Laura F. DeFina

Physical activity versus cardiorespiratory fitness: two (partly) distinct components of cardiovascular health?

Physical activity (PA) and cardiorespiratory fitness (CRF) both have inverse relationships to cardiovascular (CV) morbidity and mortality. Recent position papers and guidelines have identified the important role of both of these factors in CV health. The benefits of PA and CRF in the prevention of CV disease and risk factors are reviewed. In addition, assessment methodology and utilization in the research and clinical arenas are discussed. Finally, the benefits, methodology, and utilization are compared and contrasted to better understand the two (partly) distinct components and their impact on CV health.

Association Between Low Serum 25-Hydroxyvitamin D and Depression in a Large Sample of Healthy Adults: The Cooper Center Longitudinal Study

OBJECTIVE To investigate the association between serum vitamin D levels and depression in a large database of patients from the Cooper Clinic. PATIENTS AND METHODS We conducted a cross-sectional study of 12,594 participants seen at the Cooper Clinic from November 27, 2006, to October 4, 2010. Serum 25-hydroxyvitamin D [25(OH)D] was analyzed, and depression was defined as a Center for Epidemiologic Studies Depression Scale (CES-D) score of 10 or more. Those with and those without a history of depression represented 2 distinct populations with respect to CES-D scores; accordingly, they were analyzed separately. RESULTS In the total sample, higher vitamin D levels were associated with a significantly decreased risk [odds ratio, 0.92 (95% confidence interval, 0.87-0.97)] of current depression based on CES-D scores. The finding was stronger in those with a prior history of depression [odds ratio, 0.90 (95% confidence interval, 0.82-0.98)] and not significant in those without a history of depression [odds ratio, 0.95 (95% confidence interval, 0.89-1.02)]. CONCLUSION We found that low vitamin D levels are associated with depressive symptoms, especially in persons with a history of depression. These findings suggest that primary care patients with a history of depression may be an important target for assessment of vitamin D levels.

Physical Fitness and Risk for Heart Failure and Coronary Artery Disease

Background—Multiple studies have demonstrated strong associations between cardiorespiratory fitness and lower cardiovascular disease mortality. In contrast, little is known about associations of fitness with nonfatal cardiovascular events. Methods and Results—Linking individual participant data from the Cooper Center Longitudinal Study with Medicare claims files, we studied 20 642 participants (21% women) with fitness measured at the mean age of 49 years and who survived to receive Medicare coverage from 1999 to 2009. Fitness was categorized into age- and sex-specific quintiles (Q) according to Balke protocol treadmill time with Q1 as low fitness. Fitness was also estimated in metabolic equivalents according to treadmill time. Associations between midlife fitness and hospitalizations for heart failure and acute myocardial infarction after the age of 65 years were assessed by applying a proportional hazards model to the multivariate failure time data. After 133 514 person-years of Medicare follow-up, we observed 1051 hospitalizations for heart failure and 832 hospitalizations for acute myocardial infarction. Compared with high fitness (Q4–5), low fitness (Q1) was associated with a higher rate of heart failure hospitalization (14.3% versus 4.2%) and hospitalization for myocardial infarction (9.7% versus 4.5%). After multivariable adjustment for baseline age, blood pressure, diabetes mellitus, body mass index, smoking status, and total cholesterol, a 1 unit greater fitness level in metabolic equivalents achieved in midlife was associated with ≈20% lower risk for heart failure hospitalization after the age of 65 years (men: hazard ratio [95% confidence intervals], 0.79 [0.75–0.83]; P<0.001 and women: 0.81 [0.68–0.96]; P=0.01) but just a 10% lower risk for acute myocardial infarction in men (0.91 [0.87–0.95]; P<0.001) and no association in women (0.97 [0.83–1.13]; P=0.68). Conclusions—Fitness in healthy, middle-aged adults is more strongly associated with heart failure hospitalization than acute myocardial infarction outcomes decades later in older age.

Triglyceride-to-high-density-lipoprotein-cholesterol ratio is an index of heart disease mortality and of incidence of type 2 diabetes mellitus in men.

Background High triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) impart risk for heart disease. This study examines the relationships of TG/HDL-C ratio to mortality from all causes, coronary heart disease (CHD), or cardiovascular disease (CVD). Subjects and Methods Survival analysis was done in 39,447 men grouped by TG/HDL-C ratio cut point of 3.5 and for metabolic syndrome. National Death Index International Classification of Diseases (ICD-9 and ICD-10) codes were used for CVD and CHD deaths occurring from 1970 to 2008. Incidence of type 2 diabetes mellitus (DM) according to ratio was estimated in 22,215 men. Triglyceride/HDL-C ratio and cross-product of TG and fasting blood glucose (TyG index) were used in analysis. Results Men were followed up for 581,194 person-years. Triglyceride/HDL-C ratio predicted CHD, CVD, and all-cause mortality after adjustment for established risk factors and non–HDL-C. Mortality rates were higher in individuals with a high ratio than in those with a low ratio. Fifty-five percent of men had metabolic syndrome that was also predictive of CHD, CVD, and all-cause mortality. Annual incidence of DM was 2 times higher in men with high TG/HDL-C ratio than in those with a low ratio. Individuals with high TG/HDL-C ratio had a higher incidence of DM than those with a low ratio. The TyG index was not equally predictive of causes of mortality to TG/HDL-C, but both were equally predictive of diabetes incidence. Conclusions Triglyceride/HDL-C ratio predicts CHD and CVD mortality as well as or better than do metabolic syndrome in men. Also, a high ratio predisposes to DM. The TyG index does not predict CHD, CVD, or all-cause mortality equally well, but like TG/HDL-C ratio, it predicts DM incidence.

Effects of omega-3 supplementation in combination with diet and exercise on weight loss and body composition

BACKGROUND In addition to the metabolic and cardiovascular benefits of omega-3 (n-3) fatty acids, several studies have suggested an added weight loss-enhancing benefit to this supplement. OBJECTIVE The objective was to assess whether supplemental omega-3 fatty acids in conjunction with diet and exercise augment weight loss over a 6-mo period. DESIGN In a single-institution, placebo-controlled, randomized clinical trial, 128 individuals with a body mass index (in kg/m(2)) between 26 and 40 were assigned to receive 5 omega-3 [3.0 g eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) at a 5:1 ratio (EPA:DHA)] or placebo capsules daily in conjunction with lifestyle modification. The primary endpoint was weight loss; secondary endpoints included metabolic and psychometric variables. Analyses were by intention-to-treat. RESULTS Overweight and obese individuals were assigned to the omega-3 arm (n = 64) or to the placebo arm (n = 64). Subjects in both arms received dietary and exercise counseling. Eighty-one individuals completed the 24-wk study, and the dropout rate was 27%. Subjects in both arms lost an average of >5% of their body weight. No significant differences in weight loss were observed between the omega-3 (-5.2 kg; 95% CI: -6.0, -4.4 kg) and placebo (-5.8 kg; 95% CI: -6.7, -5.1 kg) arms. The absolute mean (±SEM) change difference was 0.61 ± 0.58 kg (P = 0.29). In addition, no significant differences in the other factors assessed were observed. CONCLUSION Omega-3 fatty acids were not effective as an adjunct for weight loss in this otherwise healthy, overweight population.

Cardiorespiratory Fitness and Long‐Term Survival in “Low‐Risk” Adults

Background We sought to establish whether cardiorespiratory fitness had important implications for long-term cardiovascular risk among individuals classified as low risk by the Framingham Risk Score (10-year coronary heart disease risk <10%). Prognostic factors of long-term cardiovascular risk are needed for low-risk subjects who make up the largest percentage of the US population. Methods and Results The study population was composed of men and women, 30 to 50 years of age, who had a baseline medical exam at the Cooper Clinic, Dallas, TX, between 1970 and 1983. Eligible individuals were defined as at low risk for coronary heart disease by Framingham Risk Score at the time of study entry and had no history of diabetes (n=11 190). Cardiorespiratory fitness was determined by maximum graded exercise treadmill tests. Over an average 27±2-year period, 15% of low-fit (quintile 1) compared to 6% of high-fit (quintile 5) individuals died (P<0.001). A 1–metabolic equivalent level increase in baseline fitness was associated with an 11% reduction in all-cause deaths and an 18% reduction in deaths due to cardiovascular disease (CVD) after adjustment for age, sex, body mass index, systolic blood pressure, total cholesterol, blood glucose levels, smoking, and early family history of coronary disease. There was an incremental decrease in CVD risk with increasing fitness quintile, such that the high fit had the lowest adjusted 30-year CVD mortality rate (hazard ratio 0.29, 95% CI: 0.16–0.51) compared to the low fit. Conclusions Cardiorespiratory fitness is associated with a significant reduction in long-term CVD among individuals identified as low risk by Framingham Risk Score. These data suggest that preventive lifestyle interventions geared to optimize cardiorespiratory fitness, even among a “low-risk” subset, should be considered to improve CVD-free survival. (J Am Heart Assoc. 2012;1:e001354 doi: 10.1161/JAHA.112.001354.)

Psychometric evaluation of the Montreal Cognitive Assessment (MoCA) in three diverse samples.

Our objective was to evaluate the utility of the Montreal Cognitive Assessment (MoCA) in both non-clinical and clinical populations. The MoCA, a tool used widely in clinical geriatric practice to detect and quantify cognitive impairment, was administered to three diverse samples to assess the psychometric properties of the instrument. Participants were 482 healthy persons seen in the Cooper Center Longitudinal Study (CCLS), 1923 healthy volunteers evaluated by the Dallas Heart Study (DHS), a population-based sample of Dallas County residents and 69 persons with known or suspected brain pathology, seen for clinical evaluation. The standard deviations in the CCLS and DHS groups were small (2.81, 3.87) and moderate in the clinical group (5.22). The corresponding raw coefficients alpha were. 50,. 63, and. 75. Thus, variability and internal consistency were associated. MoCA scores generally did not correlate with gender and correlated with age only in the clinical group. However, there were moderately strong positive correlations between MoCA scores and education in all three samples. The reliability of the MoCA was extremely low in the two non-clinical groups, but was high in the clinical group. Although useful in large non-clinical studies, the MoCA is best suited to detect and quantify cognitive impairment in clinical patients.

Changes in mid-life fitness predicts heart failure risk at a later age independent of interval development of cardiac and noncardiac risk factors: the Cooper Center Longitudinal Study.

AIMS Low mid-life fitness is associated with higher risk for heart failure (HF). However, it is unclear to what extent this HF risk is modifiable and mediated by the burden of cardiac and noncardiac comorbidities. We studied the effect of cardiac and noncardiac comorbidities on the association of mid-life fitness and fitness change with HF risk. METHODS Linking individual subject data from the Cooper Center Longitudinal Study (CCLS) with Medicare claims files, we studied 19,485 subjects (21.2% women) who survived to receive Medicare coverage from 1999 to 2009. Fitness estimated by Balke treadmill time at mean age of 49 years was analyzed as a continuous variable (in metabolic equivalents [METs]) and according to age- and sex-specific quintiles. Associations of mid-life fitness and fitness change with HF hospitalization after age of 65 years were assessed by applying a proportional hazards recurrent events model to the failure time data with each comorbidity entered as time-dependent covariates. RESULTS After 127,110 person years of Medicare follow-up, we observed 1,038 HF hospitalizations. Higher mid-life fitness was associated with a lower risk for HF hospitalization (hazard ratio [HR] 0.82 [0.76-0.87] per MET) after adjustment for traditional risk factors. This remained unchanged after further adjustment for the burden of Medicare-identified cardiac and noncardiac comorbidities (HR 0.83 [0.78-0.89]). Each 1 MET improvement in mid-life fitness was associated with a 17% lower risk for HF hospitalization in later life (HR 0.83 [0.74-0.93] per MET). CONCLUSIONS Mid-life fitness is an independent and modifiable risk factor for HF hospitalization at a later age.

Secular Change in Cardiorespiratory Fitness of Men: Cooper Center Longitudinal Study

UNLABELLED Cardiorespiratory fitness (CRF) has been shown to be an independent predictor of all-cause and cardiovascular mortality, as well as health outcomes such as cardiovascular disease, hypertension, diabetes mellitus, and metabolic syndrome. During the last four decades, national guidelines for physical activity and fitness have emerged in an ongoing effort to improve health outcomes through enhanced CRF risk profiles. PURPOSE The purpose of the study was to describe the secular trend in CRF as a function of decade and age in a large cohort of men during the past 40 yr. METHODS A cross-sectional analysis of baseline fitness data collected during comprehensive medical examinations of 52,785 men age 20-74 yr evaluated at the Cooper Clinic in Dallas, TX, from 1970 to 2009 who completed a maximum treadmill exercise test for estimation of aerobic capacity was conducted. Comparisons were made between mean fitness levels in each decade stratified by five age groups. RESULTS Mean CRF in MET from estimated V·O 2max has increased overall approximately 1 MET during a 40-yr period for each of the five age groups (P < 0.0001). The greatest change occurred during the 1970s to 1980s with minimal subsequent increase and a small decline commencing in the last decade especially in younger men. CONCLUSIONS In a large cohort of men, average CRF has improved during the last 40 yr with a slight decline in the favorable trend notable in the most recent decade.

Midlife Cardiorespiratory Fitness, Incident Cancer, and Survival After Cancer in Men: The Cooper Center Longitudinal Study

IMPORTANCE Cardiorespiratory fitness (CRF) as assessed by formalized incremental exercise testing is an independent predictor of numerous chronic diseases, but its association with incident cancer or survival following a diagnosis of cancer has received little attention. OBJECTIVE To assess the association between midlife CRF and incident cancer and survival following a cancer diagnosis. DESIGN, SETTING, AND PARTICIPANTS This was a prospective, observational cohort study conducted at a preventive medicine clinic. The study included 13 949 community-dwelling men who had a baseline fitness examination. All men completed a comprehensive medical examination, a cardiovascular risk factor assessment, and incremental treadmill exercise test to evaluate CRF. We used age- and sex-specific distribution of treadmill duration from the overall Cooper Center Longitudinal Study population to define fitness groups as those with low (lowest 20%), moderate (middle 40%), and high (upper 40%) CRF groups. The adjusted multivariable model included age, examination year, body mass index, smoking, total cholesterol level, systolic blood pressure, diabetes mellitus, and fasting glucose level. Cardiorespiratory fitness levels were assessed between 1971 and 2009, and incident lung, prostate, and colorectal cancer using Medicare Parts A and B claims data from 1999 to 2009; the analysis was conducted in 2014. MAIN OUTCOMES AND MEASURES The main outcomes were (1) incident prostate, lung, and colorectal cancer and (2) all-cause mortality and cause-specific mortality among men who developed cancer at Medicare age (≥65 years). RESULTS Compared with men with low CRF, the adjusted hazard ratios (HRs) for incident lung, colorectal, and prostate cancers among men with high CRF were 0.45 (95% CI, 0.29-0.68), 0.56 (95% CI, 0.36-0.87), and 1.22 (95% CI, 1.02-1.46), respectively. Among those diagnosed as having cancer at Medicare age, high CRF in midlife was associated with an adjusted 32% (HR, 0.68; 95% CI, 0.47-0.98) risk reduction in all cancer-related deaths and a 68% reduction in cardiovascular disease mortality following a cancer diagnosis (HR, 0.32; 95% CI, 0.16-0.64) compared with men with low CRF in midlife. CONCLUSIONS AND RELEVANCE There is an inverse association between midlife CRF and incident lung and colorectal cancer but not prostate cancer. High midlife CRF is associated with lower risk of cause-specific mortality in those diagnosed as having cancer at Medicare age.