RESUMO
AIMS: Data on the association of cardiorespiratory fitness with survival of cancer patients are limited. This study aimed to evaluate the association between midlife cardiorespiratory fitness and survival after a subsequent cancer diagnosis. METHODS: We evaluated 19,134 asymptomatic self-referred adults who were screened in preventive healthcare settings. All subjects were free of cardiovascular disease and cancer at baseline and completed a maximal exercise stress test. Fitness was categorised into age-specific and sex-specific quintiles according to the treadmill time and dichotomised to low (quintiles 1-2) and high fitness groups. RESULTS: The mean age was 50 ± 8 years and 72% were men. During a median follow-up of 13 years (interquartile range 7-16) 517 (3%) died. Overall, 1455 (7.6%) subjects developed cancer with a median time to cancer diagnosis of 6.4 years (interquartile range 3-10). Death from the time of cancer diagnosis was significantly lower among the high fitness group (Plog rank = 0.03). Time-dependent analysis showed that subjects who developed cancer during follow-up were more likely to die (P < 0.001). The association of cancer with survival was fitness dependent such that in the lower fitness group cancer was associated with a higher risk of death, whereas among the high fitness group the risk of death was lower (hazard ratio 20 vs. 15; Pfor interaction = 0.047). The effect modification persisted after applying a 4-year blanking period between fitness assessment and cancer diagnosis (Pfor interaction = 0.003). CONCLUSION: Higher midlife cardiorespiratory fitness is associated with better survival among cancer patients. Our findings support fitness assessment in preventive healthcare settings.
Assuntos
Aptidão Cardiorrespiratória , Doenças Cardiovasculares , Neoplasias , Adulto , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico , Neoplasias/epidemiologia , Aptidão Física , Fatores de RiscoRESUMO
BACKGROUND: Although cardiorespiratory fitness (CRF) is a strong independent predictor of adverse cardiovascular outcomes, it is not considered as a risk enhancer by current guidelines. METHODS: We evaluated asymptomatic self-referred adults aged 40 to 79 years of age, free of cardiovascular disease at baseline, who were screened annually and completed baseline exercise stress test. Baseline CRF was dichotomized into 2 groups: low (metabolic equivalents < 8) and high. The primary endpoint was the composite of death, nonfatal acute coronary syndrome, and stroke after excluding subjects diagnosed with metastatic cancer during follow-up. RESULTS: Study population included 15,445 subjects with median age of 49 years (interquartile range: 44-55). During median follow-up of 8 years 1362 (9%) subjects developed the study endpoint. Kaplan-Meier survival analysis showed that both fitness and atherosclerotic cardiovascular disease (ASCVD) were associated with developing of the study endpoint (P < 0.001 for both). Cox regression model with adjustment for ASCVD risk consistently showed that lower fitness was associated with a significant 23% higher risk to develop the study endpoint (P = 0.001). Continuous net reclassification improvement analysis showed an overall improvement of 11.4% (95% confidence interval, 8%-14.6%; P value < 0.001) in the accuracy of classification when fitness was added to the ASCVD model. CONCLUSIONS: Low CRF is a strong independent predictor of the cardiovascular morbidity and mortality in asymptomatic adults. Addition of fitness to the pooled cohort ASCVD risk significantly improves the accuracy of the model.