Association between different cutoff points for objectively measured moderate-to-vigorous physical activity and cardiometabolic markers in older adults

Background: Regular moderate-to-vigorous physical activity (MVPA) is inversely associated with cardiovascular diseases in older adults. However, it remains unclear how the use of different cutoff points affects the associations with cardiovascular markers. Objective: To analyze the association between different cutoff points for objectively measured MVPA and cardiometabolic markers in older adults. Methods: This was a cross-sectional study involving 425 older adults (aged >= 60 years) from the EpiFloripa Ageing cohort study. We used ActiGraph accelerometers to measure MVPA in total minutes and in bouts (>= 10 min) for at least 4 days. The tested cardiometabolic markers were waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein cholesterol (HDL-c), body mass index (BMI), triglycerides, fasting glucose and glycated hemoglobin (HbA1c). To identify MVPA, we used the cutoff points of Freedson et al. (>= 1952 counts/min), Copeland and Esliger (>= 1040 counts/min), and Troiano et al (>= 2020 counts/min). Results: We observed significant differences in MVPA (total and bouts) between the different cutoff points (p < .001). The magnitude and number of associations between cardiometabolic markers and MVPA varied according to measurement units (total minutes: WC, SBP, DBP, HDL-c, BMI, triglycerides, glucose, and HbA1c versus bouts: WC, DBP, SBP HDL-c, and BMI) and cutoff points (higher associations for the Copeland and Esliger cutoff in total minutes and for the Troiano et al. cutoff in bouts of >= 10 min). Conclusion: The use of different cutoff points in evaluating accelerometer-measured MVPA in older adults provides conflicting estimates, which emphasizes the importance of standardized thresholds.