The impact of combined health factors on cardiovascular disease mortality

BACKGROUND

The combined effect of modifiable health factors on the risk of cardiovascular disease (CVD) mortality has not been well established. The objective of this study was to determine the association between 5 modifiable health factors in combination on the risk of CVD mortality in a sample of adult men.

METHODS

A cohort of 38,110 men (aged 20-84 years and of middle and upper socioeconomic strata) was followed over time until their date of death or December 31, 2003. A health profile score (unweighted and weighted) was developed based on cardiorespiratory fitness (CRF; moderate or high vs low), self-reported physical activity (active vs inactive), smoking status (not current vs current), alcohol consumption (1-14 drinks per week vs 0 or >14 drinks per week), and body mass index (BMI; 18.5-24.9 vs >or=25.0 kg/m(2)).

RESULTS

During 16.1 +/- 8.4 years of follow-up and 613,571 man-years of exposure, there were 949 deaths from CVD. High CRF, normal BMI, being physically active, and not currently smoking were individually associated with reduced risk of CVD mortality after adjusting for confounders. When considered in combination, a minimum of 2 of 5 positive health factors reduced the risk of CVD mortality (hazard ratio = 0.67, 95% CI 0.49-0.91). The weighted score indicated that a combination of high CRF, not currently smoking, and normal BMI is of most clinical importance to CVD mortality (hazard ratio = 0.31, 95% CI 0.24-0.39).

CONCLUSIONS

Exposure to increasing numbers of beneficial health factors in adulthood reduced the risk of CVD mortality in men, and multibehavioral prevention efforts in adulthood should be encouraged.

Falls among adults: the association of cardiorespiratory fitness and physical activity with walking-related falls

BACKGROUND

Falls are a major cause of deaths, hospitalizations, and emergency room visits in the U.S., but circumstances surrounding falls are not well described. Among the elderly, balance and gait disorders and muscle weakness are associated with increased risk for falling, but the relationship of cardiorespiratory fitness and physical activity with falls is unclear.

PURPOSE

This purpose of this study is to describe characteristics of falls among adults and assess the association of cardiorespiratory fitness and physical activity with walking-related falls.

METHODS

Data on participants enrolled in the Aerobics Center Longitudinal Study (ACLS) from 1970 through 1989 who responded to questions on falls on the 1990 follow-up survey were analyzed in 2008-2009. The percentage of participants reporting at least one fall during the year before the follow-up survey was calculated and the activities at the time of falling were described. The relative risk and 95% CIs for the association of baseline fitness and physical activity with walking-related falls were calculated and logistic regression models for walking-related falls were developed.

RESULTS

Of 10,615 participants aged 20-87 years, 20% (95% CI=19%, 21%) reported falling during the past year. Of those falling, 54% (95% CI=52%, 56%) fell during sports or exercise; 15% (95% CI=14%,17%) while walking; and 4% (95% CI=3%, 5%) from a stool or ladder. People aged >or=65 years were no more likely than younger people to report falling in general, but they were more likely than people aged <45 years to report falling while walking (RR=1.9, 95% CI=1.2, 3.0 for men; RR=2.2, 95% CI=1.3, 3.9 for women). Men with a low level of fitness were more likely to fall while walking than men who were highly fit (RR=2.2, 95% CI=1.5, 3.3). In the multivariate analysis, walking-related falls were associated with low levels of fitness (AOR=1.8, 95% CI=1.1, 2.8) and with physical inactivity (AOR=1.7, 95% CI=1.1, 2.7) in men but not in women.

CONCLUSIONS

Falls are common throughout adulthood but activities at time of falls differ by age. Low fitness levels and physical inactivity may increase risk for walking-related falls.

Sedentary behaviors increase risk of cardiovascular disease mortality in men

PURPOSE

The purpose of this study was to examine the relationship between two sedentary behaviors (riding in a car and watching TV) and cardiovascular disease (CVD) mortality in men in the Aerobics Center Longitudinal Study.

METHODS

Participants were 7744 men (20-89 yr) initially free of CVD who returned a mail-back survey during 1982. Time spent watching TV and time spent riding in a car were reported. Mortality data were ascertained through the National Death Index until December 31, 2003. Cox regression analysis quantified the association between sedentary behaviors (hours per week watching TV, hours per week riding in a car, and total hours per week in these two behaviors) and CVD mortality rates.

RESULTS

Three hundred and seventy-seven CVD deaths occurred during 21 yr of follow-up. After age adjustment, time riding in a car and combined time spent in these two sedentary behaviors were positively (P(trend) < 0.001) associated with CVD death. Men who reported >10 h x wk(-1) riding in a car or >23 h x wk(-1) of combined sedentary behavior had 82% and 64% greater risk of dying from CVD than those who reported <4 or <11 h x wk(-1), respectively. The pattern of the association did not materially change after multivariate adjustment. Regardless of the amount of sedentary activity reported by these men, being older, having normal weight, being normotensive, and being physically active were associated with a reduced risk of CVD death.

CONCLUSION

In men, riding in a car and combined time spent in these two sedentary behaviors were significant CVD mortality predictors. In addition, high levels of physical activity were related to notably lower rates of CVD death even in the presence of high levels of sedentary behavior. Health promotion efforts targeting physically inactive men should emphasize both reducing sedentary activity and increasing regular physical activity for optimal cardiovascular health.

Influence of cardiorespiratory fitness on lung cancer mortality

PURPOSE

Previous studies have suggested that higher levels of physical activity may lower lung cancer risk; however, few prospective studies have evaluated lung cancer mortality in relation to cardiorespiratory fitness (CRF), an objective marker of recent physical activity habits.

METHODS

Thirty-eight thousand men, aged 20-84 yr, without history of cancer, received a preventive medical examination at the Cooper Clinic in Dallas, Texas, between 1974 and 2002. CRF was quantified as maximal treadmill exercise test duration and was grouped for analysis as low (lowest 20% of exercise duration), moderate (middle 40%), and high (upper 40%).

RESULTS

A total of 232 lung cancer deaths occurred during follow-up (mean = 17 yr). After adjustment for age, examination year, body mass index, smoking, drinking, physical activity, and family history of cancer, hazard ratios (95% confidence intervals) for lung cancer deaths across low, moderate, and high CRF categories were 1.0, 0.48 (0.35-0.67), and 0.43 (0.28-0.65), respectively. There was an inverse association between CRF and lung cancer mortality in former (P for trend = 0.005) and current smokers (P for trend < 0.001) but not in never smokers (trend P = 0.14). Joint analysis of smoking and fitness status revealed a significant 12-fold higher risk of death in current smokers (hazard ratio = 11.9, 95% confidence interval = 6.0-23.6) with low CRF as compared with never smokers who had high CRF.

CONCLUSIONS

Although the potential for some residual confounding by smoking could not be eliminated, these data suggest that CRF is inversely associated with lung cancer mortality in men. Continued study of CRF in relation to lung cancer, particularly among smokers, may further our understanding of disease etiology and reveal additional strategies for reducing its burden.

Muscular strength and incident hypertension in normotensive and prehypertensive men

The protective effects of cardiorespiratory fitness (CRF) on hypertension (HTN) are well known; however, the association between muscular strength and incidence of HTN has yet to be examined.

PURPOSE

This study evaluated the strength-HTN association with and without accounting for CRF.

METHODS

Participants were 4147 men (age = 20-82 yr) in the Aerobics Center Longitudinal Study for whom an age-specific composite muscular strength score was computed from measures of a one-repetition maximal leg and a one-repetition maximal bench press. CRF was quantified by maximal treadmill exercise test time in minutes. Cox proportional hazards regression analysis was used to estimate hazard ratios (HR) and 95% confidence intervals of incident HTN events according to exposure categories.

RESULTS

During a mean follow-up of 19 yr, there were 503 incident HTN cases. Multivariable-adjusted (excluding CRF) HR of HTN in normotensive men comparing middle- and high-strength thirds to the lowest third were not significant at 1.17 and 0.84, respectively. Multivariable-adjusted (excluding CRF) HR of HTN in baseline prehypertensive men comparing middle- and high-strength thirds to the lowest third were significant at 0.73 and 0.72 (P = 0.01 each), respectively. The association between muscular strength and incidence of HTN in baseline prehypertensive men was no longer significant after control for CRF (P = 0.26).

CONCLUSIONS

The study indicated that middle and high levels of muscular strength were associated with a reduced risk of HTN in prehypertensive men only. However, this relationship was no longer significant after controlling for CRF.

Comparisons of leisure-time physical activity and cardiorespiratory fitness as predictors of all-cause mortality in men and women

OBJECTIVE

To examine the combined associations and relative contributions of leisure-time physical activity (PA) and cardiorespiratory fitness (CRF) with all-cause mortality.

DESIGN

Prospective cohort study. Setting Aerobics centre longitudinal study.

PARTICIPANTS

31,818 men and 10 555 women who received a medical examination during 1978-2002. Assessment of risk factors Leisure-time PA assessed by self-reported questionnaire; CRF assessed by maximal treadmill test. Main outcome measures All-cause mortality until 31 December 2003.

RESULTS

There were 1492 (469 per 10,000) and 230 (218 per 10,000) deaths in men and women, respectively. PA and CRF were positively correlated in men (r = 0.49) and women (r = 0.47) controlling for age (p < 0.001 for both). PA was inversely associated with mortality in multivariable Cox regression analysis among men, but the association was eliminated after further adjustment for CRF. No significant association of PA with mortality was observed in women. CRF was inversely associated with mortality in men and women, and the associations remained significant after further adjustment for PA. In the PA and CRF combined analysis, compared with the reference group "not meeting the recommended PA (< 500 metabolic equivalent-minute/week) and unfit", the relative risks (95% CIs) of mortality were 0.62 (0.54 to 0.72) and 0.61 (0.44 to 0.86) in men and women "not meeting the recommended PA and fit", 0.96 (0.61 to 1.53) and 0.93 (0.33 to 2.58) in men and women "meeting the recommended PA and unfit" and 0.60 (0.51 to 0.70) and 0.56 (0.37 to 0.85) in men and women "meeting the recommended PA and fit", respectively.

CONCLUSIONS

CRF was more strongly associated with all-cause mortality than PA; therefore, improving CRF should be encouraged in unfit individuals to reduce risk of mortality and considered in the development of future PA guidelines.

Maximal exercise electrocardiographic responses and coronary heart disease mortality among men with metabolic syndrome

OBJECTIVE

To examine the association between abnormal exercise electrocardiographic (E-ECG) test results and mortality (all-cause and that resulting from coronary heart disease [CHD] or cardiovascular disease [CVD]) in a large population of asymptomatic men with metabolic syndrome (MetS).

PATIENTS AND METHODS

A total of 9191 men (mean age, 46.9 years) met the criteria of having MetS. All completed a maximal E-ECG treadmill test (May 14, 1979, through April 9, 2001) and were without a previous CVD event or diabetes at baseline. Main outcomes were all-cause mortality, mortality due to CHD, and mortality due to CVD. Cox regression analysis was used to quantify the mortality risk according to E-ECG responses.

RESULTS

During a follow-up of 14 years, 633 deaths (242 CVD and 150 CHD) were identified. Mortality rates and hazard ratios (HRs) across E-ECG responses were the following: for all-cause mortality: HR, 1.36; 95% confidence interval (CI), 1.09-1.70 for equivocal responses and HR, 1.41; 95% CI, 1.12-1.77 for abnormal responses (P(trend)<.001); for mortality due to CVD: HR, 1.29; 95% CI, 0.88-1.88 for equivocal responses and HR, 2.04; 95% CI, 1.46-2.84 for abnormal responses (P(trend)<.001); and for mortality due to CHD: HR, 1.62; 95% CI, 1.02-2.56 for equivocal responses and HR, 2.45; 95% CI, 1.62-3.69 for abnormal responses (P(trend)<.001). A positive gradient for CHD, CVD, and all-cause mortality rates across E-ECG categories within 3, 4, or 5 MetS components was observed (P<.001 for all).

CONCLUSION

Among men with MetS, an abnormal E-ECG response was associated with higher risk of all-cause, CVD, and CHD mortality. These findings underscore the importance of E-ECG tests to identify men with MetS who are at risk of dying.

FTO genotype and the weight loss benefits of moderate intensity exercise

The fat mass and obesity-associated (FTO) gene was genotyped for the participants in the Dose-Response to Exercise in postmenopausal Women (DREW) trial and analyses were performed to determine whether an FTO variant was associated with adiposity and cardiorespiratory fitness (CRF) before and after 6 months of moderate intensity exercise in white women (n = 234). The A/A homozygotes for rs8050136 had a higher BMI (kg/m(2)) compared to C/C homozygotes at baseline (32.8 (0.6) vs. 31.0 (0.4), respectively; P < 0.05) and at follow-up (31.9 (0.6) vs. 30.4 (0.5), respectively; P < 0.05). Weight loss occurred after exercise, but there was no significant genotype by exercise interaction over time. Exploratory analyses among women exposed to moderate intensity exercise meeting, or exceeding, the physical activity recommendation found that those homozygous A/A lost significantly more weight than the C allele carriers (-3.3 (0.7) kg vs. -1.4 (0.4) kg and -1.5 (0.5) kg, respectively; P < 0.05). CRF, defined as VO(2peak) (oxygen consumption), increased after exercise and the magnitude of the increase was similar for each genotype. In conclusion, women genetically predisposed to being obese experienced weight loss and CRF benefits with moderate intensity exercise, with additional weight loss observed when the women met or exceeded the physical activity recommendations.

Combined effects of cardiorespiratory fitness, not smoking, and normal waist girth on morbidity and mortality in men

BACKGROUND

Physical inactivity, cigarette smoking, and abdominal obesity are key modifiable risk factors for coronary heart disease (CHD). We investigated the combined effects of not having these risk factors on CHD events and cardiovascular disease (CVD) and all-cause mortality in men.

METHODS

We followed up 23 657 men, aged 30 to 79 years, who completed a medical evaluation including a maximal treadmill exercise test and self-reported health habits. A low-risk profile was defined as not smoking, moderate or high fitness, and normal waist girth. There were 482 CHD events (nonfatal myocardial infarction or fatal CHD) and 1034 deaths (306 CVD, 387 cancers, and 341 others) during a mean 14.7 years of follow-up (348 811 man-years).

RESULTS

After adjustment for age, examination year, and multiple baseline risk factors, there was an inverse association between a greater number of low-risk factors and CHD events, and CVD and all-cause mortality in men (P value for trend, <.001 for all). Men with a normal waist girth and who were physically fit and not smoking had a 59% lower risk of CHD events (95% confidence interval [CI], 39%-72%), a 77% lower risk of CVD mortality (95% CI, 65%-85%), and a 69% lower risk of all-cause mortality (95% CI, 60%-76%) compared with men with none of these low-risk factors. Men with 0 compared with 3 low-risk factors had a shorter life expectancy by 14.2 years (95% CI, 12.2-15.9 years).

CONCLUSION

Being physically fit, not smoking, and maintaining a normal waist girth is associated with lower risk of CHD events, and CVD and all-cause mortality in men.

Immunophenotype of myeloid granulocytes: a pilot study for distinguishing myelodysplastic syndrome and aplastic anemia by flow cytometry

It is often difficult to distinguish myelodysplastic syndrome (MDS) from aplastic anemia (AA) because of the considerable clinical, cytologic histologic similarities between these two disorders; however, distinguishing between AA and MDS is of great importance because there is a higher risk of progression to acute leukemia in patients with MDS compared with AA. Up to now, CD34(+) cells in MDS and AA patients have been studied extensively; however, little information is available on myeloid granulocytes. The aim of this study was to determine whether immunophenotype of myeloid granulocytes in AA patients was different from that of MDS. Flow cytometry was used to assess the immunophenotype of myeloid granulocytes in 22 patients with MDS, 12 with AA, and 10 normal subjects. Our data showed that the percentages of CD13(+) granulocytes, CD33(+) granulocytes, CD34(+) granulocytes, and HLA-DR(+) granulocytes were significantly higher in patients with MDS than in AA patients and normal subjects (P < 0.05). The percentages of CD15(+) granulocytes and CD10(+) granulocytes were significantly lower in patients with MDS than in AA patients and normal subjects (P < 0.05). There were no significant differences in the expression of these markers between patients with AA and normal subjects (P > 0.05). As refractory anemia progressing to refractory anemia with excess blasts, the percentages of CD13(+) granulocytes, CD33(+) granulocytes, CD34(+) granulocytes and HLA-DR(+) granulocytes were significantly increased, whereas, the percentage of CD15(+) granulocytes was significantly decreased (P < 0.05). These data suggest that immunophenotype of myeloid granulocytes may be a useful parameter for the differential diagnosis of MDS and AA.

Role of lifestyle and aging on the longitudinal change in cardiorespiratory fitness

BACKGROUND

Cardiorespiratory fitness (CRF) in adults decreases with age and is influenced by lifestyle. Low CRF is associated with risk of diseases and the ability of older persons to function independently. We defined the longitudinal rate of CRF decline with aging and the association of aging and lifestyle with CRF.

METHODS

We studied a cohort of 3429 women and 16 889 men, aged 20 to 96 years, from the Aerobics Center Longitudinal Study who completed 2 to 33 health examinations from 1974 to 2006. The lifestyle variables were body mass index, self-reported aerobic exercise, and smoking behavior. Cardiorespiratory fitness was measured by a maximal Balke treadmill exercise test.

RESULTS

Linear mixed models regression analysis stratified by sex showed that the decline in CRF with age was not linear. After 45 years of age, CRF declined at an accelerated rate. For each unit of increase in body mass index, the CRF of women declined 0.20 metabolic equivalents (METs) (95% confidence interval, -0.21 to -0.19); that of men, 0.32 METs (-0.33 to -0.20). Current smokers of both sexes also had lower CRF (-0.29 METs [95% confidence interval, -0.40 to -0.19] for women and -0.41 METS [-0.44 to -0.38] for men). Cardiorespiratory fitness was positively associated with self-reported physical activity.

CONCLUSIONS

Cardiorespiratory fitness in men and women declines at a nonlinear rate that accelerates after 45 years of age. Maintaining a low BMI, being physically active, and not smoking are associated with higher CRF across the adult life span.

The association between cardiorespiratory fitness and risk of all-cause mortality among women with impaired fasting glucose or undiagnosed diabetes mellitus

OBJECTIVE

To evaluate the independent and joint associations among cardiorespiratory fitness (CRF), body mass index, and risk of mortality from any cause among women with impaired fasting glucose (IFG) or undiagnosed diabetes mellitus (DM).

PATIENTS AND METHODS

Female patients (N=3044; mean age, 47.4 years) with IFG or undiagnosed DM completed a maximal exercise treadmill test (between January 26, 1971, and March 21, 2001). The women had no history of a cardiovascular disease event or diagnosed DM at baseline. Cardiorespiratory fitness was defined categorically as low (bottom 20%), moderate (middle 40%), or high (upper 40%) according to previously published Aerobics Center Longitudinal Study guidelines. Body mass index was calculated as the weight in kilograms divided by the height in meters squared (kg/m(2)).

RESULTS

During a 16-year follow-up period, 171 deaths occurred. There was an inverse association between CRF and all-cause mortality risk. Women with moderate or high CRF were at lower risk of mortality (moderate CRF, 35% lower; high CRF, 36% lower; P(trend)=.03) than those with low CRF. An exercise capacity lower than 7 metabolic equivalents was associated with a 1.5-fold higher risk of death than an exercise capacity of 9 metabolic equivalents or higher (P(trend)=.05). The multivariate adjusted hazard ratios (HRs), including adjustments for CRF, were higher for heavier patients than for patients of normal weight (overweight patients: HR, 0.86; 95% confidence interval, 0.57-1.30; obese patients: HR, 1.19; 95% confidence interval, 0.70-2.03; P(trend)=.84). Combined analyses showed that women who were overweight or obese and unfit (low CRF) were at more than twice the risk of death than women who were of normal weight and fit (moderate or high CRF).

CONCLUSION

Cardiorespiratory fitness, not body mass index, is a significant predictor of all-cause mortality among women with IFG or undiagnosed DM. Assessing CRF levels provides important prognostic information independent of traditional risk factors.

The association between cardiorespiratory fitness and risk of all-cause mortality among women with impaired fasting glucose or undiagnosed diabetes mellitus

OBJECTIVE

To evaluate the independent and joint associations among cardiorespiratory fitness (CRF), body mass index, and risk of mortality from any cause among women with impaired fasting glucose (IFG) or undiagnosed diabetes mellitus (DM).

PATIENTS AND METHODS

Female patients (N=3044; mean age, 47.4 years) with IFG or undiagnosed DM completed a maximal exercise treadmill test (between January 26, 1971, and March 21, 2001). The women had no history of a cardiovascular disease event or diagnosed DM at baseline. Cardiorespiratory fitness was defined categorically as low (bottom 20%), moderate (middle 40%), or high (upper 40%) according to previously published Aerobics Center Longitudinal Study guidelines. Body mass index was calculated as the weight in kilograms divided by the height in meters squared (kg/m(2)).

RESULTS

During a 16-year follow-up period, 171 deaths occurred. There was an inverse association between CRF and all-cause mortality risk. Women with moderate or high CRF were at lower risk of mortality (moderate CRF, 35% lower; high CRF, 36% lower; P(trend)=.03) than those with low CRF. An exercise capacity lower than 7 metabolic equivalents was associated with a 1.5-fold higher risk of death than an exercise capacity of 9 metabolic equivalents or higher (P(trend)=.05). The multivariate adjusted hazard ratios (HRs), including adjustments for CRF, were higher for heavier patients than for patients of normal weight (overweight patients: HR, 0.86; 95% confidence interval, 0.57-1.30; obese patients: HR, 1.19; 95% confidence interval, 0.70-2.03; P(trend)=.84). Combined analyses showed that women who were overweight or obese and unfit (low CRF) were at more than twice the risk of death than women who were of normal weight and fit (moderate or high CRF).

CONCLUSION

Cardiorespiratory fitness, not body mass index, is a significant predictor of all-cause mortality among women with IFG or undiagnosed DM. Assessing CRF levels provides important prognostic information independent of traditional risk factors.

Ideal weight and weight satisfaction: association with health practices

Evidence suggests that individuals have become more tolerant of higher body weights over time. To investigate this issue further, the authors examined cross-sectional associations among ideal weight, examination year, and obesity as well as the association of ideal weight and body weight satisfaction with health practices among 15,221 men and 4,126 women in the United States. Participants in 1987 reported higher ideal weights than participants in 2001, an effect particularly pronounced from 1987 to 2001 for younger and obese men (85.5 kg to 94.9 kg) and women (62.2 kg to 70.5 kg). For a given body mass index, higher ideal body weights were associated with greater weight satisfaction but lower intentions to lose weight. Body weight satisfaction was subsequently associated with greater walking/jogging, better diet, and lower lifetime weight loss but with less intention to change physical activity and diet or lose weight (P < 0.01). Conversely, body mass index was negatively associated with weight satisfaction (P < 0.01) and was associated with less walking/jogging, poorer diet, and greater lifetime weight loss but with greater intention to change physical activity and diet or lose weight. Although the health implications of these findings are somewhat unclear, increased weight satisfaction, in conjunction with increases in societal overweight/obesity, may result in decreased motivation to lose weight and/or adopt healthier lifestyle behaviors.

Metabolic syndrome and diabetes, alone and in combination, as predictors of cardiovascular disease mortality among men

OBJECTIVE

To examine cardiovascular disease (CVD) mortality risk in men with diabetes only, metabolic syndrome only, and concurrent metabolic syndrome and diabetes.

RESEARCH DESIGN AND METHODS

We examined CVD mortality risk by metabolic syndrome and diabetes status in men from the Aerobics Center Longitudinal Study (ACLS) (mean +/- SD age 45.1 +/- 10.2 years). Participants were categorized as having neither diabetes nor metabolic syndrome (n = 23,770), metabolic syndrome only (n = 8,780), diabetes only (n = 532), or both (n = 1,097). The duration of follow-up was 14.6 +/- 7.0 years with a total of 483,079 person-years of exposure and 1,085 CVD deaths.

RESULTS

Age-, examination year-, and smoking-adjusted CVD death rates (per 1,000 man-years) in men with neither metabolic syndrome nor diabetes, metabolic syndrome only, diabetes only, and both were 1.9, 3.3, 5.5, and 6.5, respectively. CVD mortality was higher in men with metabolic syndrome only (hazard ratio 1.8 [95% CI 1.5-2.0]), diabetes only (2.9 [2.1-4.0]), and both (3.4 [2.8-4.2]) compared with men with neither. The presence of metabolic syndrome was not associated (1.2 [0.8-1.7]) with higher CVD mortality risk in individuals with diabetes. In contrast, the presence of diabetes substantially increased (2.1 [1.7-2.6]) CVD mortality risk in individuals with metabolic syndrome.

CONCLUSIONS

The presence of diabetes was associated with a threefold higher CVD mortality risk, and metabolic syndrome status did not modify this risk. Our findings support the fact that physicians should be aggressive in using CVD risk-reducing therapies in all diabetic patients regardless of metabolic syndrome status.

Dietary patterns and the risk of mortality: impact of cardiorespiratory fitness

BACKGROUND

While dietary patterns that are both predictive of chronic disease and mortality have been identified, the confounding effects of cardiorespiratory fitness have not been properly addressed. The primary objective was to assess the relation between dietary patterns with all-cause mortality, while controlling for the potentially confounding effects of fitness.

METHODS

This was a prospective cohort study. Participants consisted of 13 621 men and women from the Aerobics Center Longitudinal Study (ACLS). Participants completed a clinical exam and 3-day diet record between 1987 and 1999. Participants were followed for mortality until 2003. Reduced rank regression (RRR) was used to identify dietary patterns that predicted unfavourable total and high-density lipoprotein-cholesterol, triglyceride, glucose, blood pressure, uric acid, white blood cell and body mass index values.

RESULTS

One primary dietary pattern emerged and was labelled the Unhealthy Eating Index. This pattern was characterized by elevated consumption of processed and red meat, white potato products, non-whole grains, added fat and reduced consumption of non-citrus fruits. The hazard ratio for all-cause mortality in the fifth vs the first quintile of the Unhealthy Eating Index was 1.40 (1.02-1.91). This risk estimate was reduced by 13.5 and 55.0% after controlling for self-reported physical activity and fitness, respectively.

CONCLUSION

In this study the association between diet and overall mortality was, in large part, confounded by fitness.

Muscular strength and adiposity as predictors of adulthood cancer mortality in men

BACKGROUND

We examined the associations between muscular strength, markers of overall and central adiposity, and cancer mortality in men.

METHODS

A prospective cohort study including 8,677 men ages 20 to 82 years followed from 1980 to 2003. Participants were enrolled in The Aerobics Centre Longitudinal Study, the Cooper Institute in Dallas, Texas. Muscular strength was quantified by combining 1-repetition maximal measures for leg and bench presses. Adiposity was assessed by body mass index (BMI), percent body fat, and waist circumference.

RESULTS

Cancer death rates per 10,000 person-years adjusted for age and examination year were 17.5, 11.0, and 10.3 across incremental thirds of muscular strength (P = 0.001); 10.9, 13.4, and 20.1 across BMI groups of 18.5-24.9, 25.0-29.9, and > or =30 kg/m(2), respectively (P = 0.008); 11.6 and 17.5 for normal (<25%) and high percent body fat (> or =25%), respectively (P = 0.006); and 12.2 and 16.7 for normal (< or =102 cm) and high waist circumference (>102 cm), respectively (P = 0.06). After adjusting for additional potential confounders, hazard ratios (95% confidence intervals) were 1.00 (reference), 0.65 (0.47-0.90), and 0.61 (0.44-0.85) across incremental thirds of muscular strength, respectively (P = 0.003 for linear trend). Further adjustment for BMI, percent body fat, waist circumference, or cardiorespiratory fitness had little effect on the association. The associations of BMI, percent body fat, or waist circumference with cancer mortality did not persist after further adjusting for muscular strength (all P > or = 0.1).

CONCLUSIONS

Higher levels of muscular strength are associated with lower cancer mortality risk in men, independent of clinically established measures of overall and central adiposity, and other potential confounders.

Cardiorespiratory fitness and digestive cancer mortality: findings from the aerobics center longitudinal study

Although higher levels of physical activity are inversely associated with risk of colon cancer, few prospective studies have evaluated overall digestive system cancer mortality in relation to cardiorespiratory fitness (CRF). The authors examined this association among 38,801 men ages 20 to 88 years who performed a maximal treadmill exercise test at baseline in the Aerobics Center Longitudinal Study (Dallas, TX) during 1974 to 2003. Mortality was assessed over 29 years of follow-up (1974-2003). Two hundred eighty-three digestive system cancer deaths occurred during a mean 17 years of observation. Age-adjusted mortality rates per 10,000 person-years according to low, moderate, and high CRF groups were 6.8, 4.0, and 3.3 for digestive system cancer (P(trend) < 0.001). After adjustment for age, examination year, body mass index, smoking, drinking, family history of cancer, personal history of diabetes, hazard ratios (95% confidence intervals) for overall digestive cancer deaths for those in the middle and upper 40% of the distribution of CRF relative to those in the lowest 20% were 0.66 (0.49-0.88) and 0.56 (0.40-0.80), respectively. Being fit (the upper 80% of CRF) was associated with a lower risk of mortality from colon [0.61 (0.37-1.00)], colorectal [0.58 (0.37-0.92)], and liver cancer [0.28 (0.11-0.72)] compared with being unfit (the lowest 20% of CRF). These findings support a protective role of CRF against total digestive tract, colorectal, and liver cancer deaths in men.

A prospective study of cardiorespiratory fitness and breast cancer mortality

PURPOSE

Physical activity may protect against breast cancer. Few prospective studies have evaluated breast cancer mortality in relation to cardiorespiratory fitness (CRF), an objective marker of physiologic response to physical activity habits.

METHODS

We examined the association between CRF and risk of death from breast cancer in the Aerobics Center Longitudinal Study. Women (N = 14,811), aged 20 to 83 yr with no prior breast cancer history, received a preventive medical examination at the Cooper Clinic in Dallas, Texas, between 1970 and 2001. Mortality surveillance was completed through December 31, 2003. CRF was quantified as maximal treadmill exercise test duration and was categorized for analysis as low (lowest 20% of exercise duration), moderate (middle 40%), and high (upper 40%). At baseline, all participants were able to complete the exercise test to at least 85% of their age-predicted maximal heart rate.

RESULTS

A total of 68 breast cancer deaths occurred during follow-up (mean = 16 yr). Age-adjusted breast cancer mortality rates per 10,000 woman-years were 4.4, 3.2, and 1.8 for low, moderate, and high CRF groups, respectively (trend P = 0.008). After further controlling for body mass index, smoking, drinking, chronic conditions, abnormal exercise ECG responses, family history of breast cancer, oral contraceptive use, and estrogen use, hazard ratios (95% CI) for breast cancer mortality across incremental CRF categories were 1.00 (referent), 0.67 (0.35-1.26), and 0.45 (0.22-0.95) (trend P = 0.04).

CONCLUSIONS

These results indicate that CRF is associated with a reduced risk of dying from breast cancer in women.

The association of cardiorespiratory fitness and physical activity with incidence of hypertension in men

BACKGROUND

Few prospective studies have simultaneously investigated the relationship between physical activity, cardiorespiratory fitness (CRF), and the development of hypertension in initially normotensive individuals. In the Aerobics Center Longitudinal Study (ACLS), we examined this association among initially healthy normotensive men.

METHODS

Participants were 16,601 men aged 20-82 years who completed a baseline examination during 1970-2002 and were followed for hypertension incidence. Physical activity was self-reported and CRF was quantified from the duration of a maximal treadmill test.

RESULTS

A total of 2,346 men reported hypertension during a mean 18 years of follow-up. Event rates per 10,000 man-years adjusted for age and examination year were 86.2, 76.6, and 66.7 across physical activity groups of sedentary, walker/jogger/runner (WJR), and sport/fitness, respectively, and 89.8, 78.4, and 64.6 for low, middle, and high CRF, respectively (trend P < 0.0001). These associations persisted after further adjustment for body mass index (BMI), smoking, alcohol intake, resting systolic blood pressure, baseline health status, family history of diseases, and survey response patterns.

CONCLUSION

Both physical activity and CRF are associated with lower risk of developing hypertension in a graded fashion. These findings provide a basis for health professionals to emphasize the importance of participating in regular physical activity to improve fitness for the primary prevention of hypertension in men.

Metabolic syndrome and risk of cancer mortality in men

BACKGROUND

Metabolic syndrome (MetS) has been linked with an increased risk of developing cancer; however, the association between MetS and cancer mortality remains less clear. Little research has focused on pre-cancer risk factors that may affect the outcome of treatment. The purpose of this study was to examine the association between MetS and all-cancer mortality in men.

METHODS

The participants included 33,230 men aged 20-88 years who were enrolled in the Aerobics Centre Longitudinal Study and who were free of known cancer at the baseline.

RESULTS

At baseline 28% of all the participants had MetS. During an average of 14 years follow-up, there were a total of 685 deaths due to cancer. MetS at baseline was associated with a 56% greater age-adjusted risk in cancer mortality.

CONCLUSION

These data show that MetS is associated with an increased risk of all-cause cancer mortality in men. Based on these findings, it is evident that successful interventions should be identified to attenuate the negative effects of MetS.

Associations of cardiorespiratory fitness and obesity with risks of impaired fasting glucose and type 2 diabetes in men

OBJECTIVE

The purpose of this study was to examine the associations of cardiorespiratory fitness (hereafter fitness) and various obesity measures with risks of incident impaired fasting glucose (IFG) and type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was a prospective cohort study of 14,006 men (7,795 for the analyses of IFG), who did not have an abnormal electrocardiogram or a history of heart attack, stroke, cancer, or diabetes.

RESULTS

Of the men, 3,612 (39,610 person-years) and 477 (101,419 person-years) developed IFG and type 2 diabetes, respectively. Compared with the least fit 20% in multivariate analyses, IFG and type 2 diabetes risks in the most fit 20% were 14 and 52% lower, respectively (both P < 0.001). Men with BMI > or =30.0 kg/m2, waist girth >102.0 cm, or percent body fat > or =25 had 2.7-, 1.9-, and 1.3-fold higher risks for type 2 diabetes, respectively, compared with those for nonobese men (all P < 0.01), and the results for IFG were similar. In the combined analyses, obese unfit (least fit 20%) men had a 5.7-fold higher risk for type 2 diabetes compared with normal-weight fit (most fit 80%) men. We observed similar trends for the joint associations of BMI and fitness with IFG and those of waist girth or percent body fat and fitness with both IFG and type 2 diabetes.

CONCLUSIONS

Low fitness and obesity increased the risks of IFG and type 2 diabetes by approximately similar magnitudes. When considered simultaneously, fitness attenuated but did not eliminate the increased risks of IFG and type 2 diabetes associated with obesity, and the highest risk was found in obese and unfit men.

Prospective study of cardiorespiratory fitness and depressive symptoms in women and men

Most studies of the relationship between cardiorespiratory fitness (CRF) and depression have been limited to cross-sectional designs. The objective of this study was to follow individuals over time to examine whether those with higher levels of CRF have lower risk of developing depressive symptoms. Participants were 11,258 men and 3085 women enrolled in the Aerobics Center Longitudinal Study in Dallas, TX. All participants completed a maximal treadmill exercise test at baseline (1970-1995) and a follow-up health survey in 1990 and/or 1995. Individuals with a history of a mental disorder, cardiovascular disease, or cancer were excluded. CRF was quantified by exercise test duration, and categorized into age and sex-stratified groups as low (lowest 20%), moderate (middle 40%), or high (upper 40%). Depressive symptoms were assessed using the 20-item Center for Epidemiologic Studies Depression Scale (CES-D). Those who scored 16 or more on the CES-D were considered to have depressive symptoms. After an average of 12 years of follow-up, 282 women and 740 men reported depressive symptoms. After adjusting for age, baseline examination year, and survey response year, the odds of reporting depressive symptoms were 31% lower for men with moderate CRF (odds ratio, OR 0.69; 95% confidence interval, CI 0.56-0.85) and 51% lower for men with high CRF (OR 0.49, CI 0.39-0.60), compared to men with low CRF. Corresponding ORs for women were 0.56 (CI 0.40-0.80) and 0.46 (CI 0.32-0.65). Higher CRF is associated with lower risk of incident depressive symptoms independent of other clinical risk predictors.

Oral potassium supplement use and outcomes in chronic heart failure: a propensity-matched study

BACKGROUND

Hypokalemia is common in heart failure (HF) and is associated with increased mortality. Potassium supplements are commonly used to treat hypokalemia and maintain normokalemia. However, their long-term effects on outcomes in chronic HF are unknown. We used a public-use copy of the Digitalis Investigation Group (DIG) trial dataset to determine the associations of potassium supplement use with outcomes using a propensity-matched design.

METHODS

Of the 7788 DIG participants with chronic HF, 2199 were using oral potassium supplements at baseline. We estimated propensity scores for potassium supplement use for each patient and used them to match 2131 pairs of patients receiving and not receiving potassium supplements. Matched Cox regression models were used to estimate associations of potassium supplement use with mortality and hospitalization during 40 months of median follow-up.

RESULTS

All-cause mortality occurred in 818 (rate, 1327/10,000 person-years) and 802 (rate, 1313/10,000 person-years) patients respectively receiving and not receiving potassium supplements (hazard ratio {HR} when potassium supplement use was compared with nonuse, 1.05; 95% confidence interval {CI}, 0.94-1.18; P=0.390). All-cause hospitalizations occurred in 1516 (rate, 4777/10,000 person-years) and 1445 (rate, 4120/10,000 person-years) patients respectively receiving and not receiving potassium supplements (HR, 1.15; 95% CI, 1.05-1.26; P=0.004). HRs (95% CI) for hospitalizations due to cardiovascular causes and worsening HF were respectively 1.19 (95% CI, 1.08-1.32; P=0.001) and 1.27 (1.12-1.43; P<0.0001).

CONCLUSION

The use of potassium supplements in chronic HF was not associated with mortality. However, their use was associated with increased hospitalization due to cardiovascular causes and progressive HF.

Cardiorespiratory Fitness as a Predictor of Fatal and Nonfatal Stroke in Asymptomatic Women and Men

Background and Purpose— Prospective data on the association between cardiorespiratory fitness (CRF) and stroke are largely limited to studies in men or do not separately examine risks for fatal and nonfatal stroke. This study examined the association between CRF and fatal and nonfatal stroke in a large cohort of asymptomatic women and men.

Methods— A total of 46 405 men and 15 282 women without known myocardial infarction or stroke at baseline completed a maximal treadmill exercise test between 1970 and 2001. CRF was grouped as quartiles of the sex-specific distribution of maximal metabolic equivalents achieved. Mortality follow-up was through December 31, 2003, using the National Death Index. Nonfatal stroke, defined as physician-diagnosed stroke, was ascertained from surveys during 1982 to 2004. Cox regression models quantified the pattern and magnitude of association between CRF and stroke.

Results— There were 692 strokes during 813 944 man-years of exposure and 171 strokes during 248 902 woman-years of exposure. Significant inverse associations between CRF and age-adjusted fatal, nonfatal, and total stroke rates were observed for women and men ( P trend ≤0.05 each). After adjusting for several cardiovascular disease risk factors, the inverse association between CRF and each stroke outcome remained significant ( P trend <0.05 each) in men. In women, the multivariable-adjusted relationship between CRF and nonfatal and total stroke remained significant ( P trend ≤0.01 each), but not between CRF and fatal stroke ( P trend =0.18). A CRF threshold of 7 to 8 maximal metabolic equivalents was associated with a substantially reduced rate of total stroke in both men and women.

Conclusions— These findings suggest that CRF is an independent determinant of stroke incidence in initially asymptomatic and cardiovascular disease-free adults, and the strength and pattern of the association is similar for men and women.

Association of diuretic use and overactive bladder syndrome in older adults: a propensity score analysis

Diuretic use and overactive bladder syndrome are common in older adults. However, the relationship between the two has not been well studied. Data were collected by self-administered questionnaires including the Urge Urinary Distress Inventory (Urge-UDI) and the Urge Incontinence Impact Questionnaire (Urge-IIQ), and by outpatient chart abstraction. Patients (n=172) had a mean age of 79+/-7.5 (+/-S.D.), 76% were women, and 48% were African Americans; 76% had hypertension, 32% had heart failure, and 66% were receiving diuretics (57% loop diuretics). Overall, 72%, 68%, and 73% of patients, respectively, reported urinary frequency, urgency and urge incontinence. Diuretic use was associated with increased frequency (81% versus 55% non-diuretic; odds ratio (OR)=3.48; 95% confidence interval (CI)=1.73-7.03) and urgency (74% versus 57% non-diuretic; OR=2.17; 95% CI=1.11-4.24) but not with incontinence (OR=1.74; 95% CI=0.87-3.50). When adjusted for propensity scores, diuretic use had independent associations with frequency (adjusted OR=3.09; 95% CI=1.20-7.97) and urgency (adjusted OR=2.50; 95% CI=1.00-6.27). In addition to frequency and urgency, loop diuretic use was also associated with incontinence (OR=2.54; 95% CI=1.09-5.91), which lost significance after propensity adjustment (adjusted OR=1.88; 95% CI=0.57-6.17). Overall summary mean Urge-IIQ score was 1.83+/-0.85 with 1.75+/-0.86, 1.68+/-0.76, and 2.03+/-0.88, respectively, for no diuretic, non-loop, and loop-diuretic patients (one-way analysis of variance (ANOVA) p=0.063). Overactive bladder symptoms were common among ambulatory older adults and were associated with diuretic use, and had stronger associations with loop diuretic use.

Association of chronic kidney disease with outcomes in chronic heart failure: a propensity-matched study

BACKGROUND

Chronic kidney disease (CKD) is associated with increased mortality in patients with heart failure (HF). However, its association with hospitalization in HF patients has not been well studied.

METHODS

Of 7788 patients in the Digitalis Investigation Group trial, 3527 had CKD, defined by an estimated glomerular filtration rate (GFR) <60 ml/min/1.73 m(2) body surface area (BSA). Propensity scores for CKD were calculated using a multivariable logistic regression model and used to match 2399 pairs of patients with and without CKD. Matched Cox regression analyses were used to estimate association of CKD with outcomes.

RESULTS

All-cause hospitalization occurred in 1636 (rate, 4233/10,000 person-years) and 1587 (rate, 3733/10,000 person-years) patients respectively, with and without CKD (matched hazard ratio [HR] for CKD, 1.18, 95% confidence interval [CI], 1.08-1.29; P < 0.0001). Matched HR for cardiovascular and HF hospitalization were respectively 1.17 (95% CI, 1.06-1.28, P = 0.002) and 1.28 (95% CI, 1.13-1.45, P < 0.0001). Compared to GFR >or=60 ml/min/1.73 m(2) BSA, HR for all-cause hospitalization for GFR 45-59 and <45 ml/min/1.73 m(2) BSA were respectively 1.04 (95% CI, 0.94-1.16; P = 0.422) and 1.58 (95% CI, 1.34-1.87; P < 0.0001). Similarly, HR for all-cause death for GFR 45-59 and <45 ml/min/1.73 m(2) BSA were respectively 1.03 (95% CI, 0.90-1.18; P = 0.651) and 1.70 (95% CI, 1.40-2.07; P < 0.0001). Matched HR for death due to cardiovascular causes and progressive HF were respectively 1.24 (95% CI, 1.09-1.40; P = 0.001) and 1.42 (95% CI, 1.16-1.72; P = 0.001).

CONCLUSION

CKD was associated with increased mortality and hospitalization in ambulatory patients with chronic HF, which increased progressively with worsening kidney function.

Low serum magnesium and cardiovascular mortality in chronic heart failure: a propensity-matched study

BACKGROUND

Low serum magnesium levels may cause fatal ventricular arrhythmias. However, their long-term effects on mortality and morbidity in chronic heart failure patients are relatively unknown.

METHODS

We studied 1569 chronic systolic and diastolic heart failure patients with normal sinus rhythm who participated in the Digitalis Investigation Group trial and had serum magnesium data available at one month. Of these, 741 patients had normal (>2 mEq/L) and 828 had low (< or =2 mEq/L) serum magnesium levels. Propensity scores for having low serum magnesium levels were calculated for each patient using a non-parsimonious multivariable logistic regression model, and were used to match 560 (76%) low-magnesium patients with 560 normal-magnesium patients. Effects of low-magnesium on mortality and hospitalization during a mean follow-up of 36 months were assessed using matched Cox regression analyses.

RESULTS

All-cause mortality occurred in 156 (rate, 915/10,000 person-years) normal- magnesium and 171 (rate, 1034/10,000 person-years) low-magnesium patients, respectively, during 1704 and 1653 years of follow-up (hazard ratio, 1.23; 95% confidence interval, 0.97-1.57; p=0.089). Cardiovascular mortality occurred in 110 (rate, 646/10,000 person-years) normal-magnesium and 133 (rate, 805/10,000 person-years) low-magnesium patients (hazard ratio, 1.38, 95% confidence interval, 1.04-1.83, p=0.024). Hazard ratios and 95% confidence intervals for all-cause and cardiovascular hospitalizations were respectively 1.18 (0.99-1.42; p=0.068) and 1.14 (0.94-1.39; p=0.182).

CONCLUSIONS

In a propensity-matched population of ambulatory chronic heart failure patients who were balanced in all measured baseline covariates, serum magnesium level 2 mEq/L or less was associated with increased cardiovascular mortality, but had no association with cardiovascular hospitalization.

Association between muscular strength and mortality in men: prospective cohort study

OBJECTIVE

To examine prospectively the association between muscular strength and mortality from all causes, cardiovascular disease, and cancer in men.

DESIGN

Prospective cohort study.

SETTING

Aerobics centre longitudinal study.

PARTICIPANTS

8762 men aged 20-80.

MAIN OUTCOME MEASURES

All cause mortality up to 31 December 2003; muscular strength, quantified by combining one repetition maximal measures for leg and bench presses and further categorised as age specific thirds of the combined strength variable; and cardiorespiratory fitness assessed by a maximal exercise test on a treadmill.

RESULTS

During an average follow-up of 18.9 years, 503 deaths occurred (145 cardiovascular disease, 199 cancer). Age adjusted death rates per 10,000 person years across incremental thirds of muscular strength were 38.9, 25.9, and 26.6 for all causes; 12.1, 7.6, and 6.6 for cardiovascular disease; and 6.1, 4.9, and 4.2 for cancer (all P<0.01 for linear trend). After adjusting for age, physical activity, smoking, alcohol intake, body mass index, baseline medical conditions, and family history of cardiovascular disease, hazard ratios across incremental thirds of muscular strength for all cause mortality were 1.0 (referent), 0.72 (95% confidence interval 0.58 to 0.90), and 0.77 (0.62 to 0.96); for death from cardiovascular disease were 1.0 (referent), 0.74 (0.50 to 1.10), and 0.71 (0.47 to 1.07); and for death from cancer were 1.0 (referent), 0.72 (0.51 to 1.00), and 0.68 (0.48 to 0.97). The pattern of the association between muscular strength and death from all causes and cancer persisted after further adjustment for cardiorespiratory fitness; however, the association between muscular strength and death from cardiovascular disease was attenuated after further adjustment for cardiorespiratory fitness.

CONCLUSION

Muscular strength is inversely and independently associated with death from all causes and cancer in men, even after adjusting for cardiorespiratory fitness and other potential confounders.