Blood lipid and lipoprotein adaptations to exercise: a quantitative analysis

Firefighters' physical activity: relation to fitness and cardiovascular disease risk

PURPOSE

Cardiovascular disease (CVD) accounts for 44% of on-duty deaths among US firefighters with a markedly higher event risk during strenuous duties compared with nonemergencies. Sedentary persons are most susceptible to such CVD "event-triggering" due to irregular bouts of vigorous physical activity (PA). Conversely, regular PA and increased levels of cardiorespiratory fitness (CRF) protect against CVD triggering. Therefore, the present study evaluates PA measures in structural firefighters and their relationship to CRF and CVD risk factors.

METHODS

Cross-sectional cohort study of 527 Midwestern career firefighters. PA frequency, duration, and intensity measures from a questionnaire along with total weekly aerobic exercise were analyzed. CRF was measured by maximal exercise tolerance testing. CVD risk parameters included body composition, blood pressure, and metabolic profiles. Group differences were compared using general linear models.

RESULTS

Measures of increasing frequency, duration, intensity of PA, and total weekly exercise (min) were significantly associated with higher CRF (P < 0.001) after adjustment for age, body mass index (BMI), and smoking status. After multivariate adjustment, increasing PA frequency was significantly associated with reduced total cholesterol-HDL ratio, triglycerides, and glucose, as well as HDL increments. Increasing BMI category was associated with significant decrements in CRF and unfavorable dose-response trends in CVD risk factors (P < 0.001), even for those reporting very frequent, sustained, and intense PA.

CONCLUSIONS

Increasing PA has beneficial independent effects on CRF, and PA frequency has similar favorable effects on CVD risk profiles. Whereas PA was beneficial regardless of BMI category, increasing BMI category had strong independent unfavorable effects. PA should be strongly encouraged for all firefighters with the highest priority given to PA frequency, followed by PA duration and intensity.

Cardiometabolic risk in US Army recruits and the effects of basic combat training

BACKGROUND

Cardiometabolic disease risk in US military recruits and the effects of military training have not been determined. This study examined lifestyle factors and biomarkers associated with cardiometabolic risk in US Army recruits (209; 118 male, 91 female, 23 ± 5 yr) before, during, and after basic combat training (BCT).

METHODOLOGY/PRINCIPAL FINDINGS

Anthropometrics; fasting total (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol; triglycerides (TG); glucose; and insulin were measured at baseline and every 3 wks during the 10 wk BCT course. At baseline, 14% of recruits were obese (BMI>30 kg/m(2)), 27% were cigarette smokers, 37% were sedentary, and 34% reported a family history of cardiometabolic disease. TC was above recommended levels in 8%, LDL in 39%, TG in 5%, and glucose in 8% of recruits, and HDL was below recommended levels in 33% of recruits at baseline. By week 9, TC decreased 8%, LDL 10%, TG 13%, glucose 6% and homeostasis model assessment of insulin resistance (HOMA-IR) 40% in men (P<0.05). In women, TC, LDL, glucose and HOMA-IR were decreased from baseline at weeks 3 and 6 (P<0.05), but were not different from baseline levels at week 9. During BCT, body weight declined in men but not women, while body fat percentage declined in both men and women (P<0.05).

CONCLUSIONS/SIGNIFICANCE

At the start of military service, the prevalence of cardiometabolic risk in US military recruits is comparable to that reported in similar, college-aged populations. Military training appears to be an effective strategy that may mitigate risk in young people through improvements in lipid profiles and glycemic control.

Fatness, fitness, and cardiometabolic risk factors in middle-aged white men

The objective was to test the hypothesis that traditional and novel cardiometabolic risk factors would be significantly different in groups of men of different fatness and fitness. Total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, insulin, high-sensitivity C-reactive protein, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, leptin, adiponectin, tumor necrosis factor-α, interleukin-6, interleukin-10, fibrinogen, and insulin resistance were assessed in 183 nonsmoking white men aged 35 to 53 years, including 62 who were slim and fit (waist girth ≤90 cm and maximal oxygen consumption [VO(2)max] above average), 24 who were slim and unfit (waist girth ≤90 cm and VO(2)max average or below), 39 who were fat and fit (waist girth ≥100 cm and VO(2)max above average), and 19 who were fat and unfit (waist girth ≥100 cm and VO(2)max average or below). Seventy-six percent gave blood on 2 occasions, and the average of 1 or 2 blood tests was used in statistical tests. Waist girth (centimeters) and fitness (milliliters of oxygen per kilogram of fat-free mass) were associated with high-density lipoprotein cholesterol, leptin, and insulin resistance after adjustment for age, saturated fat intake, and total energy intake. High-density lipoprotein cholesterol, triglycerides, alanine aminotransferase, and insulin resistance were significantly different in men who were fat and fit and those who were fat and unfit. These data suggest that differences in lipid and lipoprotein concentrations, liver function, and insulin resistance may explain why the risks of chronic disease are lower in men who are fat and fit than those who are fat and unfit.

American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise

The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

Physiological adaptation of a mature adult walking the Alps

Research on endurance locomotion has mainly focused on elite athletes rather than common middle-aged subjects. Our report describes the physiological and hematological adaptation of a healthy, active 62-year-old man who trekked alone along a 1300 km/3 month course of Alpine paths (Via Alpina). The following procedures were conducted: pre- and post-trekking and fortnightly field anthropometry (total and lean body mass), functional tests (isometric maximal voluntary force, spontaneous walking speed, relative metabolic cost, and peak oxygen consumption) and clinical chemistry/hematological measurements with laboratory instruments; daily self-administered effort measurements using portable devices along the route (walked distance, ascent, descent, time, metabolic consumption, and cost). Despite the tough trekking route, the subject completed the trek without any worsening of his performance, or any significant health or functional problems. In addition, his peak oxygen consumption increased by 13.2%. His successful adaptation may be attributed to his constant, repeated middle-intensity and extensive exercise and lengthy exposure to high altitude. The clinical chemistry/hematological measurements documented his physiological adaptation. In conclusion, we show how an active, middle-aged man can successfully face endurance trekking, not only without any harm to his health or functions but also with an increase in his capacity to support specific effort.

Cardiovascular and metabolic effects of community based resistance training in an older population

Ageing is associated with decreases in strength and cardiovascular fitness, and increased cardiovascular risk factors. The aim of the current study was to determine the effectiveness of 16 weeks of community based resistance compared to flexibility training on strength, cardiovascular fitness and cardiovascular and metabolic parameters in a group of previously sedentary, healthy older men and women. A randomised controlled crossover intervention study. Forty nine healthy sedentary participants (23 males; age 66.7 ± 4.3 years; weight 78.6 ± 15.4 kg; mean ± SD) completed 16 weeks of supervised community-based resistance training and 16 weeks of flexibility training in a randomised order. Prior to and following each intervention, participants were assessed for muscle strength, cardiovascular fitness (VO(2 peak)), fasted blood lipids and blood glucose, insulin and insulin resistance. Resistance training resulted in significant increases in knee extension (+25.7 Nm; p < 0.001) and knee flexion strength (+8.9 Nm; p = 0.048) and decreases in fasting total cholesterol (-0.51 mmol L(-1); p = 0.001), HDL cholesterol (-0.12 mmol L(-1); p = 0.035), LDL cholesterol (-0.35 mmol L(-1); p = 0.022), glucose (-0.42 mmol L(-1); p < 0.001), insulin (-1.28 μU/mL; p = 0.049) and insulin resistance (-0.50 μU/mL; p = 0.004) compared to the flexibility protocol. No significant changes between the treatments were observed in VO(2peak) (+2.04 mL kg(-1)min(-1); p = 0.12). Community based resistance training is suitable for improving strength and reducing cardiovascular and metabolic risk factors in healthy older individuals.

Effects of aerobic exercise on lipid profiles and high molecular weight adiponectin in Japanese workers

BACKGROUND

The metabolic syndrome is characterized by the accumulation of several metabolic risk factors. It is important to improve physical activity and dietary habits to reduce the risk of cardiovascular disease in humans.

METHODS

The study participants participated in a weekly aerobic exercise program that included a session composed of a brief meeting, warm-up exercises, and primary exercises (low and high impact, stretch, muscle training, and cooling down). To evaluate the effect of this intervention we measured body fat composition, holding power, and quality of life assessment. Blood tests were also carried out before and every 3 months during the study.

RESULTS

Of the 37 participants enrolled in the exercise group, 31 (83.8%) completed the 12-week program. The control group consisted of 42 subjects, 36 (85.7%) of whom were available for follow-up at the end of the 12-week study period. In the exercise group, weight, body fat percentage, waist circumference, the World Health Organization quality of life 26 (WHO-QOL 26) score, triglyceride, total cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol had improved significantly at the end of three months. The high molecular weight adiponectin concentration of the participants in the exercise group increased during the 9-month period of the study, although this change did not reach statistical significance compared with pre-exercise.

CONCLUSION

Aerobic exercise led to an improvement in body composition and lipid profiles. High molecular weight adiponectin concentrations tended to improve compared with pre-aerobic exercise levels.

Hypercholesterolemia and microvascular dysfunction: interventional strategies

Hypercholesterolemia is defined as excessively high plasma cholesterol levels, and is a strong risk factor for many negative cardiovascular events. Total cholesterol levels above 200 mg/dl have repeatedly been correlated as an independent risk factor for development of peripheral vascular (PVD) and coronary artery disease (CAD), and considerable attention has been directed toward evaluating mechanisms by which hypercholesterolemia may impact vascular outcomes; these include both results of direct cholesterol lowering therapies and alternative interventions for improving vascular function. With specific relevance to the microcirculation, it has been clearly demonstrated that evolution of hypercholesterolemia is associated with endothelial cell dysfunction, a near-complete abrogation in vascular nitric oxide bioavailability, elevated oxidant stress, and the creation of a strongly pro-inflammatory condition; symptoms which can culminate in profound impairments/alterations to vascular reactivity. Effective interventional treatments can be challenging as certain genetic risk factors simply cannot be ignored. However, some hypercholesterolemia treatment options that have become widely used, including pharmaceutical therapies which can decrease circulating cholesterol by preventing either its formation in the liver or its absorption in the intestine, also have pleiotropic effects with can directly improve peripheral vascular outcomes. While physical activity is known to decrease PVD/CAD risk factors, including obesity, psychological stress, impaired glycemic control, and hypertension, this will also increase circulating levels of high density lipoprotein and improving both cardiac and vascular function. This review will provide an overview of the mechanistic consequences of the predominant pharmaceutical interventions and chronic exercise to treat hypercholesterolemia through their impacts on chronic sub-acute inflammation, oxidative stress, and microvascular structure/function relationships.

Association of the LIPG 584C > T polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

BACKGROUND

Endothelial lipase (EL) is a major determinant of high-density lipoprotein-cholesterol (HDL-C) metabolism, but the association of endothelial lipase gene (LIPG) polymorphism and serum HDL-C levels is scarce and conflicting in diverse populations. Bai Ku Yao is an isolated subgroup of the Yao minority in China. This study was designed to detect the association of LIPG 584C > T (rs2000813) polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

METHODS

A total of 645 subjects of Bai Ku Yao and 638 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the LIPG 584C > T was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

RESULTS

The levels of serum total cholesterol (TC), HDL-C, low-density lipoprotein cholesterol (LDL-C) and apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.05 - 0.001). The frequency of C and T alleles was 73.5% and 26.5% in Bai Ku Yao, and 67.9% and 32.1% in Han (P < 0.01); respectively. The frequency of CC, CT and TT genotypes was 50.4%, 46.2% and 3.4% in Bai Ku Yao, and 41.4%, 53.1% and 5.5% in Han (P < 0.01); respectively. Serum HDL-C levels in both ethnic groups were different among the three genotypes (P < 0.05 for each). Serum TC levels in both ethnic groups were also different between the CC and CT/TT genotypes (P < 0.05 for each). The T allele carriers had higher serum HDL-C and TC levels than the T allele noncarriers. Multivariate logistic regression analysis showed that the levels of HDL-C and ApoB were correlated with genotypes in Bai Ku Yao (P < 0.05 for each), whereas the levels of TC and HDL-C were associated with genotypes in Han Chinese (P < 0.05 and P < 0.01). Serum lipid parameters were also correlated with several environmental factors in the both ethnic groups.

CONCLUSIONS

The frequency of LIPG 584T allele is lower in Bai Ku Yao than in Han Chinese. The LIPG 584T allele is associated with increased serum HDL-C, TC and ApoB levels. The differences in serum HDL-C, TC and ApoB levels between the two ethnic groups might partly result from different genotypic and allelic frequencies of LIPG 584C > T or different LIPG-enviromental interactions.

Effects of exercise training on physical impairment, arterial stiffness and health-related quality of life in patients with chronic kidney disease: a pilot study

BACKGROUND

Patients with chronic kidney disease (CKD) have impaired performance in physical tasks, lower health-related quality of life and high cardiovascular morbidity and mortality. Moderate intensity exercise has been shown to provide cardiovascular and metabolic benefits in healthy individuals and patients without CKD. Long-term exercise training is recommended as a vital component in the management of a number of chronic diseases. This randomized controlled pilot project examined the effects of exercise in predialysis CKD patients.

METHODS

Ten patients were randomized to 12 months of exercise (EX) and 10 to standard care (CT). We compared the difference between the two groups in physical impairment (VO(2peak) and endurance time [ET]), arterial stiffness (augmentation index [AI]) and health-related quality of life (EuroQol EQ-5D and Short Form-36 questionnaires) (all measured at baseline and 12 months).

RESULTS

The difference between EX and CT was statistically significant for VO(2peak) (3.59 ml O(2)/kg/min; 95% CI 0.92, 6.26; P = 0.01), ET (10.97 min; 95% CI 4.34, 17.59; P = 0.003) and AI (-11.7%; 95% CI -18.79, -4.61; P = 0.003). Clinically important changes were noted in EQ-5D and SF-36.

CONCLUSIONS

This study suggests that long-term exercise training improves physical impairment, arterial stiffness and health-related quality of life in patients with predialysis CKD. A larger randomized trial is required to examine the impact of exercise on markers of cardiovascular risk and quality of life in predialysis CKD patients.

A randomized clinical trial of home-based exercise combined with a slight caloric restriction on obesity prevention among women

OBJECTIVE

The study investigated the effectiveness of home-based exercise combined with a slight caloric restriction on weight change during 12 months in non-obese women.

METHODS

A randomized clinical trial with a factorial design was conducted from 2003 to 2005. Two hundred three middle-aged women (Rio de Janeiro/Brazil), 25-45 years, were randomly assigned to one of two groups: control (CG) and home-based exercise (HB). The HB group received a booklet on aerobic exercise that could be practiced at home (3 times/week-40 min/session), in low-moderate intensity, during 12 months. Both groups received dietary counseling aimed at a slight energy restriction of 100-300 calories per day.

RESULTS

The HB experienced a greater weight loss in the first 6 months (-1.4 vs. -0.8 kg; p=0.04), but after 12 months there was no differences between groups (-1.1 vs. -1.0; p=0.20). Of the serum biochemical markers, HDL cholesterol showed major change, with an increase at month 12 of 18.3mg/dl in the HB compared to 9.5 in the CG (p<0.01).

CONCLUSION

Home-based exercise promoted greater weight reduction during the first 6 months after which no further benefits are observed. Continuous favorable changes in HDL cholesterol after 1 year suggest that home-based exercise promote health benefits.

The ABC of Physical Activity for Health: a consensus statement from the British Association of Sport and Exercise Sciences

Our understanding of the relationship between physical activity and health is constantly evolving. Therefore, the British Association of Sport and Exercise Sciences convened a panel of experts to review the literature and produce guidelines that health professionals might use. In the ABC of Physical Activity for Health, A is for All healthy adults, B is for Beginners, and C is for Conditioned individuals. All healthy adults aged 18-65 years should aim to take part in at least 150 min of moderate-intensity aerobic activity each week, or at least 75 min of vigorous-intensity aerobic activity per week, or equivalent combinations of moderate- and vigorous-intensity activities. Moderate-intensity activities are those in which heart rate and breathing are raised, but it is possible to speak comfortably. Vigorous-intensity activities are those in which heart rate is higher, breathing is heavier, and conversation is harder. Aerobic activities should be undertaken in bouts of at least 10 min and, ideally, should be performed on five or more days a week. All healthy adults should also perform muscle-strengthening activities on two or more days a week. Weight training, circuit classes, yoga, and other muscle-strengthening activities offer additional health benefits and may help older adults to maintain physical independence. Beginners should work steadily towards meeting the physical activity levels recommended for all healthy adults. Even small increases in activity will bring some health benefits in the early stages and it is important to set achievable goals that provide success, build confidence, and increase motivation. For example, a beginner might be asked to walk an extra 10 min every other day for several weeks to slowly reach the recommended levels of activity for all healthy adults. It is also critical that beginners find activities they enjoy and gain support in becoming more active from family and friends. Conditioned individuals who have met the physical activity levels recommended for all healthy adults for at least 6 months may obtain additional health benefits by engaging in 300 min or more of moderate-intensity aerobic activity per week, or 150 min or more of vigorous-intensity aerobic activity each week, or equivalent combinations of moderate- and vigorous-intensity aerobic activities. Adults who find it difficult to maintain a normal weight and adults with increased risk of cardiovascular disease or type 2 diabetes may in particular benefit from going beyond the levels of activity recommended for all healthy adults and gradually progressing towards meeting the recommendations for conditioned individuals. Physical activity is beneficial to health with or without weight loss, but adults who find it difficult to maintain a normal weight should probably be encouraged to reduce energy intake and minimize time spent in sedentary behaviours to prevent further weight gain. Children and young people aged 5-16 years should accumulate at least 60 min of moderate-to-vigorous-intensity aerobic activity per day, including vigorous-intensity aerobic activities that improve bone density and muscle strength.

Effect of creatine supplementation as a potential adjuvant therapy to exercise training in cardiac patients: a randomized controlled trial

OBJECTIVE

To investigate the effect of oral creatine supplementation in conjunction with an exercise programme on physical fitness in patients with coronary artery disease or chronic heart failure.

DESIGN

Single centre double-blind randomized placebo controlled trial.

SETTING

Cardiac rehabilitation centre.

SUBJECTS AND INTERVENTION

70 (4 women) cardiac patients (age 57.5 (8.4) years) were randomized to a placebo (n = 37) or creatine (n = 33) treatment for three months. Combined aerobic endurance and resistance training (three sessions/ week) was performed during supplementation.

MAIN MEASURES

Aerobic power was determined during graded bicycle testing, knee extensor peak isometric and isokinetic strength, endurance and recovery were assessed by an isokinetic dynamometer, and health related quality of life was evaluated with the SF-36 and MacNew Heart Disease questionnaires. In addition, blood samples were taken after an overnight fast and 24 hour urinary collection was performed.

RESULTS

At baseline there were no significant differences between both groups. We observed main time effects for aerobic power, muscle performance, health related quality of life, high density lipoprotein cholesterol and triglycerides (pre vs post; P<0.05 for all). However, changes after training were similar between placebo group and creatine group (P>0.05). Further, no detrimental effect on renal or liver function was observed nor were there any reports of side effects.

CONCLUSION

Oral creatine supplementation in combination with exercise training does not exert any additional effect on the improvement in physical performance, health related quality of life, lipid profile in patients with coronary artery disease or chronic heart failure than exercise training alone.

Association of LIPC -250G>A polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations

Background

The association between -250G>A polymorphism in the promoter region of the hepatic lipase gene (LIPC) and plasma high-density lipoprotein cholesterol (HDL-C) concentration is contradictory in diverse ethnics. Bai Ku Yao is an isolated subgroup of the Yao minority in China. This study was designed to detect the association of LIPC -250G>A (rs2070895) polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

Methods

A total of 778 subjects of Bai Ku Yao and 648 participants of Han Chinese aged 15-80 were randomly selected from our previous stratified randomized cluster samples. Genotyping of the LIPC -250G>A was performed by polymerse chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

Results

The levels of serum total cholesterol (TC), HDL-C, low-density lipoprotein cholesterol (LDL-C) and apolipoprotein (Apo) AI were lower in Bai Ku Yao than in Han (P < 0.01 for all). The frequencies of GG, GA and AA genotypes were 50.0%, 43.3% and 6.7% in Bai Ku Yao, and 35.7%, 50.6% and 13.7% in Han (P < 0.01); respectively. The frequencies of G and A alleles were 71.7% and 28.3% in Bai Ku Yao, and 61.0% and 39.0% in Han (P < 0.01). The levels of HDL-C and the ratio of ApoAI to ApoB in Bai Ku Yao were lower in GG genotype than in GA or AA genotype (P < 0.05-0.01). The levels of TC, HDL-C, LDL-C and ApoB in Han were lower in GG genotype than in GA or AA genotype (P < 0.05-0.01). The levels of HDL-C and the ratio of ApoAI to ApoB in Bai Ku Yao, and the levels of HDL-C, LDL-C and ApoB in Han were correlated with genotype and/or allele (P < 0.05 for all). Serum lipid parameters were also correlated with age, sex, alcohol consumption, cigarette smoking, blood pressure, body weight, and body mass index in both ethnic groups.

Conclusions

The differences in the serum lipid profiles between the two ethnic groups might partly result from different genotypic frequency of LIPC -250G>A or different LIPC-enviromental interactions.

Resistance training improves cardiovascular risk factors in obese women despite a significative decrease in serum adiponectin levels

Increased circulating adiponectin and insulin sensitivity are usually observed after body fat loss induced by a weight-loss diet. Progressive resistance training (PRT) without a concomitant weight-loss diet significantly decreases visceral fat, thus improving insulin sensitivity. Therefore, the purpose of this study was to ascertain the effects of combined 16-week PRT and weight-loss diet on circulating adiponectin and insulin sensitivity index. Thirty-four obese (BMI: 30-40 kg/m(2)) women, aged 40-60 year, were randomized to three groups: a control group (C; n = 9); a diet group (WL; n = 12) with a caloric restriction of 500 kcal/d; and a diet plus resistance training group (WL+RT; n = 13) with the same caloric restriction as group WL and a 16-week supervised whole body PRT of two sessions/week. Both WL and WL+RT groups showed similar decreases in body mass (-6.3% and -7.7%) and visceral fat (-19.9% and -20.5%). WL resulted in an expected increase in circulating levels of adiponectin (P = 0.07) and insulin sensitivity. However, circulating total adiponectin decreased (P < 0.05) in WL+RT group, whereas an improvement in different cardiovascular risk factors (insulin sensitivity, low-density lipoprotein cholesterol (LDL-C), etc.) was observed. In conclusion, in obese women a 16-week combined PRT and weight-loss diet is accompanied by significant improvements in different cardiovascular risk factors in spite of a significant decrease of circulating adiponectin.

Leisure-time physical activity and risk of type 2 diabetes in patients with established vascular disease or poorly controlled vascular risk factors

AIM

To investigate the effect of leisure-time physical activity on the incidence of type 2 diabetes (T2DM) in patients with manifest arterial disease, or poorly controlled risk factors.

METHODS

We examined 3940 patients with manifest arterial disease, hypertension or hyperlipidemia, aged 55.2+/-12.2 years. Leisure-time physical activity was measured by a questionnaire and metabolic equivalent (MET) hours per week (h/wk) were calculated. Incident T2DM was evaluated by a specific diabetes questionnaire.

RESULTS

Most patients (65%) were physically inactive (0METh/wk), 12% were insufficiently physically active (0-10.5METh/wk) and 23% were sufficiently physically active (>or=10.5METh/wk). During a mean follow-up of 4.7 years, 194 (5%) incident cases of T2DM occurred. Sufficiently physically active patients had a lower incidence of diabetes (hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.37-0.83). Patients who were physically active and not-obese (BMI<30kg/m(2)) were at the lowest risk for developing T2DM (HR 0.18, 95% CI 0.12-0.28) compared with patients who were physically inactive and obese.

CONCLUSIONS

Leisure-time physical activity is associated with a decreased risk of T2DM in patients with manifest arterial disease, or poorly controlled risk factors. The combination of physical activity and non-obesity is associated with an even lower risk of the development of type 2 diabetes than the sum of their independent, protective effect.

The utility of physical activity in the management of global cardiometabolic risk

Major health organizations promote the adoption of a healthy lifestyle, composed of sufficient daily physical activity and a balanced diet for the prevention and management of type 2 diabetes (T2D) and cardiovascular disease risk. In particular, it is recommended that adults accumulate 30 min of moderate-intensity aerobic physical activity on most days of the week. Despite these recommendations, a physically active lifestyle is seldom adopted, and the majority of the North American population remains sedentary. Although the optimal strategy for promoting physical activity in today's environment remains elusive, the evidence for the utility of physical activity in the management of risk factors for T2D and cardiovascular disease is overwhelming. This review examines the influence of aerobic-type physical activity on components of global cardiometabolic risk, that is, the traditional and emerging risk factors for cardiovascular disease and T2D, including visceral obesity, insulin resistance, hypertension, atherogenic dyslipidemia, thrombosis, inflammation, and cardiorespiratory fitness. Where possible, specific consideration is given to the independent effects of an acute bout of physical activity vs. chronic physical activity with weight loss vs. chronic physical activity without weight loss.

Exercise training, lipid regulation, and insulin action: a tangled web of cause and effect

Lipids are a strong mediator of coronary artery disease and cardiovascular risk. Although the effects of exercise to improve high-density lipoprotein (HDL) cholesterol and serum triglycerides (TGs) have been known for some time, the effects of different amounts and intensities of exercise on fasting and postprandial serum lipids are little understood. Normal lipid physiology is perturbed in insulin resistant states, where inhibition of lipolysis is impaired, particularly in the postprandial period when excursions in insulin and serum TGs are particularly high. In our STRRIDE (Studies of a Targeted Risk Reduction Intervention through Defined Exercise) study, three important metabolic cardiovascular risk-related variables were improved more by moderate intensity than vigorous-intensity exercise. Moderate-intensity exercise was significantly more effective at lowering TGs and improving insulin sensitivity than was vigorous exercise. Additionally, a composite score for metabolic syndrome improved significantly with low-amount/moderate, but did not with low-amount/vigorous-intensity exercise. That all three of these strong, independent, cardiovascular risk factors were significantly affected by moderate-intensity exercise suggests that regular walking exercise might be as effective, if not more so, than more vigorous exercise in favorably modifying cardiovascular risk. Despite the impressive effects of regular exercise on fasting lipids and atherogenic dyslipidemia, they are more impressive when compared with the trajectory of changes that occur in individuals that remain inactive, without regular exposure to regular exercise. A scientific priority for future investigations should be to study the independent and combined effects of exercise intensity and amount on exercise responses through a direct comparison between two groups matched on amount but differing in intensity.

Endurance exercise training effects on body fatness, VO2max, HDL-C subfractions, and glucose tolerance are influenced by a PLIN haplotype in older Caucasians

Perilipins are lipid droplet-coating proteins that regulate intracellular lipolysis in adipocytes. A haplotype of two perilipin gene (PLIN) single nucleotide polymorphisms, 13041A>G and 14995A>T, has been previously associated with obesity risk. Furthermore, the available data indicate that this association may be modified by sex. We hypothesized that this haplotype would associate with body fatness, aerobic fitness, and a number of cardiovascular (CV) risk factor phenotypes before and after a 6-mo endurance exercise training program in sedentary older Caucasians. The major haplotype group (13041A/14995A; n = 57) had significantly lower body mass index (BMI) and body fatness compared with noncarriers of the AA haplotype (n = 44) before the training intervention. Training improved body composition in both groups, but fatness remained higher in noncarriers than AA carriers after training. This fat retention in noncarriers blunted their maximal oxygen uptake (Vo(2 max)) adaptation to training. Female noncarriers had substantially higher concentrations of several conventionally and NMR-measured HDL-C subfractions than male noncarriers before and after training, but only minimal differences were found between the sexes in the AA haplotype group. Haplotype group differences in baseline and after-training responses to an oral glucose tolerance test (OGTT) also differed by sex, as noncarrier men had the highest baseline area under the insulin curve (insulin AUC), but were the only group to significantly improve insulin AUC with training. The insulin sensitivity index and plasma glucose responses to the OGTT were more favorable in AA carriers than noncarriers before and after training. Overall, our findings suggest that PLIN variation explains some of the interindividual differences in the response of obesity and CV phenotypes to exercise training. Furthermore, these data contribute to the growing understanding of PLIN as a candidate gene for human obesity and the cardiometabolic consequences of excess adiposity.

Increased participation in activities of daily living is associated with lower cholesterol levels in people with spinal cord injury

Hetz SP, Latimer AE, Martin Ginis KA, Buchholz AC, and the SHAPE-SCI Research Group. Increased participation in activities of daily living is associated with lower cholesterol levels in people with spinal cord injury.

OBJECTIVE

To evaluate the relationships between activities of daily living (ADLs) participation and coronary heart disease (CHD) risk factors in people with spinal cord injury.

DESIGN

Cross-sectional.

SETTING

Community, university, hospital.

PARTICIPANTS

Participants (N=75) from the Study of Health and Activity in People With Spinal Cord Injury study (61 men, 14 women).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Physical Activity Recall Assessment for People With Spinal Cord Injury and CHD risk factor assessment including waist circumference, total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol, and triglycerides.

RESULTS

Using generalized linear models, and controlling for leisure time physical activity and covariates, increased Mobility ADLs (transferring and wheeling) were associated with lower plasma total cholesterol and LDL. No other significant relationships emerged.

CONCLUSIONS

Mobility ADLs were associated with lower total cholesterol and LDL. However, neither Total ADLs nor Domestic ADLs were associated with CHD risk. Further investigation is needed to determine causality between Mobility ADLs and CHD risk.

Dietary patterns are associated with metabolic syndrome in adult Samoans

The prevalence of metabolic syndrome has reached epidemic levels in the Samoan Islands. In this cross-sectional study conducted in 2002-2003, dietary patterns were described among American Samoan (n = 723) and Samoan (n = 785) adults (> or =18 y) to identify neo-traditional and modern eating patterns and to relate these patterns to the presence of metabolic syndrome using Adult Treatment Panel III criteria. The neo-traditional dietary pattern, similar across both polities, was characterized by high intake of local foods, including crab/lobster, coconut products, and taro, and low intake of processed foods, including potato chips and soda. The modern pattern, also similar across both polities, was characterized by high intake of processed foods such as rice, potato chips, cake, and pancakes and low intake of local foods. The neo-traditional dietary pattern was associated with significantly higher serum HDL-cholesterol in American Samoa (P-trend = 0.05) and a decrease in abdominal circumference in American Samoa and Samoa (P-trend = 0.004 and 0.01, respectively). An inverse association was found with metabolic syndrome, although it did not reach significance (P = 0.23 in American Samoa; P = 0.13 in Samoa). The modern pattern was significantly positively associated with metabolic syndrome in Samoa (prevalence ratio = 1.21 for the fifth compared with first quintile; 95% CI: 0.93.1.57; P-trend = 0.05) and with increased serum triglyceride levels in both polities (P < 0.05). Reduced intake of processed foods high in refined grains and adherence to a neo-traditional eating pattern characterized by plant-based fiber, seafood, and coconut products may help to prevent growth in the prevalence of metabolic syndrome in the Samoan islands.

Resistance exercise plus to aerobic activities is associated with better lipids' profile among healthy individuals: the ATTICA study

BACKGROUND

The influence of different types of exercise on risk factors for cardiovascular diseases has rarely been investigated. The aim of the present work was to evaluate the effect of adding resistance exercise to aerobic activities on lipid-lipoprotein profile, in a representative sample of men and women from the province of Attica, Greece.

METHODS

We randomly enrolled 1514 and 1528 healthy men and women, respectively, stratified by city, age and gender distribution. Participants were classified as inactive (INA), sufficiently active (SA) and highly active for either aerobic activities (HAA) alone or a combination of aerobic plus resistance exercise (HAC). The main outcome measures are lipid-lipoprotein profile [total, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, apolipoprotein-A1, apolipoprotein-B] and anthropometric indices.

RESULTS

From those participating in aerobic activities, 480 (31.7%) men and 502 (32.9%) women were classified as SA, 100 men (6.6%) and 93 women (6.1%) as HAA and 90 men (5.9%) and 49 women (3.2%) as HAC. After various adjustments were made, men from the HAC group had an average of 23% lower plasma triacylglycerol concentration (P = 0.04) and 10% lower LDL-cholesterol (P = 0.01) when compared with the HAA group. Moreover, women from the HAC group had 13% lower LDL-cholesterol when compared with HAA group (P = 0.051).

CONCLUSION

These data suggest that combining aerobic and resistance-type activities may confer a better effect on lipoprotein profile in healthy individuals than aerobic activities alone.

Endurance training enhances ABCA1 expression in rat small intestine

The purpose of this study was to investigate liver and intestinal ABCA1 expression and plasma HDL-C level in response to treadmill-running training in rats. Twenty adult Wistar male rats (17-18 weeks old, 300-322 g) were divided into control (n = 10) and Training (n = 10) groups. Training group trained at 25 m/min (0% grade) for 60 min/day, 5 days/week for 12 weeks. Rats were killed 48 h after the last session of training. The intestinal and liver ABCA1 mRNA expression was found to be significantly higher in trained compared to control group (P < 0.006 and P < 0.024, respectively). Intestine and liver ATP concentrations remained unchanged. Plasma HDL-C, HDL2-C, Apo A-1, pre-beta HDL-C concentration, LCAT activity, TC/HDL-C and LDL-C/HDL-C ratio significantly increased in trained group (P < 0.01, P < 0.006, P < 0.001, P < 0.001 P < 0.067, P < 0.02, and P < 0.03, respectively). However, other lipoprotein concentrations were unchanged. In conclusion, we found that endurance training induced significant elevation in plasma HDL-C and HDL2-C concentrations, accompanied by higher plasma Apo A-1, pre-beta HDL-C concentrations, LCAT activity and ABCA1 mRNA expressions in rat intestine, and liver.

Seasonal variations in physical activity and implications for human health

This review explores the implications of seasonal changes in physical activity for fitness and human health. Photosensitivity and nutrient shortages mediate animal hibernation via the hypothalamus and changes in leptin and ghrelin concentrations. Opportunities for hunting and crop cultivation determine seasonal activity in under-developed human societies, but in developed societies temperature and rainfall are dominant influences, usually over-riding innate rhythms. Both questionnaire data and objective measurements show that many groups from children to the elderly increase their physical activity from winter to spring or summer. Measurements of maximal oxygen intake and muscle strength commonly show parallel seasonal changes. However, potential effects upon body mass and body fat may be counteracted by changes of food intake; subsistence agriculturists sometimes maintain or increase physical activity at the expense of a decrease in body mass. In developed societies, body fat commonly increases during the winter, with parallel changes in blood lipids, blood pressure and blood coagulability; moreover, these changes are not always fully reversed the following summer. Most developed societies show increased all-cause and cardiac mortalities in the winter. Health consequences of seasonal variations in physical activity including an increased vulnerability to cardiac catastrophe and a year-by-year increase in total body fat seem most likely if the average level of physical activity for the year is low. Public health recommendations should underline the importance of maintaining physical activity during adverse environmental conditions by adapting clothing, modifying behaviour and exploiting any available air-conditioned indoor facilities.

RETRACTED: COMPARISON OF LIPID AND LIPOPROTEIN VALUES IN MEN AND WOMEN DIFFERING IN TRAINING STATUS

The aim of this study was to compare plasma lipid and lipoprotein concentrations of male and female subjects in different training levels and to examine the risks of cardiovascular diseases. For this purpose, 20 male athletes from the National Turkish Wrestling Team (age 23.5 +/- 1.25 years) and 44 male and 51 female students (ages 21.7 +/- 1.72 and 20.20 +/- 1.68 years, respectively) from physical education and sports department and 40 sedentary females (ages 21.14 +/- 1.72 years) participated in this study. Trigliceride (TG), total cholesterol (TC), HDL-C and LDL-C levels were determined by a Hitachi 717 Autoanalyser. Apo A-l, Apo B, and Lp(a) levels were determined by Behringer Nephelometer 100. Maximum Oxygen Consumption (VO(2) max) values were determined by 12-min run test and the anaerobic power values were measured by Jump Meter Instrument. Energy consumption of basal metabolic rates were for males 1 kcal for an hour and 0.9 kcal for females. There were no significant differences in plasma TC, TG, and small lipoprotein a (Lp(a)) values between four groups (p > .05). No significant differences were found in HDL-C, LDL-C, apolipoprotein Al (Apo-Al), and apolipoprotein B100 (Apo-B) values between wrestlers and male students, and between female students and sedentary females (p > .05). HDL-C values of female students and sedentary females were significantly higher when compared with the same values of wrestlers and male students (41.52 and 40.93 mg/100 ml versus 51.92 and 50.10 mg/100 ml). However, LDL-C values were found to be lower in females than males (121.83 and 101.10 mg/100 ml as opposed to 97.7 and 98.4 mg/100 ml) but only significantly lower than in wrestlers (p < .05). Although the wrestlers' training levels were always higher than male students, the lipid and lipoprotein values were not different. These variables were not different between female groups either. But the lipid and lipoprotein profile of female subjects was found to be better than that of males. These results showed that medium and high level of exercises did not cause significant differences in lipid and lipoprotein levels, but the sex differences were very pronounced. Lipid and lipoprotein values of the four groups have indicated that the individuals in these groups would not be exposed to danger of cardiovascular diseases.

Multicomponent exercise program improves blood lipid profile and antioxidant capacity in older women

This study intended to determine the effect of multicomponent exercise on blood lipid profile and on antioxidant capacity in older women. Forty women aged 60-80 years participated in a supervised multicomponent exercise program. Plasma contents of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-1 (Apo A-1) and apolipoprotein B (Apo B-100), total antioxidant status (TAS) and the enzymatic activities of glutathione reductase (GR) and glutathione peroxidase (GPx) were evaluated before and after 8-month training. The multicomponent exercise program induced a significant decrease in TG, TC/HDL-C and Apo B/Apo A-1 and a significant increase in HDL-C and Apo A-1 (p<0.05). There was a significant increase in plasma TAS as well as GR and GPx enzyme activities. The present data show that an 8-month supervised moderate-intensity multicomponent exercise program resulted in beneficial improvements of blood lipid profile that were accompanied by positive modulation of antioxidant capacity.

A randomized controlled trial of the effects of flaxseed lignan complex on metabolic syndrome composite score and bone mineral in older adults

A randomized double-blind placebo controlled study design was used to assess the effects of flaxseed lignan complex supplementation during exercise training on a metabolic syndrome composite score and osteoporosis risk in older adults. A total of 100 subjects (>or=50 years) were randomized to receive flaxseed lignan (543 mg.day-1 in a 4050 mg complex) or placebo while completing a 6 month walking program (30-60 min.day-1, 5-6 days.week-1). Fasting serum glucose, triacylglycerol (TAG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, total cholesterol, interleukin-6, and tumor necrosis factor-alpha were measured every 2 months, while body composition, bone mineral density, and resting blood pressure were assessed at baseline and at 6 months. A composite Z score of 6 risk factors for metabolic syndrome (fasting glucose, HDL cholesterol, TAG, abdominal adiposity, blood pressure, and inflammatory cytokines) was calculated at baseline and at 6 months. Men taking placebo increased metabolic syndrome composite Z score (p < 0.05), but there were no changes in the other groups. A significant group x sex x time interaction was noted for TAG (p = 0.017) and diastolic blood pressure (p = 0.046), with men taking flaxseed lignan decreasing diastolic blood pressure relative to men taking placebo, and men taking placebo increasing TAG relative to men taking flax lignan. There were no differences between groups for change in bone measures, body composition, lipoproteins, or cytokines. Males taking the flaxseed lignan complex reduced metabolic syndrome score relative to men taking placebo, but a similar trend was not seen in females. Flaxseed lignan had no effect on bone mineral density or content, body composition, lipoproteins, glucose, or inflammation.

Regular exercise and plasma lipid levels associated with the risk of coronary heart disease: a 20-year longitudinal study

We investigated the effects of regular exercise on the plasma lipid levels that contribute to coronary heart disease (CHD), of 20 sedentary men who participated in an exercise program over 20 consecutive years. The men, whose initial ages ranged from 30-51 years, participated in the University of Nevada-based exercise program for an average of 45 min/day, 3.5 days/week. The study examined plasma levels of low-density lipoprotein (LDL) cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglycerides (TG), and TC to HDL-C (TC/HDL-C) ratios. All lipid values improved significantly during the study (p < .05). The largest changes occurred during the first year of participation and slow, gradual improvements continued in the subsequent years. We concluded that regular exercise has positive effects on plasma lipid levels, which results in reducing the risk of CHD in middle-aged and older adults.

Physical activity as a determinant of fecal bile acid levels

Physical activity is protective against colon cancer, whereas colonic bile acid exposure is a suspected risk factor. Although likely related, the association between physical activity and bile acid levels has not been well-studied. Furthermore, the effect of triglycerides, which are known to modify bile acid levels, on this relationship has not been investigated. We conducted a cross-sectional analysis of baseline fecal bile acid levels for 735 colorectal adenoma formers obtained from participants in a phase III ursodeoxycholic acid chemoprevention trial. Compared with the lowest quartile of recreational physical activity duration, the highest quartile was associated with a 17% lower fecal bile acid concentration, adjusted for age, sex, dietary fiber intake, and body mass index (P = 0.042). Furthermore, consistent with a previously established relationship between serum triglyceride levels and bile acid metabolism, we stratified by triglyceride level and observed a 34% lower fecal bile acid concentration (highest versus lowest quartiles of physical activity) in individuals with low triglycerides (<136 mg/dL; P = 0.002). In contrast, no association between physical activity and fecal bile acid concentration was observed for subjects with high triglycerides (> or =136 mg/dL). Our results suggest that the biological mechanism responsible for the protective effect of physical activity on the incidence of colon cancer may be partially mediated by decreasing colonic bile acid exposure. However, this effect may be limited to individuals with lower triglyceride levels.

Dose-response relationship between moderate-intensity exercise duration and coronary heart disease risk factors in postmenopausal women

PURPOSE

This study was designed to investigate whether, in a dose-response manner, there would be greater health benefits in a group of postmenopausal women completing 45 minute- vs. 30 minutes of moderate intensity (50% maximal oxygen uptake reserve, VO2R) exercise 5 days . wk(-1).

METHODS

Apparently healthy but sedentary postmenopausal women (n = 33) were randomized to a nonexercise control group, a 30-minute exercise duration group, or a 45-minute exercise duration group. Exercise training was performed 5 days . wk(-1) for 12 weeks at 50% VO2R. Participants were instructed to not change their usual diet throughout the study.

RESULTS

Twenty-six women completed the study. After 12 weeks, VO2max increased significantly (p < 0.05) in both 30-minute (0.20 +/- 0.21 L . min(-1)) and 45-minute (0.41 +/- 0.10 L . min(-1)) groups. Repeated measures ANOVA identified a significant interaction between exercise duration and VO2max values (F = 4.72, p < 0.05), indicating that VO2max responded differently to 30-minute and 45-minute exercise durations. Trend analysis showed that body mass, body composition, waist circumference, and high-density lipoprotein cholesterol (HDL-C) changed favorably (p < 0.05) across control, 30-minute, and 45-minute groups.

CONCLUSIONS

Although most health organizations agree that 150 min . wk(-1) of physical activity will reduce the risk of all-cause and cardiovascular mortality, few randomized, controlled studies have examined whether completing more physical activity than the recommended amount will yield additional benefits. Findings from the present study suggest that there is a dose-response relationship between exercise duration and numerous health outcomes in postmenopausal women, including cardiorespiratory fitness, body mass, body composition, waist circumference, and HDL-C.

Physical Activity, Blood Lipids, and Lipoproteins

Dyslipidemia is a major modifiable cardiovascular disease (CVD) risk factor. While pharmacological treatment has been a focal point of dyslipidemia management for several years, increasing physical activity is a safe, cost-effective treatment option that should also be recommended by health care practitioners. Moderate aerobic exercise consistently increases high-density lipoprotein cholesterol (HDL-C) and reduces triglycerides (TG), independent of changes in body weight. However, reductions in total and low-density lipoprotein cholesterol are reported less often following aerobic exercise. Therefore, clinicians should understand that aerobic exercise is not likely to be an effective treatment option for their management. Recent empirical evidence also indicates that aerobic exercise may be of benefit for treating emerging lipid and lipoprotein risk factors such as lipoprotein particle size and number and triglyceride-rich lipoproteins. Further work is needed to clarify the impact of aerobic exercise on apolipoproteins. Based on current evidence, prescribing aerobic exercise as a means of increasing HDL-C and lowering TG is usually an efficacious strategy for treating these aspects of dyslipidemia. These effects are likely to be accompanied by changes in emerging lipid and lipoprotein risk factors.

Pharmacogenetic association of the APOA1/C3/A4/A5 gene cluster and lipid responses to fenofibrate: the genetics of lipid-lowering drugs and diet network study

BACKGROUND

The apolipoproteins (APOA1/C3/A4/A5) are key components in modulating lipoprotein metabolism. It is unknown whether variants at the APOA1/C3/A4/A5 gene cluster are associated with lipid response to pharmacologic intervention.

METHODS AND RESULTS

Plasma triglycerides (TGs) and high-density lipoprotein (HDL) levels were measured in 861 Genetics of Lipid-Lowering Drugs and Diet Network study participants who underwent a 3-week fenofibrate trial. We examined 18 common single nucleotide polymorphisms (SNPs) spanning the APOA1/C3/A4/A5 genes to investigate the effects of variants at the gene cluster on lipid response to fenofibrate treatment. We found that the minor alleles of the SNPs rs3135506 (APOA5_S19W), rs5104 (APOA4_N147S), rs4520 (APOC3_G34G), and rs5128 (APOC3_3U386) were associated with enhanced TG response to fenofibrate treatment (P= 0.0004-0.018). The minor allele of SNP rs2854117 (APOC3_M482) was associated with reduced rather than enhanced TG response (P= 0.026). The SNP rs3135506 (APOA5_S19W) was associated with HDL response, with minor allele related to reduced HDL response to fenofibrate (P= 0.002). Association analyses on haplotype provided corroborative evidence to single SNP association analyses. The common haplotypes H2, H3, and H5 were significantly associated with reduced TG response to fenofibrate.

CONCLUSION

The genetic variants at APOA1/C3/A4/A5 gene cluster may be useful markers to predict response of lipid-lowering therapy with fenofibrate. Further studies to replicate/confirm our findings are warranted.

Effects of resistance and multicomponent exercise on lipid profiles of older women

OBJECTIVE

The purpose of this study was to compare the effects of two exercise programs of 8 months duration on lipid profiles in older women.

METHODS

In 2006, 77 women from Porto, Portugal, aged 60-79 years were randomly assigned into a multicomponent exercise (ME) program or resistance exercise (RE) program. Before- and after-training, body composition, daily physical activity (DPA), aerobic endurance, plasma concentrations of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) were assessed. Training was performed twice weekly. The protocol for the ME included aerobic exercise, muscular endurance exercises and activities targeted to improve balance and flexibility. The RE protocol included leg press, leg extensions and curls, double chest raises, lateral raises, overhead press and abdominal exercises.

RESULTS

Significant decreases in TG (-5.1%, p=0.006), and significant increases in HDL-C (9.3%, p<0.001) were observed in the ME group. Following 8 months no significant changes were observed on lipid profile in RE group, although lipid- and lipoprotein-related variables tended to alter favorably. Both regimens resulted in significant improvements on 6-min walk test (6.4%, p=0.001 for ME; and 6.0%, p=0.044 for RE). No significant changes were observed in total DPA and body fat in either group after exercise interventions. No significant correlations were found between body composition, physical activity, aerobic endurance, and lipid profile.

CONCLUSIONS

The data suggested that 8 months of ME may be more effective than RE for inducing favorable changes in plasma lipoprotein and lipid profiles.

Independent and combined effects of aerobic exercise and pharmacological strategies on serum triglyceride concentrations: a qualitative review

Elevated fasting and postprandial serum triglyceride concentrations are associated with cardiovascular disease morbidity and mortality. Aerobic exercise reduces serum triglyceride concentrations in the presence or absence of weight loss. Although pharmacological interventions are often used in combination with aerobic exercise to achieve target triglyceride concentrations, information on the combined effects of aerobic exercise and lipid-modifying agents on serum triglycerides is limited. This review examines the independent and combined effects of both interventions on serum fasting and postprandial triglyceride concentrations from the available literature. Reductions in serum triglycerides after aerobic exercise are associated with an increase in skeletal muscle lipoprotein lipase activity and a decrease in hepatic triglyceride and very-low-density lipoprotein (VLDL) synthesis and secretion. Lipid-modifying agents such as niacin, omega-3 fatty acids, and statins also decrease fasting and postprandial triglycerides by increasing lipoprotein lipase (LPL) activity and/or decreasing VLDL synthesis. When combined, lipid-modifying agents may reduce fasting and postprandial triglyceride secretion to an extent in which aerobic exercise cannot provide any additional benefit. These observations indicate that aerobic exercise and pharmacological strategies reduce serum triglycerides by similar mechanisms, which may attenuate the triglyceride-lowering capacity of the concordant treatment.

Association between folate intake from different food sources in Norway and homocysteine status in a dietary intervention among young male adults

The aim of the present investigation was to study the effect of a dietary intervention which combined nutrition information with increased availability of vegetables, fruits and wholegrain bread. The effect of the intervention was determined by changes in the intake of vegetables, fruits, wholegrain bread and estimated nutrients. Furthermore, the study investigated whether changes in relative contribution from different food sources of folate were related to changes in the concentration of plasma total homocysteine (p-tHcy). The 5-month intervention study included 376 male recruits from the Norwegian National Guard, Vaernes (intervention group) and 105 male recruits from the Norwegian National Guard, Heggelia (control group). The study resulted in an increase in the total consumption of vegetables, fruits, berries and juice (P < 0·001) and of wholegrain bread (P < 0·001). The participants in the intervention group showed a higher increase in the intake of dietary fibre (P < 0·001) and folate (P < 0·001) compared with the control group. The relative contribution of folate intake from fruits, vegetables and wholegrain bread was higher in the intervention group compared with the control group (P < 0·001 for all). The increased intake of folate from wholegrain bread was inversely associated with a reduced concentration of p-tHcy (P = 0·017). In summary, the dietary intervention resulted in an increased intake of vegetables, fruits and wholegrain bread and a subsequent increase in folate intake from these food components. Reduction in the concentration of p-tHcy was significantly related to an increased folate intake due to an increased consumption of wholegrain bread.

Lifestyle approaches and dietary strategies to lower LDL-cholesterol and triglycerides and raise HDL-cholesterol

This article discusses specific dietary factors as well as dietary patterns that affect the major coronary heart disease (CHD) lipid risk factors (ie, LDL-C, HDL-C, and TG). Based on a very large evidence base, it is clear that diet and lifestyle practices can markedly affect these major CHD lipid risk factors, and consequently decrease CHD risk substantively.

Oxygen consumption during functional electrical stimulation-assisted exercise in persons with spinal cord injury: implications for fitness and health

A lesion in the spinal cord leads in most cases to a significant reduction in active muscle mass, whereby the paralysed muscles cannot contribute to oxygen consumption (VO2) during exercise. Consequently, persons with spinal cord injury (SCI) can only achieve high VO2 values by excessively stressing the upper body musculature, which might increase the risk of musculoskeletal overuse injury. Alternatively, the muscle mass involved may be increased by using functional electrical stimulation (FES). FES-assisted cycling, FES-cycling combined with arm cranking (FES-hybrid exercise) and FES-rowing have all been suggested as candidates for cardiovascular training in SCI. In this article, we review the levels of VO2 (peak [VO2peak] and sub-peak [VO2sub-peak]) that have been reported for SCI subjects using these FES exercise modalities. A systematic literature search in MEDLINE, EMBASE, AMED, CINAHL, SportDiscus and the authors' own files revealed 35 studies that reported on 499 observations of VO2 levels achieved during FES-exercise in SCI. The results show that VO2peak during FES-rowing (1.98 L/min, n = 17; 24.1 mL/kg/min, n = 11) and FES-hybrid exercise (1.78 L/min, n = 67; 26.5 mL/kg/min, n = 35) is considerably higher than during FES-cycling (1.05 L/min, n = 264; 14.3 mL/kg/min, n = 171). VO2sub-peak values during FES-hybrid exercise were higher than during FES-cycling. FES-exercise training can produce large increases in VO2peak; the included studies report average increases of +11% after FES-rowing training, +12% after FES-hybrid exercise training and +28% after FES-cycling training. This review shows that VO2 during FES-rowing or FES-hybrid exercise is considerably higher than during FES-cycling. These observations are confirmed by a limited number of direct comparisons; larger studies to test the differences in effectiveness of the various types of FES-exercise as cardiovascular exercise are needed. The results to date suggest that FES-rowing and FES-hybrid are more suited for high-intensity, high-volume exercise training than FES-cycling. In able-bodied people, such exercise programmes have shown to result in superior health and fitness benefits. Future research should examine whether similar high-intensity and high-volume exercise programmes also give persons with SCI superior fitness and health benefits. This kind of research is very timely given the high incidence of physical inactivity-related health conditions in the aging SCI population.

Exercise training alters effect of high-fat feeding on the ACTH stress response in pigs

Eating and physical activity behaviors influence neuroendocrine output. The purpose of this study was to test, in an animal model of diet-induced cardiovascular disease, the effects of high-fat feeding and exercise training on hypothalamo-pituitary-adrenocortical (HPA) axis activity. We hypothesized that a high-fat diet would increase circulating free fatty acids (FFAs) and decrease the adrenocorticotropic hormone (ACTH) and cortisol response to an acute stressor. We also hypothesized that exercise training would reverse the high-fat diet-induced changes in FFAs and thereby restore the ACTH and cortisol response. Pigs were placed in 1 of 4 groups (normal diet, sedentary; normal diet, exercise training; high-fat diet, sedentary; high-fat diet, exercise training; n = 8/group). Animals were placed on their respective dietary and activity treatments for 16-20 weeks. After completion of the treatments animals were anesthetized and underwent surgical intubation. Blood samples were collected after surgery and the ACTH and cortisol response to surgery was determined and the circulating concentrations of FFAs, glucose, cholesterol, insulin, and IGF-1 were measured. Consistent with our hypothesis, high-fat feeding increased FFAs by 200% and decreased the ACTH stress response by 40%. In exercise-trained animals, the high-fat diet also increased FFA; however, the increase in FFA in exercise-trained pigs was accompanied by a 60% increase in the ACTH response. The divergent effect of high-fat feeding on ACTH response was not expected, as exercise training alone had no effect on the ACTH response. Results demonstrate a significant interaction between diet and exercise and their effect on the ACTH response. The divergent effects of high-fat diet could not be explained by changes in weight gain, blood glucose, insulin, or IGF-1, as these were altered by high-fat feeding, but unaffected by exercise training. Thus, the increase in FFA with high-fat feeding may explain the blunted ACTH response to an acute stressor in sedentary animals, but cannot explain the exaggerated response in exercise trained animals.

The benefit of strength training on arterial blood pressure in patients with type 2 diabetes mellitus measured with ambulatory 24-hour blood pressure systems

BACKGROUND

An ambulatory 24-hour BP-monitoring (ABPM) is of paramount importance, while patients are engaged in their usual activities, for a better representation of blood pressure (BP). ABPM provides not only automated measurements of brachial-artery pressure over a 24-hour period but also a highly reproducible circadian profile. The purpose of this investigation was to evaluate the effect of strength training (ST) on BP in patients with type 2 diabetes mellitus (T2D) and to obtain new and important information on BP profiles over 24-hour by using an ABPM.

MATERIAL AND METHODS

We recruited ten patients (mean age: 59.7 +/- 7.3) from our Diabetes Department who participated in a 4-month systematic ST program on three non-consecutive days of the week. The ST program consisted of exercises for all major muscle groups. The numbers of sets for each muscle group were systematically increased from 3 at the beginning of the program to 4, 5 and finally 6 sets per week at the end of the program. The ABPM equipment (oscillometric Model Mobil-O-Graph CE 0434) was applied before and after 4-month training period. Routine HbA1C levels were measured using standard techniques. All subjects took a cycling test to measure maximum oxygen uptake (VO2peak) and maximum workload (Wmax) before and after the training period. Maximal strength was determined by one repetition maximum (1RM) in kp for the bench press, bench pull and leg press exercises, using the Concept 2 Dyno.

RESULTS

Analysis of the pooled daytime and night-time data showed a significant reduction of mean arterial BP (from 93.8 +/- 19.2 to 90.6 +/- 14.3 mmHg; p > 0.01) after a 4-month ST (-3.4% mmHg). VO2peak (p < 0.05), Wmax (p < 0.05), 1RM for all muscle groups (p < 0.01), lean body mass (p < 0.05) and percent body fat (p < 0.05) improved significantly after a 4-month of ST. HbA1C showed a significant reduction by 14.5% (from 8.3 +/- 1.7 to 7.1 +/- 0.9%; p < 0.01).

CONCLUSION

We found a significant reduction of mean arterial BP after a 4-month ST, measured by the ABPM system. These results demonstrate that ST may not only increase muscle strength but also decrease BP and perhaps the risk of future CVD development.

Is weight loss the optimal target for obesity-related cardiovascular disease risk reduction?

In the present review, it is argued that while weight loss is associated with substantial reduction in obesity-related cardiovascular disease risk and remains a desired outcome of relevant treatment strategies, increasing physical activity is associated with marked reduction in waist circumference, visceral fat and cardiometabolic risk factors, concurrent with an increase in cardiorespiratory fitness despite minimal or no change in body weight. Failure to recognize the benefits of exercise independent of weight loss masks opportunities to counsel and educate patients whose sole criteria for gauging obesity reduction success is the bathroom scale.

Interactions between alcohol intake and the polymorphism of rs708272 on serum high-density lipoprotein cholesterol levels in the Guangxi Hei Yi Zhuang population

Both alcohol consumption and the polymorphism of the cholesteryl ester transfer protein (CETP) TaqIB gene (rs708272) influence plasma high-density lipoprotein cholesterol (HDL-C) levels. However, their interactions on serum HDL-C levels is not well known. The present study was undertaken to detect the interactions between alcohol consumption and the rs708272 polymorphism on serum lipid levels in the Guangxi Hei Yi Zhuang population. Genotyping of the rs708272 in 342 nondrinkers and 416 drinkers aged 15-70 years was performed by polymerase chain reaction and restriction fragment length polymorphism. Interactions between rs708272 genotype and alcohol consumption was assessed using a cross-product term between genotypes and the aforementioned factor. Statistical significance was evaluated with analysis of co-variance. The frequency of B1 allele was 65.8% in nondrinkers and 64.7% in drinkers (P>.05), respectively. The frequencies of B1B1, B1B2, and B2B2 genotypes were 45.0%, 41.5%, and 13.5% in nondrinkers, and 41.3%, 46.6%, and 12.0% in drinkers (P>.05), respectively. The levels of HDL-C and apolipoprotein (Apo) AI in nondrinkers were higher in B2B2 genotype than in B1B1 genotype (P<.05 for each), whereas triglyceride (TG) levels in drinkers were higher in B1B1 genotype than in B1B2 genotype (P<.05). The levels of TG, HDL-C, Apo AI in B1B1 genotype, and HDL-C and Apo AI in B1B2 genotype were higher in drinkers than in nondrinkers (P<.05-.01), whereas the levels of low-density lipoprotein cholesterol (LDL-C) and Apo B in B2B2 genotype, and the levels of LDL-C in B1B1 genotype were lower in drinkers than in nondrinkers (P<.05-.01). The levels of HDL-C were positively correlated with female sex and genotype in nondrinkers (P<.001 for each), and were positively associated with age and alcohol consumption in drinkers (P<.005 and<.01, respectively). This study suggests that the B1 carriers benefited more from alcohol consumption than the B2 carriers in increasing serum HDL-C and Apo AI levels, and lowering LDL-C levels.