Submitted to: Journal of Nutrition in Gerontology and Geriatrics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/21/2013
Publication Date: 3/5/2014
Citation: Ford, D.W., Hartman, T.L., Still, C., Wood, C., Mitchell, D.C., Erickson, P., Bailey, R., Smiciklas-Wright, H., Coffman, D.L., Jensen, G.L. 2013. Body mass index, poor diet quality and health related quality of life are associated with mortality in rural older adults. Journal of Nutrition in Gerontology and Geriatrics. 33(1):23-34. DOI:10.1080/21551197.2014.875819. Interpretive Summary: There are several modifiable factors that may impact mortality in an aging population such as diet quality, body mass index (BMI) and health-related quality of life. The associations between these factors and mortality are controversial. This study examines the associations between all-cause mortality, BMI, diet quality and health-related quality of life in the Geisinger Rural Aging Study cohort. Being underweight and poor diet quality was associated with associated with increased risk mortality and being overweight, higher diet quality and higher health-related quality of life was associated with decreased risk of mortality. These findings highlight the priority to better understand the health-related characteristics of “old older” persons in relation to mortality outcomes as they may not be appropriately extrapolated from those of younger samples.
Technical Abstract: In an aging population, potentially modifiable factors impacting mortality such as diet quality, body mass index (BMI), and health-related quality of life (HRQOL) are of interest. Surviving members of the Geisinger Rural Aging Study (GRAS) (n = 5,993; aged =74 years) were contacted in the fall of 2009. Participants in the present study were the 2,995 (1,267 male33:1, 23-34, 1,728 female; mean age 81.4 ± 4.4 years) who completed dietary and demographic questionnaires and were enrolled in the Geisinger Health Plan over follow-up (mean = 3.1 years). Cox proportional hazards multivariate regression models were used to examine the associations between all-cause mortality and BMI, diet quality, and HRQOL. Compared to GRAS participants with BMIs in the normal range, a BMI < 18.5 was associated with increased mortality (HR 1.85 95% CI 1.09, 3.14, P = 0.02), while a BMI of 25–29.9 was associated with decreased risk of mortality (HR 0.71 95% CI 0.55, 0.91, P = 0.007). Poor diet quality increased risk for mortality (HR 1.53 95% CI 1.06, 2.22, P = 0.02). Finally, favorable health-related quality of life was inversely associated with mortality (HR 0.09 95% CI 0.06, 0.13, P < 0.0001). Higher diet quality and HALex scores, and overweight status, were associated with reduced all-cause mortality in a cohort of advanced age. While underweight (BMI < 18.5) increased risk of all-cause mortality, no association was found between obesity and all-cause mortality in this aged cohort.