Physical activity, physical fitness, blood pressure, and fibrinogen in the Northern Ireland health and activity survey

The association of physical activity with all-cause, cardiovascular, and cancer mortalities among older adults

OBJECTIVE

To evaluate the association of physical activity with all-cause, cardiovascular, and cancer mortalities among older adults.

METHODS

A study sample consisting of 77,541 community-dwelling Taipei citizens aged ≥ 65 years was selected based on data obtained from the government-sponsored Annual Geriatric Health Examination Program between 2006 and 2010. Subjects were asked how many times they had physical activity for ≥ 30 min during the past 6 months. Mortality was determined by matching cohort identifications with national death files.

RESULTS

Compared to subjects with no physical activity, those who had 1-2 times of physical activity per week had a decreased risk of all-cause mortality [hazard ratio (HR): 0.77; 95% confidence interval (CI): 0.71-0.85). Subjects with 3-5 times of physical activity per week had a further decreased risk of all-cause mortality (HR: 0.64; 95% CI: 0.58-0.70). An inverse dose-response relationship was observed between physical activity and all-cause, cardiovascular, and cancer mortality. According to stratified analyses, physical activity was associated with a decreased risk of mortality in most subgroups.

CONCLUSIONS

Physical activity had an inverse association with all-cause, cardiovascular, and cancer mortality among older adults. Furthermore, most elderly people can benefit from an active lifestyle.

Mortality benefits of population-wide adherence to national physical activity guidelines: a prospective cohort study

We quantified the mortality benefits and attributable fractions associated with engaging in physical activity across a range of levels, including those recommended by national guidelines. Data were from the Allied Dunbar National Fitness Survey, a population-based prospective cohort comprising 1,796 male and 2,122 female participants aged 16–96 years, randomly selected from 30 English constituencies in 1990. Participants were tagged for mortality at the Office for National Statistics. Cox multivariable regression quantified the association between self-reported achievement of activity guidelines—150 min of at least moderate activity per week, equivalent here to 30 or more 20-min episodes of at least moderate activity per month—and mortality adjusting for age, sex, smoking status, social class, geographical area, anxiety/depression and interview season. There were 1,175 deaths over a median (IQR) of 22.9 (3.9) years follow-up; a mortality rate of 15.2, 95 % confidence interval (CI) 14.4–16.1 per 1,000 person years. Compared with being inactive (no 20-min bouts per month), meeting activity guidelines (30+ bouts) was associated with a 25 % lower mortality rate, adjusting for measured confounders. If everyone adhered to recommended-, or even low-activity levels, a substantial proportion of premature mortality might be avoided (PAF, 95 % CI 20.6, 6.9–32.3 and 8.9, 4.2–13.4 %, respectively). Among a representative English population, adherence to activity guidelines was associated with significantly reduced mortality. Efforts to increase population-wide activity levels could produce large public health benefits and should remain a focus of health promotion efforts.

Clustering of body composition, blood pressure and physical activity in Portuguese families

AIM

The purposes of this study were: (i) to identify familial resemblances in body fat, blood pressure (BP) and total physical activity (TPA); (ii) to estimate the magnitude of their genetic and environmental influences; and (iii) to investigate shared familial aggregation among these phenotypes.

SUBJECTS AND METHODS

The sample comprised 260 nuclear families from Portugal. Body fat was assessed by bioelectrical impedance. BP was measured by an oscillometric device. TPA was estimated by the Baecke questionnaire. Familial correlation analyses were performed using Generalized Estimating Equations. Quantitative genetic modelling was used to estimate maximal heritability, genetic and environmental correlations.

RESULTS

Familial intra-trait correlations ranged from 0.15-0.38. Genetic and common environmental factors explained from 30%--44% of fat mass depots and BP and 24% of TPA. Genetic correlations were significant between BP and the fat mass traits (p < 0.05). Environmental correlations were statistically significant between diastolic BP and total body fat, trunk fat and arm fat (p < 0.05) and TPA and other phenotypes.

CONCLUSIONS

The results suggest familial resemblance in the variation of body fat, BP and TPA, showing partial pleiotropic effects in the variation in body fat phenotypes and BP. TPA only shares common environmental influences with BP and body fat traits.

The effect of physical activity on long-term income

Empirical evidence for the direct effects of physical activities on long-term labor market outcomes is limited. This state of affairs is surprising, because there is a growing amount of support on the positive effects of physical activities on health on the one hand and on the effects of good health on labor market outcomes on the other hand. We examine the long-term income effects of physical activity using a large sample (N = 5042) of male twins from Finland (Older Finnish Twin Cohort Study, 1975, 1981, 1990), matched to detailed register-based income data (Finnish Longitudinal Employer-Employee Data, 1990-2004). Our primary income measure is calculated over a fifteen-year period and it covers the prime working age of the twins that we study. We use the twin dimension of the data to control for unobservable genetic and family confounding factors. Our within-twin estimates show that being physically active has a positive impact on the long-term income. We argue that our results are not easily reconciled with the intuitive explanation of physical activity enhancing long-term income via health or more intense labor market attachment. We reason that instead, there may be various non-cognitive mechanisms at work: Physical activity can, for example, make people more persistent in the face of work-related difficulties and increase their desire to partake in competitive situations, with greater expected pecuniary rewards.

Physical activity and sedentary behaviour at different life stages and adult blood pressure in the 1958 British cohort

OBJECTIVES

To investigate whether physical activity or sedentary behaviour at different life stages is associated with blood pressure (BP) in mid-adulthood; activity levels have accumulative associations with BP; and adult body mass index (BMI) mediates associations.

METHODS

Information on activity and television-viewing was available at several ages (23, 33, 42, 45 years) and BP at 45 years for the 1958 British birth cohort (n = 9927). Associations were examined with and without adjustment for covariates.

RESULTS

Active adults, generally, had lower mean systolic and diastolic BP and risk of hypertension than nonactive, although varying by age. After adjustment for covariates, systolic and diastolic BP for active men at 23 years or at 45 years were 1-2 mmHg lower; similar associations were seen for women active at 33 years. Some but not all associations attenuated with further adjustment for BMI: odds ratio (OR) for hypertension associated with 23 years activity changed from 0.82 [95% confidence interval (CI) 0.74, 0.91] to 0.79 (0.70, 0.90) after BMI adjustment. Independent associations of activity at more than one age were found, such that prevalence of hypertension was higher in men active at 23 years but not at 45 years, than men sustaining activity (39 vs. 31%). Sitting at work was unrelated to BP, but there was a trend of higher BP with greater television-viewing: for example risk of hypertension was higher by 10-12% per h/day television-viewing at 45 years after adjustment for covariates, attenuating after allowance for BMI.

CONCLUSION

Our study suggests that there are benefits to BP of becoming and sustaining active lifestyles and minimizing television-viewing over many years of adulthood, with a mediating role for BMI.

Associations of visceral adiposity and exercise participation with C-reactive protein, insulin resistance, and endothelial dysfunction in Korean healthy adults

The aim of the current study was to examine the associations of visceral adiposity and exercise participation with C-reactive protein (CRP), insulin resistance, and endothelial dysfunction in Korean adults selected from the general population. We studied 160 Korean adults (aged 41.3 +/- 13.0 years; n = 38 men and n = 122 women) who volunteered in a health promotion program. Subjects were divided into 2 groups based upon spontaneous exercise participation for using a cross-sectional approach. We measured anthropometric factors (body mass index [BMI], percentage body fat, waist-hip ratio [WHR], and abdominal fat area by computed tomographic scanning), blood pressure (BP), blood levels of glucose, lipids, fibrinogen, CRP, leptin, hemoglobin A(1c), homeostasis model assessment (HOMA), and carotid intima media thickness (IMT; via ultrasonography). Associations among the variables were assessed by Pearson partial correlation and linear regression, controlling for age and sex. Independent t tests were used to assess differences between exercise participants and nonparticipants. Significance was accepted at P < .05. As expected, the measures of adiposity (BMI, percentage body fat, WHR, abdominal fat area) were highly correlated with each other (r = .49-.86, P < .01). Blood levels of high-sensitivity CRP (hsCRP), leptin, and HOMA were modestly correlated with all measures of adiposity. Visceral fat area was the most important predictor of hsCRP, explaining 19.6% of the variance using stepwise linear regression analysis (P < .01). As visceral fat area tertiles increased from low to high, a significant stepwise increment in blood levels of CRP (P < .001), HOMA (P = .005), and left carotid IMT (P = .035) was observed. However, hsCRP and HOMA were not significantly different when compared across whole-body fat tertiles. Systolic BP, diastolic BP, and left carotid IMT were modestly correlated with WHR and visceral fat area (P < .05); but systolic BP and diastolic BP were also correlated with BMI and percentage body fat (P < .05). Therefore, the relative importance of central adiposity as opposed to total body fatness in endothelial dysfunction is unclear. Compared with the nonexercise group, exercise participants had significantly lower (P < .05) WHR, visceral fat area, ratio of visceral fat area to subcutaneous area, hsCRP, hemoglobin A(1c), and HOMA, with no significant differences in BMI, percentage body fat, and physical fitness. Central obesity with high visceral fat is strongly associated with blood level of hsCRP, insulin resistance, and endothelial dysfunction-related factors in healthy Korean adults. In addition, exercise participation, even in the absence of difference in physical fitness, may be protective against development of central obesity and insulin resistance in this understudied Korean population.

Acute effects of walking on inflammatory and cardiovascular risk in sedentary post-menopausal women

Biochemical markers of inflammation are emerging as new predictors of risk of cardiovascular disease (CVD) and may alter acutely with exercise. Few studies have been conducted on the effects of walking on these markers or whether different walking intensities elicit varied effects. As there is growing interest in modifiable lifestyle factors such as walking to reduce CVD risk, these inflammatory responses warrant investigation. The aim of this study was to compare the effects of walking at 50% versus 70% of predicted maximal heart rate on C-reactive protein (CRP), plasma fibrinogen, and triglycerides in sedentary post-menopausal women. Twelve post-menopausal women (mean age 58 years, s +/-6; stature 1.62 m, s+/-0.06; body mass 66.8 kg, s +/-6.2) completed two 30-min treadmill walks in a randomized cross-over design. Fasted blood samples were taken (for the determination of plasma fibrinogen, CRP, and lipids) before, immediately after, and 1 and 24 h after exercise. Triglyceride concentrations decreased from pre-exercise to 24 h post exercise at both walking intensities (time x group interaction, P < 0.05). No significant effects were observed for plasma fibrinogen, CRP, total cholesterol, low-density or high-density lipoprotein cholesterol (time x group interaction, P > 0.05). The results of this study suggest that fasting plasma triglycerides are decreased on the morning after 30 min of brisk walking at either 50% or 70% of maximal heart rate (moderate and vigorous intensity).

Physiotherapy, rehabilitation and sports in countries with limited replacement coagulation factor supply

It is well documented that physiotherapy and rehabilitation benefit people with haemophilia by strengthening the key muscle groups and protecting joints from the adverse effects of repeated haemorrhages. Rehabilitation, in conjunction with the availability of replacement coagulation factor products, has revolutionized approaches to the management of patients with haemophilia in developed countries and has led to a substantial decrease in both the morbidity and mortality rates among the haemophilic population. Modern treatment approaches have also enabled persons with haemophilia to participate in sporting activities along with their peers; however, these improvements in care have not been achieved in developing nations, where health-care resources and facilities are scarce and the supply of coagulation factor products is limited. This article attempts to address the following questions about the management of haemophilic patients in developing countries: Can physiotherapy, rehabilitation and sports prevent disabilities and preserve independence? Is participation in sports activities possible in developing countries? Do countries differ with regard to guidelines for participation in sports? Should we be encouraging participation in sports or allowing patients with haemophilia to do as they choose?

Physical Activity and Markers of Inflammation and Thrombosis Related to Coronary Heart Disease

Epidemiologic studies have provided strong evidence of the beneficial effects of physical activity in patients with coronary heart disease; however, the mechanisms for the cardioprotective effect of physical activity are not fully understood. The more favorable changes in coronary risk profiles of physically active individuals and the favorable changes observed on several of the established coronary risk factors in exercise intervention studies must play a partial role in that protection. In more recent years, inflammatory and thrombotic factors have been implicated in the development and progression of atherosclerosis. Physical activity has been associated with lower levels of several inflammatory markers; however, the effect of physical activity on coagulation markers remains controversial. The authors summarize the studies on the effect of physical activity on several inflammatory and thrombotic variables. The importance of physical activity in the prevention of cardiovascular disease through modification of the inflammatory and thrombogenic processes is also addressed.

Diet, exercise and the metabolic syndrome

The metabolic syndrome is a combination of metabolic disorders, such as dyslipidemia, hypertension, impaired glucose tolerance, compensatory hyperinsulinemia and the tendency to develop fat around the abdomen. Individuals with the metabolic syndrome are at high risk for atherosclerosis and, consequently, cardiovascular disease. However, as a result of several epidemiologic studies and some clinical trials, it has been suggested that people with the metabolic syndrome may benefit from intensive lifestyle modifications including dietary changes and adopting a physically more active lifestyle. In this review we summarize the effects of diet and physical activity on the development of the metabolic syndrome.

Blood pressure and the global burden of disease 2000. Part 1: Estimates of blood pressure levels

OBJECTIVE

To provide global estimates of blood pressure by age and sex for adults aged > or = 30 years, by WHO subregion.

DESIGN AND METHODS

Data were obtained from studies identified in a literature review of population-based surveys. These were complemented by data from MONICA and INTERSALT studies. Estimates of the shape of the age-systolic blood pressure (SBP) association were made from survey data utilizing parametric and non-parametric analyses. A linear sex-specific association of SBP with age was demonstrated from 30 to 70 years in females and 20 to 70 years for males in each subregion. Mean age- and sex-specific estimates of SBP were estimated for each WHO subregion separately, based on study and country-weighted SBP data.

RESULTS

Analyses were based on data from about 230 surveys and over 660 000 participants. Age-specific mean SBP values ranged from 114 to 164 mmHg for females, and 117-153 mmHg for males. Females typically had lower SBP levels than males in the 30-44-year age groups, but in all subregions, SBP levels rose more steeply with age for females than males. Therefore, SBP levels in those aged > or = 60 years tended to be higher in females. Subregions with consistently high mean SBP levels included parts of eastern Europe and Africa. Mean SBP levels were lowest in south-east Asia and parts of the western Pacific.

CONCLUSIONS

These global estimates of blood pressure by age, sex and subregion show considerable variation in estimated levels. The lack of data in developing countries is substantial, and this is an important limitation given the role of blood pressure in increasing cardiovascular disease levels.

Does occupational social class predict coronary heart disease after retirement? A 12-year follow-up study in Sweden

AIMS

To examine whether socioeconomic status and coronary heart disease (CHD) risk factors remain significant predictors of CHD among people aged >or=65 years. Previous studies in this age group are few and inconsistent.

METHODS

Follow-up study of a simple random sample of Swedish women and men aged >or=65 years interviewed in a national survey 1988-89 and followed up until 31 December 2000, for CHD incidence rates. Cox regression was used to study the association between socioeconomic status (occupation) and CHD, after adjustment for age, sex, physical activity, smoking, BMI, diabetes, and hypertension. Participants with CHD hospitalization two years before the start of the study and those who rated their general health as poor were excluded.

RESULTS

Among manual workers and lower-level employees the risk of CHD was significantly higher than among middle-level employees and professionals (49% and 50%, respectively), after adjustment for age and sex. The association between low socioeconomic status and increased CHD risk disappeared after adjustment for the CHD risk factors, which were more prevalent among those with low socioeconomic status. All the CHD risk factors (with the exception of BMI) were associated with increased CHD incidence rates.

CONCLUSIONS

Low socioeconomic status remains a significant predictor of CHD among people aged >or=65 years. Healthcare policies among elderly patients should encourage physical activity and smoking cessation in all socioeconomic groups.

The long-term effect of physical activity on incidence of coronary heart disease: a 12-year follow-up study

BACKGROUND

This study analyzed the long-term effect of leisure-time physical activity on incident cases of coronary heart disease (CHD) among women and men.

METHODS

A national, random sample of 2,551 women and 2,645 men, aged 35-74, was interviewed in 1988 and 1989 and followed until December 31, 2000, with respect to CHD incident cases. Women and men hospitalized for CHD 2 years before the start of the study and those who rated their general health as poor were not included in the sample. Leisure-time physical activity was divided into four levels according to the frequency of physical activity. The relationship between leisure-time physical activity and CHD was studied in a Cox regression model, adjusted for sex, age, income, smoking, and BMI.

RESULTS

When leisure-time physical activity increased, the risk of CHD decreased. Women and men who were physically active at least twice a week had a 41% lower risk of developing CHD than those who performed no physical activity (hazard ratio = 0.59, CI = 0.37-0.95), after adjustment for all the explanatory variables.

CONCLUSIONS

The positive long-term effect of leisure-time physical activity on CHD risk among women and men remains even after accounting for income and other important CHD risk factors.

Relationship between blood pressure and physical activity assessed with stable isotopes

Intrapopulation and interpopulation variation in blood pressure (BP) often reflects the joint effect of a complex set of risk factors, including lifestyle factors such as physical activity, diet, smoking and alcohol use. In this study, we set out to quantify the impact of habitual levels of physical activity on BP within and between three populations at contrasting levels of population risk of hypertension. Individuals were randomly sampled from communities in Nigeria (n=57), Jamaica (from Kingston, n=35) and the United States (from the Chicago area, n=32). Activity energy expenditure (AEE) (estimated from resting energy expenditure measured by indirect calorimetry and total expenditure measured with doubly labelled water) was used as an objective estimate of physical activity. In each of the three samples, there was a consistent negative correlation between BP and AEE. This negative association persisted after adjustment for age, sex and body fat (body mass index or percent fat mass). In multivariate models, adiposity was no longer a significant predictor of BP after accounting for low AEE. In conclusion these data suggest that habitual levels of physical activity may have a generalizable relationship with BP in populations with widely different social and environmental characteristics.

The associations between leisure-time physical activity and inflammatory and coagulation markers related to cardiovascular disease: the ATTICA Study

BACKGROUND

As coronary heart disease is increasingly seen as an inflammation process, we evaluated the hypothesis whether physical activity reduces coronary heart disease risk by modifying the levels of inflammatory and coagulation markers.

METHODS

From May 2001 to December 2002, we randomly enrolled 1524 adult men and 1518 women, without any evidence of cardiovascular disease, stratified by age-gender (census 2001), from the greater area of Athens, Greece. We assessed the relationship between self-reported physical activity status and inflammation markers (high sensitivity C-reactive protein, serum amyloid-A, fibrinogen, interleukin-6, tumor necrosis factor-alpha, and white blood cell counts), after taking into account the effect of several confounders.

RESULTS

Eight hundred seventy-four (57%) of men and 903 (59%) of women were classified as sedentary. Multivariate statistical analysis after adjustment for gender, age, smoking habits, body mass index, total cholesterol, blood glucose, and systolic and diastolic blood pressure levels showed that participants devoted to high physical activity (>7 kcal/min expended) had 29% lower levels of C-reactive protein, 19% of white blood cell counts, 22% lower concentrations of amyloid-A, 20% lower levels of tumor necrosis factor-alpha, 32% of interleukin-6, and 11% of fibrinogen (all P<0.05) as compared to those who were devoted to sedentary life.

CONCLUSIONS

Our findings suggest that the adoption of a physically active lifestyle modifies the inflammation process in healthy individuals.

Stability and change of volume and intensity of physical activity as predictors of hypertension

AIMS

Controversy exists concerning intensity of physical activity and risk of hypertension. Also, the association between long-term changes in physical activity and hypertension is poorly known. Therefore we investigated how the stability and change of volume and intensity of physical activity are associated with the risk of hypertension in Finnish men and women.

METHODS

A total of 3,931 men and 4,381 women responded to three questionnaires on health and lifestyle. Baseline data were gathered from two questionnaires, in 1975 and 1981. The subjects were 24-51 years of age, healthy, and non-hypertensive at baseline (1981). At the end of the follow-up, in 1990, the subjects responded to a third questionnaire, according to which we assessed the cumulative incidence of hypertension between 1982 and 1990.

RESULTS

The cumulative incidence of hypertension from 1982 to 1990 was 10.2% in men and 8.0% in women. In men, the risk of hypertension was higher among those who were persistently not participating in vigorous physical activity (i.e. in both 1975 and 1981) (odds ratio, 1.60; 95% confidence interval, 1.15 to 2.24; p=0.006) than among those persistently participating, when all confounding factors were adjusted for. Among those participating in vigorous activity only in 1975 or in 1981 the risk was not significantly increased compared with those participating persistently. Volume of physical activity was not associated with hypertension. In women, there was no association between physical activity and incidence of hypertension.

CONCLUSIONS

Compared with inactivity, persistent vigorous physical activity predicts a low risk of hypertension in men.

Relative roles of heredity and physical activity in adolescence and adulthood on blood pressure

Part of the association between physical activity and low blood pressure (BP) may be a consequence of genetic selection. We investigated the association of genetic factors and physical activity in adolescence and adulthood with BP. BP was measured with a Finapres device in 71 monozygotic and 104 dizygotic male twin pairs using no antihypertensive medication. Subjects' mean age was 50.4 yr (range 40–72 yr). Subjects were interviewed about their lifetime exercise and other health habits. Exercise was classified as aerobic, power, or other, and these were further divided into adolescence (12–20 yr of age), the previous year, and lifetime. Genetic modeling was conducted to estimate genetic and environmental components of variance of systolic and diastolic BP. Aerobic exercise in adolescence and high-intensity aerobic exercise throughout the lifetime were associated with low diastolic BP in adulthood. Of the variance in diastolic BP, genetic factors accounted for 35% and aerobic exercise in adolescence for 5%. For systolic BP, genetic factors accounted for 39% of the variance. In turn, genetic factors accounted for 44% of the variance in aerobic exercise in adolescence. The genetic factors in part accounting for the variance in diastolic BP and those in part accounting for variance in aerobic exercise in adolescence were correlated. The association between aerobic exercise in adolescence and low diastolic BP in adulthood is a new finding, as is the observation that the factors partly share the same genes.

Frequent and occasional physical activity in the elderly: a 12-year follow-up study of mortality

BACKGROUND

The positive health effects of physical activity are well known. However, there are few studies of the association between different levels of physical activity and all-cause mortality among elderly people.

METHODS

A national random sample of 3206 women and men aged >/=65 were interviewed in 1988 and 1989 and followed until December 31, 2000, for all-cause mortality. Cox regression was used to analyze the association between five different levels of physical activity and all-cause mortality, after adjustment for gender, age, education, smoking habits, body mass index, diabetes, hypertension, and self-rated health. All analyses were conducted in 2003.

RESULTS

For elderly people who were physically active occasionally, the risk of all-cause mortality was 28% lower than for those who were physically inactive (hazard ratio [HR]=0.72; confidence interval [CI]=0.64-0.81), after adjustment for all explanatory variables. For those who were physically active once a week, the risk of all-cause mortality was 40% lower than for those who were physically inactive (HR=0.60; CI=0.50-0.71). For those who were physically active more frequently, the reduction in all-cause mortality risk was about the same as for those who were physically active once a week. Diabetes, hypertension, and daily smoking were, as expected, significant risk factors for all-cause mortality.

CONCLUSIONS

Physical activity, even occasionally, decreases the risk of all-cause mortality among elderly people. Preventive resources among the elderly should include moderate exercise such as walking.

Established and recently identified coronary heart disease risk factors in young people: the influence of physical activity and physical fitness

Epidemiological studies have identified several risk factors for coronary heart disease (CHD), many of which are present in young people. [For the purpose of this review, the phrase "young people" embraces both children and adolescents.] One such risk factor is hypertension. In adults, exercise is thought to have a positive effect on blood pressure levels; however, findings are inconclusive for young people. Despite its association with CHD, obesity is on the increase in Western society's young population; prevention and intervention during early years is needed. An active lifestyle is considered to have a beneficial effect on body fatness. Lipoprotein profiles are directly associated with CHD status. In adults, there is some evidence that physical activity and/or fitness have a favourable effect on lipoprotein levels. Although information regarding the younger population is more ambiguous, it tends to concur with these findings. High levels of lipoprotein(a), are considered an independent risk factor for CHD. Relatively little has been written on young people, although some studies have postulated a favourable relationship with physical activity. An inverse relationship between aerobic fitness and CHD has been confirmed in adults; an association is not as easily verified for young people. Physical activity is similarly deemed to have a beneficial effect on health status. A high-fat diet has been linked to CHD in adults, and evidence to date reports similar findings for young people. Smoking increases the risk of CHD and even moderate smoking during youth could have damaging long-term consequences. There is some evidence that smoking is related to physical activity and fitness levels in young people. In adults, high levels of homocyst(e)ine have been associated with CHD. As yet, little has been written on the relationship between physical activity or physical fitness and homocysteine status in young people. High levels of plasma fibrinogen have been linked to CHD. Several studies have explored the relationship between plasma fibrinogen and physical activity and/or fitness in adults, but findings are inconclusive; for young people, the ambiguity is even greater. C-reactive protein is a molecular marker for CHD but, to date, little attention has been given to this aspect, especially amongst young people. The link between high levels of plasminogen activator inhibitor-1 and CHD has been confirmed, although the essence of this relationship is not established. There is a paucity of data on the younger population and the relevance of collating such information is questionable. For the younger population, most research is limited to the established CHD risk factors and further investigations of recently identified CHD risk factors are needed.

Leisure-time physical activity and reduced plasma levels of obesity-related inflammatory markers

OBJECTIVE

This study investigated the relationship between physical activity and the obesity-related inflammatory markers C-reactive protein, interleukin-6, and soluble tumor necrosis factor receptors (sTNF-Rs) 1 and 2. Furthermore, we examined the relationship between physical activity and insulin sensitivity (insulin, C-peptide, and hemoglobin A(1c) levels) and whether inflammatory markers mediate this association.

RESEARCH METHODS AND PROCEDURES

Biomarkers were measured in 405 healthy men and 454 healthy women from two large ongoing prospective studies. Information about physical activity and other variables was assessed by questionnaires.

RESULTS

After adjustment for other predictors of inflammation, physical activity was inversely associated with plasma levels of sTNF-R1, sTNF-R2, interleukin-6, and C-reactive protein (p = 0.07, p = 0.004, p = 0.04, and p = 0.009). After further adjustment for BMI and leptin, as a surrogate for fat mass, most of these associations were no longer significant. Physical activity was also inversely related to insulin and C-peptide levels (p = 0.008 and p < 0.001); however, in contrast to BMI and leptin, levels of inflammatory markers explained only very little of this inverse relationship.

DISCUSSION

These results suggest that frequent physical activity is associated with lower systemic inflammation and improved insulin sensitivity. These associations can partially be explained by a lower degree of obesity in physically active subjects. Although inflammatory markers may mediate obesity-dependent effects of physical activity on inflammatory related diseases such as type 2 diabetes or coronary heart disease, our study suggests that they do not directly account for the beneficial effects of physical activity on insulin resistance.

Variables associated with fibrinogen in a population-based study: interaction between smoking and age on fibrinogen concentration

The aim of the study was to assess the association between fibrinogen and other cardiovascular risk factors. A cross-sectional population-based study in Gerona (Spain) was designed, 1544 subjects (747 men, 797 women) participated. Anthropometric measurements, blood pressure and blood samples were obtained. Fibrinogen was measured by a coagulometric method. Smoking habits, alcohol consumption and physical activity practice were recorded by questionnaires. Fibrinogen was directly related to age, body mass index (BMI) and female gender and inversely to alcohol and moderate-heavy physical activity practice. Fibrinogen was also higher in men and young women who smoked. In the multivariate analysis, age (regression coefficient (RC): 1.33; standard error (SE): 0.13; unit = 1 year), female gender (RC: 12.24; SE: 3.56) and BMI (RC: 1.83; SE: 0.39; unit = 1 kg/m2) were directly associated with fibrinogen, whereas alcohol (RC: -0.04; SE: 0.01; unit = 1 g/d) was inversely associated. A statistically significant interaction between smoking and age was observed. Age was the strongest variable associated with fibrinogen and modifies the association between smoking and fibrinogen; the magnitude of this association increases with age.

Relative associations of fitness and fatness to fibrinogen, white blood cell count, uric acid and metabolic syndrome

OBJECTIVE

To examine the relation between fitness and fibrinogen, white blood cell count, uric acid and metabolic syndrome across levels of adiposity in apparently healthy, nonsmoking men.

DESIGN

Cross-sectional study of 4057 men from the Aerobics Center Longitudinal Study examining the age-adjusted resting levels and risk of having a clinically significant elevation of fibrinogen, white blood cell count, uric acid and metabolic syndrome score across nine fitness-body fatness combinations. Fitness categories (low fitness, moderately fit or high fitness) were based on a maximal treadmill test. Body mass index (BMI) <25.0 was classified as normal weight, BMI > or = 25.0 but <30.0 as overweight and BMI > or = 30.0 as obese.

RESULTS

Fitness (inversely) and BMI (directly) were independently related to the age-adjusted values of all four variables (P for trend P<0.0001 for each). For all four variables, the greatest age-adjusted risk of having a clinically relevant value was found in the low fitness-obese category and the lowest age-adjusted risk was found in the high fitness-normal weight group.

CONCLUSION

Fibrinogen, white blood cells, uric acid and metabolic syndrome score are independently related to both fitness (inversely) and fatness (directly). Within levels of fatness, risk for significant elevations in fibrinogen, white blood cells, uric acid and metabolic syndrome score is lower for the higher fitness groups.

Immigration and leisure-time physical inactivity: a population-based study

OBJECTIVE

To investigate the relationship between migration status and sedentary leisure-time physical activity status in the city of Malmö, Sweden.

METHODS

The public health survey in 1994 is a cross-sectional study. A total of 5,600 individuals aged 20-80 completed a postal questionnaire. The response rate was 71%. The population was categorized according to country of birth. Multivariate analysis was performed using a logistic regression model to investigate the importance of possible confounders for the differences in sedentary leisure-time physical activity status.

RESULTS

The prevalence of a sedentary leisure-time physical activity status was 18.1% among men and 26.7% among women. The odds ratio of a sedentary leisure-time physical activity status was significantly higher among men born in Arabic-speaking countries, in All other countries, and among women born in Yugoslavia, Poland, Arabic-speaking countries, and the category all other countries', compared to the reference group born in Sweden. The multivariate analysis including age, sex, and education did not alter these results.

CONCLUSION

There were significant ethnic differences in leisure-time physical activity status. This is a CVD risk factor that could be affected by intervention programs aimed at specific ethnic subgroups of the population.

Socioeconomic differences in leisure-time physical activity: the role of social participation and social capital in shaping health related behaviour

Several studies have shown socioeconomic differences in leisure-time physical activity. One explanation may be socioeconomic differences in relevant psychosocial conditions. The Malmö Diet and Cancer Study is a prospective cohort study including inhabitants in Malmö, Sweden. The baseline questionnaire used in this cross-sectional study was completed by the 11,837 participants born 1926-1945 in 1992-1994. Leisure-time physical activity was measured by an item presenting a variety of activities. These activities were aggregated into a summary measure of leisure-time physical activity that takes both the intensity and duration of each specific activity into consideration. The effects of the psychosocial variables on the socioeconomic differences in leisure-time physical activity were calculated in a multivariate logistic regression analysis. The quartile with the lowest degree of leisure-time physical activity was not evenly distributed between the socioeconomic groups. Socioeconomic differences were seen as odds ratios 1.5 for skilled and 1.5 for unskilled male manual workers, compared to the high level non-manual employees. An OR 1.6 was observed for female unskilled manual workers. Self-employed men and female pensioners also had a significantly increased risk of low leisure-time physical activity. Adjustment for age, country of origin and previous/current diseases had no effect on these SES differences. Finally, adjusting for social participation almost completely erased the SES differences. Among the psychosocial variables, social participation was the strongest predictor of low physical activity, and a strong predictor for socioeconomic differences in low leisure-time physical activity. Social participation measures the individual's social activities in, for example political parties and organisations. It therefore seems possible that some of the socioeconomic differences in leisure-time physical activity are due to differing social capital between socioeconomic groups.

Association between physical activity and markers of inflammation in a healthy elderly population

Higher levels of physical activity are associated with lower risk of cardiovascular disease. There is growing evidence that the development of the atherosclerotic plaque is associated with inflammation. In this study, the authors investigated the cross-sectional association between physical activity and markers of inflammation in a healthy elderly population. Data obtained in 1989-1990 and 1992-1993 from the Cardiovascular Health Study, a cohort of 5,888 men and women aged >/=65 years, were analyzed. Concentrations of the inflammation markers-C-reactive protein, fibrinogen, Factor VIII activity, white blood cells, and albumin-were compared cross-sectionally by quartile of self-reported physical activity. Compared with persons in the lowest quartile, those in the highest quartile of physical activity had 19%, 6%, 4%, and 3% lower concentrations of C-reactive protein, white blood cells, fibrinogen, and Factor VIII activity, respectively, after adjustment for gender, the presence of cardiovascular disease, age, race, smoking, body mass index, diabetes, and hypertension. Multivariate regression models suggested that the association of higher levels of physical activity with lower levels of inflammation markers may be mediated by body mass index and glucose. There was no association between physical activity and albumin. Higher levels of physical activity were associated with lower concentrations of four out of five inflammation markers in this elderly cohort. These data suggest that increased exercise is associated with reduced inflammation. Prospective studies will be required for verification of these findings.

Plasma viscosity and its biochemical predictors: associations with lifestyle factors in healthy middle-aged men

The association of lifestyle factors and biochemical variables with plasma viscosity was examined in a sample of middle-aged males of high social status. Analyses were performed on a subsample of men that had relevant rheological and biochemical variables determined during a preventive medical assessment conducted between 1992 and 1996. Among 622 subjects (64 smokers), measures of physical activity or predicted VO2max and adiposity (sum of subcutaneous skinfolds) were the lifestyle factors significantly associated with plasma viscosity (both P < 0.001). Among the biochemical variables, serum total protein and plasma fibrinogen concentrations accounted for most of the explained variability in plasma viscosity within subjects (combined adjusted r2 = 65.5%). Logarithm-transformed triglyceride, leukocyte count and serum globulin together contributed an additional 3.0% of the variance in plasma viscosity. Serum total protein, In triglycerides and leukocyte count decreased significantly across higher quartiles of predicted VO2max (all P < 0.0001), with trends towards lower fibrinogen and globulin concentrations (P = 0.054 and P = 0.050, respectively). Higher levels of adiposity were also significantly associated with higher levels of serum total protein (P < 0.0001), globulin (P < 0.0001), fibrinogen (P < 0.01), leukocyte count (P < 0.05), and triglycerides (P < 0.0001). The association of lifestyle factors with the biochemical predictors of plasma viscosity may result directly from a pro-inflammatory state of adipose tissue origin and/or a larger plasma volume related to higher levels of cardiorespiratory fitness. Randomised controlled trials of the effects of regular physical activity of different intensities on plasma viscosity, with reference to body composition, are now required.

Path analysis of efficacy expectations and exercise behaviour in older adults

The benefits of regular exercise for older adults are well documented and include improvements in physical, functional, as well as psychological, health. The purpose of this descriptive study was to test a theoretically and empirically based model describing the factors that influence exercise behaviour of older adults in the United States of America. The hypothesized model suggested that age, gender, and mental and physical health have an effect on self-efficacy and outcome expectations, and that all these variables influence exercise behaviour. Exercise behaviour was hypothesized to have a reciprocal relationship with self-efficacy expectations and mental and physical health. The convenience sample was 187 older adults living in a continuing care retirement community (CCRC) in Baltimore, Maryland. A one-time health interview was conducted which included a measure of self-efficacy and outcome expectations related to exercise, a measure of health status (SF-12), and gathering of information from participants about their actual exercise behaviour. Of the 187, 71 (38%) reported participating in 20 minutes of continuous aerobic exercise at least three times per week over the previous 3 months. Six hypothesized paths were significant. The model fitted the data and accounted for 32% of the variance in exercise behaviour. Interventions that focus on strengthening self-efficacy and outcome expectations can improve exercise behaviour in older adults.

Leisure time physical activity, cardiorespiratory fitness, and plasma fibrinogen concentrations in nonsmoking middle-aged men

PURPOSE

The relationship of both leisure time physical activity and predicted maximum oxygen consumption (VO2max) with plasma fibrinogen concentration was examined within a cohort of employed middle-aged men.

METHODS

Analyses were performed on a subsample of 635 nonsmoking men (46.7 +/- 7.7 yr) who completed a preventive medical assessment between 1992 and 1996.

RESULTS

Among nonsmokers, mean age-adjusted fibrinogen concentration decreased significantly with higher physical activity index (PAL) categories and quartiles of predicted VO2max (mL x kg(-1) x min(-1)) (both P = 0.001). Mean age-adjusted plasma fibrinogen concentrations were significantly different (P < 0.05) between inactive and vigorous PAI groups and extreme quartiles of predicted VO2max (mL x kg(-1) x min(-1)). These relationships were no longer significant after adjustment for the confounding effect of other ischemic heart disease risk factors. Stepwise multiple regression analyses showed that age, sum of skinfolds, and blood leukocyte count were the strongest predictors of plasma fibrinogen concentration.

CONCLUSION

These data do not confirm a significant independent association of both physical activity and predicted VO2max (mL x kg(-1) x min(-1)) with fibrinogen concentrations among nonsmoking middle-aged men of similar high social class.

Physical activity, cardiorespiratory fitness, and the primary components of blood viscosity

PURPOSE

The relationship of both self-reported leisure time physical activity (LTPA) and predicted maximum oxygen consumption (VO2max) with plasma viscosity and hematocrit (Hct) concentration was examined within a cross-sectional sample of employed middle-aged men.

METHODS

Analyses were performed on a subsample of nonsmoking men who completed a preventive medical assessment between 1992-1996.

RESULTS

Among nonsmokers the mean age-adjusted levels of plasma viscosity (N = 590) and Hct concentration (N = 632) were significantly lower with higher Physical Activity Index (PAI) categories (P = 0.001 and P = 0.01, respectively). Following adjustment for conventional IHD risk factors and blood leukocyte count, a significant inverse relationship remained for Hct (P = 0.044) but not plasma viscosity. Mean age-adjusted plasma viscosity and Hct concentration also showed a significant decrease with higher quartiles of predicted VO2max (mL x kg(-1) x min(-1))(P = < 0.00005 and P = 0.0004, respectively). Following adjustment for all confounding variables mean plasma viscosity and Hct concentration remained significantly lower with higher quartiles of predicted VO2max (mL x kg(-1) x min(-1))(P = < 0.00005 and P = 0.047).

CONCLUSIONS

These data confirm the inverse relationship between LTPA and/or predicted VO2max with plasma viscosity and Hct concentration within nonsmoking middle-aged men of high socioeconomic status.

Physical fitness and sport activity of children and adolescents: methodological aspects of a regional survey

Measurement of physical fitness and physical activity in children and adolescents raise a lot of methodological issues, explaining the scarcity of surveys in European countries and in Switzerland. This article exposes the design and the methods used in a survey on physical fitness, physical activity and health conducted in a region of Switzerland, and discuss the choice of the instruments and the quality control procedure selected to measure physical activity and physical fitness. The survey was conducted in a sample of 3540 students 9-19 years-old and included a battery of physical fitness tests, anthropometrics measurements and a self-report questionnaire on physical activity, sports activity and life styles. An ancillary study in a sub sample assessed daily physical activity with a pedometer, dietary intake with a 3-day dietary record, serum lipids and nutritional status. Some results are displayed as example. Quality control techniques are exposed and the choice of the instrument to assess physical fitness, physical activity, sports, and dietary intake are discussed. Local reference tables are now available for fitness tests and the practicability of fitness testing has been demonstrated in physical education. The research process has induced the sensitisation of schools toward health promotion through physical activity.

Physical fitness, lipids, and apolipoproteins in the Northern Ireland Health and Activity Survey

The objective of this study was to investigate the relationship between physical fitness, lipids, and apolipoproteins in a cross-sectional study using a two-stage probability sample of the population of Northern Ireland. The main outcome measures were physical fitness using VO2max estimated by extrapolation from submaximal oxygen uptake while walking on a motor driven treadmill, and total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, HDL2 and HDL3, and Lp(a). There were no significant relationships with fitness, after adjustment for possible confounders, with the exception of a positive relationship with HDL2 in males (P < or = 0.01) and Lp(a) in females (P < or = 0.05). There was also a relationship between physical fitness and HDL:apo AI ratio in males and females after adjustment for possible confounders (P < or = 0.05). We concluded that there were few relationships between lipid parameters and physical fitness after adjustment for possible confounders. The relationship between physical fitness and Lp(a) in females suggests a benefit associated with physical fitness and the relationship between physical fitness and HDL:apo AI ratio was in keeping with improved HDL cholesterol transport.