Physical activity and incidence of diabetes: the Honolulu Heart Program

The association of a healthy lifestyle index and imaging-based body fat distribution with glycemic status and Type 2 diabetes in the Multi Ethnic Cohort: a cross-sectional analysis

INTRODUCTION

As several behaviors captured by the Lifestyle Risk Factor Index (LSRI) are protective against Type 2 diabetes (T2D) and may affect body fat distribution, we examined its relation with both outcomes.

METHODS

In a subset of the Multiethnic Cohort, participants from five ethnic groups (60-77 years) were assigned LSRI scores (one point each for consuming <1 (women)/<2 (men) alcoholic drinks/day, ≥1.5 physical activity hours/week, not smoking, and adhering to ≥3/7 dietary recommendations). All participants completed an extensive Quantitative Food Frequency Questionnaire to allow estimation of adherence to intake recommendations for fruits, vegetables, refined and whole grains, fish, processed and non-processed meat. Glycemic/T2D status was classified according to self-reports and fasting glucose. We estimated prevalence odds ratios (POR) of LSRI with glycemic/T2D status and DXA- and MRI-based body fat distribution using logistic regression.

RESULTS

Of 1713 participants, 43% had normoglycemia, 30% Pre-T2D, 9% Undiagnosed T2D, and 18% T2D. Overall, 39% scored 0-2, 49% 3, and 12% 4 LSRI points. T2D prevalence was 55% (POR 0.45; 95% confidence intervals 0.27, 0.76) lower for 4 vs. 0-2 LSRI points with weaker associations for abnormal glycemic status. Despite the low adherence to dietary recommendations (22%), this was the only component related to lower T2D prevalence. The inverse LSRI-T2D association was only observed among Latinos and Japanese Americans in ethnic-specific models. Visceral fat measures were higher in T2D patients and attenuated the LSRI-T2D association.

CONCLUSION

These findings support the role of a healthy lifestyle, especially diet, in T2D prevention with differences across ethnicity.

Device-measured physical activity and type 2 diabetes mellitus risk

Objectives

We investigated how device-measured physical activity (PA) volume (PA energy expenditure [PAEE]) and intensity (fraction of PAEE from moderate-to-vigorous PA [FMVPAEE]) were associated with the incidence of type 2 diabetes mellites (T2DM).

Methods

This population-based prospective cohort study included 90,044 participants. The primary exposures were PAEE and FMVPAEE. The secondary exposures were energy expenditure exerted during light, moderate, and vigorous PA and their fraction of PAEE.

Results

Each 1-SD increase in PAEE was associated with a 17% lower risk of T2DM (hazard ratio [HR]: 0.83, 95% confidence interval [CI]: 0.78-0.98). Each 1-SD increase in FMVPAEE was associated with a 21% lower incidence of T2DM (HR: 0.79, 95% CI: 0.74-0.83). Achieving the same PA volume (KJ/kg/day) through vigorous PA (HR: 0.88, 95% CI: 0.85-0.91) was more effective in preventing T2DM than moderate PA (HR: 0.97, 95% CI: 0.96-0.98) and light PA (HR: 0.99, 95% CI: 0.98-1.00).

Conclusion

A higher PA volume is associated with a lower incidence of T2DM. Achieving the same PA volumes through higher-intensity PA is more effective than low-intensity PA in reducing T2DM incidence.

Healthy Aging Within an Image: Using Muscle Radiodensitometry and Lifestyle Factors to Predict Diabetes and Hypertension

The strong age dependency of many deleterious health outcomes likely reflects the cumulative effects from a variety of risk and protective factors that occur over one's life course. This notion has become increasingly explored in the etiology of chronic disease and associated comorbidities in aging. Our recent work has shown the robust classification of individuals at risk for cardiovascular pathophysiology using CT-based soft tissue radiodensity parameters obtained from nonlinear trimodal regression analysis (NTRA). Past and present lifestyle influences the incidence of comorbidities like hypertension (HTN), diabetes (DM) and cardiac diseases. 2,943 elderly subjects from the AGES-Reykjavik study were sorted into a three-level binary-tree structure defined by: 1) lifestyle factors (smoking and self-reported physical activity level), 2) comorbid HTN or DM, and 3) cardiac pathophysiology. NTRA parameters were extracted from mid-thigh CT cross-sections to quantify radiodensitometric changes in three tissue types: lean muscle, fat, and loose-connective tissue. Between-group differences were assessed at each binary-tree level, which were then used in tree-based machine learning (ML) models to classify subjects with DM or HTN. Classification scores for detecting HTN or DM based on lifestyle factors were excellent (AUCROC: 0.978 and 0.990, respectively). Finally, tissue importance analysis underlined the comparatively-high significance of connective tissue parameters in ML classification, while predictive models of DM onset from five-year longitudinal data gave a classification accuracy of 94.9%. Altogether, this work serves as an important milestone toward the construction of predictive tools for assessing the impact of lifestyle factors and healthy aging based on a single image.

Secondary analyses of global datasets: do obesity and physical activity explain variation in diabetes risk across populations?

Type 2 diabetes rates vary significantly across geographic regions. These differences are sometimes assumed to be entirely driven by differential distribution of environmental triggers, including obesity and insufficient physical activity (IPA). In this review, we discuss data which conflicts with this supposition. We carried out a secondary analysis of publicly available data to unravel the relative contribution of obesity and IPA towards diabetes risk across different populations. We used sex-specific, age-standardized estimates from Non-Communicable Disease Risk Factor Collaboration (NCD-RisC) on diabetes (1980-2014) and obesity (1975-2016) rates, in 200 countries, and from WHO on IPA rates in 168 countries in the year 2016. NCD-RisC and WHO organized countries into nine super-regions. All analyses were region- and sex-specific. Although obesity has been increasing since 1975 in every part of the world, this was not reflected in a proportional increase in diabetes rates in several regions, including Central and Eastern Europe, and High-income western countries region. Similarly, the association of physical inactivity with diabetes is not homogeneous across regions. Countries from different regions across the world could have very similar rates of diabetes, despite falling on opposite ends of IPA rate spectrum. The combined effect of obesity and IPA on diabetes risk was analyzed at the worldwide and country level. The overall findings highlighted the larger impact of obesity on disease risk; low IPA rates do not seem to be protective of diabetes, when obesity rates are high. Despite that, some countries deviate from this overall observation. Sex differences were observed across all our analyses. Overall, data presented in this review indicate that different populations, while experiencing similar environmental shifts, are apparently differentially subject to diabetes risk. Sex-related differences observed suggest that males and females are either subject to different risk factor exposures or have different responses to them.

Mediation of the Associations of Physical Activity With Cardiovascular Events and Mortality by Diabetes in Older Mexican Americans

Low physical activity (PA) among older adults increases the risk of cardiovascular disease (CVD) and mortality through metabolic disorders such as type 2 diabetes. We aimed to elucidate the extent to which diabetes mediates the effect of nonoccupational PA levels on CVD and mortality among older Mexican Americans. This study included 1,676 adults from the Sacramento Area Latino Study on Aging (1998-2007). We employed Cox proportional hazards regression models to investigate associations of PA level with all-cause mortality, fatal CVD, and nonfatal CVD events. Utilizing causal mediation analysis within a counterfactual framework, we decomposed the total effect of PA into natural indirect and direct effects. Over a median of 8 years of follow-up, low PA (<25th percentile) was associated with increased risks of all-cause mortality (hazard ratio (HR) = 1.36, 95% confidence interval (CI): 1.06, 1.75), fatal CVD (HR = 2.05, 95% CI: 1.42, 2.97), and nonfatal CVD events (HR = 1.67, 95% CI: 1.18, 2.37) in comparison with high PA (>75th percentile). Diabetes mediated 11.0%, 7.4%, and 5.2% of the total effect of PA on all-cause mortality, fatal CVD, and nonfatal CVD events, respectively. Our findings indicate that public health interventions targeting diabetes prevention and management would be a worthwhile strategy for preventing CVD and mortality among older Mexican Americans with insufficient PA levels.

Physical Activity Levels and Diabetes Prevalence in US Adults: Findings from NHANES 2015-2016

INTRODUCTION

Diabetes is a major public health problem that is strongly influenced by lifestyle-related factors, with previous epidemiologic studies finding an inverse relationship between physical activity and the prevalence of diabetes. We aimed to quantify the prevalence of diabetes and determine whether a dose-response relationship is present between physical activity levels and diabetes.

METHODS

Population characteristics were compared between diabetic and nondiabetic subjects. Multiple logistic regression models were used to assess the association between different levels of physical activity and diabetes. Restricted cubic spline analysis was used to examine the dose-response relationship between physical activity and diabetes prevalence.

RESULTS

Compared with those in the lowest physical activity quartile, participants in the highest quartile had a 42% lower prevalence of diabetes (odds ratio = 0.58, 95% confidence interval = 0.44-0.75, p < 0.001). A nonlinear dose-response relationship was observed (p nonlinearity < 0.05), with increased physical activity associated with a decreased prevalence of diabetes, with steeper reductions in the prevalence of diabetes at low activity levels than at high activity levels. These results were robust in both subgroup and sensitivity analyses.

CONCLUSIONS

Higher levels of physical activity are associated with a lower prevalence of diabetes. The data indicated the presence of a nonlinear dose-response relationship in all of the included subjects, with steeper reductions in the prevalence of diabetes at low activity levels than at high activity levels. Increasing physical activity is therefore potentially a useful intervention for reducing the prevalence of diabetes.

Non-pharmacological Treatment Options in the Management of Diabetes Mellitus

The global prevalence of diabetes, especially type 2 diabetes mellitus, has reached epidemic proportions in the last few decades of the 20th century because of the obesity pandemic resulting from adverse lifestyles. Diabetes as a consequence of obesity (diabesity), continues to increase exponentially in the 21st century. Although there are a multitude of drugs for the effective management of diabesity with modest benefits, most patients will require insulin for control of diabetes at some stage that would worsen obesity, and thereby diabesity. Therefore, effective non-pharmacological therapy needs to be expedited in all patients with diabesity. These measures include medical nutrition interventions, change of lifestyles and bariatric surgery. Non-pharmacological interventions are also useful for the effective management of even type 1 diabetes mellitus when used along with insulin therapy especially in those with obesity. This review summarises the current evidence base for the non-pharmacological interventions in the management of diabetes.

Protective role of physical activity on type 2 diabetes: Analysis of effect modification by race-ethnicity

BACKGROUND

It is well known physical activity (PA) plays a role in the prevention of type 2 diabetes (T2D). However, the extent to which PA may affect T2D risk among different race-ethnic groups is unknown. Therefore, the aim of the present study was to systematically examine the effect modification of race-ethnicity on PA and T2D.

METHODS

The PubMed and Embase databases were systematically searched through June 2016. Study assessment for inclusion was conducted in three phases: title review (n = 13 022), abstract review (n = 2200), and full text review (n = 265). In all, 27 studies met the inclusion criteria and were used in the analysis. Relative risks (RRs) and 95% confidence intervals (CIs) were extracted and analyzed using Comprehensive Meta-Analysis software. All analyses used a random-effects model.

RESULTS

A significant protective summary RR, comparing the most active group with the least active PA group, was found for non-Hispanic White (RR 0.71, 95% CI 0.60-0.85), Asians (RR 0.76, 95% CI 0.67-0.85), Hispanics (RR 0.75, 95% CI 0.64-0.89), and American Indians (RR 0.73, 95% CI 0.60-0.88). The summary effect for non-Hispanic Blacks (RR 0.91, 95% CI 0.76-1.08) was not significant.

CONCLUSIONS

The results of the present study indicate that PA (comparing most to least active groups) provides significant protection from T2D, with the exception of non-Hispanic Blacks. The results also indicate a need for race-ethnicity-specific reporting of RRs in prospective cohort studies that incorporate multiethnic samples.

Physical activity and incident type 2 diabetes mellitus: a systematic review and dose-response meta-analysis of prospective cohort studies

AIMS/HYPOTHESIS

Inverse associations between physical activity (PA) and type 2 diabetes mellitus are well known. However, the shape of the dose-response relationship is still uncertain. This review synthesises results from longitudinal studies in general populations and uses non-linear models of the association between PA and incident type 2 diabetes.

METHODS

A systematic literature search identified 28 prospective studies on leisure-time PA (LTPA) or total PA and risk of type 2 diabetes. PA exposures were converted into metabolic equivalent of task (MET) h/week and marginal MET (MMET) h/week, a measure only considering energy expended above resting metabolic rate. Restricted cubic splines were used to model the exposure-disease relationship.

RESULTS

Our results suggest an overall non-linear relationship; using the cubic spline model we found a risk reduction of 26% (95% CI 20%, 31%) for type 2 diabetes among those who achieved 11.25 MET h/week (equivalent to 150 min/week of moderate activity) relative to inactive individuals. Achieving twice this amount of PA was associated with a risk reduction of 36% (95% CI 27%, 46%), with further reductions at higher doses (60 MET h/week, risk reduction of 53%). Results for the MMET h/week dose-response curve were similar for moderate intensity PA, but benefits were greater for higher intensity PA and smaller for lower intensity activity.

CONCLUSIONS/INTERPRETATION

Higher levels of LTPA were associated with substantially lower incidence of type 2 diabetes in the general population. The relationship between LTPA and type 2 diabetes was curvilinear; the greatest relative benefits are achieved at low levels of activity, but additional benefits can be realised at exposures considerably higher than those prescribed by public health recommendations.

Time Spent Walking and Risk of Diabetes in Japanese Adults: The Japan Public Health Center-Based Prospective Diabetes Study

Background

The association between time spent walking and risk of diabetes was investigated in a Japanese population-based cohort.

Methods

Data from the Japan Public Health Center-based Prospective Diabetes cohort were analyzed. The surveys of diabetes were performed at baseline and at the 5-year follow-up. Time spent walking per day was assessed using a self-reported questionnaire (<30 minutes, 30 minutes to <1 hour, 1 to <2 hours, or ≥2 hours). A cross-sectional analysis was performed among 26 488 adults in the baseline survey. Logistic regression was used to examine the association between time spent walking and the presence of unrecognized diabetes. We then performed a longitudinal analysis that was restricted to 11 101 non-diabetic adults who participated in both the baseline and 5-year surveys. The association between time spent walking and the incidence of diabetes during the 5 years was examined.

Results

In the cross-sectional analysis, 1058 participants had unrecognized diabetes. Those with time spent walking of <30 minutes per day had increased odds of having diabetes in relation to those with time spent walking of ≥2 hours (adjusted odds ratio [OR] 1.23; 95% CI, 1.02–1.48). In the longitudinal analysis, 612 participants developed diabetes during the 5 years of follow-up. However, a significant association between time spent walking and the incidence of diabetes was not observed.

Conclusions

Increased risk of diabetes was implied in those with time spent walking of <30 minutes per day, although the longitudinal analysis failed to show a significant result.

Physical activity and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis

We investigated the association between specific types of physical activity and the risk of type 2 diabetes in a systematic review and meta-analysis of published studies. PubMed, Embase and Ovid databases were searched for prospective studies and randomized trials up to 2nd of March 2015. Summary relative risks (RRs) were calculated using a random effects model. Eighty-one studies were included. The summary RRs for high versus low activity were 0.65 (95 % CI 0.59-0.71, I(2) = 18 %, n = 14) for total physical activity, 0.74 (95 % CI 0.70-0.79, I(2) = 84 %, n = 55) for leisure-time activity, 0.61 (95 % CI 0.51-0.74, I(2) = 73 %, n = 8) for vigorous activity, 0.68 (95 % CI 0.52-0.90, I(2) = 93 %, n = 5) for moderate activity, 0.66 (95 % CI 0.47-0.94, I(2) = 47 %, n = 4) for low intensity activity, and 0.85 (95 % CI 0.79-0.91, I(2) = 0 %, n = 7) for walking. Inverse associations were also observed for increasing activity over time, resistance exercise, occupational activity and for cardiorespiratory fitness. Nonlinear relations were observed for leisure-time activity, vigorous activity, walking and resistance exercise (p nonlinearity < 0.0001 for all), with steeper reductions in type 2 diabetes risk at low activity levels than high activity levels. This meta-analysis provides strong evidence for an inverse association between physical activity and risk of type 2 diabetes, which may partly be mediated by reduced adiposity. All subtypes of physical activity appear to be beneficial. Reductions in risk are observed up to 5-7 h of leisure-time, vigorous or low intensity physical activity per week, but further reductions cannot be excluded beyond this range.

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.

Role of exercise in optimizing the functional status of patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is frequently concomitant with obesity. This article discusses factors that influence health and functional outcomes of people who develop NAFLD, including increased burden of illness, whole body function, performance, and perception of self-efficacy. Changes in macronutrients, amount of calories consumed, and decreased physical activity all negatively influence patient outcome. The benefits of exercise in this population are also discussed. To be effective, exercise must be performed, regularly and in conjunction with dietary and other behavioral change. Therefore, a lifelong commitment to exercise, activity, and diet are needed if NAFLD is to be successfully treated.

Physical activity, smoking, and alcohol consumption in association with incidence of type 2 diabetes among middle-aged and elderly Chinese men

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a prevalent chronic disease worldwide. The prevalence of T2DM is increasing rapidly in China. Understanding the contribution of modifiable lifestyle factors on T2DM risk is imperative to prevent the development of T2DM in China.

METHODS

We examined associations between lifestyle factors including physical activity, smoking and alcohol consumption with incidence of T2DM among middle-aged and elderly men in urban Shanghai. Information on socio-demographics, lifestyle habits, dietary habits, and disease history was collected via in-person interviews. Anthropometric measurements were taken. A total of 51 464 Chinese men aged 40-74 years free of T2DM, coronary heart disease (CHD), and stroke at baseline were included in the current study. Incident T2DM was identified through follow-up surveys conducted every 2-3 years. Cox proportional hazard analyses were conducted to evaluate associations between lifestyle risk factors and incidence of T2DM.

RESULTS

We documented 1304 new cases of T2DM during 276 929 person-years of follow-up (average: 5.4 years). Physical activity was inversely associated with T2DM risk. Daily living, commuting, and total physical activity METs had inverse negative dose-response relationships with T2DM (P-trend = 0.0033, 0.0022, and <0.0001, respectively). Regular participation in exercise or sports reduced T2DM risk (HR = 0.86, 95%CI: 0.76-0.98). Moderate alcohol intake (1-3 drinks/day) was inversely related to T2DM risk (HR = 0.80, 95%CI: 0.67-0.94). Cigarette smoking, on the other hand, was associated with increased T2DM risk; HRs were 1.25 (95%CI: 1.00-1.56) for smoking more than 20 cigarettes per day and 1.28 (95%CI: 1.04-1.57) for smoking more than 40 pack-years.

CONCLUSIONS

Physical activity and moderate alcohol intake are inversely associated with T2DM risk, whereas smoking was positively associated with T2DM risk among middle-age and elderly Chinese men. Preventive measures should be developed to focus on these modifiable lifestyle habits to reduce the upward trend of T2DM.

Objective measurements of daily physical activity patterns and sedentary behaviour in older adults: Age, Gene/Environment Susceptibility-Reykjavik Study

BACKGROUND

objectively measured population physical activity (PA) data from older persons is lacking. The aim of this study was to describe free-living PA patterns and sedentary behaviours in Icelandic older men and women using accelerometer.

METHODS

from April 2009 to June 2010, 579 AGESII-study participants aged 73-98 years wore an accelerometer (Actigraph GT3X) at the right hip for one complete week in the free-living settings.

RESULTS

in all subjects, sedentary time was the largest component of the total wear time, 75%, followed by low-light PA, 21%. Moderate-vigorous PA (MVPA) was <1%. Men had slightly higher average total PA (counts × day(-1)) than women. The women spent more time in low-light PA but less time in sedentary PA and MVPA compared with men (P < 0.001). In persons <75 years of age, 60% of men and 34% of women had at least one bout ≥10 min of MVPA, which decreased with age, with only 25% of men and 9% of women 85 years and older reaching this.

CONCLUSION

sedentary time is high in this Icelandic cohort, which has high life-expectancy and is living north of 60° northern latitude.

Physical activity, cardiorespiratory fitness, and exercise training in primary and secondary coronary prevention

Substantial data have established that higher levels of physical activity (PA), participating in exercise training (ET), and higher overall cardiorespiratory fitness (CRF) provide considerable protection in the primary and secondary prevention of coronary heart disease (CHD). This review surveys data from epidemiological and prospective ET studies supporting the favorable impact of PA, ET, and CRF in primary CHD prevention. Clearly, cardiac rehabilitation and ET (CRET) programs have been underutilized for patients with CHD, particularly considering the effect of CRET on CHD risk factors, including CRF, obesity indices, fat distribution, plasma lipids, inflammation, and psychological distress, as well as overall morbidity and mortality. These data strongly support the routine referral of patients with CHD to CRET programs and that patients should be vigorously encouraged to attend CRET following major CHD events.

Physical activity, physical fitness, and risk of type 2 diabetes mellitus

Type 2 diabetes mellitus (DM) is a common chronic disease. Cardiovascular disease is the most prevalent complication of DM. In the past decade, the associations of physical activity, physical fitness, and changes in lifestyle with the risk of type 2 DM have been assessed by a number of prospective epidemiologic studies and clinical trials. Several studies also evaluate the joint associations of physical activity, body mass index, and glucose levels with the risk of type 2 DM. The results of 21 prospective studies and four clinical trials demonstrated that moderate or high levels of physical activity or physical fitness, as well as changes in lifestyle (dietary modification and enhanced physical activity) could prevent type 2 DM.

Lifestyle and the risk of dementia in Japanese-american men

OBJECTIVES

To determine whether adhering to a healthy lifestyle in midlife may reduce the risk of dementia.

DESIGN

Case-control study nested in a prospective cohort.

SETTING

The Honolulu-Asia Aging Study, Oahu, Hawaii.

PARTICIPANTS

Three thousand four hundred sixty-eight Japanese-American men (mean age 52 in 1965-1968) examined for dementia 25 years later.

MEASUREMENTS

Men at low risk were defined as those with the following midlife characteristics: nonsmoking, body mass index (BMI) less than 25.0 kg/m(2) , physically active, and having a healthy diet (based on alcohol, dairy, meat, fish, fruits, vegetables, cereals, and ratio of monounsaturated to saturated fat). Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for developing overall dementia, Alzheimer's disease (AD), and vascular dementia (VaD), adjusting for potential confounders.

RESULTS

Dementia was diagnosed in 6.4% of men (52.5% with AD, 35.0% with VaD). Examining the risk factors individually, BMI was most strongly associated with greater risk of overall dementia (OR = 1.87, 95% CI = 1.26-2.77; BMI > 25.0 vs <22.6 kg/m(2) ). All of the individual risk factors except diet score were significantly associated with VaD, whereas none were significantly associated with AD alone. Men with all four low-risk characteristics (7.2% of the cohort) had the lowest OR for overall dementia (OR = 0.36, 95% CI = 0.15-0.84). There were no significant associations between the combined low-risk characteristics and the risk of AD alone.

CONCLUSION

Among Japanese-American men, having a healthy lifestyle in midlife is associated with a lower risk of dementia in late life.

Physical activity in the Japan population: association with blood lipid levels and effects in reducing cardiovascular and all-cause mortality

According to many prospective cohort studies and meta-analyses of those studies, physical inactivity and/or low levels of physical fitness are associated with an elevated risk for the development of metabolic syndrome, type 2 diabetes, hypertension, coronary artery disease (CAD), and stroke, and with an increased risk of cardiovascular disease (CVD) mortality and all-cause mortality. Most of these analyses, however, were conducted on non-Japanese populations in the West. This report summarizes prospective observational and clinical studies in Japan. The annual national nutrition survey has shown a gradual decline in the number of walking steps in both genders and in all age groups over the last 10 years. While exercise habits have been gradually increasing in the elderly, only one-fifth of young and middle-aged people undertake leisure-time physical activity. Prospective cohort studies have shown that increased physical fitness and greater physical activity in either daily life or leisure time are of benefit in preventing all-cause mortality and CVD mortality. The daily number of walking steps is positively associated with HDL cholesterol levels and negatively associated with triglyceride levels. According to a random-effects model meta-analysis of 4 randomized controlled trials comparing supervised aerobic exercise training with non-exercise control in subjects without CAD, exercise resulted in a significant increase in HDL-cholesterol (10.01 mg/dL, 95% CI 5.38 to 14.65, p< 0.0001). While this confirms the importance of physical activity in preventing CVD mortality and all-cause mortality, the levels of physical activity are on a declining trend in Japan, particularly among the young.

Dietary exercise as a novel strategy for the prevention and treatment of metabolic syndrome: effects on skeletal muscle function

A sedentary lifestyle can cause metabolic syndrome to develop. Metabolic syndrome is associated with metabolic function in the skeletal muscle, a major consumer of nutrients. Dietary exercise, along with an adequate diet, is reported to be one of the major preventive therapies for metabolic syndrome; exercise improves the metabolic capacity of muscles and prevents the loss of muscle mass. Epidemiological studies have shown that physical activity reduces the risk of various common diseases such as cardiovascular disease, diabetes, and cancer; it also helps in reducing visceral adipose tissue. In addition, laboratory studies have demonstrated the mechanisms underlying the benefits of single-bout and regular exercise. Exercise regulates the expression/activity of proteins associated with metabolic and anabolic signaling in muscle, leading to a change in phenotype. The extent of these changes depends on the intensity, the duration, and the frequency of the exercise. The effect of exercise is also partly due to a decrease in inflammation, which has been shown to be closely related to the development of various diseases. Furthermore, it has been suggested that several phytochemicals contained in natural foods can improve nutrient metabolism and prevent protein degradation in the muscle.

Neighborhood walkability, physical activity, and walking behavior: the Swedish Neighborhood and Physical Activity (SNAP) study

More knowledge concerning the association between physical activity and objectively measured attributes of the built environment is needed. Previous studies on the association between objectively measured neighborhood walkability, physical activity, and walking have been conducted in the U.S. or Australia and research findings are available from only one country in Europe - Belgium. The first aim of this Swedish study of 2269 adults was to examine the associations between neighborhood walkability and walking for active transportation or leisure, and moderate-to-vigorous physical activity (MVPA) and whether these hypothesized associations are moderated by age, gender, income, marital status and neighborhood-level socioeconomic status. The second aim was to determine how much of the total variance of the walking and physical activity outcomes can be attributed to neighborhood-level differences. Neighborhood walkability was objectively measured by GIS methods. An index consisting of residential density, street connectivity, and land use mix was constructed to define 32 highly and less walkable neighborhoods in Stockholm City. MVPA was measured objectively during 7 days with an accelerometer and walking was assessed using the validated International Physical Activity Questionnaire (IPAQ). Multilevel linear as well as logistic models (mixed-effects, mixed-distribution models) were used in the analysis. The statistically significant and "adjusted" results for individuals living in highly walkable neighborhoods, as compared to those living in less walkable neighborhoods, were: (1) 77% and 28% higher odds for walking for active transportation and walking for leisure, respectively, (2) 50 min more walking for active transportation/week, and (3) 3.1 min more MVPA/day. The proportion of the total variance at the neighborhood level was low and ranged between 0.0% and 2.1% in the adjusted models. The findings of the present study stress that future policies concerning the built environment must be based on context-specific evidence, particularly in the light of the fact that neighborhood redevelopments are time-consuming and expensive.

Physical inactivity among adults with diabetes mellitus and depressive symptoms: results from two independent national health surveys

OBJECTIVE

To examine the association between depressive symptoms and physical inactivity in community samples of patients with diabetes mellitus (DM).

METHODS

Two representative samples of Israeli adults (age ≥21 years) were analyzed: The First Israeli National Health Interview Survey (INHIS-1) (n=9509) and the Israel National Health Survey (INHS) (n=4859). Information was obtained about past-month depressive symptoms, physician-diagnosed DM and physical activity. Multiple logistic regression models were used to examine the association between level of depressive symptoms and physical inactivity among individuals with DM, adjusting for potential confounders.

RESULTS

Prevalence of DM ranged from 7.2% (INHIS-1) to 8.7% (INHS). In both samples, physical inactivity was significantly more prevalent among persons with significant depressive symptoms, compared to those without depressive symptoms [INHIS-1: 67.0% vs. 50.6%; adjusted odds ratio (AOR): 1.57; 95% confidence interval (95% CI), 1.05-2.35, P=.03; INHS: 71.4% vs. 43.9%; AOR: 2.67; 95% CI, 1.67-4.27, P<.0001].

CONCLUSIONS

Depressive symptoms were associated with a higher likelihood of physical inactivity in persons with DM. Body mass index of patients reporting no regular physical activity was elevated compared to persons who were physically active. This finding supports the view that identification and management of depression should be part of interventions designed to improve self care behaviors in patients with DM.

A systematic review of the evidence for Canada's Physical Activity Guidelines for Adults

This systematic review examines critically the scientific basis for Canada's Physical Activity Guide for Healthy Active Living for adults. Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases (cardiovascular disease, stroke, hypertension, colon cancer, breast cancer, type 2 diabetes (diabetes mellitus) and osteoporosis). The strength of the relationship between physical activity and specific health outcomes is evaluated critically. Literature was obtained through searching electronic databases (e.g., MEDLINE, EMBASE), cross-referencing, and through the authors' knowledge of the area. For inclusion in our systematic review articles must have at least 3 levels of physical activity and the concomitant risk for each chronic disease. The quality of included studies was appraised using a modified Downs and Black tool. Through this search we identified a total of 254 articles that met the eligibility criteria related to premature all-cause mortality (N = 70), cardiovascular disease (N = 49), stroke (N = 25), hypertension (N = 12), colon cancer (N = 33), breast cancer (N = 43), type 2 diabetes (N = 20), and osteoporosis (N = 2). Overall, the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified. Moreover, higher levels of physical activity reduce the risk for premature all-cause mortality. The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality.

Physical activity, fitness and fatness: relations to mortality, morbidity and disease risk factors. A systematic review

The purpose of this systematic review was to study the relative health risks of poor cardio-respiratory fitness (or physical inactivity) in normal-weight people vs. obesity in individuals with good cardio-respiratory fitness (or high physical activity). The core inclusion criteria were: publication year 1990 or later; adult participants; design prospective follow-up, case-control or cross-sectional; data on cardio-respiratory fitness and/or physical activity; data on BMI (body mass index), waist circumference or body composition; outcome data on all-cause mortality, cardiovascular disease mortality, cardiovascular disease incidence, type 2 diabetes or cardiovascular and type 2 diabetes risk factors. Thirty-six publications filled the criteria for inclusion. The data indicate that the risk for all-cause and cardiovascular mortality was lower in individuals with high BMI and good aerobic fitness, compared with individuals with normal BMI and poor fitness. In contrast, having high BMI even with high physical activity was a greater risk for the incidence of type 2 diabetes and the prevalence of cardiovascular and diabetes risk factors, compared with normal BMI with low physical activity. The conclusions of the present review may not be applicable to individuals with BMI > 35.

Alberta Diabetes and Physical Activity Trial (ADAPT): a randomized theory-based efficacy trial for adults with type 2 diabetes--rationale, design, recruitment, evaluation, and dissemination

BACKGROUND

The primary aim of this study was to compare the efficacy of three physical activity (PA) behavioural intervention strategies in a sample of adults with type 2 diabetes.

METHOD/DESIGN

Participants (N = 287) were randomly assigned to one of three groups consisting of the following intervention strategies: (1) standard printed PA educational materials provided by the Canadian Diabetes Association [i.e., Group 1/control group)]; (2) standard printed PA educational materials as in Group 1, pedometers, a log book and printed PA information matched to individuals' PA stage of readiness provided every 3 months (i.e., Group 2); and (3) PA telephone counseling protocol matched to PA stage of readiness and tailored to personal characteristics, in addition to the materials provided in Groups 1 and 2 (i.e., Group 3). PA behaviour measured by the Godin Leisure Time Exercise Questionnaire and related social-cognitive measures were assessed at baseline, 3, 6, 9, 12 and 18-months (i.e., 6-month follow-up). Clinical (biomarkers) and health-related quality of life assessments were conducted at baseline, 12-months, and 18-months. Linear Mixed Model (LMM) analyses will be used to examine time-dependent changes from baseline across study time points for Groups 2 and 3 relative to Group 1.

DISCUSSION

ADAPT will determine whether tailored but low-cost interventions can lead to sustainable increases in PA behaviours. The results may have implications for practitioners in designing and implementing theory-based physical activity promotion programs for this population.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov identifier: NCT00221234.

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

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

Effects of lifestyle changes to reduce risks of diabetes and associated cardiovascular risks: results from large scale efficacy trials

The increasing prevalence of type 2 diabetes throughout the world is now recognized as a major health problem. A growing segment of the population has impaired glucose tolerance (IGT), which is a strong predictor of progression to type 2 diabetes. Further, 24% of Americans now meet the criteria for the metabolic syndrome, a risk factor for both type 2 diabetes and cardiovascular disease (CVD). The diabetes epidemic is associated with changes in lifestyle-most notably increased energy intake, changes in diet composition and decreased levels of physical activity-and the development of overweight and obesity. This review examines the effects of several intensive lifestyle intervention trials on the risk of diabetes and CVD among high-risk populations. Common features of these lifestyle interventions are dietary modification, weight loss and increased physical activity. These trials indicate that lifestyle modification is effective in decreasing the progression from IGT to type 2 diabetes and reducing CVD risk factors. However, the effectiveness of lifestyle interventions for reductions in CVD events has yet to be determined.

Physical activity and incident diabetes in American Indians: the Strong Heart Study

The authors examined the association between total physical activity (leisure-time plus occupational) and incident diabetes among 1,651 American Indians who participated in the Strong Heart Study, a longitudinal study of cardiovascular disease and its risk factors among 13 American Indian communities in 4 states (North Dakota, South Dakota, Oklahoma, and Arizona). Discrete Cox models were used to examine the association between physical activity level (in tertiles), compared with no physical activity, and incident diabetes, after adjustment for potential confounders. During 10 years of follow-up (f1989-1999), 454 incident cases of diabetes were identified. Compared with participants who reported no physical activity, those who reported any physical activity had a lower risk of diabetes: Odds ratios were 0.67 (95% confidence interval (CI): 0.46, 0.99), 0.67 (95% CI: 0.45, 0.99), and 0.67 (95% CI: 0.45, 0.99) for increasing tertile of physical activity, after adjustment for age, sex, study site, education, smoking, alcohol use, and family history of diabetes. Further adjustment for body mass index and other potential mediators attenuated the risk estimates. These data suggest that physical activity is associated with a lower risk of incident diabetes in American Indians. This study identifies physical activity as an important determinant of diabetes among American Indians and suggests the need for physical activity outreach programs that target inactive American Indians.

[A prospective cohort study of exercise and the incidence of type 2 diabetes in impaired fasting glucose group]

OBJECTIVES

To determine the relationship between exercise and the incidence of type 2 diabetes in an impaired fasting glucose group.

METHODS

This prospective cohort study was conducted in 19,440 men and 4,297 women, aged 30-69 years, with impaired fasting glucose at baseline who had undergone biennial medical evaluation through the National Health Insurance Corporation from 2000 to 2004. Impaired fasting glucose was defined as fasting glucose of 100 to 125 mg/dl and the subjects were divided into 3 groups depending on weekly exercise frequency. Multivariate logistic regression analysis was used to evaluate the association between the baseline exercise status and incidence of type 2 diabetes.

RESULTS

During the 4-year follow-up, a total of 3,239 men and 283 women developed type 2 diabetes, a cumulative incidence of 16.6% for men, and 6.5% for women. Also, 1,688 men (21.2%) and 127 women (15.2%) developed type 2 diabetes in the obese group. The adjusted relative risk (RR) of developing type 2 diabetes in non-exercising men was significantly higher than exercising men regularly (RR= 1.375, 95% CI=1.236-1.529)(p<0.0001), and the RR for non-exercising women was higher than exercising women regularly (RR=1.124, 95% CI=0.711-1.778). The RR for non-exercise men/women in the obese group was 1.571 (95% CI=1.351-1.827)(p<0.0001)/1.869(95% CI=0.846-4.130).

CONCLUSIONS

Regular exercise is effective in preventing type 2 diabetes in people with impaired fasting glucose, and particularly in obese people. People with risk factors for diabetes should participate in a regular exercise program.

Changes in vigorous physical activity and incident diabetes in male runners

OBJECTIVE

We examined the relationship between changes in reported vigorous exercise and self-reported physician-diagnosed diabetes in 25,988 active men.

RESEARCH DESIGN AND METHODS

The dose-response relationship between changes in reported vigorous exercise (running distance, change in kilometers per week) and self-reported physician-diagnosed diabetes was followed prospectively for 7.8 +/- 1.8 years (means +/- SD).

RESULTS

Logistic regression analyses showed that the log odds for diabetes declined significantly in relation to men's change in running distance (coefficient +/- SE: -0.012 +/- 0.004, P < 0.01), which remained significant when adjusted for BMI (-0.018 +/- 0.003, P < 0.0001). The decline in the log odds for diabetes was related to the distance run at the end of follow-up when adjusted for baseline distance, with (-0.024 +/- 0.005, P < 0.0001) or without (-0.027 +/- 0.005, P < 0.0001) adjustment for BMI. Baseline distance was unrelated to diabetes incidence when adjusted for the distance at the end of follow-up. Compared with men who ran < 8 km/week at the end of follow-up, incidence rates in those who ran > or = 8 km/week were 95% lower between 35 and 44 years of age (P < 0.0001), 92% lower between 45 and 54 (P < 0.0001), 87% lower between 55 and 64 (P < 0.0001), and 46% lower between 65 and 75 (P = 0.30). For the subset of 6,208 men who maintained the same running distance during follow-up (+/-5 km/week), the log odds for diabetes declined with weekly distance run (-0.024 +/- 0.010, P = 0.02) but not when adjusted for BMI (-0.005 +/- 0.010, P = 0.65).

CONCLUSIONS

Vigorous exercise significantly reduces diabetes incidence, due in part to the prevention of age-related weight gain and in part to other exercise effects.

Epidemiological studies of exercise in diabetes prevention

Type 2 diabetes is one of the fastest growing public health problems in both developed and developing countries. It is estimated that the number of people with diabetes in the world will double in coming years, from 171 million in 2000 to 366 million in 2030. Cardiovascular disease accounts for more than 70% of total mortality among patients with type 2 diabetes. The associations of physical activity, physical fitness, and changes in the lifestyle with the risk of type 2 diabetes have been assessed by a number of prospective studies and clinical trials in the past decade. Several studies have also evaluated the joint associations of physical activity, body mass index, and glucose levels with the risk of type 2 diabetes. Prospective studies and clinical trials have shown that moderate or high levels of physical activity or physical fitness and changes in the lifestyle (dietary modification and increase in physical activity) can prevent type 2 diabetes. Our review of the scientific evidence confirms that 30 min/d of moderate- or high-level physical activity is an effective and safe way to prevent type 2 diabetes in all populations.

Long-term effects of leisure time physical activity on risk of insulin resistance and impaired glucose tolerance, allowing for body weight history, in Danish men

AIMS

To determine if the level of leisure time physical activity (LTPA) in young adulthood in obese and non-obese men reduces the risk of insulin resistance (IR) and impaired glucose tolerance (IGT) in middle age, and if such an effect is explained by the current level of LTPA, or by the body mass index (BMI) history preceding and subsequent to the assessment of LTPA.

METHODS

Longitudinal study of groups of obese and randomly selected non-obese men identified at around age 19, and re-examined at mean ages of 32, 44 and 51. BMI was measured at all four examinations. LTPA was assessed by self-administrated questionnaires at the last three examinations. IR and the presence of IGT was determined by an oral glucose tolerance test at the last examination.

RESULTS

LTPA in young adulthood reduced the risk of IR and IGT in middle age throughout the range of BMI. Adjustment for the BMI history preceding and subsequent to the assessment of LTPA attenuated the association with IR and IGT, but active men remained at low risk of IR and IGT. Adjustment for subsequent and current levels of LTPA, smoking habits, alcohol intake, educational level and family history of diabetes had no notable influence on the results.

CONCLUSION

LTPA appears to reduce the risk of IR and IGT, an effect which is not explained by the current level of physical activity, and only partially explained by the BMI history preceding and subsequent to the assessment of LTPA.

Occupational and other risk factors for hand-grip strength: the Honolulu-Asia Aging Study

BACKGROUND

In certain occupations, including farm work, workers are exposed to hazardous substances, some of which are known to be toxic to the nervous system and may adversely affect muscle strength. Measurement of hand-grip strength may be useful for detecting neurotoxic exposure.

METHODS

The authors studied 3522 participants of the Honolulu Heart Program and the Honolulu-Asia Aging Study to determine whether occupational exposures to pesticides, solvents, and metals assessed at exam I (1965-68) are associated with hand-grip strength at exam IV (1991-93) and change in hand-grip strength over 25 years. Correlation, analysis of variance and covariance, and linear regression were used to evaluate the associations.

RESULTS

At exam IV, participants ranged in age from 71-93 years; mean hand-grip strength was 39.6 kg at exam I and 30.3 kg at exam IV. Over 25 years, the decline in hand-grip strength was an average of 8-9 kg for all exposures. Hand-grip strength was inversely associated with age and glucose but directly associated with cognitive function, BMI, and haemoglobin level. No other exposures were associated with hand-grip strength.

CONCLUSION

This study did not provide evidence that occupational exposure to pesticides, solvents, and metals adversely affected hand-grip strength in this population, but confirmed other important associations with hand-grip strength.

Midlife physical activity and mobility in older age: The InCHIANTI study

BACKGROUND

Among older adults, loss of mobility represents a critical stage in the disablement process, whereby the risk for disability is significantly increased. Physical activity is a modifiable risk factor that is associated with reduced risk of losing mobility in older adulthood; however, few studies have examined physical activity performed earlier in life in relation to mobility later in life.

METHODS

Data from a population-based study of 1155 adults aged 65 years and older living in the Chianti region of Italy in 1998-2000 were analyzed in 2005 and 2006. Participants retrospectively recalled their physical activity levels in midlife and underwent mobility testing and medical examination. Two objective mobility outcomes were examined as a function of past physical activity: the Short Physical Performance Battery (SPPB) and the ability to walk 400 meters.

RESULTS

Older Italian adults (mean age 74.8, standard deviation 7.3) who engaged in higher levels of physical activity in midlife were significantly more likely to perform better on the SPPB than individuals who were less physically active in midlife. In addition, failure to complete the 400-meter walk test was significantly less likely among physically active men (Level II) (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.15-0.93) and very active men (Level III) (OR = 0.23, 95% CI = 0.09-0.63) when compared to men who were less active (Level I) in the past (p for trend, 0.008). These associations remained after adjustment for demographic factors, medical conditions, and physiologic impairments.

CONCLUSIONS

Older adults who reported higher levels of physical activity in midlife had better mobility in old age than less physically active ones.

Changing Our Future

Obesity, or overweight, in childhood is a major risk factor for the metabolic syndrome in adolescence, as the prevalence in US children tripled between 1970 and 2000. An increase in the metabolic syndrome in youth has followed this increase. In population-based studies, the prevalence of the syndrome ranged from 3.6% to 4.2%. In smaller studies with many overweight youth, the prevalence was 28.7% to 39.7% in those who were overweight and 49.7% in those who were severely obese. Overweight children are likely to have hyperinsulinemia, high-density lipoprotein cholesterol, high triglycerides, and hypertension, which are components of the metabolic syndrome. Nurses have an important role in screening for these metabolic syndrome components. Screening is especially important in boys and girls who are overweight and in girls with early menarche. A problem when screening children and adolescents is determining normative values, but guidelines are available. Prevention and management of the metabolic syndrome are not specific to the syndrome, but rather should be focused on the underlying problem of overweight and related problems that comprise the syndrome. We must use all avenues available to us, including influencing public and school policies, and pay close attention to overweight and metabolic syndrome components in our clinical practice, whether with children or adults. Preventing and managing the metabolic syndrome should be a family matter, and the necessary lifestyle changes will benefit the entire family.

Prevenção do diabetes mellitus tipo 2

Diabetes mellitus do tipo 2 (DM2) é uma doença metabólica complexa, multifatorial e de presença global, que afeta a qualidade e o estilo de vida dos acometidos, podendo levar a uma redução pronunciada na expectativa de vida dessa população. Portadores de diabetes podem ter uma redução de 15 ou mais anos de vida, com a grande maioria morrendo em decorrência das complicações cardiovasculares. Faz-se necessário o estabelecimento de estratégias efetivas para a redução do impacto do DM2 para os próximos anos. Para isso, urge a necessidade de maior atenção no tocante às estratégias de prevenção, sobretudo para as populações de maior risco de desenvolvimento da doença. Nesse contexto, os portadores de tolerância diminuída à glicose (TDG) e glicemia de jejum alterada (GJA) devem, cada vez mais, ser alvos de estratégias de intervenção na busca de minimização de risco para o diabetes, devendo para isso terem direcionamento para a efetivação de mudanças comportamentais (fatores dietoterápicos e prática de atividade física) e, quando necessário e aprovado, o uso de agentes farmacológicos. Estudos conduzidos pelo mundo têm confirmado a eficácia do uso de estratégias comportamentais e mesmo do uso de agentes farmacológicos para a prevenção de DM2.

Occupational exposures and movement abnormalities among Japanese-American men: the Honolulu-Asia Aging Study

OBJECTIVE

The authors analyzed data on 1,049 men aged 71-93 years (excluding those with prevalent Parkinson's disease and stroke) from the Honolulu Heart Program (1965-1968) and the Honolulu-Asia Aging Study (1991-1999) to determine whether occupational exposures to pesticides, solvents, metals, manganese, and mercury during middle age were associated with 14 movement abnormalities 25 years later.

METHODS

Analyses of variance and multivariate logistic regression were used to assess associations of interest.

RESULTS

After adjustment for age, BMI, cognitive functioning, smoking, alcohol drinking, education, and physical activity, there was a positive association between abnormal 'facial expression' and the highest exposure to metals [odds ratio (OR) = 2.62; 95% confidence interval (CI) = 1.35-5.11; trend, p = 0.02], and the highest exposure to mercury (OR = 1.91; 95% CI = 1.04-3.49; trend, p = 0.03). Age was positively associated with all movement abnormalities, and cognitive function, body mass index and physical activity were inversely associated with most movement abnormalities.

CONCLUSION

Higher exposure to any metal, and specifically mercury, was associated with abnormal facial expression.

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.

Epidemiological evidence for the role of physical activity in reducing risk of type 2 diabetes and cardiovascular disease

Epidemiological studies suggest that physically active individuals have a 30-50% lower risk of developing type 2 diabetes than do sedentary persons and that physical activity confers a similar risk reduction for coronary heart disease. Risk reductions are observed with as little as 30 min of moderate-intensity activity per day. Protective mechanisms of physical activity include the regulation of body weight; the reduction of insulin resistance, hypertension, atherogenic dyslipidemia, and inflammation; and the enhancement of insulin sensitivity, glycemic control, and fibrinolytic and endothelial function. Public health initiatives promoting moderate increases in physical activity may offer the best balance between efficacy and feasibility to improve metabolic and cardiovascular health in largely sedentary populations.

Prevention of Type 2 Diabetes by Diet and Lifestyle Modification

Diabetes mellitus is an epidemic of our time. This disease affects nearly 150 million adults worldwide and nearly 11 million in the United States in 2000. Because of the prevalence of obesity and diabetes and associated vascular complications, preventing even a small proportion of cases would save thousands of lives and billions of dollars in healthcare costs and lost productivity. Researchers have made great strides in identifying many lifestyle and dietary factors associated with diabetes, but solidifying the scientific basis for prevention and control of this disease as well as implementation at a national level remains a difficult challenge. The literature on the influence of diet and lifestyle in the development of diabetes is reviewed here, with emphasis on epidemiologic data. We outline a systematic approach to primary and secondary prevention of this disease by evaluating and prioritizing risk factors for which intervention is effective and developing a framework for application of intervention strategies. Effective interventions must target not only the affected individuals but also families, workplaces, schools and communities. Prevention of this devastating disease calls for the identification of culture-sensitive measures that can be applied to the population in general and some high-risk minority groups in particular.

Lifestyle intervention for the prevention of type 2 diabetes mellitus: putting theory to practice

Type 2 diabetes mellitus is a serious, growing, and costly public health problem. The disease is chronic and degenerative, and thus primary prevention is desirable. Observational studies have linked type 2 diabetes to specific lifestyle behaviors. Several recent major clinical trials confirm that type 2 diabetes can be delayed or prevented in people at high risk; multicomponent lifestyle modification can reduce the incidence of diabetes up to 58%. The American Diabetes Association has recently recommended that lifestyle interventions to prevent or delay diabetes be delivered to people with prediabetes. Delivery of lifestyle interventions in practice is fraught with challenges, but there are several tools and practical strategies available for the implementation of trial findings.

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.

Effects of exercise and diet on chronic disease

Currently, modern chronic diseases, including cardiovascular diseases, Type 2 diabetes, metabolic syndrome, and cancer, are the leading killers in Westernized society and are increasing rampantly in developing nations. In fact, obesity, diabetes, and hypertension are now even commonplace in children. Clearly, however, there is a solution to this epidemic of metabolic disease that is inundating today's societies worldwide: exercise and diet. Overwhelming evidence from a variety of sources, including epidemiological, prospective cohort, and intervention studies, links most chronic diseases seen in the world today to physical inactivity and inappropriate diet consumption. The purpose of this review is to 1) discuss the effects of exercise and diet in the prevention of chronic disease, 2) highlight the effects of lifestyle modification for both mitigating disease progression and reversing existing disease, and 3) suggest potential mechanisms for beneficial effects.