Racial Differences in the Association Between Nonexercise Estimated Cardiorespiratory Fitness and Incident Stroke

OBJECTIVE

To examine the association between estimated cardiorespiratory fitness (eCRF) and incident stroke by black and white race.

PARTICIPANTS AND METHODS

A total of 24,162 participants from the REasons for Geographic And Racial Differences in Stroke study (13,232 [54.8%] women; 9543 [39.5%] blacks; mean age, 64.6±9.3 years) without stroke at enrollment between January 15, 2003, and October 30, 2007, were followed for incident stroke through March 31, 2016. Baseline eCRF in maximal metabolic equivalents was determined using nonexercise sex-specific algorithms and further grouped into age- and sex-specific tertiles.

RESULTS

Over a mean of 8.3±3.2 years of follow-up, 945 (3.9%) incident strokes occurred (377 in blacks and 568 in whites). The association between eCRF and stroke risk differed significantly by race (P_Interaction<.001). In whites, after adjustment for stroke risk factors and physical functioning score, the hazard ratio of stroke was 0.82 (95% CI, 0.67-1.00) times lower in the middle tertile of eCRF than in the lowest tertile and was 0.54 (95% CI, 0.43-0.69) times lower in the highest tertile of eCRF. The protective effect of higher levels of eCRF on stroke incidence was more pronounced in those 60 years or older among whites. No association between eCRF and stroke risk was observed in blacks.

CONCLUSION

Estimated cardiorespiratory fitness measured using nonexercise equations is a useful predictor of stroke in whites. The lack of an overall association between eCRF and stroke risk in blacks suggests that the assessment of eCRF in blacks may not be helpful in primary stroke prevention.

Association of Resistance Exercise With the Incidence of Hypercholesterolemia in Men

OBJECTIVE

To examine the associations of resistance exercise, independent of and combined with aerobic exercise, with the risk of development of hypercholesterolemia in men.

PATIENTS AND METHODS

This study used data from the Aerobics Center Longitudinal Study, which is a cohort examining the associations of clinical and lifestyle factors with the development of chronic diseases and mortality. Participants received extensive preventive medical examinations at the Cooper Clinic in Dallas, Texas, between January 1, 1987, and December 31, 2006. A total of 7317 men aged 18 to 83 years (mean age, 46 years) without hypercholesterolemia at baseline were included. Frequency (times per week) and total amount (min/wk) of resistance and aerobic exercise were determined by self-report. Hypercholesterolemia was defined as a total cholesterol level of 240 mg/dL or higher or physician diagnosis.

RESULTS

During a median (interquartile range) follow-up of 4 (2 to 7) years, hypercholesterolemia developed in 1430 of the 7317 men (20%). Individuals meeting the resistance exercise guidelines (≥2 d/wk) had a 13% lower risk of development of hypercholesterolemia (hazard ratio [HR], 0.87; 95% CI, 0.76-0.99; P=.04) after adjustment for general characteristics, lifestyle factors, and aerobic exercise. In addition, less than 1 h/wk and 2 sessions per week of resistance exercise were associated with 32% and 31% lower risks of hypercholesterolemia (HR, 0.68; 95% CI, 0.54-0.86; P=.001; and HR, 0.69; 95% CI, 0.54-0.88; P=.003), respectively, compared with no resistance exercise. Higher levels of resistance exercise did not provide benefits. Meeting both resistance and aerobic exercise guidelines (≥500 metabolic equivalent task min/wk) lowered the risk of development of hypercholesterolemia by 21% (HR, 0.79; 95% CI, 0.68-0.91; P=.002). compared with meeting none of the guidelines.

CONCLUSION

Compared with no resistance exercise, less than 1 h/wk of resistance exercise, independent of aerobic exercise, is associated with a significantly lower risk of development of hypercholesterolemia in men (P=.001). However, the lowest risk of hypercholesterolemia was found at 58 min/wk of resistance exercise. This finding suggests that resistance exercise should be encouraged to prevent hypercholesterolemia in men. However, future studies with a more rigorous analysis including major potential confounders (eg, diet, medications) are warranted.

Is There a Dose-Response Relationship between Tea Consumption and All-Cause, CVD, and Cancer Mortality?

BACKGROUND

A small change in tea consumption at population level could have large impact on public health. However, the health benefits of tea intake among Americans are inconclusive.

OBJECTIVE

To evaluate the association between tea consumption and all-causes, cardiovascular disease (CVD) and cancer mortality in the Aerobics Center Longitudinal study (ACLS).

METHODS

11808 participants (20-82 years) initially free of CVD and cancers enrolled in the ACLS and were followed for mortality. Participants provided baseline self-report of tea consumption (cups/day). During a median follow-up of 16 years, 842 participants died. Of others, 250 died from CVD, and 345 died from cancer, respectively. A Cox proportional hazard model was used to produce hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Compared with participants consuming no tea, tea drinkers had a survival advantage ( Log-2 = 10.2, df = 3, P = 0.017); however, the multivariate hazard ratios (HRs) of all-cause mortality for those drinking 1-7, 8-14, and >14 cups/week were 0.95 (95% CI, 0.81-1.12), 1.00 (95% CI, 0.82-1.22), and 0.98 (95% CI, 0.76-1.25), respectively (P for linear trend = 0.83). The multivariate HR were 1.16 (95% CI, 0.86-1.56), 1.22 (95% CI, 0.85-1.76), and 0.94 (95% CI, 0.56-1.54) for CVD mortality (P for linear trend = 0.47), and 0.97 (95% CI, 0.75-1.25), 0.85 (95% CI, 0.60-1.16), and 0.94 (95% CI, 0.64-1.38) for cancer mortality (P for trend = 0.62).

CONCLUSIONS

There were week or null relationships between tea consumption and mortality due to all-cause, CVD disease or cancer were observed in ACLS.

Change in Submaximal Cardiorespiratory Fitness and All-Cause Mortality

OBJECTIVE

To evaluate the relationship between change in submaximal cardiorespiratory fitness (sCRF) and all-cause mortality risk in adult men and women.

PATIENTS AND METHODS

A prospective study with at least 2 clinical visits (mean follow-up time, 4.2±3.0 years) between April 1974 and January 2002 was conducted to assess the relationship between change in sCRF and mortality risk during follow-up. Participants were 6106 men and women. Submaximal CRF was determined using the heart rate obtained at the 5-minute mark of a graded maximal treadmill test used to determine maximal CRF (mCRF). Change in sCRF from baseline to follow-up was categorized into 3 groups: increased fitness (decreased heart rate, <-4.0 beats/min), stable fitness (heart rate, -4.0 to 3.0 beats/min), and decreased fitness (increased heart rate, >3.0 beats/min).

RESULTS

The mean change in sCRF at follow-up for all 6106 study participants was -0.5±10.0 beats/min, and the mean change in mCRF was -0.3±1.4 metabolic equivalents. Change in sCRF was related to change in mCRF, though the variance explained was small (R²=0.21; P<.001). The hazard ratios (95% CIs) for all-cause mortality were 0.60 (0.38-0.96) for stable and 0.59 (0.35-1.00) for increased sCRF compared with decreased sCRF after adjusting for age, change in weight, and other common risk factors for premature mortality. The hazard ratios for changes in sCRF and mCRF were not significant after adjusting for changes in mCRF (P=.29) and sCRF (P=.60), respectively.

CONCLUSION

A simple 5-minute submaximal test of CRF identified that adults who maintained or improved sCRF were less likely to die from all causes during follow-up than were adults whose sCRF decreased.

Cardiorespiratory Fitness and Incidence of Type 2 Diabetes in United States Veterans on Statin Therapy

BACKGROUND

Impact of cardiorespiratory fitness on statin-related incidence of type 2 diabetes has not been assessed. We assessed the cardiorespiratory fitness and diabetes incidence association in dyslipidemic patients on statins.

METHODS

We identified dyslipidemic patients with a normal exercise test performed during 1986 and 2014 at the Veterans Affairs Medical Centers in Washington, DC or Palo Alto, Calif. The statin-treated patients (n = 4092; age = 58.8 ± 10.9 years) consisted of 2701 Blacks and 1391 Whites. None had evidence of type 2 diabetes prior to statin therapy. We formed 4 fitness categories based on age and peak metabolic equivalents achieved: Least-fit (n = 954), Low-fit (n = 1201), Moderate-fit (n = 1242), and High-fit (n = 695). The non-statin-treated cohort (n = 3001; age = 57.2 ± 11.2 years) with no evidence of type 2 diabetes prior to the exercise test served as controls.

RESULTS

Diabetes incidence was 24% higher in statin-treated compared with non-statin-treated patients (P <.001). In the statin-treated cohort, 1075 (26.3%) developed diabetes (average annual incidence rate of 30.6 events/1000 person-years). Compared with the Least-fit, adjusted risk decreased progressively with increasing fitness and was 34% lower for High-fit patients (hazard ratio [HR] 0.66; 95% confidence interval [CI], 0.53-0.82; P <.001). Compared with the nonstatin cohort, elevated risk was evident only in the Least-fit (HR 1.50; 95% CI, 1.30-1.73; P <.001) and Low-fit patients (HR 1.22; 95% CI, 1.06-1.41; P = .006).

CONCLUSIONS

Risk of diabetes in statin-treated dyslipidemic patients was inversely and independently associated with cardiorespiratory fitness. The increased risk was evident only in relatively low-fitness patients. Improving fitness may modulate the potential diabetogenic effects of statins.

Association of Resistance Exercise, Independent of and Combined With Aerobic Exercise, With the Incidence of Metabolic Syndrome

OBJECTIVE

To determine the association of resistance exercise, independent of and combined with aerobic exercise, with the risk of development of metabolic syndrome (MetS).

PATIENTS AND METHODS

The study cohort included adults (mean ± SD age, 46±9.5 years) who received comprehensive medical examinations at the Cooper Clinic in Dallas, Texas, between January 1, 1987, and December, 31, 2006. Exercise was assessed by self-reported frequency and minutes per week of resistance and aerobic exercise and meeting the US Physical Activity Guidelines (resistance exercise ≥2 d/wk; aerobic exercise ≥500 metabolic equivalent min/wk) at baseline. The incidence of MetS was based on the National Cholesterol Education Program Adult Treatment Panel III criteria. We used Cox regression to generate hazard ratios (HRs) and 95% CIs.

RESULTS

Among 7418 participants, 1147 (15%) had development of MetS during a median follow-up of 4 years (maximum, 19 years; minimum, 0.1 year). Meeting the resistance exercise guidelines was associated with a 17% lower risk of MetS (HR, 0.83; 95% CI, 0.73-0.96; P=.009) after adjusting for potential confounders and aerobic exercise. Further, less than 1 hour of weekly resistance exercise was associated with 29% lower risk of development of MetS (HR, 0.71; 95% CI, 0.56-0.89; P=.003) compared with no resistance exercise. However, larger amounts of resistance exercise did not provide further benefits. Individuals meeting both recommended resistance and aerobic exercise guidelines had a 25% lower risk of development of MetS (HR, 0.75; 95% CI, 0.63-0.89; P<.001) compared with meeting neither guideline.

CONCLUSION

Participating in resistance exercise, even less than 1 hour per week, was associated with a lower risk of development of MetS, independent of aerobic exercise. Health professionals should recommend that patients perform resistance exercise along with aerobic exercise to reduce MetS.

Nonexercise Estimated Cardiorespiratory Fitness and Mortality Due to All Causes and Cardiovascular Disease: The NHANES III Study

OBJECTIVE

To investigate associations of estimated cardiorespiratory fitness (eCRF) and all-cause and cardiovascular disease (CVD) mortality in a representative US population.

PARTICIPANTS AND METHODS

A total of 12,834 participants, aged 20 to 86 years at baseline, were included in the Third National Health and Nutrition Examination Survey. They were followed up from October 18, 1988, through December 31, 2011, for all-cause and CVD death. Cardiorespiratory fitness was estimated from a nonexercise algorithm and further grouped into tertiles. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% CIs.

RESULTS

A total of 3439 deaths (999 due to CVD) occurred during median follow-up of 19.2 years. After adjusting for race/ethnicity, education, age, hypertension, diabetes, hypercholesterolemia, baseline CVD, and cancer status, each metabolic equivalent increase of eCRF was associated with an 18% (range, 15%-21%) lower risk of all-cause mortality and a 19% (range, 15%-24%) lower risk of CVD mortality in men and a 24% (range, 20%-28%) lower risk of all-cause mortality and a 24% (18%-30%) lower risk of CVD mortality in women. Compared with the lower eCRF group, the HRs (95% CIs) of the middle and upper groups were 0.72 (0.61-0.85) and 0.56 (0.47-0.67) for all-cause mortality and 0.76 (0.57-1.01) and 0.48 (0.34-0.66) for CVD mortality in men; and 0.80 (0.66-0.97) and 0.49 (0.40-0.60) for all-cause mortality and 0.84 (0.60-1.17) and 0.46 (0.33-0.66) for CVD mortality in women (trend P<.001 for all).

CONCLUSION

High eCRF was associated with lower risk of all-cause and CVD mortality in a national representative population. The eCRF method has great potential for initial clinical risk stratification and mortality prediction.

Cardiorespiratory Fitness and All-Cause Mortality in Men With Emotional Distress

OBJECTIVE

Mental health and emotional disorders are often associated with higher mortality risk. Whether higher cardiorespiratory fitness (CRF) reduces the risk for all-cause mortality in individuals with emotional distress is not well known.

PATIENTS AND METHODS

Participants were 5240 men (mean age 46.5±9.5 years) with emotional distress (including depression, anxiety, thoughts of suicide, or a history of psychiatric or psychological counseling) who completed an extensive medical examination between 1987 and 2002, and were followed for all-cause mortality through December 31, 2003. Cardiorespiratory fitness was quantified as maximal treadmill exercise test duration and was grouped for analysis as low, moderate, and high. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% CIs.

RESULTS

During a median of 8.7 years (range, 1.0-16.9 years) and 46,217 person-years of follow-up, there were 128 deaths from any cause. Age- and examination year-adjusted all-cause mortality rates per 10,000 person-years according to low, moderate, and high CRF groups were 64.7 (95% CI, 44.9-89.3), 28.0 (95% CI, 23.8-31.5), and 19.6 (95% CI, 17.1-21.6) (trend P<.001) in men who reported any emotional distress. Overall, the multivariable-adjusted HRs and 95% CIs across incremental CRF categories were 1.00 (referent), 0.54 (0.32-0.90), and 0.47 (0.26-0.85), linear trend P =.03.

CONCLUSION

Among men with emotional distress, higher CRF is associated with lower risk of dying, independent of other clinical mortality predictors. Our findings underscore the importance of promoting physical activity to maintain a healthful level of CRF in individuals with emotional distress.

Relation Between Estimated Cardiorespiratory Fitness and Atrial Fibrillation (from the Reasons for Geographic and Racial Differences in Stroke Study)

Estimated cardiorespiratory fitness (e-CRF) based on readily available clinical and self-reported data is a promising alternative to the costly traditional assessment of CRF using exercise equipment, but its role as a predictor for incident atrial fibrillation (AF) is unclear. This study included 10,126 participants (54.5% women, 35% African-American, mean age 63.2 years) from the Reasons for Geographic and Racial Differences in Stroke study who were free of AF at baseline. Baseline (2003 to 2007) e-CRF was determined using a previously validated nonexercise algorithm. Incident AF cases were identified at a follow-up examination by electrocardiogram and self-reported medical history of previous physician diagnosis. After a median follow-up of 9.4 years, 906 participants (8.9%) developed AF. In a multivariable logistic regression model adjusted for sociodemographics and baseline cardiovascular disease risk factors as well as incident coronary heart disease, heart failure, and stroke, each 1-metabolic equivalent of task increase in e-CRF was associated with a 5% lower risk of AF development (odds ratio [95% CI] 0.95 [0.92 to 0.99]; p = 0.0129). This association was stronger in women (OR [95% CI] 0.85 (0.79, 0.92) than in men (OR (95% CI) 0.88 (0.84, 0.93), interaction p value = 0.05. No significant interactions by age, race, history of cardiovascular disease, or physical limitations were observed. In conclusion, e-CRF using a nonexercise algorithm is a useful predictor of incident AF, which is consistent with previous reports using traditional CRF. This suggests that e-CRF using nonexercise algorithms may serve as a useful alternative to CRF measured by costly and time-consuming exercise testing.

Addition of estimated cardiorespiratory fitness to the clinical assessment of 10-year coronary heart disease risk in asymptomatic men

The Framingham Risk Score (FRS) was developed to quantify a patient's coronary heart disease (CHD) risk. Non-exercise estimated CRF (e-CRF) may provide a clinically practical method for describing cardiorespiratory fitness. We computed e-CRF and tested its association with the FRS and CHD.

Male participants (n = 29,854) in the Aerobics Center Longitudinal Study (ACLS) who completed a baseline examination between 1979–2002 were followed for 12 years to determine incident CHD defined by self-report of myocardial infarction, revascularization, or CHD mortality. e-CRF was defined from a 7-item scale and categorized using age-specific tertiles. Multivariable survival analysis determined associations between FRS, e-CRF, and CHD. Interaction between e-CRF and FRS was tested by stratified analysis by ‘low’ and ‘moderate or high’ 10-year CHD risk.

Men with high e-CRF were significantly (p-value < 0.0001) younger, and less likely to be smokers, compared to men with low e-CRF. Multivariable survival analysis reported men with high e-CRF were 29% (HR = 0.71; 95% 0.56, 0.88) less likely to experience a CHD event compared to men with low e-CRF. Stratified analyses showed men with ‘low’ 10-year FRS predicted CHD risk and high e-CRF had a 28% (HR = 0.72; 95% CI 0.57, 0.91) lower CHD-mortality risk compared to men with low e-CRF, no association was found in this group and men with moderate e-CRF. Men who were more fit had a decreased risk for CHD compared to men in the lowest third of fitness. Estimated CRF may add clinical value to the FRS and help clinicians better predict long-term CHD risk.

•

Men with low e-CRF had a higher proportion of CHD events compared to high-fit men.

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E-CRF was a protective factor of CHD in crude and adjusted analysis.

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E-CRF could be used to capture patient CRF during clinic visits.

Longitudinal Patterns of Cardiorespiratory Fitness Predict the Development of Hypertension Among Men and Women

BACKGROUND

Most of the existing literature has linked a baseline cardiorespiratory fitness or change between baseline and one follow-up measurement of cardiorespiratory fitness to hypertension. The purpose of the study is to assess the association between longitudinal patterns of cardiorespiratory fitness changes with time and incident hypertension in adult men and women.

METHODS

Participants were aged 20 to 82 years, were free of hypertension during the first 3 examinations, and received at least 4 preventive medical examinations at the Cooper Clinic in Dallas, Texas, from 1971 to 2006. They were classified into 1 of 5 groups based on all of the measured cardiorespiratory fitness values (in metabolic equivalents) during maximal treadmill tests. Logistic regression was used to compute odds ratios and 95% confidence intervals.

RESULTS

Among 4932 participants (13% women), 1954 developed hypertension. After controlling for baseline potential confounders, follow-up duration, and number of follow-up visits, odds ratios (95% confidence intervals) for hypertension were 1.00 for the decreasing group (referent), 0.64 (0.52-0.80) for the increasing group, 0.89 (0.70-1.12) for the bell-shape group, 0.78 (0.62-0.98) for the U-shape group, and 0.83 (0.69-1.00) for the inconsistent group. The general pattern of the association was consistent regardless of participants' baseline cardiorespiratory fitness or body mass index levels.

CONCLUSIONS

An increasing pattern of cardiorespiratory fitness provides the lowest risk of hypertension in this middle-aged relatively healthy population. Identifying specific pattern(s) of cardiorespiratory fitness change may be important for determining associations with comorbidity, such as hypertension.

CUL4A promotes proliferation and metastasis of colorectal cancer cells by regulating H3K4 trimethylation in epithelial-mesenchymal transition

Increasing evidence suggests that CUL4A, a ubiquitin ligase, is involved in the promotion of cancer malignancy and correlated with worse clinical prognosis in several kinds of human cancers. Although its effect and mechanism on the progression of colorectal cancer (CRC) remain unknown. Our clinical data show that CUL4A protein is overexpressed, positively associated with lymph nodes status, differentiation degree, tumor size, and poor prognosis in 80 CRC patients. CUL4A overexpression promotes cell proliferation and colony formation of CRC cells. Knockdown of CUL4A inhibits cell proliferation and migration. CUL4A can significantly promote the in vitro migration of CRC cells via induction of the epithelial–mesenchymal transition process. And the modulation of CUL4A expression altered the level of H3K4 trimethylation at the E-cadherin, N-cadherin, and vimentin gene promoters, which in turn transcriptionally regulated their expression. Moreover, knockdown of CUL4A also decreased the tumor volume and tumor weight in vivo. Together, our results reveal that CUL4A plays as an oncogene in CRC and may become a potential therapeutic target in the treatment of colorectal cancer.

Prediction of Cardiovascular Mortality by Estimated Cardiorespiratory Fitness Independent of Traditional Risk Factors: The HUNT Study

OBJECTIVE

To assess the predictive value of estimated cardiorespiratory fitness (eCRF) and evaluate the additional contribution of traditional risk factors in cardiovascular disease (CVD) mortality prediction.

PARTICIPANTS AND METHODS

The study included healthy men (n=18,721) and women (n=19,759) aged 30 to 74 years. A nonexercise algorithm estimated cardiorespiratory fitness. Cox proportional hazards models evaluated the primary (CVD mortality) and secondary (all-cause, ischemic heart disease, and stroke mortality) end points. The added predictive value of traditional CVD risk factors was evaluated using the Harrell C statistic and net reclassification improvement.

RESULTS

After a median follow-up of 16.3 years (range, 0.04-17.4 years), there were 3863 deaths, including 1133 deaths from CVD (734 men and 399 women). Low eCRF was a strong predictor of CVD and all-cause mortality after adjusting for established risk factors. The C statistics for eCRF and CVD mortality were 0.848 (95% CI, 0.836-0.861) and 0.878 (95% CI, 0.862-0.894) for men and women, respectively, increasing to 0.851 (95% CI, 0.839-0.863) and 0.881 (95% CI, 0.865-0.897), respectively, when adding clinical variables. By adding clinical variables to eCRF, the net reclassification improvement of CVD mortality was 0.014 (95% CI, -0.023 to 0.051) and 0.052 (95% CI, -0.023 to 0.127) in men and women, respectively.

CONCLUSION

Low eCRF is independently associated with CVD and all-cause mortality. The inclusion of traditional clinical CVD risk factors added little to risk discrimination and did not improve the classification of risk beyond this simple eCRF measurement, which may be proposed as a practical and cost-effective first-line approach in primary prevention settings.

Cardiorespiratory Fitness and Incidence of Major Adverse Cardiovascular Events in US Veterans: A Cohort Study

OBJECTIVE

To assess the association between exercise capacity and the risk of major adverse cardiovascular events (MACEs).

PATIENTS AND METHODS

A symptom-limited exercise tolerance test was performed to assess exercise capacity in 20,590 US veterans (12,975 blacks and 7615 whites; mean ± SD age, 58.2±11.0 years) from the Veterans Affairs medical centers in Washington, District of Columbia, and Palo Alto, California. None had a history of MACE or evidence of ischemia at the time of or before their exercise tolerance test. We established quintiles of cardiorespiratory fitness (CRF) categories based on age-specific peak metabolic equivalents (METs) achieved. We also defined the age-specific MET level associated with no risk for MACE (hazard ratio [HR], 1.0) and formed 4 additional CRF categories based on METs achieved below (least fit and low fit) and above (moderately fit and highly fit) that level. Multivariate Cox models were used to estimate HR and 95% CIs for mortality across fitness categories.

RESULTS

During follow-up (median, 11.3 years; range, 0.3-33.0 years), 2846 individuals experienced MACEs. The CRF-MACE association was inverse and graded. The risk for MACE declined precipitously for those with a CRF level of 6.0 METs or higher. When considering CFR categories based on the age-specific MET threshold, the risk increased for those in the 2 CFR categories below that threshold (HR, 1.95; 95% CI, 1.73-2.21 and HR, 1.41; 95% CI, 1.27-1.56 for the least-fit and low-fit individuals, respectively) and decreased for those above it (HR, 0.77; 95% CI, 0.68-0.87 and HR, 0.57; 95% CI, 0.48-0.67 for moderately fit and highly fit, respectively).

CONCLUSION

Increased CRF is inversely and independently associated with the risk for MACE. When an age-specific MET threshold was defined, the risk for MACE increased significantly for those below that threshold and decreased for those above it (P<.001).

Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association

Mounting evidence has firmly established that low levels of cardiorespiratory fitness (CRF) are associated with a high risk of cardiovascular disease, all-cause mortality, and mortality rates attributable to various cancers. A growing body of epidemiological and clinical evidence demonstrates not only that CRF is a potentially stronger predictor of mortality than established risk factors such as smoking, hypertension, high cholesterol, and type 2 diabetes mellitus, but that the addition of CRF to traditional risk factors significantly improves the reclassification of risk for adverse outcomes. The purpose of this statement is to review current knowledge related to the association between CRF and health outcomes, increase awareness of the added value of CRF to improve risk prediction, and suggest future directions in research. Although the statement is not intended to be a comprehensive review, critical references that address important advances in the field are highlighted. The underlying premise of this statement is that the addition of CRF for risk classification presents health professionals with unique opportunities to improve patient management and to encourage lifestyle-based strategies designed to reduce cardiovascular risk. These opportunities must be realized to optimize the prevention and treatment of cardiovascular disease and hence meet the American Heart Association's 2020 goals.

A cross-sectional study of cardiorespiratory fitness and gallbladder disease

PURPOSE

To determine the association of different levels of cardiorespiratory fitness (CRF), an objective indicator of habitual physical activity, with gallbladder disease.

METHODS

In the Aerobics Center Longitudinal Study (ACLS) database, 41,528 men and 13,206 women aged 20-90 years, with body mass index of 18.5 or more and without history of cardiovascular disease and cancer, received a preventive examination at the Cooper Clinic in Dallas, Texas, between 1970 and 2003. CRF was quantified as maximal metabolic equivalents and classified as low, moderate, and high based on traditional ACLS cut points. Gallbladder disease was defined as physician-diagnosed gallbladder disease.

RESULTS

When compared with low CRF, adjusted odds ratios and 95% confidence intervals for gallbladder disease for those with moderate and high CRF were 0.74 (0.55-0.99) and 0.59 (0.42-0.82), respectively when adjusted for all the potential confounders. Each one metabolic equivalent increment of CRF was associated with 10% lower odds of gallbladder disease in all participants (P for trend <.001), 13% lower in women (P for trend <.001), and 8% lower in men (P for trend = .08). The association was consistent across age, history of diabetes mellitus, and physical inactivity subgroups.

CONCLUSIONS

CRF is inversely related to the prevalence of gallbladder disease among relatively healthy men and women in the ACLS cohort.

FTO genotype and weight loss: systematic review and meta-analysis of 9563 individual participant data from eight randomised controlled trials

OBJECTIVE

 To assess the effect of the FTO genotype on weight loss after dietary, physical activity, or drug based interventions in randomised controlled trials.

DESIGN

 Systematic review and random effects meta-analysis of individual participant data from randomised controlled trials.

DATA SOURCES

 Ovid Medline, Scopus, Embase, and Cochrane from inception to November 2015.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

 Randomised controlled trials in overweight or obese adults reporting reduction in body mass index, body weight, or waist circumference by FTO genotype (rs9939609 or a proxy) after dietary, physical activity, or drug based interventions. Gene by treatment interaction models were fitted to individual participant data from all studies included in this review, using allele dose coding for genetic effects and a common set of covariates. Study level interactions were combined using random effect models. Metaregression and subgroup analysis were used to assess sources of study heterogeneity.

RESULTS

 We identified eight eligible randomised controlled trials for the systematic review and meta-analysis (n=9563). Overall, differential changes in body mass index, body weight, and waist circumference in response to weight loss intervention were not significantly different between FTO genotypes. Sensitivity analyses indicated that differential changes in body mass index, body weight, and waist circumference by FTO genotype did not differ by intervention type, intervention length, ethnicity, sample size, sex, and baseline body mass index and age category.

CONCLUSIONS

 We have observed that carriage of the FTO minor allele was not associated with differential change in adiposity after weight loss interventions. These findings show that individuals carrying the minor allele respond equally well to dietary, physical activity, or drug based weight loss interventions and thus genetic predisposition to obesity associated with the FTO minor allele can be at least partly counteracted through such interventions.

SYSTEMATIC REVIEW REGISTRATION

 PROSPERO CRD42015015969.