Abstract 19920: Long-term Change in Cardiorespiratory Fitness and All-cause Mortality: A Follow-up Study

Abstract

Background: The few studies that have assessed the association between changes in cardiorespiratory fitness and all-cause mortality have relied on exercise scores and other indirect measures of cardiorespiratory fitness (CRF). The aim of the study was to investigate whether long-term changes CRF, as assessed by the gold-standard method of respiratory gas exchange during exercise, are associated with all-cause mortality. Methods: Prospective cohort study (Kuopio Ischaemic Heart Disease Risk Factor Study), with a baseline examination between 1984 and 1989 (V1), a re-examination at 11 years (V2), and up to 15 years of follow-up from V2. VO 2 max was measured at both visits using respiratory gas exchange during maximal exercise test. The difference (ΔVO 2 max) was estimated as VO 2 max (V2) - VO 2 max(V1). This study was based on a population-based sample of men 42 to 60 years of age without no missing data on baseline and 11-year exercise test were included (N=579). Results: The mean ΔVO 2 max was -5.2 ml/min*kg. During a median follow-up of 13.3 (interquartile range: 12.5-14.0) years from V2, 123 (21.2%) all-cause deaths were recorded. In a multivariate analysis adjusted for baseline age, VO 2 max, systolic blood pressure, smoking status, low- and high-density lipoprotein cholesterol and triglycerides, C-reactive protein, body mass index, alcohol consumption, physical activity, socioeconomic status, and history of type 2 diabetes mellitus and ischaemic heart disease, 1 ml/min*kg higher ΔVO 2 max was associated with a 9% relative risk reduction of all-cause mortality (HR 0.91; 95% CI: 0.87 to 0.95) (Figure). Conclusions: In this population, long-term CRF reduction was associated with an increased risk of mortality, suggesting the importance of maintaining good CRF over the decades.