Sedentary Time and White Matter Hyperintensity Volume in Older Adults

Purpose Cerebrovascular disease in the form of white matter hyperintensities (WMH) increases with age and is associated separately with sedentary time and reduced kidney function. A better understanding of the relationships among these variables would help clarify whether sedentary time should be considered more closely in older adults at particular levels of kidney function to reduce the risk of WMH. Methods We analyzed information from 94 healthy community-dwelling older adults to determine the association of sedentary time and WMH in non-demented, non-depressed older adults, and whether level of kidney function was an effect modifier of the relationship between sedentary time and WMH. Sedentary behavior was measured using the Sedentary Behavior Questionnaire. WMH was assessed using whole-brain 3T MRI T1- and T2-weighted images. Kidney function was calculated by the epi-CKD formula for estimated glomerular filtration rate (eGFR). Exposures or predictors were sedentary time, age, sex, education in years, Framingham stroke risk 10-year prediction score (FSRP-10), and eGFR. The analytical approach was multiple linear regression. Results Adjusting for age, sex, education in years, FSRP-10, greater sedentary time was associated with greater WMH but this effect was dependent on level of eGFR (sedentary time*eGFR interaction b=-0.0005, p=.022). At eGFR values of 69, 81, and 93 ml/min/per 1.73m2 (the 25th, 50th, and 75th percentiles), sedentary time b coefficients were b=0.021 (95% CI 0.011-0.031), b=0.015 (95% CI 0.008-0.022), and b=0.009 (95% CI 0.003-0.016). The effect weakened linearly as eGFR increased, with no significant association at eGFR ≥97 ml/min/per 1.73m2. Conclusions Findings suggest that sedentary time is associated with WMH in persons with an eGFR ≤96 ml/min/per 1.73m2 and that this association is stronger with lower levels of kidney function. Corresponding Author: Ulf G. Bronas, PhD, ATC, FSVM, FAHA, Associate Professor, University of Illinois at Chicago, College of Nursing, Department of Biobehavioral Health Science (M/C 802), 845 S. Damen Ave., Chicago, IL 60612-7350. Tel: (312) 355-5886. Email: bronas@uic.edu This work was supported by the National Institutes of Health, National Institute on Aging: K01 AG040192 (ML) and R21 AG048176 (ML). Additionally, aspects of this project were supported by the National Center for Advancing Translational Sciences and National Center for Research Resources, National Institutes of Health, through Grants UL1TR002003 and 1S10RR028898. The authors have no conflicts of interest to report. Accepted for publication: 14 February 2019. © 2019 American College of Sports Medicine

from Sports Medicine via xlomafota13 on Inoreader https://ift.tt/2GU1Cs7
via IFTTT