Association of objectively measured physical activity with established and novel cardiovascular biomarkers in elderly subjects: every step counts

OBJECTIVE: To analyse the relationship between objectively measured daily walking duration and cardiovascular biomarkers of inflammation, cardiac dysfunction and renal impairment. METHODS: Between March 2009 and April 2010, physical activity was assessed in 1253 community-dwelling individuals living in Germany aged ≥65 years (57% men) over 1 week using a thigh-worn accelerometer. C reactive protein (CRP), white blood cells (WBC), N-terminal pro-brain natriuretic peptide, high-sensitive troponin T (hsTnT), creatinine (Cr) and cystatin C (CysC) were also measured. Least-square means of daily walking duration were calculated for quartiles of each biomarker adjusted for sex, age, pre-existing cardiovascular disease and smoking status. RESULTS: After adjustment for covariates, statistically significant linear associations with walking duration were observed for WBC, hsTnT, Cr and CysC. CRP quartiles 1 and 2 showed no significant difference followed by a significant inverse dose-response relationship. A similar pattern, but less pronounced, was seen for N-terminal pro-brain natriuretic peptide. Mean differences between the first two quartiles of CRP and its fourth quartile were 17 min. Between categories 1 (more beneficial) and 4 of WBC, hsTnT, Cr and CysC the differences were 15, 12, 23 and 20 min, respectively. CONCLUSION: Increased walking duration is associated with a more favourable profile of cardiovascular biomarkers in elderly subjects.