The prevalence and incidence of chronic kidney disease (CKD), defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73m2, increases markedly with age. Yet, the general approach to management of CKD is based on evidence from young and middle-aged adults and may not apply to older adults. This is because at younger ages, CKD is often a progressive disorder and as kidney function worsens patients may develop end-stage renal disease (ESRD) requiring dialysis or kidney transplant. However, over 90% of older adults with CKD die without progressing to ESRD. While the risk of progression to ESRD among patients with CKD may decrease with age, among older adults, CKD is associated with increased mortality and declines in the ability to perform activities of daily living (ADLs) even after adjustment for traditional cardiovascular disease risk factors (e.g. hypertension, high cholesterol, diabetes). Older adults with CKD also have a higher prevalence of geriatric-specific risk factors, defined as conditions that are common among older adults, but not traditionally considered risk factors in CKD patients. These factors are part of the comprehensive geriatric assessment and include cognitive impairment, depression, falls, polypharmacy and poor physical performance. Geriatric-specific risk factors are associated with mortality and functional decline in the general geriatric population and may explain part of the excess mortality and functional decline among older adults with CKD. However, there are few data on the contribution of these factors on the excess mortality and higher rate of functional decline in this population. Therefore, we propose the following specific aims (1) To determine if geriatric-specific factors explain the excess mortality risk among older adults with CKD and (2) To determine if geriatric-specific factors and poor physical performance explain the higher rate of functional decline among older adults with CKD.
For Aim 1, we will use data on 7,492 participants ? 70 years of age in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study to determine the degree to which each geriatric-specific risk factor accounts for a proportion of the association between CKD and mortality.
For Aim 2, we will use data on 400 participants ? 69 years of age from the UAB Study of Aging to determine the degree to which each geriatric-specific risk factor and poor physical performance accounts for a proportion of the association between CKD and functional decline. Identifying factors that explain the excess risk for mortality and functional decline associated with CKD in this population is a broad, but necessary first step to achieving our goal to improve "health span" for older adults with CKD. This approach bridges nephrology and aging research using rich and complementary existing data from the REGARDS study and the UAB Study of Aging. The proposed study will determine geriatric-specific risk factors that will lead to patient-centered interventions to reduc risks for mortality and functional decline among older adults with CKD.

Public Health Relevance

Chronic kidney disease (CKD) is more common as people age and associated with increased risk of death or loss of functional abilities. However, prior research has focused on young and middle-age adults with CKD and less is known about CKD in older adults. In the proposed study, we will determine if conditions that are common in older CKD patients such as cognitive impairment, depression, falls, the use of multiple medications and poor physical performance explain why older adults with CKD are more likely to die or have functional decline.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Small Research Grants (R03)
Project #
5R03AG042336-02
Application #
8517545
Study Section
Special Emphasis Panel (ZAG1-ZIJ-9 (M1))
Program Officer
Murthy, Mahadev
Project Start
2012-08-01
Project End
2014-07-31
Budget Start
2013-08-01
Budget End
2014-07-31
Support Year
2
Fiscal Year
2013
Total Cost
$69,221
Indirect Cost
$21,971
Name
University of Alabama Birmingham
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
063690705
City
Birmingham
State
AL
Country
United States
Zip Code
35294
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Bowling, C Barrett; Sharma, Pradeep; Muntner, Paul (2014) Prevalence, trends and functional impairment associated with reduced estimated glomerular filtration rate and albuminuria among the oldest-old U.S. adults. Am J Med Sci 348:115-20
Kutner, Nancy G; Zhang, Rebecca; Allman, Richard M et al. (2014) Correlates of ADL difficulty in a large hemodialysis cohort. Hemodial Int 18:70-7
Bowling, C Barrett; Booth 3rd, John N; GutiƩrrez, Orlando M et al. (2014) Nondisease-specific problems and all-cause mortality among older adults with CKD: the REGARDS Study. Clin J Am Soc Nephrol 9:1737-45
Bowling, C Barrett; Booth 3rd, John N; Safford, Monika M et al. (2013) Nondisease-specific problems and all-cause mortality in the REasons for Geographic and Racial Differences in Stroke study. J Am Geriatr Soc 61:739-46
Bowling, C Barrett; Sharma, Pradeep; Fox, Caroline S et al. (2013) Prevalence of reduced estimated glomerular filtration rate among the oldest old from 1988-1994 through 2005-2010. JAMA 310:1284-6