Differences in Muscle and Adipose Tissue Gene Expression and Cardio-Metabolic Risk Factors in the Members of Physical Activity Discordant Twin Pairs

High physical activity/aerobic fitness predicts low morbidity and mortality. Our aim was to identify the most up-regulated gene sets related to long-term physical activity vs. inactivity in skeletal muscle and adipose tissues and to obtain further information about their link with cardio-metabolic risk factors. We studied ten same-sex twin pairs (age range 50–74 years) who had been discordant for leisure-time physical activity for 30 years. The examinations included biopsies from m. vastus lateralis and abdominal subcutaneous adipose tissue. RNA was analyzed with the genome-wide Illumina Human WG-6 v3.0 Expression BeadChip. For pathway analysis we used Gene Set Enrichment Analysis utilizing active vs. inactive co-twin gene expression ratios. Our findings showed that among the physically active members of twin pairs, as compared to their inactive co-twins, gene expression in the muscle tissue samples was chronically up-regulated for the central pathways related to energy metabolism, including oxidative phosphorylation, lipid metabolism and supportive metabolic pathways. Up-regulation of these pathways was associated in particular with aerobic fitness and high HDL cholesterol levels. In fat tissue we found physical activity-associated increases in the expression of polyunsaturated fatty acid metabolism and branched-chain amino acid degradation gene sets both of which associated with decreased ‘high-risk’ ectopic body fat and plasma glucose levels. Consistent with other findings, plasma lipidomics analysis showed up-regulation of the triacylglycerols containing the polyunsaturated fatty acids. Our findings identified skeletal muscle and fat tissue pathways which are associated with the long-term physical activity and reduced cardio-metabolic disease risk, including increased aerobic fitness. In particular, improved skeletal muscle oxidative energy and lipid metabolism as well as changes in adipocyte function and redistribution of body fat are associated with reduced cardio-metabolic risk.     

某军医大学学生2013年营养及体能状况调查

目的:探讨某军医大学学生2013年某一时段营养及体能情况,以提高军校医学生身体素质。方法:选取2013年1月~2013年2月某军医大学在学校餐厅集体就餐的学员682人,采用称重法调查膳食,测定学员体重、身高,计算体重指数(BMI),对学员的体能状况进行测试。结果:调查学生蛋类、食用油摄入过多,而禽肉、豆类、蔬菜、牛奶、水果等均低于军标;Vit A、Vit C以及钙元素每日摄入量明显不足;学生每日获得热能的分配比例较好,均已达到军标;调查学生中男生体能状况优于女生(x2=22.035,P0.001),女生的超重人数明显多于男生(x2=20.142,P0.001)。结论:建议该校对餐厅炊事人员增加供应学生的食物品种,特别是水产、牛奶等富含优质蛋白的食品;强化学生体育锻炼的监督和指导工作,帮助他们增强自身体质,为国防现代化服务。     

Physical,Behavioral, and Body Image Characteristics in a Tri‐Racial Group of Adolescent Girls

Objectives: The purpose of this study was to evaluate physical characteristics, nutrient intake, physical activity level, and body image in white (CC), African‐American (AA), and Hispanic‐American (HA) female adolescents. Research Methods and Procedures: High school volunteers were solicited for this study. Self‐reported information was used to determine subject characteristics, family income, physical activity, body image, and nutrient intake. Physical evaluations were used to determine body mass index, percent body fat, fat distribution, resting heart rate, and blood pressure (BP). Results: Results showed that AA girls displayed significantly higher diastolic BP than HA girls (p = 0.029). CC adolescents showed greater physical activity (p = 0.010) and lower adiposity than HA adolescents (p = 0.048), as well as lower subscapular skinfold than AA adolescents (p = 0.018). AA adolescents selected a higher ideal body size than CC girls (p = 0.038). There was also a significant difference in percentage carbohydrates (p < 0.034) and cholesterol consumed (p < 0.016) among groups, with CC girls showing the highest values for carbohydrates and lowest values for cholesterol intake among groups. Discussion: Given our findings of higher adiposity and lower physical activity levels in HA adolescents and greater diastolic BP levels and subscapular skinfold in AA adolescents, more interventions should be targeted toward improving health‐related variables among minority populations.     

Did School Food and Nutrient-Based Standards in England Impact on 11–12Y Olds Nutrient Intake at Lunchtime and in Total Diet? Repeat Cross-Sectional Study

Introduction

In September 2009, middle and secondary schools in England were required to comply with food and nutrient-based standards for school food. We examined the impact of this policy change on children’s lunchtime and total dietary intake.

Methods

We undertook repeat cross-sectional surveys in six Northumberland middle schools in 1999–2000 and 2009–10. Dietary data were collected from 11–12 y olds (n = 298 in 1999–2000; n = 215 in 2009–10). Children completed two consecutive 3-day food diaries, each followed by an interview. Linear mixed effect models examined the effect of year, lunch type and level of socio-economic deprivation on children’s mean total dietary intake.

Results

We found both before and after the introduction of the food and nutrient-based standards children consuming a school lunch, had a lower per cent energy from saturated fat (−0.5%; p = 0.02), and a lower intake of sodium (−143 mg; p = 0.02), and calcium (−81 mg; p = 0.001) in their total diet, compared with children consuming a home-packed lunch. We found no evidence that lunch type was associated with mean energy, or absolute amounts of NSP, vitamin C and iron intake. There was marginal evidence of an association between lunch type and per cent energy NMES (p = 0.06). In 1999–2000, children consuming a school lunch had a higher per cent energy from fat in their total diet compared with children consuming a home-packed lunch (2.8%), whereas by 2009–10, they had slightly less (−0.2%) (year by lunch type interaction p<0.001; change in mean differences −3%).

Conclusions

We found limited evidence of an impact of the school food and nutrient-based standards on total diet among 11–12 year olds. Such policies may need to be supported by additional measures, including guidance on individual food choice, and the development of wider supportive environments in school and beyond the school gates.     

An Environmental Approach to Obesity Prevention in Children: Medical College of Georgia FitKid Project Year 1 Results

Objective: To test the hypothesis that third grade children (mean age = 8.7, SD = 0.5) who attended an 8‐month after‐school program would exhibit favorable changes in body composition, cardiovascular fitness, blood pressure, total cholesterol, and high‐density lipoprotein‐cholesterol compared with children in control condition. Research Methods and Procedures: Subjects were 61% African‐American, 31% white, and 8% other racial background from 18 public schools. Sixty‐eight percent were eligible for free or reduced price lunch. Percentage body fat and bone mineral density were assessed by DXA, cardiovascular fitness by heart rate response to a step test, resting blood pressure with a Dinamap, and non‐fasting total cholesterol and high‐density lipoprotein‐cholesterol by finger stick. Data pre‐ and post‐intervention were available for 447 children. Children in the nine intervention schools who attended at least 40% of the after‐school sessions were compared with control subjects. Results: Compared with the control subjects and after controlling for race, sex, free/reduced price lunch status, and school‐level covariates, youths in the intervention group showed a relative reduction of percentage body fat [?0.76 (95% confidence interval (CI), ?1.42, ?0.09)], a greater relative gain in bone mineral density [0.008 (95% CI, 0.001, 0.005)], and a greater relative reduction in heart rate response to the step test [?4.4 (95% CI, ?8.2, 0.6)]. The other outcome variables showed non‐significant trends in favor of the intervention subjects. Discussion: These results are promising in light of the potential impact on the emerging childhood obesity epidemic. The Medical College of Georgia FitKid Project has the potential to be institutionalized because it is built on the existing infrastructure in most public schools in the U.S.     

Fat Distribution,Aerobic Fitness,Blood Lipids,and Insulin Sensitivity in African‐American and European‐American Women

The purpose of this study was to determine independent relationships of intra‐abdominal adipose tissue (IAAT), leg fat, and aerobic fitness with blood lipids and insulin sensitivity (S_i) in European‐American (EA) and African‐American (AA) premenopausal women. Ninety‐three EA and ninety‐four AA with BMI between 27 and 30 kg/m² had IAAT by computed tomography, total fat and leg fat by dual‐energy X‐ray absorptiometry, aerobic fitness by a graded exercise test, African admixture (AFADM) by ancestry informative markers, blood lipids by the Ektachem DT system, and S_i by glucose tolerance test. Independent of age, aerobic fitness, AFADM, and leg fat, IAAT was positively related to low‐density lipoprotein–cholesterol (LDL‐C), cholesterol‐high‐density lipoprotein (HDL) ratio, triglycerides (TGs), and fasting insulin (standardized β varying 0.16–0.34) and negatively related to HDL‐cholesterol (HDL‐C) and S_i (standardized β ?0.15 and ?0.25, respectively). In contrast, independent of age, aerobic fitness, AFADM, and IAAT, leg fat was negatively related to total cholesterol, LDL‐C, cholesterol‐HDL ratio, TGs, and fasting insulin (standardized β varying ?0.15 to ?0.21) and positively related to HDL‐C and S_i (standardized β 0.16 and 0.23). Age was not independently related to worsening of any blood lipid but was related to increased S_i (standardized β for S_i 0.25, insulin ?0.31). With the exception of total cholesterol and LDL‐C, aerobic fitness was independently related to worsened blood lipid profile and increased S_i (standardized β varying 0.17 to ?0.21). Maintenance of favorable fat distribution and aerobic fitness may be important strategies for healthy aging, at least in premenopausal EA and AA women.     

Physical activity and body functionality: implications for obesity prevention and treatment

Physical activity promotes metabolic adaptations that improve body functionality and contribute to the prevention of some diseases. With respect to energy and fat balance, physical activity facilitates the equilibrium between energy intake and expenditure as well as between fat intake and fat oxidation. When combined with a healthy diet that favors satiety with a reduced energy intake, exercise can induce a substantial mass loss in obese individuals. However, even the impact of an exemplary lifestyle does not seem to have the potential to decrease body mass in obese individuals down to the mass range of lean people. Up to now, we have not been able to induce mass changes exceeding 12%-15% initial body mass in obese male subjects under tolerable exercise and dietary habits, and this moderate success was accompanied by modifications in appetite and energy expenditure susceptible to compromise subsequent mass stability. As described in this paper, many environmental factors can influence energy balance and the ability to lose body fat in response to a healthy diet and (or) physical activity program. Particular attention is given to preliminary data obtained in our laboratory that suggest that knowledge-based work does not favor the same potential mass reducing effects as physical work. In fact, the acute effects of knowledge-based work suggest that this work modality may be rather susceptible to promote a more pronounced positive energy balance compared with what we may expect from a sedentary relaxing activity. This is problematic for obesity prevention in the future since knowledge-based work now represents the main working modality in a context of modernity.     

Shift Work and Metabolic Syndrome: Respective Impacts of Job Strain,Physical Activity,and Dietary Rhythms

The impact of shift work on cardiovascular disease (CVD) risk factors and metabolic syndrome are not yet completely understood. The objectives of this study were to evaluate the impact of shift work on metabolic syndrome according to two different definitions in a population of strictly rotating shift workers (3×8 h) compared to paired counterparts working only day hours, and to study whether shift work itself is a determinant of metabolic syndrome after taking into account a large panel of confusing factors. We conducted a cross‐sectional study comparing 98 strictly rotating shift workers to 100 regular day‐workers (all subjects had a long experience of their working rhythms) within the same petrochemical plant. Clinical, behavioral, occupational, and biological data were collected, and a detailed nutritional investigation was done. Shift and day workers were comparable in terms of major CVD factors, and both had a 10 yr Framingham risk scoring of 11%. Shift workers reported an increased job strain and higher total and at‐work physical activity. Alterations in metabolic parameters were evident with a rise in triglycerides, free fatty acids, and gamma glutamyl transpeptidase and lower HDL‐cholesterol. Multiple logistic regression analysis demonstrated that shift work was associated with occurrence of metabolic syndrome, as defined by the National Cholesterol Education Program‐ATPIII criteria, OR: 2.38 (1.13–4.98), but not using the more recent score from the International Diabetes Federation, which gives a major emphasis on abdominal obesity. Total energy intake and contributions of the major nutrients did not differ between the two groups, with the notable exception of saturated lipids (+10% in shift workers). Meal distribution was clearly different: energy intake was more fractionated within the day, with a lesser contribution of breakfast and lunch but with increased intakes during intermediate light meals, particularly in the afternoon and night. Multivariate analyses were performed to test for the influence of dietary rhythms on the development of an NCEP‐ATPIII metabolic syndrome. Dietary intakes at breakfast and during intermediate light meals appear to be “protective” against metabolic syndrome, while a high load at dinner favors its occurrence. A high intake at lunch is particularly deleterious to shift workers. However, in all tested models, shift work remained significantly associated with metabolic syndrome, after taking into account potential covariates like job strain, physical activity, quantitative dietary parameters, and meal distribution. A specific follow‐up of shift workers should be recommended to occupational physicians.     

Physical fitness in community‐dwelling older adults is linked to dietary intake,gut microbiota,and metabolomic signatures

When humans age, changes in body composition arise along with lifestyle‐associated disorders influencing fitness and physical decline. Here we provide a comprehensive view of dietary intake, physical activity, gut microbiota (GM), and host metabolome in relation to physical fitness of 207 community‐dwelling subjects aged +65 years. Stratification on anthropometric/body composition/physical performance measurements (ABPm) variables identified two phenotypes (high/low‐fitness) clearly linked to dietary intake, physical activity, GM, and host metabolome patterns. Strikingly, despite a higher energy intake high‐fitness subjects were characterized by leaner bodies and lower fasting proinsulin‐C‐peptide/blood glucose levels in a mechanism likely driven by higher dietary fiber intake, physical activity and increased abundance of Bifidobacteriales and Clostridiales species in GM and associated metabolites (i.e., enterolactone). These factors explained 50.1% of the individual variation in physical fitness. We propose that targeting dietary strategies for modulation of GM and host metabolome interactions may allow establishing therapeutic approaches to delay and possibly revert comorbidities of aging.     

Obesity Is Associated With Altered Lung Function Independently of Physical Activity and Fitness

Measures of obesity, especially central adiposity, have been associated with reduced lung function. However, previous studies may have been affected by confounding by physical activity and fitness. This study aimed to examine the relationship among body fatness, fat distribution, and lung function, adjusted for physical activity energy expenditure (PAEE) and aerobic fitness (VO₂max), in a cohort of British white adults with a family history of type 2 diabetes. A total of 320 adults (mean age 40.4 ± 6.0 years) attended for anthropometric and VO₂max testing, and had ambulatory heart rate monitoring for 4 days to determine PAEE. Spirometry was used to measure forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC). The tests were repeated 12 months later, and a cross‐sectional analysis using linear regression with repeated measures was performed. Measures of obesity (BMI, waist circumference (WC), fat mass (FM), body fat percentage (BF%)) were associated with lower lung function in men and women (P < 0.01), while waist‐to‐hip ratio (WHR) was associated with lower lung function in men only (P < 0.001). Associations remained after adjusting for age, smoking status, height, PAEE, and VO₂max. The estimated difference in mean FEV₁ and FVC per unit increase in the exposure measures were consistently stronger in men compared to women (P for interaction <0.001). Obesity is inversely associated with lung function in adults, but central fat distribution appears to have a stronger relationship with respiratory mechanics in men than in women. These associations were independent of the degree of physical activity and aerobic fitness in this cohort.     

Seasonal variation and diet quality among Spanish people aged over 55 years

There is evidence supporting the importance of a healthy diet; however, there are few studies analyzing the seasonal variation of food intake. The present study was aimed to evaluate seasonal variation of food and energy intake in Spanish elderly also to investigate diet quality based on the Healthy Eating Index (HEI) score. From a cross-sectional study, 28 individuals (39% males) aged over 55 years volunteered for a longitudinal follow-up. Dietary assessment was evaluated through 24-h dietary recalls. Energy and nutrient intake were calculated using DIAL software. Furthermore, diet quality was measured using HEI. Data was analyzed considering the interaction of sex, age, fitness status, and body composition. Cereals intake was significantly lower in summer than in winter and autumn (both p?<?0.05); whereas, drinks intake was significantly higher in summer than in winter, spring, and autumn (all p?<?0.01). Daily energy intake was significant higher in spring than in summer, and in autumn than in summer (p?<?0.05), and energy intake from lunch was also statistically higher in spring than in summer (p?<?0.01). The HEI was classified as good; however, a negative and significant association was observed between HEI and cholesterol, alcohol, and monounsaturated fatty acids intake (p?<?0.01). Cereals and drinks intake and total daily energy intake changed according to seasons. This should be considered in nutritional studies. Diet quality seems not to be affected by these seasonal changes, and HEI did not show a good association with the majority of foods and macro- and micronutrients.     

Body mass index change in females after short-time life style intervention is not dependent on the FTO polymorphisms

Variants within the FTO gene are important determinants of body mass index (BMI), but their role in determination of BMI changes after combined dietary/physical activity intervention is unclear. We have analyzed 107 unrelated overweight non-diabetic Czech females (BMI over 27.5 kg/m(2), age 49.2+/-12.3 years). FTO variants rs17817449 (first intron) and rs17818902 (third intron) were genotyped. The life style modification program (10 weeks) consisted of an age-matched reduction of energy intake and exercise program (aerobic exercise 4 times a week, 60 min each). The mean BMI before intervention was 32.8+/-4.2 kg/m(2) and the mean achieved weight loss was 4.8+/-3.5 kg (5.3+/-3.5 %, max. -15.5 kg, min. +2.0 kg, p<0.01). No significant association between BMI decrease and FTO variants was found. Also waist-to-hip ratio, body composition (body fat, water, active tissue), lipid parameters (total, LDL and HDL cholesterol, triglycerides) glucose and hsCRP changes were independent on FTO variants. FTO variants rs17817449 and rs17818902 are not associated with BMI changes after combined short time dietary/physical activity intervention in overweight females.     

Acquired liver fat is a key determinant of serum lipid alterations in healthy monozygotic twins

Objective: The effects of acquired obesity on lipid profile and lipoprotein composition in rare BMI‐discordant monozygotic (MZ) twin pairs were studied. Design and Methods: Abdominal fat distribution, liver fat (magnetic resonance imaging and spectroscopy), fasting serum lipid profile (ultracentrifugation, gradient gel‐electrophoresis, and colorimetric enzymatic methods), and lifestyle factors (questionnaires and diaries) were assessed in 15 BMI‐discordant (within‐pair difference [Δ] in BMI >3 kg/m²) and nin concordant (ΔBMI <3 kg/m²) MZ twin pairs, identified from two nationwide cohorts of Finnish twins. Results: Despite a strong similarity of MZ twins in lipid parameters (intra‐class correlations 0.42‐0.90, P < 0.05), concentrations of apolipoprotein B (ApoB), intermediate‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol (LDL‐C), high‐density lipoprotein 3a% (HDL3a%), and HDL3c% were higher (P < 0.05) and those of HDL cholesterol, HDL2‐C, and HDL2b% were lower (P < 0.01) in the heavier co‐twins of BMI‐discordant pairs. The composition of lipoprotein particles was similar in the co‐twins. When BMI‐discordant pairs were further divided into liver fat‐discordant and concordant (based on median for Δliver fat, 2.6%), the adverse lipid profile was only seen in those heavy co‐twins who also had high liver fat. Conversely, BMI‐discordant pairs concordant for liver fat did not differ significantly in lipid parameters. In multivariate analyses controlling for Δsubcutaneous, Δintra‐abdominal fat, sex, Δsmoking and Δphysical activity, Δliver fat was the only independent variable explaining the variation in ΔApoB, Δtotal cholesterol, and ΔLDL‐C concentration. Conclusions: Several pro‐atherogenic changes in the amounts of lipids but not in the composition of lipoprotein particles were observed in acquired obesity. In particular, accumulation of liver fat was associated with lipid disturbances, independent of genetic effects.     

Dietary and Physical Activity Correlates of Long-Term Weight Loss

Covariations in body mass index (BMI), physical activity, macronutrient intake, and the frequency of consumption of specific foods were examined among 82 men and 75 women participating in a behavioral weight loss program over a period of 18 months. Results of repeated measures analyses of covariance showed that BMI change was inversely related to change in physical activity and change in frequency of vegetable consumption. BMI change was positively related to change in calorie intake from fat and change in frequency of consumption of beef, hot dogs, and sweets. Change in fat calories predicted BMI change better than change in total calories. In addition, change in the frequency of consumption of specific foods accounted for a larger percentage of the variance in BMI change than did change in macronutrients (10.4% vs. 5.2%). No differences were found between predictors of weight loss vs. weight maintenance.     

Objectively Measured Intensity of Physical Activity and Adiposity in Middle‐Aged Women

Objective: The aim of this study was to evaluate the relationship between objectively measured physical activity (ACT), particularly intensity of physical activity (iACT), and body fat percentage (BF%) in 278 middle‐aged women. Secondary purposes were to ascertain the association between physical activity duration (dACT) and BF% and the extent to which potentially confounding factors, including total ACT, energy intake, body weight, and season of assessment, influenced the relationship between iACT and BF%. Research Methods and Procedures: A cross‐sectional design was used. Subjects were apparently healthy, 35 to 45 years old, premenopausal, nonsmokers, with BMIs < 30 kg/m². Approximately 90 percent were white, 81% were married, and 37% were college graduates. ACT was assessed using Computer Science and Application accelerometers worn for 7 consecutive days. The accelerometers recorded movement continuously, and activity counts were collapsed into 10‐minute epochs. Intensity was indexed using seven activity count cut‐off points, and duration was based on the number of 10‐minute epochs at each intensity level. BF% was assessed using multiple measurements in the Bod Pod. Energy intake was measured using 7‐day weighed diet records during the same week subjects wore the accelerometers. Results: BF% was strongly and inversely associated with iACT and dACT. Controlling for energy intake and body weight strengthened the relationships among iACT, dACT, and BF%. Control of total ACT weakened the association. Discussion: Engaging in higher intensity and/or longer duration ACT is associated with lower BF% compared with lower intensity and/or shorter durations of activity.     

Physical fitness differences between prepubescent boys and girls

The purpose of this study was to analyze in which physical capabilities boys and girls are closer or distant. An additional objective was to find which of the body fat, physical activity, and somatotype factors have a greater effect on prepubescent children's physical fitness. This was a cross-sectional study involving 312 children (10.8 ± 0.4 years). The physical fitness assessment employed sets of aerobic fitness, strength, flexibility, speed, agility, and balance. The boys presented higher values in all selected tests, except tests of balance and flexibility, in which girls scored better. Gender differences in the physical fitness were greatest in the explosive strength of upper (p ≤ 0.01, η(p)(2) = 0.09) and lower limbs (p ≤ 0.01, η(p)(2) = 0.08), although with a medium-size effect of gender, and smaller in the abdominal (p > 0.05, η(p)(2) = 0.007) and upper limbs (p > 0.05, η(p)(2) = 0.003) muscular endurance, and trunk extensor strength and flexibility (p > 0.05, η(p)(2) = 0.001). The endomorphic (p ≤ 0.01, η(p)(2) = 0.26) in the girls, and the ectomorphic (p ≤ 0.01, η(p)(2) = 0.31) and mesomorphic (p ≤ 0.01, η(p)(2) = 0.26) in the boys, had the high-sized effect on the physical fitness. The physical activity in the girls, and the endomorphic and body fat in the boys, did not have a significant effect. These findings can help in the planning of activities that take into account the success and motivation of both boys and girls and thus increase levels of physical activity and physical fitness at school. However, in prepubescent children, one cannot neglect the influence of genetic determinism, observed from the morphoconstitutional point of view.     

Nutrition survey of schoolchildren in greater Winnipeg. II. Dietary intake and biochemical assessment.

The total dietary intake of energy and of individual nutrients of 99 grades 3 and 6 children from 10 greater Winnipeg shcools were generally comparable to those reported by Nutrition Canada for the Manitoba and national samples, although the percentile distributions of total caloric intake and dietary intake of vitamin A for the Winnipeg children tended to be lower. The median daily intake of protein was 212% of the Canadian Dietary Standard and most came from animal sources. Dietary fat was largely from animal sources as well. Hemoglobin concentrations were marginally low in four children, and urinary riboflavin:creatinine ratios were low in six children. There was no biochemical evidence of thiamin deficiency. The results suggest a need for change in dietary patterns and for education in nutrition, including relative nutrient/cost benefits. A well planned school snack program with an education component is a medium by which change could be introduced. This should preferable be part of a total school health program.     

Effects of low and moderate exercise intensity on postprandial lipemia and postheparin plasma lipoprotein lipase activity in physically active men.

This study was designed to assess differences in the intensity of exercise to attenuate postprandial lipemia (PPL). Thirteen healthy men (age 23.8 +/- 0.9 yr) participated in three random-ordered trials: in low-(25% peak oxygen consumption; Low) and moderate-intensity (65% peak oxygen consumption; Mod) exercise trials, which were completed 1 h before a high-fat meal (1.3 g fat/kg body mass), and a control (Con), fat meal only, trial. Venous blood samples were obtained before the fat meal, and at 2, 4, 6, 8, and 20 h after the fat meal. PPL in the Mod trial (267 +/- 50 mg.dl-1.8 h) was lower compared with that in either Con (439 +/- 81 mg.dl-1.8 h) or Low (403 +/- 91 mg.dl-1.8 h) trials (P < 0.05), whereas there was no difference in PPL between Con and Low trials (P > 0.05). High-density lipoprotein cholesterol (HDL-C) and HDL subtype 2 cholesterol were not different between or within trials (P > 0.05). Postprandial insulinemia was lower in the Mod trial (20.5 +/- 5.7 microIU.ml-1.8 h; P < 0.05), but not in the Low trial (31.4 +/- 4.7 microIU.ml-1.8 h), compared with that in the Con trial (34.9 +/- 5.0 microIU.ml-1.8 h). Postheparin lipoprotein lipase activity at 8 h was higher in the Low trial compared with that in either Con or Mod trials, whereas there were no differences between trials at 20 h. These results suggest that, when exercise is performed 1 h before a fat meal, only exercise of moderate but not of low intensity attenuates PPL and that this effect is not associated with changes in postheparin lipoprotein lipase activity.     

Physical training and plasma intermediate density lipoprotein cholesterol levels in men with hypertriglyceridemia

Plasma lipoprotein lipid levels including IDL cholesterol concentration, physical fitness parameters, and anthropometric data were measured in 10 men with primary hypertriglyceridemia during a 12 week program of moderate physical training. Reduced pulse rate at submaximal workload and increased work performed on the treadmill indicated that the men had increased their physical fitness during the training period. Body weight (-4.9%) and total skinfold thickness (-15.6%) fell during the training program. A characteristic fall (-23%) in plasma triglyceride levels was seen over the first 8 weeks training. Plasma IDL cholesterol concentration fell (-18%) after 2 weeks training but then rose after 8 weeks to levels which tended to be higher than baseline values. Our data suggest that regular physical exercise is more likely to raise levels of the "proatherogenic" IDL than to lower them in hypertriglyceridemic patients.     

Effects of a low fat diet with and without intermittent saturated fat and cholesterol ingestion on plasma lipid, lipoprotein, and apolipoprotein levels in normal volunteers

Diets low in saturated fat and cholesterol are recommended to the American public for improving plasma lipoprotein patterns and reducing the risk of heart disease. However, since dietary intake cannot always be controlled, the effects of different degrees of dietary saturated fat lowering and occasional high saturated fat and cholesterol meals on the expected lipoprotein pattern improvement of these diets needs to be defined. In the current study, we compared lipid, lipoprotein, and apolipoprotein levels in 14 young normal volunteers on a metabolic ward when they were consuming a high saturated fat diet (42% fat), an AHA Phase II diet (25% fat), and a third diet which approximated the AHA Phase I diet (30% fat). The latter actually consisted of intermittent ingestion of meals high in saturated fat and cholesterol on the background of an AHA Phase II diet (Intermittent Saturated Fat diet). When compared to the high saturated fat diet, the AHA Phase II diet significantly reduced total, low density lipoprotein (LDL), and high density lipoprotein (HDL) cholesterol, apoB, and apoA-I levels, and improved the LDL/HDL cholesterol ratio, whereas the intermittent saturated fat diet lowered total and LDL cholesterol and apoB levels, and also improved the LDL/HDL cholesterol ratio. When compared to the AHA Phase II diet, the intermittent saturated fat diet raised total and HDL cholesterol levels. Thus, in these normal volunteers, intermittent saturated fat ingestion, in the context of an overall 30% fat diet and a 25% fat diet, did not differ with respect to the effect on improving the LDL/HDL cholesterol ratio.