•  
  •  
 

POTENTIAL MEDIATING EFFECTS OF SOCIAL SUPPORT AND PHYSICAL ACTIVITY ON COGNITIVE FUNCTION AND MORTALITY RISK

MB Zipperer

Abstract

Madeline Breck Zipperer. University of North Florida, Jacksonville, FL.

BACKGROUND: Low cognitive function has been shown to be an independent predictor of all-cause and cardiovascular disease (CVD)-related mortality. However, there is limited evidence examining the potential mediating effects of social support network size and physical activity on cognitive function and mortality risk. This study examines the potential mediating effects of social support network size and total physical activity volume (TPAV) on cognitive function and all-cause and CVD-related mortality risk in a large, nationally representative sample of U.S. older adults. METHODS: Study sample (N =2,550) included older adult (≥ 60 years of age) participants in the 1999-2002 National Health and Nutrition Examination Survey. Quartiles of cognitive function were created using Digit Symbol Substitution Test scores. Social support network size was determined using the number of reported close friends. TPAV was determined from self-reported domestic physical activity, transportation physical activity, and leisure time physical activity. The total weekly METs were determined for all three physical activity domains and quartiles of TPAV were created. RESULTS: Cox proportional hazards regression analysis revealed an approximate 3-fold increase in all-cause and CVD-related mortality risk in participants in the lowest quartile of cognitive function, compared to the highest quartile of cognitive function (Hazards Ratio [HR] 2.89; 95% Confidence Interval [CI] 2.33-3.59) and (HR 2.67; 95% CI 1.54-4.64), respectively. These relationships are independent of social support network size and TPAV. Linear and non-linear inverse dose-response relationships were also revealed between cognitive function and increased all-cause and CVD-related mortality risk, respectively (P for trend for both P < 0.0001). CONCLUSIONS: In a large, nationally representative sample of U.S. older adults, low cognitive function was associated with increased all-cause and CVD-related mortality risk. However, in contrast to previous evidence, both relationships were independent of social support network size and TPAV.

This document is currently not available here.

Share

COinS