Indeed, time spent in vigorous activity was the only significant predictor of total cholesterol and LDL-cholesterol in multiple linear regression models. Exercise status had little influence on triglycerides and HDL-cholesterol (HDL-C), and unfavourable levels were only evident among obese sedentary men. Waist girth was the sole predictor of triglycerides and HDL-C, explaining 44 and 31% of the variance, respectively.

CONCLUSIONS

These findings suggest that the CVD risk factor profile of habitual exercisers is attributable to leanness and exercise. Leanness is associated with favourable levels of HDL-C and triglycerides, while exercise is associated with lower levels of total cholesterol, LDL-cholesterol and apo B.

Response of Blood Lipids to Physical Exercise in Elderly Subjects

Regular physical activity plays an important role in nonpharmacologic management of hyperlipidemia, in both the primary and secondary prevention of coronary heart disease. Training intensity and duration, health status (especially the presence of cardiovascular disease), and concomitant changes in body mass and dietary habits are the most important factors that can modify the physical activity-blood lipid profile relationship in the elderly. The benefit of regular exercise goes beyond direct influence on blood lipids; it aids in reducing weight, decreasing fat mass, increasing lean body mass, reducing elevated blood pressure, and increasing insulin sensitivity. Regular physical activity has become widely recommended as an important element of healthy and successful aging and should be encouraged in individuals without contraindications. (c)2001 CHF, Inc.

Health effects resulting from exercise versus those from body fat loss

OBJECTIVE

The purpose of this review was to assess whether body weight confounds the relationships between physical activity and its health benefits.

METHODS

The review includes 80 reports from population-based studies (Evidence Category C) of physical activity or fitness and cardiovascular disease (CVD) or coronary heart disease (CHD).

RESULTS

Eleven of 64 reports on activity found no relationship between physical activity and disease. Of the remaining 53 reports, 11 did not address the possible confounding effects of body weight, nine cited reasons that weight differences should not explain their observed associations, and 33 statistically adjusted for weight (as required). Only three of these changed their associations from significant to nonsignificant when adjusted. Ten of 16 reports on cardiorespiratory fitness and CHD or CVD used statistical adjustment, and none of these changed their findings to nonsignificant. Population studies show that vigorously active individuals also have higher high-density lipoprotein (HDL)-cholesterol concentration, a major risk factor for CHD and CVD, than sedentary individuals when statistically adjusted for weight. In contrast, intervention studies, which relate dynamic changes in weight and HDL, suggest that adjustment for weight loss largely eliminates the increase in HDL-cholesterol in sedentary men who begin exercising vigorously. Adjusting the cross-sectional HDL-cholesterol differences for the dynamic effects of weight loss eliminates most of the HDL-cholesterol difference between active and sedentary men.

CONCLUSION

Population studies show that the lower incidence of CHD and CVD and higher HDL of fit, active individuals are not because of lean, healthy individuals choosing to be active (i.e., self-selection bias). Nevertheless, metabolic processed associated weight loss may be primarily responsible for the HDL differences between active and sedentary men, and possibly also their differences in CHD and CVD.

Determinants of body composition in postmenopausal women

BACKGROUND

Little is known about the effects of different levels of long-term physical activity on total body and regional fat and whether hormone replacement therapy interacts with physical activity level to affect body composition in postmenopausal women.

METHODS

We determined the associations between different levels of habitual physical activity, hormone replacement therapy (HRT), and total and regional body composition in postmenopausal women. Twenty sedentary, 20 active nonathletic, and 23 endurance-trained women (approximately half on HRT) had total and regional body composition assessed by dual-energy x-ray absorptiometry. The athletes and active nonathletic women had been active for the same number of years and the same number of hours per week.

RESULTS

The athletes and sedentary women weighed the same, but the active nonathletic groups on and not on HRT weighed 3-12 kg more (p < .05). Athletes had less trunk, arm, leg, and total body fat than sedentary and active nonathletic women (p < .05). Women on HRT tended to have lower total body (p = .07), but not regional, fat values. Linear regression analyses indicated that VO2max in ml/kg/min was the major independent determinant of total and regional body fat accounting for 52% to 70% of their variances. Athletes had greater caloric and carbohydrate intake than their less active peers, but all groups had similar protein, fat, saturated fat, monounsaturated fat, and polyunsaturated fat intakes.

CONCLUSIONS

Intense training, but not low- to moderate-intensity physical activity, is associated with markedly lower levels of total and regional body fat in postmenopausal women. HRT has less of an effect on body composition than intense exercise training in postmenopausal women.

Therapeutic and physical fitness exercise prescription for older adults with joint disease: an evidence-based approach

Aging with joint disease does necessarily result in chronic pain, adoption of a sedentary lifestyle, and functional dependency. Several randomized controlled trials clearly show that regular exercise does not exacerbate pain or accelerate disease progression. On the contrary, these studies suggest that exercise training may increase the physiologic reserve and reduce the risk for functional dependency in older adults with joint disease. The goals for an exercise program should be directed toward increasing flexibility, muscle strength, endurance, and cardiovascular fitness. An exercise training program that is tailored specifically to an older adult's physical limitations may achieve these goals, and by optimizing patient safety lead to improve long-term exercise compliance.

Cardiovascular fitness, body composition, and lipoprotein lipid metabolism in older men

BACKGROUND

Lipoprotein lipids in older individuals are affected by family history of coronary artery disease (CAD), obesity, diet, and physical activity habits.

METHODS

The relationship of obesity and physical fitness (VO2max) to lipoprotein lipids and postheparin lipases was examined in a cross-sectional study of 12 lean (LS) and 26 obese (OS) sedentary men and 18 master athletes (MAs) aged 65+/-1 years (mean +/- SE). The men were healthy, had no family history of CAD, and were weight stable on AHA diets at the time of study.

RESULTS

VO2max was similar in LS and OS men but higher in the MAs. The OS men had a higher percentage of body fat (%BF), waist circumference, and waist:hip ratio (WHR) than the MA and LS men, but MA and LS men differed only in waist circumference. Total and LDL-C levels were comparable, but HDL-C, HDL2-C, and %HDL2b subspecies were higher in MAs than in OS and LS men, and in LS than in OS men. Triglyceride (TG) was similar in MAs and LS men but higher in OS men. Across groups, two multiple regression analyses models (VO2max, %BF, and WHR or waist circumference) showed that %BF and VO2max independently predicted HDL-C and HDL2, whereas WHR predicted TG (r2 = .45) more strongly than waist circumference (r2 = .39). Postheparin lipoprotein lipase activity (LPL) was comparable among groups and correlated independently with VO2max. Total postheparin lipolytic activity (PHLA), hepatic lipase activity (HL), and HL:PHLA ratio were similar in MAs and LS men but higher in OS men. In both multiple regression analysis models, only %BF predicted HL activity and the HL:PHLA ratio. The HL:PHLA ratio independently predicted HDL-C, HDL2-C, %HDL2b, %HDL3 subspecies, and the cholesterol:HDL-C ratio, whereas LPL activity predicted TG.

CONCLUSIONS

Increased fitness and reduced total and abdominal fatness in MAs are associated with lower HL and higher LPL activities, which may mediate their higher HDL-C and lower TG levels relative to their sedentary peers.

Relationship of physical activity and fitness to lipid and lipoprotein (a) in elderly subjects

PURPOSE

To determine, both by a cross-sectional and longitudinal study design, the relationship of maximal oxygen consumption (VO2max) and physical activity (PA) to blood lipids and lipoprotein(a) [Lp(a)] in a population of healthy and weight-stable elderly volunteers aged 66-84 yr.

METHODS

In a cross-sectional study in 52 subjects (23 men and 29 women), all independent variables (age, anthropometric, VO2max, and PA indices) were used in a multiple stepwise regression analysis to select variables influencing lipid and lipoprotein parameters. In a prospective nonintervention study, 38 subjects (17 men and 21 women) were reexamined after 6 months.

RESULTS

In a cross-sectional study, sports activity index contributed significantly to total cholesterol (TC), low density lipoprotein (LDL) cholesterol (LDL-C), TC/high density lipoprotein (HDL) cholesterol (HDL-C) ratio, and LDL-C/HDL-C ratio variance in men, whereas VO2max accounted for 23% variance of apolipoprotein A-I in women. In a prospective study, there was no indication that any measured variable was correlated with absolute or relative changes in PA indices in the total group or when analyzed by gender.

CONCLUSIONS

These data confirm that favorable relationship between PA/fitness and blood lipid profile is visible in elderly people but spontaneous changes in habitual PA are not a sufficient stimulus to alter serum lipid and lipoprotein levels in this population. Furthermore, there is no direct association between Lp(a) levels and PA, fitness, or body composition in the elderly men and women.

Expanded blood volumes contribute to the increased cardiovascular performance of endurance-trained older men

To determine whether expanded intravascular volumes contribute to the older athlete's higher exercise stroke volume and maximal oxygen consumption (VO2 max), we measured peak upright cycle ergometry cardiac volumes (99mTc ventriculography) and plasma (125I-labeled albumin) and red cell (NaCr51) volumes in 7 endurance-trained and 12 age-matched lean sedentary men. The athletes had approximately 40% higher VO2 max values than did the sedentary men and larger relative plasma (46 vs. 38 ml/kg), red cell (30 vs. 26 ml/kg), and total blood volumes (76 vs. 64 ml/kg) (all P < 0.05). Athletes had larger peak cycle ergometer exercise stroke volume indexes (75 vs. 57 ml/m2, P < 0.05) and 17% larger end-diastolic volume indexes. In the total group, VO2 max correlated with plasma, red cell, and total blood volumes (r = 0.61-0.70, P < 0.01). Peak exercise stroke volume was correlated directly with the blood volume variables (r = 0.59-0.67, P < 0.01). Multiple regression analyses showed that fat-free mass and plasma or total blood volume, but not red cell volume, were independent determinants of VO2 max and peak exercise stroke volume. Plasma and total blood volumes correlated with the stroke volume and end-diastolic volume changes from rest to peak exercise. This suggests that expanded intravascular volumes, particularly plasma and total blood volumes, contribute to the higher peak exercise left ventricular end-diastolic volume, stroke volume, and cardiac output and hence the higher VO2 max in master athletes by eliciting both chronic volume overload and increased utilization of the Frank-Starling effect during exercise.

Coronary heart disease risk factors of vigorously active sexagenarians and septuagenarians

OBJECTIVE

To examine the dose-response relationship between coronary heart disease risk factors and vigorous exercise in older men.

DESIGN

Physician-supplied medical data were compared with running distance and performance in a national cross-sectional survey of 175 septuagenarian, 935 sexagenarians, and 8672 younger male runners.

RESULTS

Older runners ran significantly more slowly than younger runners. Nevertheless, men 60 years of age and older who ran further had significantly higher plasma high-density lipoprotein (HDL)-cholesterol concentrations (regression slope +/- SE: 0.16 +/- 0.02 mg/dL per km/week, P < .001), and significantly lower ratios of total cholesterol to HDL-cholesterol (-0.009 +/- 0.002 per km/week, P < .001), plasma triglyceride concentrations (-0.309 +/- 0.107 mg/dL per km/week, P < or = .004), systolic and diastolic blood pressures (-0.066 +/- 0.028, and -0.042 +/- 0.016 mm Hg per km/week, respectively, P < or = .02), body mass indices (-0.039 +/- 0.004 kg/m2 per km/week, P < .001), and waist circumferences (-0.107 +/- 0.010 cm per km/week, P < .001). Better 10-kilometer race performance times were also associated (P < or = .001) with higher HDL-cholesterol levels and lower adiposity, blood pressure, triglycerides, and ratios of total cholesterol to HDL-cholesterol levels. Septuagenarians who ran faster and further also had significantly (P < or = .03) higher HDL-cholesterol, lower ratios of total cholesterol to HDL-cholesterol, and slimmer waists. Compared with those less than age sixty, older runners had significantly greater calculated reductions in waist (P = .039) and chest circumferences (P = .009) but significantly less reduction in low-density lipoprotein (LDL) cholesterol (P = .020) per kilometer run per week.

CONCLUSIONS

Age does not limit the potential for vigorous activity to increase HDL-cholesterol or to reduce blood pressure, adiposity, or triglycerides, but it may attenuate improvements in LDL-cholesterol. Sexagenarians and septuagenarians are expected to have reduced heart disease risk in proportion to their vigorous activity.

Physically active women demonstrate less adverse age-related changes in plasma lipids and lipoproteins

The results of this study support the hypothesis that women who exercise regularly have less adverse changes in plasma lipids and lipoproteins with age than sedentary women. This may contribute to the smaller age-related increase in the incidence of coronary heart disease observed in physically active women.

Increases in high-density lipoprotein cholesterol with endurance exercise training are blunted in obese compared with lean men

The effectiveness of endurance exercise training (without concomitant weight loss) for improving lipoprotein lipid levels in obese individuals remains controversial. The purpose of this study was to determine whether lipoprotein lipid responses to endurance exercise training are affected by obesity. Healthy middle-aged and older (57 +/- 2 years) lean (n = 16; body mass index [BMI], 22 to 26 kg/m2), moderately obese (n = 15; BMI, 27 to 30 kg/m2), and obese (n = 15; BMI, 31 to 37 kg/m2) men underwent a 9-month endurance exercise training program. The groups differed in the initial degree of obesity, waist circumference, and waist to hip ratio (WHR), but not in age or maximal aerobic capacity ( VO2max). The obese group had lower baseline levels of high-density lipoprotein cholesterol (HDL-C) and HDL2-C, and higher triglyceride (TG) levels than the lean group. Exercise training increased VO2max to a comparable degree in lean, moderately obese, and obese groups (18%, 24%, and 18%, respectively, P < .01). Exercise training significantly decreased TG levels in all groups, whereas total cholesterol and low-density lipoprotein cholesterol (LDL-C) decreased only in the obese group. Exercise training increased HDL-C and HDL2-C levels in lean (14% and 81%, respectively, P < .05) and moderately obese (7% and 59%, respectively, P < .05) men, whereas neither HDL-C nor HDL2-C changed in obese men. The change in HDL-C correlated negatively with initial BMI (r = -.42, P < .01) and waist circumference (r = -.43, P < .01). These results show that the effects of exercise training on HDL-C are blunted in obese middle-aged and older men, whereas improvements in TG occur independently of the degree of obesity.

Blood pressure risks factors in healthy postmenopausal women: physical activity and hormone replacement

The prevalence of cardiovascular disease (CVD) increases with advancing age in women, particularly after menopause. CVD risk is lower in physically active women relative to their sedentary peers, but the responsible mechanisms are not well understood. The aims of this study were to test the hypotheses that 1) physically active postmenopausal women demonstrate more favorable blood pressure (BP)-related risk factors for CVD than do sedentary healthy women and 2) women on hormone replacement therapy (HRT) also have more favorable levels of these CVD risk factors. BP-related CVD risk factors were measured in physically active women (n = 18; age 55 +/- 1 yr; n = 8 on HRT) and in healthy less-active controls (n = 34; age 59 +/- 1 yr; n = 17 on HRT). Maximal oxygen consumption was higher in the active group, whereas waist-to-hip ratio and waist circumference were lower (all P < 0.005). The active women demonstrated marginally lower (5-8 mmHg; P < or = 0.10) levels of casual, 24-h, and daytime systolic BP (SBP). They also tended to have lower (P = 0.11) daytime SBP loads (percentage of BP recordings > 140/90 mmHg) and lower daytime and nighttime BP variabilities (P = 0.04) and a reduced (P < 0.007) SBP response to submaximal exercise. Women on HRT tended to have lower (3-4 mmHg; P = 0.07) levels of 24-h and nighttime diastolic BP (DBP) relative to the nonusers and smaller (P < 0.04) daytime and 24-h DBP loads. Stepwise multiple regression indicated that waist circumference was the primary predictor of most of the SBP-related CVD risk factors while HRT use was the best predictor for DBP loads. These findings indicate that, in general, physically active postmenopausal women demonstrate more favorable SBP-related CVD risk factors relative to their less-active healthy peers, which may be mediated, in party, by their lower levels of abdominal adiposity. In addition, HRT use tends to be associated with lower levels of DBP-related CVD risk factors.

Relationship of body composition and cardiovascular fitness to lipoprotein lipid profiles in master athletes and sedentary men

A number of studies demonstrate that highly conditioned older athletes are leaner than their sedentary counterparts, and have lipoprotein profiles similar to that of young individuals. It is not clear whether the high maximal aerobic capacity (VO2max) or lean body habitus is the major determinant of the favorable lipoprotein lipid profiles present in older athletes. The objective of this study was to determine whether body composition or VO2max was the major determinant of lipoprotein lipid profiles among 61 master (age 63 +/- 6 years, mean +/- SD) athletes (VO2max > 40 mL/kg/min), 39 age-matched lean (% body fat < 25%), and 51 obese (% body fat > 25%) sedentary men. Plasma high density lipoprotein cholesterol (HDL-C) concentrations were 25% higher in that athletes than in the lean sedentary men, and 42% higher than in the obese sedentary men. Triglyceride (TG) concentrations were 24% lower in the master athletes than in the lean sedentary men, and 51% lower than in the obese sedentary group. Plasma low density lipoprotein cholesterol (LDL-C) levels were 9% lower in the athletes than in the other groups of sedentary individuals. In stepwise multiple regression analysis the percent body fat was the major independent predictor of HDL-C and TG levels accounting for 29% and 41% of the variation in these levels, respectively. The VO2max accounted for an additional 6% of the variance in HDL-C levels and 2% of the variance in TG levels. These cross-sectional results suggest that the favorable lipoprotein profile of master athletes is largely due to their lean body habitus, with a small independent contribution from their higher levels of cardiovascular fitness. Thus, regular vigorous aerobic exercise and maintenance of low body fat may prevent the commonly observed age-associated deterioration in lipoprotein concentrations.

Hemostatic, metabolic, and androgenic risk factors for coronary heart disease in physically active and less active postmenopausal women

Physically active postmenopausal women have a lower incidence of coronary heart disease (CHD) than their more sedentary peers, but little information is available concerning the responsible mechanisms. The primary aim of this study was to test the hypothesis that physically active post-menopausal women demonstrate more favorable levels of hemostatic, metabolic, and androgenic CHD risk factors than less active control subjects. If so, a secondary aim was to determine which of the characteristics associated with a physically active lifestyle, ie, low body fat, a high-carbohydrate/low-fat diet, high maximal aerobic capacity (aerobic fitness), and high levels of physical activity, are most closely related to this lower risk profile. To address these aims, we compared CHD risk factors in physically very active women (n = 14; age, 55 +/- 2 years) with those in healthy, nonobese sedentary control subjects (n = 17; age, 56 +/- 1 years). Maximal aerobic capacity (fitness) was 83% higher (P < .001) in the physically active women. Concentrations of plasminogen activator inhibitor type 1 activity and tissue plasminogen activator antigen were lower (more favorable) (P < .005) in the physically active women versus control subjects, whereas plasma fibrinogen levels did not differ. The physically active women had lower (P < .01) fasting plasma insulin and glucose concentrations as well as smaller responses to an oral glucose challenge. Both total-body and abdominal fat levels were lower (P < .001) and lipid and lipoprotein profiles were generally more favorable (P < .05) in the physically active women.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of long-term low intensity aerobic training and detraining on serum lipid and lipoprotein concentrations in elderly men and women

The effects of long-term low intensity aerobic training and detraining on serum lipid and lipoprotein concentrations were examined in 30 elderly men and women. These subjects were randomly divided into two groups. The training group [n = 15; 7 men and 8 women; mean age 75.5 (SD 5.6) years] agreed to take part in physical training using a treadmill with an exercise intensity at the blood lactate concentration threshold for 30 min 3-6 times a week for 9 months. The other group [n = 15; 7 men and 8 women; mean age 73.7 (SD 4.4) years] did not perform any particular physical training and was followed as the control. Following this training period the high density lipoprotein-cholesterol (HDL-C) had increased significantly (P < 0.01) while the total cholesterol (TC):HDL-C ratio had decreased significantly (P < 0.01) in the training group after 9 months but had not changed in the control group. The TC, triglyceride (TG) and low density lipoprotein-cholesterol (LDL-C) had not changed significantly in either group. No significant difference was seen between the groups throughout the period for TC. LDL-C or TG. There was, however, a significant correlation between the initial TC:HDL-C ratio and the change in the TC:HDL-C ratio following 3 months of training (P < 0.05). After 1 month of detraining in 5 patients, the HDL-C had decreased significantly (P < 0.05) while the TC:HDL-C had increased significantly in the training group (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Risk due to inactivity in physically capable older adults

OBJECTIVES

This study examined the association between recreational physical activity among physically capable older adults and functional status, incidence of selected chronic conditions, and mortality over 3 and 6 years.

METHODS

Data are from three sites of the Established Populations for Epidemiologic Studies of the Elderly.

RESULTS

A high level of recreational physical activity reduced the likelihood of mortality over both 3 and 6 years. Moderate to high activity reduced the risk of physical impairments over 3 years; this effect diminishes after 6 years. A consistent relationship between activity and new myocardial infarction or stroke or the incidence of diabetes or angina was not found after 3 or 6 years.

CONCLUSIONS

Findings suggest that physical activity offers benefits to physically capable older adults, primarily in reducing the risk of functional decline and mortality. Future work must use more objective and quantifiable measures of activity and assess changes in activity levels over time.

Influence of dietary fat, cholesterol and energy on serum lipids at vigorous physical exercise

Seven healthy male volunteers participated in four different heavy cross-country ski trips in the mountains, 1 year apart, wearing a back-pack weighing 30 kg. Each trip lasted for 8 days covering a total distance of 160 km. Serum triglycerides and lipoprotein cholesterol were measured before and after the trip. The different experiments were carried out with the same participants and under the same conditions, but with a varying diet composition. With the four different diets used, a standard diet (3800 kcal day-1, 26% fat, 260 mg cholesterol day-1), a low-energy diet (2300 kcal day-1, 21% fat, 110 mg cholesterol day-1, a high-fat-high-cholesterol diet (3800 kcal day-1, 52% fat, 480 mg cholesterol day-1) and a high-cholesterol diet (3800 kcal day-1, 29% fat, 410 mg cholesterol day-1), a decrease in very low-density lipoprotein-low-density lipoprotein (VLDL-LDL) fraction by 38%, 50%, 41%, and 54%, respectively, was obtained. No significant increase in high-density lipoprotein (HDL) cholesterol was found in the experiments with the standard diet and the low-energy diet, but in the high-fat-high-cholesterol diet experiment the HDL cholesterol increased by 19% and the ratio HDL cholesterol:total cholesterol from 0.327 to 0.490. With the high-cholesterol diet an increase in HDL cholesterol of about the same extent was obtained. In all experiments the serum triglycerides decreased by more than 30% and no significant difference for the different diets was obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of fitness level and the regional distribution of fat on carbohydrate metabolism and plasma lipids in middle- to older-aged men

Many cross-sectional studies have demonstrated the influences of fitness level or the regional distribution of fat on lipid and carbohydrate metabolism; however, the relative contribution of these two variables in the same subjects has not been extensively examined. The purpose of this study was to determine the impact of regional adiposity on plasma lipids and carbohydrate metabolism in middle- to older-aged men with a wide range of fitness levels. Forty-six sedentary and exercise-trained men (age [mean +/- SE], 52.8 +/- 0.88 years) were included in this study. Fitness level was assessed by (a) time to exhaustion, and (2) maximal oxygen uptake achieved during an incremental treadmill test. Plasma lipid levels were determined in the basal, fasting state. Carbohydrate metabolism was evaluated by the glucose and insulin responses (total glucose and insulin areas under the curve, insulin sensitivity index [ISI]) to a 75-g, 2-hour oral glucose tolerance test (OGTT). Abdomen to hip ratio (AHR) was used as the index of regional adiposity. Multiple regression analysis indicated that fitness level and the percentage of body fat were significant predictors (approximately 56% of total variance) for total insulin area under the curve and the ISI. A comparison between the sedentary and trained subjects showed that training resulted in an improved ISI at an equal AHR. Fitness level was also the only significant multiple regression predictor for high-density lipoprotein (HDL)-cholesterol (25% of total variance) and accounted for the greatest amount of variance in triglyceride levels (34%), although AHR was also a significant predictor (6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Weight set-point theory and the high-density lipoprotein concentrations of long-distance runners

Long-distance runners have higher high-density lipoprotein (HDL)-cholesterol concentrations and lower adiposity than sedentary men. Most cross-sectional studies claim that the runners' elevated HDL-cholesterol is not due to the runners' leanness. However, when cross-sectional studies use analysis of covariance (ANCOVA) to adjust for adiposity, or when they compare runners with lean sedentary men, they make an incorrect tacit assumption. They assume that the relationship between change in adiposity and change in HDL-cholesterol in men who have lost fat by running is the same as the cross-sectional difference in HDL-cholesterol between naturally fat and lean sedentary men. Regression slopes for HDL-cholesterol versus adiposity during and at the end of 1 year of running in 35 initially sedentary men suggest this assumption is incorrect; the increase in HDL-cholesterol that accompanies weight loss (-4.28 +/- 1.01 mg/100 mL per kg/m2) is considerably greater than the increase in HDL-cholesterol that is associated with lower adiposity cross-sectionally (-0.78 +/- 0.46 mg/100 mL per kg/m2). These results suggest the following theory: long-distance runners have the HDL metabolism of men who are below their sedentary set-point weight rather than the HDL metabolism of men who are naturally lean without exercising or dieting. This theory was applied to data from 23 published comparisons between long-distance runners and sedentary men.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of body composition and exercise capacity on glucose tolerance, insulin, and lipoprotein lipids in healthy older men: a cross-sectional and longitudinal intervention study

The relationships of age, body composition, and physical conditioning status to glucose tolerance, insulin, and lipoprotein levels were examined in 77 healthy, nonsmoking white male volunteers, aged 46 to 73 years with no evidence of coronary artery or endocrine-metabolic disease. The men had a wide range of body fat (13% to 39%), indexed as waist-to-hip ratio (WHR, 0.84 to 1.08), and maximal aerobic capacity (VO2max, 17 to 48 mL/kg.min). Multiple regression analysis with age, VO2max, WHR, and percent body fat as independent variables demonstrated that fasting plasma insulin, triglyceride (TG), and high density lipoprotein cholesterol (HDL-C) levels were independently related to both percent body fat and WHR. In contrast, fasting plasma glucose levels and insulin responses during oral glucose tolerance tests (OGTT) correlated independently with percent body fat, and glucose responses to OGTT correlated only with WHR. Although fasting plasma TG and HDL-C correlated with glucose and insulin levels, in multiple regression analyses only percent body fat and WHR were the significant independent variables. Fasting total and low density lipoprotein cholesterol values were not related to these variables. To test the effects of weight loss and exercise training on these relationships, 20 obese men of comparable age, percent body fat, WHR, and VO2max were randomly assigned to weight loss or aerobic exercise training programs. A 12% +/- 3% loss in body weight (P less than .01, mean +/- SD) resulted in a 19% +/- 9% decline in body fat (P less than .01) with no change in fat free mass, WHR, or VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)

Physical fitness for retirees

Demographic projections predict a substantial growth in adults age 65 or older relative to the rest of the population. Currently, the cost to employers to provide health benefits for retirees has skyrocketed. To address this issue, a change in the concept of health promotion is advocated to include the maintenance and rehabilitation of functional capacity for retired employees. The physiological and psychological benefits of group exercise are presented. The development of a group exercise program to meet the specific needs of older adults is discussed. Future trends in corporate health promotion are suggested, and issues relevant to the development of exercise programs for older adults are addressed.

Relation of running distance to plasma HDL-cholesterol level in middle-aged male runners

This study examined the relation of training distance to plasma high density lipoprotein cholesterol (HDLC) concentration in runners. Forty-eight male endurance runners, aged from 30 to 57 years, were classified into three groups according to training distance (Grade I: n = 12, 30 km/week; Grade II: n = 22, 60 km/week; Grade III: n = 14, 100 km/week in average running distance), with 12 non-lean and 12 lean subjects as age-matched untrained controls. There were no significant differences in plasma total cholesterol among the groups (194-208 mg/dl on average). HDLC level was significantly higher in the untrained, lean group than in the untrained, non-lean men (63 +/- 13 vs. 46 +/- 8 mg/dl, mean +/- SD). HDLC levels in all the runner groups were significantly higher than in untrained, lean subjects, and no differences were observed among Grade I, II and III runner groups (76 +/- 15, 76 +/- 13, 77 +/- 11 mg/dl, respectively). This study suggests that further increases in HDLC could not occur in response to further elevation of training distance in well-trained runners.

Plasma lipid and lipoprotein profile in elderly male long-distance runners

The purpose of this study was to evaluate plasma lipid and lipoprotein profiles in 30 elderly male long-distance runners (aged 66 +/- 5 years, body fat 12 +/- 2%, mean +/- SD) by comparing them with 30 middle-aged untrained men (43 +/- 8 years, 17 +/- 3%), 30 middle-aged endurance-trained men (45 +/- 8 years, 12 +/- 2%) who were matched for training distance to the elderly runners, and 15 elderly sedentary persons (65 +/- 4 years, 16 +/- 4%). Both elderly and middle-aged runners averaged 43 km/week in the latest year. Maximal oxygen uptake in the elderly runners (48 +/- 5 ml/kg/min) was 60% higher than in age-matched untrained men, but 15% lower than in middle-aged runners. Plasma high-density lipoprotein cholesterol (HDLC) was significantly higher in the elderly runners than in their age-matched counterparts (77 vs. 59 mg/dl), but not different from the middle-aged runners. The middle-aged runners had lower plasma low-density lipoprotein cholesterol (LDLC) concentrations than their untrained counterparts (114 vs. 129 mg/dl), whereas LDLC level in the elderly runners was almost identical to that of the age-matched untrained men (127 vs. 119 mg/dl). Total cholesterol concentration in the elderly runners (219 mg/dl) was 11% higher than in the age-matched untrained men, whereas there was no difference between the middle-aged trained and untrained men. The remarkable reduction of the LDLC/HDLC ratio in the elderly runners, therefore, is attributable to the elevated HDLC rather than lowered LDLC compared with the age-matched sedentary men (1.7 vs. 2.2).(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of 7 years of intense exercise training on patients with coronary artery disease

The purpose of this study was to evaluate the effects of long-term exercise training on maximal aerobic exercise capacity, evidence of myocardial ischemia and plasma lipid-lipoprotein concentrations in patients with coronary artery disease. Nine men with coronary artery disease, aged 57 +/- 2 years, who had completed 12 months of supervised intense exercise training were restudied after 6 additional years during which they continued to exercise. The first 12 months of training resulted in a 44% increase in maximal oxygen consumption (VO2max) from 25.0 +/- 1.3 to 35.9 +/- 1.5 ml X kg-1 X min-1 (p less than 0.001). The VO2max after 6 additional years (total 7 years) of intense training was 36.8 +/- 2.4 ml X kg-1 X min-1. Plasma high density lipoprotein (HDL)-cholesterol concentration increased from 38 +/- 3 to 45 +/- 4 mg X dl-1 at 12 months and rose further to 53 +/- 5 mg X dl-1 at 6 years of follow-up (p less than 0.05). The atherogenic index (total cholesterol/HDL-cholesterol ratio) decreased from 5.8 +/- 0.4 to 4.9 +/- 0.4 by 12 months (p less than 0.01) and to 4.1 +/- 0.4 after 6 additional years of training (p less than 0.05). Although the maximal heart rate-pressure product was 14% higher after 12 months of training, maximal ST segment depression was significantly less, 0.27 +/- 0.06 versus 0.19 +/- 0.04 mV (p less than 0.05); this improvement was maintained after 6 years of additional training. These data provide evidence that the beneficial effects of a program of intense exercise training can be maintained for long periods in some motivated patients with coronary artery disease who continue to exercise.

Fitness, Heart Disease, and High-Density Lipoproteins: A Look at the Relationships

In brief: Coronary heart disease (CHD) causes over 500,000 deaths per year in the United States, although this rate is declining. Preventive strategies have focused on reducing modifiable risk factors such as hypertension, cigarette smoking, and serum cholesterol levels. However, physical activity can exert a preventive effect as well. High-density lipoprotein cholesterol (HDL-C), which seems to be the most critical determinant of risk of CHD, increases with greater fitness levels. On the basis of this literature review, the author recommends that future research programs include more precise measurements of fitness as well as determination of certain parameters of lipid metabolism, such as HDL-C, apolipoproteins, and lipoprotein lipase.

Glucose tolerance and lipid-lipoprotein levels in middle-aged powerlifters

The purpose of this study was to obtain information regarding the effects of a form of strength training (powerlifting) on certain coronary artery disease (CAD) risk factors in middle-aged men. The risk factors studied were the plasma lipid-lipoprotein profile, glucose tolerance and plasma insulin levels, all of which have been shown to be favourably influenced by endurance training in middle-aged and older men. Five elite powerlifters (52 +/- 9 years) were compared to distance runners and sedentary controls of similar age with whom they were matched in terms of body fatness as estimated from skin-fold thickness measurements. The powerlifters had a significantly (P less than 0.01) lower HDL cholesterol (HDL-C) level (34 +/- 4 mg/100 ml) than the sedentary controls (48 +/- 12 mg/100 ml) and runners (54 +/- 8 mg/100 ml). The total cholesterol to HDL-C ratio, a good indicator of CAD risk, was 41% higher in the powerlifters than in the controls, and 57% higher than in the runners (both P less than 0.01). The total area under the glucose tolerance curve during an oral glucose tolerance test (OGTT) for the powerlifters was 74% higher than for the sedentary controls (P less than 0.05) and 229% higher than for runners (P less than 0.01). Similarly, the total area under the OGTT insulin curve for the powerlifters was 68% higher than for sedentary controls and 332% higher than for the runners (P less than 0.001). These findings suggest that middle-aged powerlifters, in marked contrast to endurance athletes, have an increased risk of developing CAD.