Interaction of physical activity and diet: implications for lipoprotein metabolism

Association of Dietary Fatty Acid Consumption Patterns with Risk of Hyper-LDL Cholesterolemiain Korean Adults

This study aimed to identify the association between the risk of hyper-LDL cholesterolemia (hyper-LDLC) and fatty acid consumption patterns (FACPs) using the data from the Korean Genome and Epidemiology Study (KoGES) prospective cohort. A total of 6542 middle-aged Korean adults were included in the analysis. Four FACPs were identified through principal component analysis of the reported intakes of 34 fatty acids (FAs): “long-chain FA pattern”; “short & medium-chain saturated fatty acid (SFA) pattern”; “n-3 polyunsaturated fatty acid (PUFA) pattern”; and “long-chain SFA pattern”. The “long-chain SFA pattern” lowered the risk of hyper-LDLC (relative risk (RR), 0.82; 95% confidence interval (CI), 0.72–0.94; p for trend, 0.004) and the “short & medium-chain SFA pattern” increased the risk of hyper-LDLC (RR, 1.17; 95% CI, 1.03–1.32; p for trend = 0.004). In sex-stratified analyses, the associations of the “long-chain SFA pattern” (RR, 0.73; 95% CI, 0.58–0.93; p for trend = 0.007) and the “short & medium-chain SFA pattern” (RR, 1.34; 95% CI, 1.07–1.69; p for trend = 0.003) with the hyper-LDLC risk were observed only in men, but not in women. These results suggest that FACPs with a high intake of long-chain SFA or a low intake of short and medium-chain SFA may protect Korean adults from hyper-LDLC.

Association of Dietary Fatty Acids with Blood Lipids is Modified by Physical Activity in Adolescents: Results from the GINIplus and LISA Birth Cohort Studies

The role of consuming different types of fatty acids (FA) at the expense of carbohydrates (CHO), on the blood lipid profile of adolescents is largely unknown, as is the modulating effect of different levels of physical activity (PA). Children from the GINIplus and LISA birth cohorts, with complete data on dietary FA (assessed by food-frequency questionnaires), objectively-measured PA (assessed by accelerometers) and blood lipids (lipoprotein cholesterol and triglycerides) at age 15 years, were included (N = 837). Sex-stratified associations between dietary FA and blood lipids were assessed by linear regression in substitution models which represented isocaloric replacements of CHO with saturated FA (SFA), monounsaturated FA (MUFA), n-3 polyunsaturated FA (PUFA) or n-6 PUFA. To assess the interactions with PA, analyses were then performed stratified by tertiles of different PA levels (sedentary, lifestyle, moderate-to-vigorous (MVPA)). Both sexes presented a significant inverse association between MUFA and triglycerides, and females a direct association between n-3 PUFA and high-density lipoprotein. Stratifying by PA tertiles, associations were mainly restricted to participants with the lowest levels of lifestyle PA, or the highest time spent sedentary. The effects of dietary FA on the lipid profile vary in an activity-specific manner, emphasizing possible synergistic roles of diet and PA.

Alterations of plasma nitric oxide, vascular endothelial growth factor, and soluble form of its receptor (sFlt-1) after resistance exercise: An experimental study

BACKGROUND

This study was aimed to investigate the alterations of some plasma angiogenic factors after resistance exercise in male rats.

MATERIALS AND METHODS

TWENTY MALE RATS WERE DIVIDED INTO TWO GROUPS: Sedentary and trained (n = 10 each). The animals in the trained group undertook one training session per day, 3 days/week. After 4 weeks; plasma nitric oxide (NO), vascular endothelial growth factor (VEGF), and soluble form of VEGF receptor-1 (sFlt-1) concentrations were measured.

RESULTS

Plasma NO concentration was not different between groups (P > 0.05). Plasma VEGF concentration was also not different between sedentary and trained groups (142.73 ± 3.74 and 144.5 ± 5.1 pg/mL, respectively; P > 0.05). Resistance training did not significantly change plasma sFlt-1 concentration (P > 0.05). VEGF/sFlt-1 ratio did not alter after exercise.

CONCLUSION

Resistance training does not alter plasma angiogenic factors (NO, VEGF, and sFlt-1), at least in normal rats. More studies are needed to show the effect of resistance training on angiogenesis process.

The Prevalence of Metabolic Syndrome Among Soldiers of the Military Police of Bahia State, Brazil

The mortality rate of men is generally higher than that of women, irrespective of the age group. Currently, a key concern for health care professionals is the prevalence of risk factors associated with cardiovascular disease and metabolic syndrome. This study aimed at assessing the prevalence of individual risk factors for cardiovascular disease as well as the prevalence of metabolic syndrome among men serving in the Military Police Corps of the state of Bahia, Brazil. This service employs mostly men, and they are known to experience high levels of occupational stress and professional victimization. We conducted a cross-sectional study among military police soldiers (n = 452) who were candidates for a military police training course in Bahia, Brazil. All candidates who attended the selection process were evaluated according to the criteria of the National Cholesterol Education Program's Adult Panel III in order to assess the presence of medical disorders that could contribute to cardiovascular disease and metabolic syndrome. The authors identified a high prevalence of hypertension (55.76%), hypertriglyceridemia (50.85%), waist circumference of >102 cm (31.76%), low high-density lipoprotein cholesterol levels (30.46%), and impaired fasting glucose (28.15%) in our subjects. The overall prevalence of metabolic syndrome was 38.54%. The authors suggest that measures should be taken to ensure that military policemen receive continued medical care, both in their professional capacity and in their personal circumstances, and that attention be focused on intervention programs.

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.

Obesity and cancer

Obesity has become the second leading preventable cause of disease and death in the United States, trailing only tobacco use. Weight control, dietary choices, and levels of physical activity are important modifiable determinants of cancer risk. Physicians have a key role in integrating multifactorial approaches to prevention and management into clinical care and advocating for systemic prevention efforts. This article provides an introduction to the epidemiology and magnitude of childhood and adult obesity; the relationship between obesity and cancer and other chronic diseases; potential mechanisms postulated to explain these relationships; a review of recommended obesity treatment and assessment guidelines for adults, adolescents, and children; multilevel prevention strategies; and an approach to obesity management in adults using the Chronic Care Model.

Cardiorespiratory fitness and sedentary lifestyle in the morbidly obese

BACKGROUND

Sedentary lifestyles and poor physical fitness are major contributors to the current obesity and cardiovascular disease pandemic.

HYPOTHESIS

Daily physical activity and cardiorespiratory fitness are correlated in morbidly obese individuals in their free-living environment.

METHODS

Ten morbidly obese participants continuously wore an activity sensor that measured caloric expenditure, minute-by-minute physical activity, and steps/day over a 72-h period. Following collection of the device data, structured cardiorespiratory fitness testing was performed on each subject.

RESULTS

Mean caloric expenditure for all individuals was 2,668+/-481 kcal/d. On average, subjects took 3,763+/-2,223 steps. On average 23 h and 51.6 min per d were spent sleeping or engaged in sedentary activity (<3 metabolic equivalents [METs]) and the remaining 8.4 min were spent in moderate activity (3-6 METs). Average peak VO2 was 16.8+/-4.7 mL/kg/min. Higher peak VO2 correlated with higher total caloric expenditure (TCE; r=0.628, p=0.05) and trended with higher steps/day (r=0.591, p=0.07).

CONCLUSIONS

Most morbidly obese participants in this study were markedly sedentary. These study results may provide important links between obesity, poor fitness, and cardiovascular disease.

Lipid profile in men and women with different levels of sports participation and physical activity

Objective

The purpose of the present study was to analyse the lipid profile in men and women differentiated according to energy expenditure during sports participation (EESPORT), energy expenditure during active leisure time (EEALT) and overall energy expenditure (EETOTAL).

Design

The subjects were grouped by sex, age, EESPORT, EEALT and EETOTAL. Group differences were analysed using analyses of covariance with BMI and alcohol consumption as covariates.

Setting

Physical activity was assessed using the Flemish Physical Activity Computerised Questionnaire. Fasting blood samples were taken to measure total cholesterol (TC), TAG, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C) and the ratio TC:HDL-C.

Subjects

The study sample consisted of 1170 Flemish men and women between 18 and 75 years of age.

Results

Differences in lipid profile were observed in the younger age group (<45 years), all in favour of the most active group. More specifically, when differentiating by EEALT and EETOTAL, men had a healthier lipid profile for TAG, HDL-C and TC:HDL-C. Differentiation according to EESPORT revealed the same significant results except for TAG. In women significant results for HDL-C, LDL-C and TC:HDL-C were found when differentiated by EESPORT.

Conclusions

Men and women <45 years of age with higher levels of energy expenditure due to sport show a better lipid profile than their sedentary counterparts. When differentiating subjects according to energy expenditure during active leisure time or overall energy expenditure, only in men was a healthier lipid profile observed in favour of the most active subjects.

The interplay of obesity and asthma

The relationships, interactions, and association between obesity and asthma are complex, and are active sources of hypotheses and research. An association between obesity and asthma has been reported in many studies, although considerable debate about the existence of the association and its meaning still exists. Potential associative relationships may result from genetics, immune system modifications, and mechanical mechanisms. The rising prevalence of asthma and obesity in children and adults, and the significant morbidity from both, make it imperative that clinicians recognize the importance of weight management in patients with and without asthma.

Micronutrientes e capacidade antioxidante em adolescentes sedentários e corredores

OBJETIVO: Este estudo objetivou comparar a composição corporal, a ingestão dietética, os índices bioquímicos de micronutrientes antioxidantes e a capacidade antioxidante em adolescentes sedentários (n=15) e corredores (n=18), pós-púberes. MÉTODOS: A composição corporal foi aferida por meio das dobras cutâneas, massa corporal total e estatura; a ingestão de micronutrientes foi determinada através de freqüência de consumo alimentar e os indicadores bioquímicos por coleta de sangue em jejum. Em sangue total foram determinados hematócrito e hemoglobina; em plasma, testosterona, alfa-tocoferol, cobre, zinco, e ceruloplasmina; em eritrócitos, fragilidade osmótica, zinco, Cu-Zn superóxido dismutase e metalotioneína. RESULTADOS: A capacidade antioxidante, a ingestão dietética e a composição corporal foram similares, exceto o somatório de dobras cutâneas, que foi menor nos corredores (p<0,05). Somente a ingestão de vitamina E foi inferior às recomendações nutricionais. Não houve diferença entre os grupos para a concentração plasmática de alfa-tocoferol, que se apresentou, em média, abaixo do valor de referência. Os níveis plasmáticos de cobre e zinco foram, em média, adequados, sendo os níveis de cobre similares entre os dois grupos e os de zinco maiores nos corredores. Nos sedentários a fragilidade osmótica dos eritrócitos relacionou-se com a metalotioneína (r= -0,50; p<0,05) e com Cu-Zn superóxido dismutase (r= -0,50; p<0,005); nos corredores, houve relação entre Cu-Zn superóxido dismutase e zinco nos erirócitos (r=0,49; p<0,005). CONCLUSÃO: Os resultados sugerem que a modalidade estudada - corrida - não alterou a capacidade antioxidante além do próprio crescimento. No entanto, a prática regular de exercício favorece uma composição corporal mais adequada para os adolescentes. Há necessidade de maior atenção quanto ao estado nutricional de alfa-tocoferol em adolescentes.

Gender differences in carbohydrate metabolism and carbohydrate loading

Prior to endurance competition, many endurance athletes participate in a carbohydrate loading regimen in order to help delay the onset of fatigue. The "classic" regimen generally includes an intense glycogen depleting training period of approximately two days followed by a glycogen loading period for 3–4 days, ingesting approximately 60–70% of total energy intake as carbohydrates, while the newer method does not consist of an intense glycogen depletion protocol. However, recent evidence has indicated that glycogen loading does not occur in the same manner for males and females, thus affecting performance. The scope of this literature review will include a brief description of the role of estradiol in relation to metabolism and gender differences seen in carbohydrate metabolism and loading.

Aerobic exercise training and cardiovascular reactivity to psychological stress in sedentary young normotensive men and women

Forty-five (22 women) sedentary young (18-30 years old) nonsmoking normotensive volunteers engaged in either 6 weeks of aerobic training (AT), weight training (WT), or a no-treatment (NT) condition to determine whether AT lowers systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR), and rate-pressure product (RPP) during rest, psychological stress, and recovery periods. Estimated VO(2)max increased for the AT (32.1+/-1.1 to 38.4+/-1.0 ml.kg(-1).min(-1)). A smaller increase for the WT (30.5+/-1.1 to 33.8+/-1.0) was likely due to increased leg strength, and VO(2)max did not change for the NT (32.5+/-1.1 to 32.9+/-1.0). Heart rate and RPP levels were lower during psychological stress and recovery after training for AT relative to the WT and NT. Overall SBP was also lower in the AT relative to the NT but not the WT. In conclusion, aerobic training lowered cardiovascular activity levels during psychological stress and recovery in healthy young adults, implying a protective role against age-related increases in coronary heart disease for individuals who adopt aerobic exercise early in life and maintain the behavior across the life span.

Physical activity and levels of inactivity in adolescent females ages 11-16 years in the United Arab Emirates

The purpose of this study was to investigate patterns of physical activity and levels of inactivity in adolescent females in the United Arab Emirates (UAE). A total of 58 adolescent females, age 11-16 years, were recruited from two female-only governmental schools in Abu-Dhabi. Subjects were divided into two groups: 11-13 years (n = 22) and 14-16 years (n = 36). Physical activity patterns were determined from a 3-day activity diary. Total energy expenditure (TEE) was estimated using a factorial approach. The amount of physical activity was expressed as the physical activity level (PAL) and the activity-related energy expenditure (AEE). The number of hours spent watching television was estimated from the activity diaries. There were no significant differences in the energy expenditure parameters between age groups or between schooldays and weekends. PAL was low in both age groups. Television was the predominant leisure time pursuit. The number of hours per day spent watching television (median and interquartile range) was 2.5 (2.3-3.1) in 11-13 years and 2.5 (2.3-2.8) in 14-16 years. Television-watching was significantly higher during the weekend than schooldays: 11-13 years (P = 0.006) and 14-16 years (P < 0.001). In conclusion, the amount of physical activity undertaken by adolescent females in the UAE was very low. Cultural and weather restrictions and social change of the community in the UAE are not conducive to physical activity and play a major role in levels of physical inactivity. This may explain, in part, the rise in the incidence of obesity in this population.

Exercise improves plasma lipid profiles and modifies lipoprotein composition in guinea pigs

These studies were conducted to determine the effects of exercise training on plasma lipoprotein levels and metabolism in the guinea pig to evaluate potential utilization of this model for studies of exercise-mediated effects on the regulation of sterol and lipoprotein metabolism and atherosclerosis regression. Male guinea pigs (n = 5 per group) were randomly assigned to either a control or an exercise group. The exercise protocol consisted of a 7-week training program, 5 days/wk on a rodent treadmill. Final speed and duration were 33 meters/min for 30-40 min per session. Guinea pigs in the exercise group had 33% lower plasma triacylglycerol concentrations (P < 0.01), 66% higher HDL cholesterol levels (P < 0.05) and 31% lower plasma free fatty acids (P < 0.05) than guinea pigs from the non-exercised group. In addition, lipoprotein lipase activity in the heart was 50% higher (P < 0.025) in guinea pigs allocated to the exercise protocol. Exercise training resulted in modifications in composition and size of lipoproteins. The concentrations of free cholesterol in LDL and HDL were higher in the exercised guinea pigs. The LDL peak density values were lower in guinea pigs from the exercise group compared to controls suggesting that exercise training resulted in larger LDL particles. In contrast, no significant effects due to exercise were observed in hepatic cholesterol concentrations, hepatic HMG-CoA reductase activity or LDL binding to guinea pig hepatic membranes. These data indicate that exercise had a more pronounced effect on the intravascular processing of lipoproteins than on hepatic cholesterol metabolism. In addition, the pattern of changes in guinea pig lipoprotein metabolism, in response to exercise training, was similar to reported effects in humans.

The effect of bulimia nervosa on plasma glucose and lipids

This analysis examined changes in plasma lipids and glucose after 3 years in women treated for bulimia nervosa (BN). One hundred and thirty-five women aged 17-45 years with DSM-III-R BN entered a 12-week cognitive behavioral therapy treatment programme. Prior to and 3 years after treatment, patients completed psychiatric and behavioral assessments and fasting blood samples were drawn. At 3-year follow-up, 105 women were available, 67.6% of whom had no eating disorder and 32.4% of whom had any eating disorder (16.2% with eating disorder not otherwise specified and 16.2% with BN). Women with no eating disorder diagnosis at 3-year follow-up experienced a significant mean decrease in plasma glucose from pretreatment to 3-year follow-up compared to those with any eating disorder diagnosis. Eating disorder diagnosis at 3-year follow-up was independently associated with change in plasma glucose when potential confounders were adjusted for. Plasma triglyceride concentrations did not change in the group as a whole. Plasma HDL-cholesterol increased and total cholesterol decreased significantly from pretreatment to 3-year follow-up in the group as a whole. The decrease in serum cholesterol was significant in women with no eating disorder, but not in the women with any eating disorder diagnosis at 3-year follow-up. We conclude that a protracted course of BN may result in clinically insignificant increases in glucose concentrations and may attenuate the decrease in total cholesterol that is observed in women who recover from BN.

Timing of vagal stimulation affects postprandial lipid metabolism in humans

BACKGROUND

Vagal stimulation combined with an oral fat load enhances postprandial lipemia in animals and humans.

OBJECTIVE

We assessed whether the observed postprandial increase in plasma lipids could be explained by changes in exogenous (chylomicron) or endogenous (VLDL) lipid metabolism and whether the timing of vagal stimulation in relation to fat intake was important.

DESIGN

Vagal stimulation was achieved by using the modified sham feeding (MSF) technique, in which food is tasted and chewed but not swallowed. Seven healthy men consumed an oral fat load (50 g) on one occasion (control protocol). On 2 other occasions, they consumed an oral fat load combined with MSF of an appetizing meal. MSF was performed for either 1 h before or 1 h after the oral fat load. Blood was collected for 7 h and was analyzed for hormones and metabolites.

RESULTS

The postprandial triacylglycerol response differed significantly (P < 0.001) between the 3 protocols. Both MSF studies resulted in significantly higher plasma pancreatic polypeptide concentrations compared with the control. Compared with MSF for 1 hour after fat intake, MSF for 1 h before fat intake resulted in significantly higher plasma insulin concentrations (P = 0.013), a more rapid rise in chylomicron triacylglycerol concentrations (P = 0.04), and higher VLDL triacylglycerol and apoliprotein B-100 concentrations.

CONCLUSIONS

Vagal stimulation enhanced postprandial lipemia via effects on both chylomicron and VLDL metabolism. MSF before fat intake had more dramatic effects on postprandial lipemia than did MSF after fat intake, possibly because of increased parasympathetic activity at the time of ingestion.