@article {1148, title = {Physical activity and rapid decline in kidney function among older adults.}, journal = {Arch Intern Med}, volume = {169}, year = {2009}, month = {2009 Dec 14}, pages = {2116-23}, abstract = {

BACKGROUND: Habitual physical activity (PA) has both physiologic and metabolic effects that may moderate the risk of kidney function decline. We tested the hypothesis that higher levels of PA are associated with a lower risk of kidney function decline using longitudinal data from a large cohort of older adults.

METHODS: We studied 4011 ambulatory participants aged 65 or older from the Cardiovascular Health Study (CHS) who completed at least 2 measurements of kidney function over 7 years. We calculated a PA score (range, 2-8) by summing kilocalories expended per week (ordinal score of 1-5 from quintiles of kilocalories per week) and walking pace (ordinal score for categories of <2, 2-3, and >3 mph). Rapid decline in kidney function decline (RDKF) was defined by loss of more than 3.0 mL/min/1.73 m(2) per year in glomerular filtration rate, which we estimated by using longitudinal measurements of cystatin C levels.

RESULTS: A total of 958 participants had RDKF (23.9\%; 4.1 events per 100 person-years). The estimated risk of RDKF was 16\% in the highest PA group (score of 8) and 30\% in the lowest PA group (score of 2). After multivariate adjustment, we found that the 2 highest PA groups (scores of 7-8) were associated with a 28\% lower risk of RDKF (95\% confidence interval, 21\%-41\% lower risk) than the 2 lowest PA groups (score of 2-3). Greater kilocalories of leisure-time PA and walking pace were also each associated with a lower incidence of RDKF.

CONCLUSION: Higher levels of PA are associated with a lower risk of RDKF among older adults.

}, keywords = {Aged, Cystatin C, Female, Glomerular Filtration Rate, Humans, Kidney Function Tests, Longitudinal Studies, Male, Motor Activity, Renal Insufficiency, Time Factors}, issn = {1538-3679}, doi = {10.1001/archinternmed.2009.438}, author = {Robinson-Cohen, Cassianne and Katz, Ronit and Mozaffarian, Dariush and Dalrymple, Lorien S and de Boer, Ian and Sarnak, Mark and Shlipak, Mike and Siscovick, David and Kestenbaum, Bryan} } @article {1322, title = {The risk of infection-related hospitalization with decreased kidney function.}, journal = {Am J Kidney Dis}, volume = {59}, year = {2012}, month = {2012 Mar}, pages = {356-63}, abstract = {

BACKGROUND: Moderate kidney disease may predispose to infection. We sought to determine whether decreased kidney function, estimated by serum cystatin C level, was associated with the risk of infection-related hospitalization in older individuals.

STUDY DESIGN: Cohort study.

SETTING \& PARTICIPANTS: 5,142 Cardiovascular Health Study (CHS) participants with measured serum creatinine and cystatin C and without estimated glomerular filtration rate (eGFR) <15 mL/min/1.73 m(2) at enrollment.

PREDICTOR: The primary exposure of interest was eGFR using serum cystatin C level (eGFR(SCysC)).

OUTCOME: Infection-related hospitalizations during a median follow-up of 11.5 years.

RESULTS: In adjusted analyses, eGFR(SCysC) categories of 60-89, 45-59, and 15-44 mL/min/1.73 m(2) were associated with 16\%, 37\%, and 64\% greater risk of all-cause infection-related hospitalization, respectively, compared with eGFR(SCysC) >=90 mL/min/1.73 m(2). When cause-specific infection was examined, eGFR(SCysC) of 15-44 mL/min/1.73 m(2) was associated with an 80\% greater risk of pulmonary and 160\% greater risk of genitourinary infection compared with eGFR(SCysC) >=90 mL/min/1.73 m(2).

LIMITATIONS: No measures of urinary protein, study limited to principal discharge diagnosis.

CONCLUSIONS: Lower kidney function, estimated using cystatin C level, was associated with a linear and graded risk of infection-related hospitalization. These findings highlight that even moderate degrees of decreased kidney function are associated with clinically significant higher risks of serious infection in older individuals.

}, keywords = {Aged, Cohort Studies, Female, Glomerular Filtration Rate, Hospitalization, Humans, Infection, Kidney, Male, Risk Factors}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2011.07.012}, author = {Dalrymple, Lorien S and Katz, Ronit and Kestenbaum, Bryan and de Boer, Ian H and Fried, Linda and Sarnak, Mark J and Shlipak, Michael G} } @article {6136, title = {Kidney function and prevalent and incident frailty.}, journal = {Clin J Am Soc Nephrol}, volume = {8}, year = {2013}, month = {2013 Dec}, pages = {2091-9}, abstract = {

BACKGROUND AND OBJECTIVES: Kidney disease is associated with physiologic changes that may predispose to frailty. This study sought to investigate whether lower levels of kidney function were associated with prevalent or incident frailty in Cardiovascular Health Study (CHS) participants.

DESIGN, SETTING, PARTICIPANTS, \& MEASUREMENTS: CHS enrolled community-dwelling adults age >=65 years between 1989-1990 and 1992-1993. To examine prevalent frailty, included were 4150 participants without stroke, Parkinson disease, prescribed medications for Alzheimer disease or depression, or severely impaired cognition. To examine incident frailty, included were a subset of 3459 participants without baseline frailty or development of exclusion criteria during follow-up. The primary predictor was estimated GFR (eGFR) calculated using serum cystatin C (eGFR(cys)). Secondary analyses examined eGFR using serum creatinine (eGFR(SCr)). Outcomes were prevalent frailty and incident frailty at 4 years of follow-up. Frailty was ascertained on the basis of weight loss, exhaustion, weakness, slowness, and low physical activity.

RESULTS: The mean age was 75 years and the median eGFR(cys) was 73 ml/min per 1.73 m(2). Among participants with an eGFR(cys) <45 ml/min per 1.73 m(2), 24\% had prevalent frailty. In multivariable analysis and compared with eGFR(cys) >=90 ml/min per 1.73 m(2), eGFR(cys) categories of 45-59 (odds ratio [OR], 1.80; 95\% confidence interval [CI], 1.17 to 2.75) and 15-44 (OR, 2.87; 95\% CI, 1.72 to 4.77) were associated with higher odds of frailty, whereas 60-75 (OR, 1.14; 95\% CI, 0.76 to 1.70) was not. In multivariable analysis, eGFR(cys) categories of 60-75 (incidence rate ratio [IRR], 1.72; 95\% CI, 1.07 to 2.75) and 15-44 (IRR, 2.28; 95\% CI, 1.23 to 4.22) were associated with higher incidence of frailty whereas 45-59 (IRR, 1.53; 95\% CI, 0.90 to 2.60) was not. Lower levels of eGFR(SCr) were not associated with higher risk of prevalent or incident frailty.

CONCLUSIONS: In community-dwelling elders, lower eGFR(cys) was associated with a higher risk of prevalent and incident frailty whereas lower eGFR(SCr) was not. These findings highlight the importance of considering non-GFR determinants of kidney function.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Aging, Biomarkers, Creatinine, Cross-Sectional Studies, Cystatin C, Fatigue, Female, Frail Elderly, Geriatric Assessment, Glomerular Filtration Rate, Humans, Incidence, Independent Living, Kidney, Kidney Diseases, Logistic Models, Male, Motor Activity, Multivariate Analysis, Muscle Weakness, Odds Ratio, Phenotype, Prevalence, Prospective Studies, Risk Factors, Time Factors, United States, Weight Loss}, issn = {1555-905X}, doi = {10.2215/CJN.02870313}, author = {Dalrymple, Lorien S and Katz, Ronit and Rifkin, Dena E and Siscovick, David and Newman, Anne B and Fried, Linda F and Sarnak, Mark J and Odden, Michelle C and Shlipak, Michael G} }