Low-Intensity Physical Activity and Cardiometabolic Risk Factors among Older Adults with Multiple Chronic Conditions

Introduction
Cardiovascular disease (CVD) is the leading cause of death among older adults in the Unites States and is driven largely by cardiometabolic risk factors including elevated blood pressure and blood glucose. Studies have found the protective effect of moderate intensity physical activity (MIPA) and vigorous intensity physical activity (VIPA) on cardiometabolic risk factor; however, the association between light physical activity (LIPA) and cardiometabolic risk factor among older adults is not clear.

Objectives
1). Examine the association between LIPA and cardiometabolic risk factors. 2). Examine whether the association between LIPA and cardiometabolic risk factor is moderated by multiple chronic conditions.

Methods
Data from the Health and Retirement Study (HRS) were used for this study. We ascertained 2006 and 2008 HRS data from the Public Use Dataset, the RAND HRS Data File (Version N), and the HRS Biomarker Dataset. There were11890 participants aged 50 or older for cross-sectional analysis. Physical activity was converted to metabolic equivalent of tasks (METS) and outcome variables (systolic and diastolic blood pressure and HbA1c) were measured objectively. Mean levels of blood pressure and HbA1c were compared across physical activity intensity groups. Separate linear regression models were used to examine the association between LIPA and cardiometabolic risks adjusting for potential sociodemographic, behavioral, and clinical confounders.

Results
In the final study sample, 28.75% were sedentary, 9.46% regularly engaged in LIPA, 34.68% engaged in MIPA, and 27.12% engaged in VIPA. We did not find significant associations between LIPA and systolic blood pressure (B 0.235; 95% confidence interval (CI), -1.127, 1.597), diastolic blood pressure (B = -0.167; 95% CI, -0.954, 0.621), or HbA1c levels (B -0.009; 95% CI, -0.049, 0.066). The average HbA1c was significantly lower only among individuals who engaged in MIPA (B -0.097; 95% CI, -0.174, -0.020) and MIPA ( B -0.140; 95% CI, -0.218, -0.063) in comparison to individuals who were categorized as in sedentary group

Conclusion
The findings from our study do not suggest that LIPA is independently associated with lower cardiometabolic risk factors among older adults. Associations between physical activity intensity and cardiometabolic risk factors among older adults with multiple chronic conditions need to be verified in studies using more objective measurement of physical activity.