Mating system patterns of natural populations of Pinus koraiensis along its post-glacial colonization route in northeastern China

To understand the genetic mechanisms underlying the endangerment of Pinus koraiensis, we studied the mating system of 49 families of this species in 3 natural populations along its post-glacial colonization route across ~1500 km in northeastern China using the chloroplast simple sequence repeat technique. We analyzed 11 polymorphic loci with clear and repeating bands, and we calculated the multi-locus outcrossing rate (tm), single-locus outcrossing rate, inbreeding index, and fixation index (F). Intra-population variation was not observed, but a large inter-population variation was observed in the outcrossing rate, and the tm increased from 0.767 (the south population) to 0.962 (the north population) along the post-glacial colonization route. The tm values within a population did not change with time over 2 consecutive years. The F values for the 3 populations were <0, which indicates an excess of heterozygotes. The mean effective number of alleles, Shannon diversity index, and Nei's genetic diversity index did not show a south-north pattern. The north population had the highest outcrossing rate but the lowest genetic diversity. The average genetic differentiation of P. koraiensis populations was 0.1251, which was within the average range of woody plants with outcrossing and wind pollination. This study suggests that the current endangerment of P. koraiensis is not related to its genetic structure; perhaps it is mainly caused by man-made and natural disturbances such as deforestation and fire. Therefore, reducing disturbances and enhancing habitats, rather than the genetic aspects, play more important roles in the long-term protection of P. koraiensis.

Association between Cardiorespiratory Fitness and Health-Related Quality of Life among Patients at Risk for Cardiovascular Disease in Uruguay

PURPOSE

To examine the association between objectively measured CRF and physical and mental components of HRQoL in a Uruguayan cohort at risk for developing CVD.

METHODS

Patient data records from 2002-2012 at the Calidad de Vida Center were examined. To assess CRF, participants performed a submaximal exercise test. During the evaluation, participants also completed the SF-36, a HRQoL measure comprised of eight dimensions that are summarized by physical and mental component scores (PCS and MCS, respectively). ANCOVA was used to examine the relationship between HRQoL dimensions and CRF. Logistic regression was then used to compare the odds of having a HRQoL component score above the norm across CRF. All analyses were performed separately for males and females with additional stratified analyses across age and BMI conducted among significant trends.

RESULTS

A total of 2,302 subjects were included in the analysis. Among females, a significant relationship was observed between CRF and vitality, physical functioning, physical role, bodily pain, and general health dimensions. However, for males the only dimension found to be significantly associated with CRF was physical health. After adjusting for potential confounders, a significant linear trend (p<0.001) for PCS scores above the norm across CRF levels was observed for females only.

CONCLUSION

Among females with one or more risk factors for developing CVD, higher levels of CRF were positively associated with the vitality and physical dimensions of HRQoL, as well as the overall PCS. However, among males the only dimension associated with CRF was physical functioning. Future studies should examine this relationship among populations at risk for developing CVD in more detail and over time.

Relationship of Physical Activity and Healthy Eating with Mortality and Incident Heart Failure among Community-Dwelling Older Adults with Normal Body Mass Index

AIMS

Normal body mass index (BMI) is associated with lower mortality and may be achieved by physical activity (PA), healthy eating (HE), or both. We examined the association of PA and HE with mortality and incident heart failure (HF) among 2040 community-dwelling older adults aged ≥ 65 years with baseline BMI 18.5 to 24.99 kg/m² during 13 years of follow-up in Cardiovascular Health Study.

METHODS AND RESULTS

Baseline PA was defined as ≥500 weekly metabolic equivalent task-minutes (MET-minutes) and HE as ≥5 daily servings of vegetable and fruit intake. Participants were categorized into 4 groups: (1) PA-/HE- (n=384); (2) PA+/HE- (n=992); (3) PA-/HE+ (n=162); and (4) PA+/HE+ (n=502). Participants had a mean age of 74 (±6) years, mean BMI of 22.6 (±1.5) kg/m², 61% were women, and 4% African American. Compared with PA-/HE-, age-sex-race-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality for PA-/HE+, PA+/HE-, and PA+/HE+ groups were 0.96 (0.76-1.21), 0.61 (0.52-0.71) and 0.62 (0.52-0.75), respectively. These associations remained unchanged after multivariable adjustment and were similar for cardiovascular and non-cardiovascular mortalities. Respective demographic-adjusted HRs (95% Cis) for incident HF among 1954 participants without baseline HF were 1.21 (0.81-1.81), 0.71 (0.54-0.94) and 0.71 (0.51-0.98). These later associations lost significance after multivariable-adjustment.

CONCLUSION

Among community-dwelling older adults with normal BMI, physical activity, regardless of healthy eating, was associated with lower risk of mortality and incident HF, but healthy eating had no similar protective association in this cohort.

Exercise capacity and risk of chronic kidney disease in US veterans: a cohort study

OBJECTIVE

To assess the association between exercise capacity and the risk of developing chronic kidney disease (CKD).

PATIENTS AND METHODS

Exercise capacity was assessed in 5812 male veterans (mean age, 58.4±11.5 years) from the Veterans Affairs Medical Center, Washington, DC. Study participants had an estimated glomerular filtration rate of 60 mL/min per 1.73 m(2) or more 6 months before exercise testing and no evidence of CKD. Those who developed CKD during follow-up were initially identified by the International Classification of Diseases, Ninth Revision and further verified by at least 2 consecutive estimated glomerular filtration rate values of less than 60 mL/min per 1.73 m(2) 3 months or more apart. Normal kidney function for CKD-free individuals was confirmed by sequential normal eGFR levels. We established 4 fitness categories on the basis of age-stratified quartiles of peak metabolic equivalents (METs) achieved: least-fit (≤25%; 4.8±0.90 METs; n=1258); low-fit (25.1%-50%; 6.5±0.96 METs; n=1614); moderate-fit (50.1%-75%; 7.7±0.91 METs; n=1958), and high-fit (>75%; 9.5±1.0 METs; n=1436). Multivariable Cox proportional hazard models were used to assess the association between exercise capacity and CKD.

RESULTS

During a median follow-up period of 7.9 years, 1010 developed CKD (20.4/1000 person-years). Exercise capacity was inversely related to CKD incidence. The risk was 22% lower (hazard ratio, 0.78; 95% CI, 0.75-0.82; P<.001) for every 1-MET increase in exercise capacity. Compared with the least-fit individuals, hazard ratios were 0.87 (95% CI, 0.74-1.03) for low-fit, 0.55 (95% CI, 0.47-0.65) for moderate-fit, and 0.42 (95% CI, 0.33-0.52) for high-fit individuals.

CONCLUSION

Higher exercise capacity attenuated the risk of developing CKD. The association was independent and graded.

A prospective study of fitness, fatness, and depressive symptoms

Being overweight or obese might be a risk factor for developing depression. It is also possible that low cardiorespiratory fitness, rather than overweight or obesity, is the better predictor of depressive symptom onset. Adults in the Aerobics Center Longitudinal Study (Dallas, Texas) underwent fitness and fatness assessments between 1979 and 1998 and later completed a questionnaire about depressive symptoms in 1990, 1995, or 1999. Separate logistic regression models were used to test the associations between 3 fatness measures (body mass index, waist circumference, and percentage of body fat) and the onset of depressive symptoms. Analyses were repeated using fitness as the predictor variable. Additional analyses were performed to study the joint association of fatness and fitness with the onset of depressive symptoms. After controlling for fitness, no measure of fatness was associated with the onset of depressive symptoms. In joint analyses, low fitness was more strongly associated with the onset of elevated depressive symptoms than was fatness, regardless of the measure of fatness used. Overall, results from the present study suggest that low fitness is more strongly associated with the onset of elevated depressive symptoms than is fatness. To reduce the risk of developing depression, individuals should be encouraged to improve their fitness regardless of body fatness.

Associations between television watching and car riding behaviors and development of depressive symptoms: a prospective study

OBJECTIVE

To examine the longitudinal association between sedentary behaviors and risk of development of depressive symptoms.

PATIENTS AND METHODS

The study population consisted of 4802 participants in the Aerobics Center Longitudinal Study (1012 women and 3790 men) aged 18 to 80 years who did not report depressive moods when they completed a health survey during 1982 in which they reported their time spent watching television (TV) and riding in a car each week. All participants completed a follow-up health survey when they responded to the 10-item Center for Epidemiologic Studies Depression Scale. Those who scored 8 or more on the Center for Epidemiologic Studies Depression Scale were considered to have depressive symptoms.

RESULTS

Among the 4802 participants, 568 reported depressive symptoms during a mean follow-up of 9.3 years. After multivariate adjustment including moderate- and vigorous-intensity physical activity, time riding in a car, time watching TV, and combined time spent in the 2 sedentary behaviors were positively associated with depressive symptoms (each P<.05 for trend). Individuals who reported 9 h/wk or more riding in a car, more than 10 h/wk watching TV, or 19 h/wk or more of combined sedentary behavior had 28%, 52%, and 74% greater risk of development of depressive symptoms than those who reported less than 5 h/wk, less than 5 h/wk, or less than 12 h/wk, respectively, after adjusting for baseline covariates and moderate- and vigorous-intensity physical activity. The positive association between time riding in a car or time watching TV and depressive symptoms was only observed among individuals who did not meet the current physical activity guidelines.

CONCLUSION

More time reported in these 2 sedentary behaviors was positively associated with depressive symptoms. However, the direct associations between time spent in car riding and TV viewing and depressive symptoms were only significant among those who did not meet the current physical activity recommendations.

Association of changes in fitness and body composition with cancer mortality in men

INTRODUCTION

Both baseline cardiorespiratory fitness and adiposity predict the risk of cancer mortality. However, the effects of changes in these two factors over time have not been evaluated thoroughly. The aim of this study was to examine the independent and joint associations of changes in cardiorespiratory fitness and body composition on cancer mortality.

METHODS

The cohort consisted of 13,930 men (initially cancer-free) with two or more medical examinations from 1974 to 2002. Cardiorespiratory fitness was assessed by a maximal treadmill exercise test, and body composition was expressed by body mass index (BMI) and percent body fat. Changes in cardiorespiratory fitness and body composition between the baseline and the last examination were classified into loss, stable, and gain groups.

RESULTS

There were 386 deaths from cancer during an average of 12.5 yr of follow-up. After adjusting for possible confounders and BMI, change hazard ratios (95% confidence intervals) of cancer mortality were 0.74 (0.57-0.96) for stable fitness and 0.74 (0.56-0.98) for fitness gain. Inverse dose-response relationships were observed between changes in maximal METs and cancer mortality (P for linear trend = 0.05). Neither BMI change nor percent body fat change was associated with cancer mortality after adjusting for possible confounders and maximal METs change. In the joint analyses, men who became less fit had a higher risk of cancer mortality (P for linear trend = 0.03) compared with those who became more fit, regardless of BMI change levels.

CONCLUSIONS

Being unfit or losing cardiorespiratory fitness over time was found to predict cancer mortality in men. Improving or maintaining adequate levels of cardiorespiratory fitness appears to be important for decreasing cancer mortality in men.

Parental history of premature cardiovascular disease, estimated GFR, and rate of estimated GFR decline: results from the Aerobics Center Longitudinal Study

BACKGROUND

Despite cardiovascular disease (CVD) and chronic kidney disease sharing similar causes and interplay, it is unknown if a broader relationship between these diseases exists across generations. We investigated the association between parental CVD history and estimated glomerular filtration rate (eGFR) in the community.

STUDY DESIGN

Cross-sectional and longitudinal analyses.

SETTING & PARTICIPANTS

13,241 community-based adults with serum creatinine measurement and follow-up visits (from 1-8 visits ~2 years apart) from the Aerobics Center Longitudinal Study.

PREDICTORS

Premature parental CVD history (before age 50 years).

OUTCOMES

eGFR, decreased eGFR (<60 mL/min/1.73 m(2)), and rate of eGFR decline.

MEASUREMENTS

Information for parental history was collected by protocol-standardized questionnaires. eGFR was assessed with serum creatinine.

RESULTS

3,339 (25.2%) participants reported a history of parental CVD. Individuals with parental CVD had significantly lower eGFRs compared with those without parental CVD (69.4 ± 12.9 vs 74.8 ± 14.2 mL/min/1.73 m(2); P<0.001). After multivariable adjustment, parental CVD was associated independently with higher odds of having decreased eGFR (adjusted OR, 1.68; 95% CI, 1.52-1.86). Random-coefficient models showed that individuals with parental CVD had a faster decline in eGFR compared with those without parental CVD (sex- and ethnicity-adjusted annual change of -0.47 vs -0.41 mL/min/1.73 m(2); P=0.06).

LIMITATIONS

~70% of participants did not attend a second examination.

CONCLUSIONS

Parental history of CVD was associated with lower baseline eGFR, higher odds of decreased eGFR, and a nominally faster rate of eGFR decline in the offspring. Such findings may imply previously unrecognized cross-generational links between both diseases and be of support in community screening programs.

[Analysis of ND4 gene mutations in acute myelogenous leukemia]

OBJECTIVE

To investigate the relationship of the mutational status of the ND4 gene and the clinical features of acute myelogenous leukemia (AML) patients with ND4 mutations.

METHODS

Using PCR combined with directly sequencing, we identified somatic mutations of ND4 in 121 primary AML patients to couple with their clinical features.

RESULTS

There were 58 male patients and 63 female patients (median age 49 years, 10-86 years). Eight of 121 patients (6.6%) with de novo AML were found harboring missense mutation of ND4 gene, including 3 patients with A131V (3/8, 37.5%), 2 patients with A404T (2/8, 25%), 1 patient with F149L (1/8, 12.5%), 1 patient with G242D (1/8, 12.5%) and 1 patient with Y409H (1/8, 12.5%), respectively. Patients with ND4 mutations were associated with good karyotype (P=0.049), regardless of gender, age, white blood cell, hemoglobin, platelet, blast cells of bone marrow or immunophenotype (P>0.05). There were no statistical significance in mutations of FLT3-ITD, NPM1, CEBPA, c-KIT and DNMT3A between patients with ND4 mutation and wild-type (wt) ND4 (P>0.05). The median overall survival of patients with ND4 mutations and wt ND4 were all not reached. The median relapse-free survival were not reached and 29(2-53) months, respectively (P>0.05). There was no significance in the ratio of CR and RR patients between wt ND4 and ND4 mutated groups (P>0.05).

CONCLUSION

It was concluded that novel ND4 mutations could be found in de novo AML patients, especially in patients with good karyotype. Thus, ND4 mutations might play an important role in AML prognosis. However, whether the mitochondria dysfunction contribute to leukemogenesis needs to be further investigated.

Secular change in cardiorespiratory fitness and body composition of women: the Aerobics Center Longitudinal Study

OBJECTIVE

To investigate secular change of cardiorespiratory fitness (CRF) and body composition during 35 years in a large sample of women enrolled in the Aerobics Center Longitudinal Study.

PATIENTS AND METHODS

A cross-sectional analysis of baseline fitness data collected during preventive medical examination of 13,037 women aged 20 to 64 years evaluated at the Cooper Clinic in Dallas, Texas, from January 1, 1970, through December 30, 2004, who underwent a body composition assessment and a maximal treadmill exercise test. Women were stratified by examination year (5 years for each group) and age. Analysis of covariance was used to ascertain secular change of CRF and body composition.

RESULTS

Adjusted CRF levels, as indicated by maximal metabolic equivalent or relative maximum oxygen consumption, among women in the cohort increased significantly during a 35-year period for both age groups (P<.001). The greatest change occurred during the 1970s to 1980s, with a small decrease in 2000 through 2004 in both age groups. Adjusted body mass index increased 9.05% during the past 35 years (P<.001), but adjusted percentage of body fat was significantly higher in 1980 through 1984 than in the other groups (P<.001).

CONCLUSIONS

In a large cohort of women, the mean CRF has improved during the past 35 years, with a slight decrease in 2000 through 2004. From 1980 through 2004, the increase in body weight was mainly attributable to the increase in fat-free mass.

Physical fitness and depressive symptoms during army basic combat training

INTRODUCTION

Mental health-related problems are a significant cause of attrition during basic combat training (BCT). Evidence in civilian populations suggests that physical fitness is associated with psychological benefits in civilians, but little is known about the association between physical fitness and psychological adjustment during BCT.

METHODS

This study prospectively examined the association between physical fitness and depressive symptoms in 300 BCT soldiers from May to July 2012 at Fort Jackson, Columbia, SC. Soldiers completed a baseline Army Physical Fitness Test (APFT) and survey within 1 wk of arriving at BCT and an end-of-cycle survey after 8 wk of BCT. Soldiers were assigned to the "high" fitness category if they had a passing score on the standard APFT of greater than or equal to 180 out of 300 points. Soldiers scoring less than 180 points on the APFT were assigned to the "low" fitness category. Depressive symptoms were measured using the 20-item Center for Epidemiologic Studies Depression scale.

RESULTS

In multivariate analyses, adjusting for baseline demographics, self-reported sleep before BCT, BCT confidence, Army identification, and depressive symptoms, the odds of reporting depressive symptoms were 60% lower for soldiers in the high fitness category (odds ratio, 0.40; 95% confidence interval, 0.19-0.84) compared with soldiers in the low fitness category.

CONCLUSIONS

Analogous to other positive outcomes of soldier fitness, improvement of soldier physical fitness before BCT might improve soldiers' psychological health outcomes.

Effects of insufficient physical activity on mortality and life expectancy in Jiangxi province of China, 2007-2010

BACKGROUND

Physical inactivity remains an under-researched field in terms of studying burden of disease at provincial level, and no studies have examined the effects of inactivity on life expectancy (LE) in China. The purpose of this study was to estimate mortality risk and LE effects associated with insufficient levels of physical activity in Jiangxi province.

METHODS/FINDINGS

Prevalence of risk factors and mortality counts were extracted from Chronic Diseases and Risk Factors Surveillance Survey (CDRFSS) and Disease Surveillance Points system (DSP), respectively. Insufficient physical activity (IPA) was defined as less than 150 minutes of moderate-intensity physical activity or 60 minutes of vigorous-intensity physical activity per week, accumulated across work, home, transport and discretionary domains. Population-attributable fractions (PAF) were used to calculate the mortality attributable to risk factors, and life table methods were used to estimate the LE gains and LE shifts. Monte Carlo simulation techniques were used for uncertainty analysis. Overall, 5 885 (95% uncertainly interval (UI), 5 047-6 506) and 8 578 (95% UI, 8 227-9 789) deaths in Jiangxi province were attributable to IPA in 2007 and 2010, respectively. The LE gains for elimination of attributable deaths were 0.68 (95% UI, 0.61-076) in 2007, and increased to 0.91 (95% UI, 0.81-1.10) in 2010. If the prevalence of IPA in 2010 had been decreased by 50% or 30%, 3 678 (95% UI, 3 220-4 229) or 2 090 (95% UI, 1 771-2 533) deaths would be avoided, and 0.40 (95% UI, 0.34-0.53) or 0.23 (95% UI, 0.16-0.31) years of LE gained, respectively.

CONCLUSIONS

Adults in Jiangxi province of China have a high and increasing prevalence of IPA. Due to the deaths and potential LE gains associated with IPA, there is an urgent need to promote physical activity, one of the most modifiable risk factors, within China's health care reform agenda.

Effects of cardiorespiratory fitness on blood pressure trajectory with aging in a cohort of healthy men

BACKGROUND

Although the trajectory of blood pressure (BP) with aging is well known, there is a lack of data on how cardiorespiratory fitness (hereafter referred to as fitness) affects age-associated changes in BP.

OBJECTIVES

The objective of the study was to investigate whether fitness alters the aging-BP trajectory.

METHODS

A cohort from the Aerobics Center Longitudinal Study totaling 13,953 men between 20 and 90 years of age who did not have hypertension, cardiovascular disease, or cancer completed 3 to 28 (mean of 3.8) follow-up medical examinations between 1970 and 2006. Fitness was measured by a maximal treadmill exercise test. Longitudinal data were analyzed using linear mixed models.

RESULTS

Diastolic blood pressure (DBP) tended to increase until nearly 60 years of age, when a decrease was observed. Systolic blood pressure (SBP) tended to increase over all age periods. On multivariate analysis, average SBP increased by 0.30 mm Hg (95% confidence interval: 0.29 to 0.31) with 1-year age increment after adjusting for body fat percent, fitness, resting heart rate, glucose level, triglyceride level, cholesterol level, current smoking, heavy alcohol consumption, and parental history of hypertension. DBP had a yearly increase of 0.14 mm Hg (95% confidence interval: 0.13 to 0.15) before age 60 years. Overall, abnormal SBP (>120 mm Hg) began to occur at approximately 50 years of age and abnormal DBP (>80 mm Hg) began to occur at 60 years of age. Men with higher fitness levels experienced abnormal SBP later than those with low fitness levels.

CONCLUSIONS

Our findings underscore the potential modifying effect of fitness on BP trajectory with aging over the male adult life span. Improving fitness levels might extend the normal SBP and DBP ranges, delaying the development of hypertension.

The association between resistance exercise and cardiovascular disease risk in women

OBJECTIVES

The objective of this study was to examine the association between resistance exercise and cardiovascular disease risk, independent of body composition, physical activity and aerobic capacity, in healthy women.

DESIGN

A cross-sectional analysis including 7321 women with no history of heart disease, hypertension or diabetes was performed.

METHODS

Participation in resistance exercise was self-reported and body weight and height was measured. A single cardiovascular disease risk score was established via factor analysis including percent body fat, mean arterial pressure, fasting glucose, total cholesterol and triglyceride levels. Physical activity level was determined based on questionnaire data and aerobic capacity was assessed via a maximal treadmill exercise test.

RESULTS

Women reporting resistance exercise had lower total cardiovascular disease risk at any age. Specifically, resistance exercise was associated with lower body fat, fasting glucose and total cholesterol. The association between resistance exercise and cardiovascular disease risk, however, remained only in normal weight women after adjusting for physical activity and aerobic capacity.

CONCLUSION

Results of the present study underline the importance of resistance exercise as part of a healthy and active lifestyle in women across all ages. Our results suggest that resistance exercise may be particularly beneficial to independently improve cardiovascular disease risk profiles in women with normal weight. In overweight/obese women, total physical activity and aerobic capacity may have a stronger association with cardiovascular disease risk.

Body adiposity index and incident hypertension: the Aerobics Center Longitudinal Study

BACKGROUND AND AIM

The body adiposity index (BAI) has been recently proposed as a new method to estimate the percentage of body fat. The association between BAI and hypertension risk has not been investigated yet. The aim of our study was to evaluate the ability of BAI to predict hypertension in males and females compared with traditional body adiposity measures.

METHODS AND RESULTS

The present follow-up analysis comprised 10,309 individuals (2259 females) free of hypertension from the Aerobics Center Longitudinal Study, who completed a baseline examination between 1988 and 2003. Body adiposity measures included BAI, body mass index (BMI), waist circumference, hip circumference, percentage of body fat and waist to hip ratio (WHR). Incident hypertension was ascertained from responses to mail-back surveys between 1990 and 2004. During an average of 9.1 years of follow-up, 872 subjects (107 females) became hypertensive. Hazard ratios (HRs) and 95% confidence intervals (95% CI) showed that males in the highest categories of all body adiposity measures showed a higher incident risk of hypertension (HRs ranged from 1.37 to 2.09). Females showed a higher incident risk of hypertension only in the highest categories of BAI, BMI and WHR (HRs ranged from 1.84 to 3.36).

CONCLUSION

Our results suggest that in order to predict incident hypertension BAI could be considered as an alternative to traditional body adiposity measures.

Age-Specific Exercise Capacity Threshold for Mortality Risk Assessment in Male Veterans

Background—

Mortality risk decreases beyond a certain fitness level. However, precise definition of this threshold is elusive and varies with age. Thus, fitness-related mortality risk assessment is difficult.

Methods and Results—

We studied 18 102 male veterans (8305 blacks and 8746 whites). All completed an exercise test between 1986 and 2011 with no evidence of ischemia. We defined the peak metabolic equivalents (METs) level associated with no increase in all-cause mortality risk (hazard ratio, 1.0) for the age categories of <50, 50 to 59, 60 to 69, and ≥70 years. We used this as the threshold group to form additional age-specific fitness categories based on METs achieved below and above it: least-fit (>2 METs below threshold; n=1692), low-fit (2 METs below threshold; n=4884), moderate-fit (2 METs above threshold; n=4646), fit (2.1–4 METs above threshold; n=1874), and high-fit (>4 METs above threshold; n=1301) categories. Multivariable Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality across fitness categories. During follow-up (median=10.8 years), 5102 individuals died. Mortality risk for the cohort and each age category increased for the least-fit and low-fit categories (HR, 1.51; 95% CI, 1.37–1.66; and HR, 1.21; 95% CI, 1.12–1.30, respectively) and decreased for the moderate-fit; fit and high-fit categories (HR, 0.71; 95% CI, 0.65–0.78; HR, 0.63; 95% CI, 0.56–0.78; and HR, 0.49; 95% CI, 0.41–0.58, respectively). The trends were similar for 5- and 10-year mortality risk.

Conclusion—

We defined age-specific exercise capacity thresholds to guide assessment of mortality risk in individuals undergoing a clinical exercise test.

Factors related to coronary heart disease risk among men: validation of the Framingham Risk Score

Introduction

Coronary heart disease (CHD) remains a leading cause of death in the United States. The Framingham Risk Score (FRS) was developed to help clinicians in determining their patients’ CHD risk. We hypothesize that the FRS will be significantly predictive of CHD events among men in the Aerobics Center Longitudinal Study (ACLS) population.

Methods

Our study consisted of 34,557 men who attended the Cooper Clinic in Dallas, Texas, for a baseline clinical examination from 1972 through 2002. CHD events included self-reported myocardial infarction or revascularization or death due to CHD. During the 12-year follow-up 587 CHD events occurred. Multivariable-adjusted hazard ratios generated from ACLS analysis were compared with the application of FRS to the Framingham Heart Study (FHS).

Results

The ACLS cohort produced similar hazard ratios to the FHS. The adjusted Cox proportional hazard model revealed that men with total cholesterol of 280 mg/dL or greater were 2.21 (95% confidence interval (CI), 1.59–3.09) times more likely to have a CHD event than men with total cholesterol from 160 through 199mg/dL; men with diabetes were 1.63 (95% CI, 1.35–1.98) times more likely to experience a CHD event than men without diabetes.

Conclusion

The FRS significantly predicts CHD events in the ACLS cohort. To the best of our knowledge, this is the first report of a large, single-center cohort study to validate the FRS by using extensive laboratory and clinical measurements.

Leisure-time running reduces all-cause and cardiovascular mortality risk

BACKGROUND

Although running is a popular leisure-time physical activity, little is known about the long-term effects of running on mortality. The dose-response relations between running, as well as the change in running behaviors over time, and mortality remain uncertain.

OBJECTIVES

We examined the associations of running with all-cause and cardiovascular mortality risks in 55,137 adults, 18 to 100 years of age (mean age 44 years).

METHODS

Running was assessed on a medical history questionnaire by leisure-time activity.

RESULTS

During a mean follow-up of 15 years, 3,413 all-cause and 1,217 cardiovascular deaths occurred. Approximately 24% of adults participated in running in this population. Compared with nonrunners, runners had 30% and 45% lower adjusted risks of all-cause and cardiovascular mortality, respectively, with a 3-year life expectancy benefit. In dose-response analyses, the mortality benefits in runners were similar across quintiles of running time, distance, frequency, amount, and speed, compared with nonrunners. Weekly running even <51 min, <6 miles, 1 to 2 times, <506 metabolic equivalent-minutes, or <6 miles/h was sufficient to reduce risk of mortality, compared with not running. In the analyses of change in running behaviors and mortality, persistent runners had the most significant benefits, with 29% and 50% lower risks of all-cause and cardiovascular mortality, respectively, compared with never-runners.

CONCLUSIONS

Running, even 5 to 10 min/day and at slow speeds <6 miles/h, is associated with markedly reduced risks of death from all causes and cardiovascular disease. This study may motivate healthy but sedentary individuals to begin and continue running for substantial and attainable mortality benefits.

The effect of resistance exercise on all-cause mortality in cancer survivors

OBJECTIVE

To examine the independent associations of leisure-time aerobic physical activity (PA) and resistance exercise (RE) on all-cause mortality in cancer survivors.

PATIENTS AND METHODS

Patients included 2863 male and female cancer survivors, aged 18 to 81 years, who received a preventive medical examination between April 8, 1987, and December 27, 2002, while enrolled in the Aerobics Center Longitudinal Study in Dallas, Texas. Physical activity and RE were assessed by self-report at the baseline medical examination. Cox proportional hazards regression analysis was performed to determine the independent associations of PA and RE with all-cause mortality in participants who had a history of cancer.

RESULTS

Physical activity in cancer survivors was not associated with a lower risk of all-cause mortality. In contrast, RE was associated with a 33% lower risk of all-cause mortality (95% CI, 0.45-0.99) after adjusting for potential confounders, including PA.

CONCLUSION

Individuals who participated in RE during cancer survival had a lower risk for all-cause mortality. The present findings provide preliminary evidence for benefits of RE during cancer survival. Future randomized controlled trials examining RE and its effect on lean body mass, muscular strength, and all-cause mortality in cancer survivors are warranted.

Association of exercise heart rate response and incidence of hypertension in men

OBJECTIVE

To examine the association of heart rate (HR) responses at rest, during exercise, and after exercise with incident hypertension (HTN) in men.

PARTICIPANTS AND METHODS

A total of 10,418 healthy normotensive men without abnormalities on electrocardiography or a history of myocardial infarction, stroke, cancer, or diabetes underwent a maximal exercise test and were followed up for incidence of HTN. Heart rate reserve was defined as the maximal HR minus resting HR. Heart rate recovery was defined as HR 5 minutes after the exercise test.

RESULTS

During a mean follow-up of 6 years, there were 2831 cases of HTN. Compared with men who had lower HR reserve, the risk of incident HTN was significantly lower for men with higher HR reserve (hazard ratio, 0.84; 95% CI, 0.74-0.95 for the highest quartile vs the lowest quartile of HR reserve; P=.002) when adjusted for age, baseline examination year, smoking, heavy drinking, body mass index, resting blood pressure, cholesterol and glucose levels, and cardiorespiratory fitness. Compared with men who had higher HR recovery, the risk of incident HTN was significantly lower for men with lower HR recovery (hazard ratio, 0.90; 95% CI, 0.80-0.99 for quartile 3 vs highest quartile; P=.04) after adjusting for the aforementioned confounders. However, the overall linear trend for HR recovery was not significant (P=.26).

CONCLUSION

The risk of HTN decreased in men with higher HR reserve. Therefore, HR reserve may be considered as a useful exercise parameter for predicting the risk of HTN in men.