Changes in lipids associated with change in regular exercise in free-living men

The associations of "fatness," "fitness," and physical activity with all-cause mortality in older adults: A systematic review

OBJECTIVE

This review explored whether cardiorespiratory fitness or physical activity act as either confounders or effect modifiers of the relationship between adiposity markers and all-cause mortality in older adults.

METHODS

Systematic searches were carried out to identify observational studies that examined the association of adiposity markers (BMI, waist circumference, and waist-hip ratio) with all-cause mortality in adults aged ≥ 60 which took into account cardiorespiratory fitness or physical activity. Data from each included study was analyzed to produce a graphical representation of this relationship.

RESULTS

Fourteen of the fifteen identified studies found that increasing BMI had a non-positive association with all-cause mortality, with persistence of the obesity paradox despite adjustment for physical activity or cardiorespiratory fitness. Physical activity measurement methods were all subjective and often unvalidated. The two studies stratifying for cardiorespiratory fitness did not find that fitness had a significant impact on the relationship between excess adiposity and mortality but found that overweight and fit people had better survival than normal-weight unfit people,

CONCLUSIONS

The predominant use of poor physical activity measurement suggests that studies are currently not adequately accounting for possible physical activity confounding. More studies are needed for addressing the modification of the relationship between adiposity markers and mortality by cardiorespiratory fitness.

Gender differences in the relationship between anxiety symptoms and physical inactivity in a community-based sample of adults with type 2 diabetes

OBJECTIVE

To examine the association between physical inactivity and anxiety symptoms in a community-based sample of men and women with type 2 diabetes mellitus.

METHODS

Eligibility criteria included residents of Quebec, Canada aged between 40 and 75 years, having a diagnosis of type 2 diabetes (≤10 years), being insulin-naive and having participated in a previous telephone-based survey of diabetes treatments. Of the 2028 eligible respondents, 1953 (96.3%) provided information on anxiety symptoms and were included in this analysis. Participants were interviewed and provided information on diabetes-related clinical and sociodemographic factors.

RESULTS

A total of 27.3% of participants reported being physically inactive. The prevalence of mild to severe anxiety symptoms was 22.9%. Persons with mild anxiety symptoms and moderate to severe anxiety symptoms were 1.4 times and 1.7 times more likely to report being inactive than persons without anxiety symptoms, respectively. Subgroup analyses according to gender revealed that women who had mild anxiety symptoms were 1.5 times more likely to report being inactive compared with women who did not have anxiety symptoms, whereas men who had moderate to severe anxiety symptoms were 2.5 times more likely to be inactive than men who did not have anxiety symptoms.

CONCLUSIONS

Anxiety symptoms in the mild and moderate to severe range are a relevant clinical comorbidity in persons with type 2 diabetes, and men may represent a particularly vulnerable subgroup. Future research is recommended to further assess the relationship between anxiety symptoms and diabetes-related health behaviours.

Contribution of cardiorespiratory fitness to the obesity paradox

Until recently, cardiorespiratory fitness (CRF) has been overlooked as a potential modifier of the inverse association between obesity and mortality (the so-called obesity paradox), observed in patients with known or suspected cardiovascular (CV) disease. Evidence from five observational cohort studies of 30,104 patients (87% male) with CV disease indicates that CRF significantly alters the obesity paradox. There is general agreement across studies that the obesity paradox persists among patients with low CRF, regardless of whether adiposity is assessed by body mass index, waist circumference, or percentage body fat. However, among patients with high CRF, risk of all-cause mortality is lowest for the overweight category in some, but not all, studies, suggesting that higher levels of fitness may modify the relationship between body fatness and survival in patients manifesting an obesity paradox. Further study is needed to better characterize the joint contribution of CRF and obesity on mortality in diverse populations.

A walking intervention to reduce inflammation in patients with diabetes and peripheral arterial/artery disease: A pilot study

Objectives:

In this pilot study, we sought to determine whether walking reduces inflammation in patients with diabetes mellitus and peripheral arterial/artery disease.

Methods:

We obtained blood samples from patients with diabetes mellitus and peripheral arterial/artery disease. Intervention participants were advised to walk for 50 min 3 days per week for 6 months. Participants completed assessments of comorbidities and walking ability. Difference-in-difference analyses were used to assess the relationship between group assignment and each biomarker over time.

Results:

We randomized 55 participants (control = 25 and intervention = 30). At 6 months and based on p values of <0.20, vascular cellular adhesion molecule, beta-2 microglobulin, total cholesterol, and triglycerides demonstrated a greater decrease among participants randomized to the intervention compared to the control.

Conclusions:

Walking may reduce inflammation in persons with diabetes mellitus and peripheral arterial/artery disease. Further research is needed to determine the impact of walking on inflammation in persons with vascular disease.

Cardiorespiratory fitness and metabolic risk factors in obesity

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Fitness and abdominal obesity are independently associated with cardiovascular risk

OBJECTIVES

To examine the relationship between cardiovascular fitness (VO(2)max) and abdominal obesity (waist circumference) and individual cardiovascular disease (CVD) risk factors, as well as a clustered risk factor profile, and to study the impact of gender, age and smoking on these relationships.

DESIGN

Cross-sectional.

SETTING

Astrand Laboratory of Work Physiology, Swedish School of Sport and Health Sciences, Stockholm, Sweden.

SUBJECTS

Men (n = 781) and women (n = 890) from two random population-based samples of Swedish women and men aged 20 to 65 years.

MAIN OUTCOMES

Odds ratios.

RESULTS

Each unit of higher fitness was associated with a decrease in all individual risk factors ranging from 2% to 4% independent of waist circumference, each unit of higher waist circumference was associated with an increased risk ranging from 2% to 5% independent of fitness. For clustering of three or more of the risk factors, each unit of fitness was associated with a 5% decrease in risk and each unit of waist circumference with a 5% increase in risk. The clustered risk was higher in unfit participants who were older or smoked daily, regardless of waist circumference. Obese participants were at higher risk if they were men or older, regardless of fitness level. However, neither a higher fitness level nor lean status reduced the risk associated with smoking.

CONCLUSIONS

Higher fitness and lower waist circumference are each independently associated to a similar extent with a lower CVD risk. Simultaneous evaluation of both fitness and abdominal obesity status in clinical practice is important.

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.

Low-intensity training dissociates metabolic from aerobic fitness

This study investigated the effect of prolonged whole-body low-intensity exercise on blood lipids, skeletal muscle adaptations and aerobic fitness. Seven male subjects completed a 32-day crossing of the Greenland icecap on cross-country skies and before and after this arm or leg cranking was performed on two separate days and biopsies were obtained from arm and leg muscle, and venous blood was sampled. During the crossing, subjects skied for 342+/-42 min/day and body mass was decreased by 7.1+/-0.7 kg. Peak leg oxygen uptake (4.6+/-0.2 L/min) was decreased (P<0.05) by 7% whereas peak arm oxygen uptake (3.0+/-0.2 L/min) remained unchanged. Total and low-density lipoprotein cholesterol (5.0+/-0.2 and 3.20.2 mmol/L) were decreased by 8% and 20%, respectively. Muscle beta-hydroxy-acyl-CoA dehydrogenase activity was increased with 22% in arm (P=0.08) and remained unchanged in leg muscle. Hormone sensitive lipase activity was similar in arm and leg muscle prior to the expedition and was not significantly affected by the crossing. In conclusion, an improved blood lipid profile and thus metabolic fitness was present after prolonged low-intensity training and this occurred in spite of a decreased aerobic fitness and an unchanged arm and leg muscle hormone-sensitive lipase activity.

Feeding a corn oil/sucrose-enriched diet enhances steatohepatitis in sedentary rats

The current study investigated the combined effects of feeding a high-fat/high-sucrose (HF/HS) diet to rodents rendered sedentary via hindlimb unloading (HU). For 3 wk before HU, male Wistar rats were fed chow or a diet in which 32% of calories were derived from corn oil fat and 48% of calories from sucrose. Feeding continued during an additional 3-wk period of HU. Subsequently, blood samples were collected for determination of circulating leukocyte counts, insulin levels, and portal vein endotoxin. Inflammation, necrosis, and steatosis were assessed in formalin-fixed liver sections. No biochemical or histological evidence of injury was observed in control rats fed chow or HF/HS. HU increased circulating neutrophils and resulted in hyperinsulinemia. Mild hepatic fat accumulation and minimal focal necroinflammation were observed in this group. Feeding HF/HS during HU exacerbated hyperinsulinemia, hepatic steatosis, Kupffer cell content, and cytokine expression. Significant portal endotoxemia was noted in HU rats but was not influenced by HF/HS diet. On the other hand, feeding HF/HS significantly enhanced lipid peroxidation end products in liver of HU rats by approximately threefold compared with chow-fed rats. In summary, these findings demonstrate that feeding a high-calorie diet potentiates steatosis and injury in sedentary HU rats. Mechanisms underlying enhanced injury most likely involved lipid peroxidation. Importantly, these findings suggest that dietary manipulation combined with physical inactivity can be used to model steatohepatitis.

Associations between estimated aerobic fitness and cardiovascular risk factors in adults with different levels of abdominal obesity

BACKGROUND

We investigated the association between estimated aerobic fitness and cardiovascular risk factors, and how the association is affected by abdominal obesity.

DESIGN

Cross-sectional population study.

METHODS

Participants comprised 3820 adults aged 25 to 64 years from the FINRISK 2002 Study in Finland. Aerobic fitness was estimated using a non-exercise test. Waist-to-hip ratio (WHR), blood pressure, total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglycerides, HDL-C to total cholesterol ratio, and gamma-glutamyl transferase (GGT) levels were measured by standardized methods.

RESULTS

After controlling for age, smoking and alcohol consumption, aerobic fitness was inversely associated with systolic (P=0.027) and diastolic (P<0.001) blood pressure, total cholesterol (P=0.009), triglycerides (P=0.001), and GGT (P<0.001), and directly associated with HDL-C (P<0.001) and HDL-C to total cholesterol ratio (P<0.001) in men. In women, inverse associations were found for diastolic blood pressure (P=0.027) and triglycerides (P<0.001), and direct association for HDL-C (P<0.001) and HDL-C to total cholesterol ratio (P<0.001). Waist-to-hip ratio was independently associated with a better risk factor profile in both sexes. Interactions were found between fitness and WHR in relation to total cholesterol (P=0.001), HDL-C to total cholesterol ratio (P=0.005), triglycerides (P=0.001), and systolic (P=0.009) and diastolic (P<0.001) blood pressure among men only.

CONCLUSIONS

Our data suggest that good estimated aerobic fitness is associated with a better cardiovascular risk factor profile, regardless of the level of abdominal obesity in Finnish men and women. Men in the highest WHR third seem to have more benefit of aerobic fitness on their cardiovascular risk levels than men with lower WHR.

Physical activity and atherosclerosis: which animal model?

Atherosclerosis is a progressive disease that is the most important single contributor to human cardiovascular morbidity and mortality. Epidemiologic studies show that physical activity, or routine exercise, reduces the risk of developing cardiovascular disease. The mechanisms through which exercise may function in primary or secondary prevention of atherosclerosis remain largely to be established. Most studies in humans are performed after the onset of clinical signs when disease is well advanced and the prescription of exercise is based on empirical evidence of benefit in secondary prevention. Animal models per-mit the study of the initiation and progression of preclinical stages of atherosclerosis. In order to provide information relevant to treatment and prevention, these models should mimic human disease and interactions of physical activity with disease processes as closely as possible. The purpose of this review is to compare animal models of atherosclerosis and to summarize the available data in those models in regard to the effects of exercise.

Self-reported physical activity among South Carolina adults trying to maintain or lose weight

OBJECTIVES

The obesity epidemic is related to widespread physical inactivity in the United States. This study determined the proportion of South Carolinians trying to maintain or lose weight and within that subpopulation, the number who practiced a restricted diet and engaged in physical activity.

METHODS

Data from the 2002 South Carolina Behavioral Risk Factor Surveillance System survey were used to classify adults who were trying to maintain weight or lose weight. Self-reported prevalence of restricted diet and participation in physical activity were investigated. Of those who reported weight control practices, levels of physical activity were analyzed to determine if those trying to maintain weight or lose weight were meeting the national guidelines for moderate or vigorous physical activity.

RESULTS

More than 70% of South Carolina adults reported trying to control their weight and the majority reported using physical activity for weight control. Though the majority reported use of restricted diet and physical activity, more than one-half of those individuals did not meet the minimum standards for physical activity designed for heart health.

CONCLUSIONS

Although most adults who are trying to maintain or lose weight are participating in physical activity, public health efforts need to focus on encouraging these adults to increase their levels of physical activity to meet the minimum standards for health benefits. Health care providers have an opportunity to educate and encourage patients about the recommended levels of physical activity to obtain maximum health benefits.

Molecular Epidemiology of Physical Activity and Cancer

As in other areas of epidemiology, researchers studying physical activity and cancer have begun to include laboratory analyses of biological specimens in their studies. The incorporation of these “biomarkers” into epidemiology has been termed molecular epidemiology and is an approach primarily developed to study chemical carcinogens. Thus far, there has been no discussion in the field on how the established molecular epidemiologic framework might be adapted for research into physical activity, what methodologic needs exist, what the goals of such an approach might be, and what limitations exist. This article relates the literature on molecular epidemiology to the needs of physical activity research and tries to set research priorities for the field as it moves in this new direction. Although this approach will be very useful for investigating the mechanisms through which physical activity exerts effects, there are several challenges for physical activity epidemiologists in adapting molecular epidemiologic approaches. Primarily, there are currently no available biomarkers that might be considered measures of exposure or biologically effective dose. In addition, most available biomarkers of intermediate effects have been tested in training studies at activity levels much higher than those seen in population-based epidemiologic studies. Thus, it is not clear whether these biomarkers are valid at lower activity levels. Furthermore, the nature of the relationship between activity and many available biomarkers depends very much on the context of the activity. Addressing these issues should be a priority if we are to develop a molecular epidemiologic paradigm for studying physical activity.

Physical activity and its effects on lipids

Physical activity is an important component of weight control, and is widely recommended to prevent and treat obesity-related complications such as diabetes and coronary heart disease (CHD). Although the cardiovascular benefits of increased physical activity are likely multifactorial, much of the attention has been focused on the known high-density lipoprotein (HDL) cholesterol-raising properties of regular physical activity. Physical activity, however, can also reliably lower triglycerides and favorably affect both low-density lipoprotein (LDL) and HDL particle sizes. Limited data on resistance exercise suggest that this type of physical activity may reduce LDL cholesterol. Although these lipid effects are modest and variable, they are likely to be particularly important in reducing the morbidity and mortality from CHD on a population level, and may be especially important in patients with atherogenic dyslipidemia.

Enhanced expression of hepatic lipogenic enzymes in an animal model of sedentariness

The hindlimb-suspended rat was used as animal model to investigate the effects induced by immobilization of the skeletal muscle in the expression of the genes encoding hepatic lipogenic enzymes. Following a 14-day period of immobilization, rats were injected intraperitoneally with radioactive acetate, and the labeling of hepatic lipids and cholesterol was evaluated 15 min after the isotope injection. The incorporation of labeled acetate in lipids and cholesterol was almost three times higher in the liver of immobilized rats than in control animals as a consequence of the enhanced transcription of the genes encoding acetyl-CoA synthase, acetyl-CoA carboxylase, fatty acid synthase, and 3-hydroxy-3-methylglutaryl-CoA reductase. The high expression of the key enzymes for fatty acid and cholesterol synthesis induced by immobilization was not paralleled by an increase of the hepatic sterol-regulatory element binding protein (SREBP)-1 and SREBP-2 mRNA content. However, the expression of the mature form of SREBP-1 and SREBP-2 was higher in the nuclear fraction of immobilized rat liver than in controls due to a significant increase of the cleavage of the native proteins. Immobilization also affected the expression of proteins involved in lipid degradation. In fact, the hepatic content of peroxisome proliferator-activated receptor-alpha (PPARalpha) mRNA and of PPARalpha target genes encoding carnitine palmitoyl transferase-1 and acyl-CoA oxidase were significantly increased upon immobilization.

Comparison of modifiable determinants of lipids and lipoprotein levels among African-Americans, Hispanics, and Non-Hispanic Caucasians > or =65 years of age living in New York City

Information on determinants of plasma lipids and lipoproteins and how these factors would differ among race/ethnic groups in elderly populations is scarce. We studied cross-sectionally the distribution and predictors of lipids and lipoproteins in 1,118 free-living elderly subjects (> or =65 years of age), in a multiethnic urban community (22% non-Hispanic Caucasian, 34% African-American, and 44% Hispanic). Mean levels of total cholesterol, total/high-density lipoprotein (HDL) cholesterol ratio, and triglycerides decreased with increasing age (p <0.001). Low-density lipoprotein cholesterol and total cholesterol were lower among men, whereas women had higher levels of HDL cholesterol (p <0.001). Hispanics had lower low-density lipoprotein cholesterol, total cholesterol, and HDL cholesterol levels, whereas African-Americans had a lower total/HDL cholesterol ratio and triglyceride levels along with higher HDL cholesterol levels (p <0.001). Diabetes was more prevalent among Hispanics and African-Americans (p = 0.002), and body mass index was higher in African-Americans (p = 0.009). Hispanics were less likely to drink alcohol (p <0.0001), but more likely to drink larger amounts of coffee (p <0.0001). A greater proportion of African-Americans were active smokers (p <0.001). In multivariate regression models, body mass index was a significant independent predictor of total cholesterol (beta = 0.74, p <0.001). Waist circumference predicted lower HDL cholesterol levels (0.57 mg/dl lower per inch, p <0.001) and a higher total/HDL cholesterol ratio (beta = 0.05, p <0.001). Alcohol intake (>2 g/day) predicted higher HDL cholesterol (beta = 6.20, p <0.001). Diabetic status predicted lower HDL cholesterol (beta = -2.47, p <0.05), higher total/HDL cholesterol ratio (beta = 0.35, p <0.001), and triglycerides (beta = 37.10, p <0.001). Physical activity, coffee intake, and a calorie-adjusted atherogenicity index did not show independent predictive value. These findings indicate that obesity, alcohol intake, and diabetes mellitus are potentially modifiable independent determinants of lipids and lipoprotein levels in an elderly multiethnic population.

Physical activity may modulate effects of ApoE genotype on lipid profile

Increased levels of physical activity may improve the lipid profile, but is this effect identical across apolipoprotein E (apoE) genotypes? A population-based cross-sectional survey conducted from 1999 to 2000 included 1708 randomly selected men and women aged 35 to 74 years. A validated physical activity questionnaire measured, for each participant, the total energy expenditure and its percentage used in high-intensity activities (%high-intensity activity), eg, brisk walking and sports. The effects of the apoEx%high-intensity activity interaction on the lipid profile were investigated by using multiple linear regression models. Among men, increased %high-intensity activity had greater protective effects in the apoE4 group regarding (1) high density lipoprotein (HDL) cholesterol (P<0.001), compared with either the apoE2 (interaction P=0.05) or apoE3 (interaction P<0.03) groups, and (2) triglycerides (P<0.03), compared with the apoE3 group (interaction P=0.07). A 10% increase of %high-intensity activity by an apoE4 man would correspond with a 0.07-mmol/L increase in HDL cholesterol and a -0.15-mmol/L decrease in triglycerides. Among women, only the protective effects of physical activity on HDL cholesterol in the apoE4 group versus the apoE2 group was statistically significant. Spending a larger fraction of the total energy expenditure in high-intensity activities may counteract the atherogenic effects of the epsilon4 allele on the lipid profile.

The association between physical activity, physical fitness, and type 2 diabetes mellitus

Recent studies have shown that cardiorespiratory fitness--an objective measurement of physical activity--is a strong predictor of type 2 diabetes. Self-reported physical activity is also associated with decreased risk of developing diabetes.

Alcohol and survival in the Italian rural cohorts of the Seven Countries Study

BACKGROUND

Middle-aged men who regularly drink a moderate amount of alcohol have lower mortality rates from all causes in comparison with abstainers and heavy drinkers. This cohort study looks at the relationship between alcohol consumption and long-term survival, adjusting for smoking habit and physical activity.

METHODS

In 1965, a total of 1536 Italian males aged 45-65 years underwent an examination which included: a general questionnaire, anthropometric measurements, an overall physical examination, ECG recording, blood pressure and serum cholesterol measurements and measurement of food consumption including alcohol. The cohort was followed for total mortality from 1965 to 1995.

RESULTS

During a period of 30 years 1096 deaths occurred. Age-adjusted life expectancy for men assuming a mean daily quantity of 63 g of alcohol (range 4-7 drinks per day) was 21.6 +/- 0.4 years, roughly 2 years more than men taking a mean quantity of 3.7 g (</=1 drink) and men consuming >10 drinks per day. Taking smoking habit into account, the longest survival of 22.4 +/- 0.5 years was observed in non-smokers drinking 4-7 drinks daily; the lowest, 18.5 +/- 0.7 years, in smokers drinking >10 drinks. Stratifying for physical activity, the longest survival (23.4 +/- 0. 7 years) was experienced by men engaged in heavy physical activity at work drinking 1-4 drinks per day.

CONCLUSIONS

The relationship between life expectancy and alcohol consumption (97% wine in this Italian cohort and mostly red wine) is confirmed to be non-linear. Men aged 45-64 at entry drinking about 5 drinks per day have a longer life expectancy than occasional and heavy drinkers.

Diet and waist-to-hip ratio: important predictors of lipoprotein levels in sedentary and active young men with no evidence of cardiovascular disease

OBJECTIVE

Healthy, young men were studied to determine the relationship of energy and nutrient intake and physical activity to concentrations of plasma lipoprotein and cholesteryl ester transfer protein.

DESIGN

A cross-sectional study compared active and sedentary male subjects (17 to 35 years old) with no personal or family history of coronary heart disease. Participants kept 20-day food and activity journals. Individual intakes of energy, protein, carbohydrate, fat, saturated fat, monounsaturated fatty acids, polyunsaturated fatty acids, dietary fiber, and alcohol were evaluated. Measurements of blood lipids (total cholesterol and triglycerides, high- and low-density lipoprotein cholesterol); apolipoproteins; cholesteryl ester transfer protein; anthropometric variables (body mass index, waist-to-hip ratio, percentage of body fat); and aerobic capacity were taken during fall and spring data collection periods. SUBJECT SELECTION: Subjects were selected on the basis of normal blood lipid levels, absence of underlying disease, and willingness to comply with their current level of physical activity for the duration of the study. Minimal sample size for statistical power was 12 men per group: 12 of 15 subjects who exercised and 13 of 15 subjects who were sedentary completed all phases of the study.

STATISTICAL ANALYSES

Statistical analyses consisted of 2-way analysis of variance (activity level and season). Pearson product moment correlations and multiple regression analyses were conducted to assess whether energy and nutrient intakes, physical activity status, and/or anthropometric variables predicted plasma concentrations of lipids and apolipoproteins.

RESULTS

Lower waist-to-hip ratio, and not specifically activity level, was associated with higher levels of high-density lipoprotein cholesterol (HDL-C) and lower levels of low-density lipoprotein cholesterol (LDL-C). Dietary intake of saturated and monounsaturated fats and alcohol predicted changes in some apolipoprotein and lipoprotein levels.

APPLICATIONS

Use of waist-to-hip ratio in the primary prevention of coronary heart disease is a simple and cost-effective measure to predict development of abnormal lipoprotein profiles in young men. Specific dietary recommendations include adoption of a heart-healthy diet with emphasis on monounsaturated fatty acids (10% to 12% of energy or one third of total fat intake) and the suggestion that small amounts of alcohol (< 3 drinks per week) may, indeed, be beneficial. Because alcohol and waist-to-hip ratio were both important predictors of LDL-C level, even in active young men, the consumption of low levels of alcohol may be beneficial only if waist-to-hip ratio is maintained within the healthful range by achieving an appropriate balance of physical activity and macronutrient intake.