Obesity and change in estimated GFR among older adults.
BACKGROUND
The prevalence of chronic kidney disease is growing most rapidly among older adults; however, determinants of impaired kidney function in this population are not well understood. Obesity assessed in midlife has been associated with chronic kidney disease.


METHODS
Cohort study.


METHODS
4,295 participants in the community-based Cardiovascular Health Study, aged >or= 65 years.


METHODS
Body mass index, waist circumference, and fat mass measured using bioelectrical impedance.


RESULTS
Change in glomerular filtration rate (GFR) during 7 years of follow-up.


METHODS
Longitudinal estimates of GFR calculated using the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation.


RESULTS
Estimated GFR decreased by an average of 0.4 +/- 3.6 mL/min/1.73 m(2)/y, and rapid GFR loss (>3 mL/min/1.73 m(2)/y) occurred in 693 participants (16%). Baseline body mass index, waist circumference, and fat mass were each associated with increased risk of rapid GFR loss: ORs, 1.19 (95% CI, 1.09-1.30) per 5 kg/m(2), 1.25 (95% CI, 1.16-1.36) per 12 cm, and 1.14 (95% CI, 1.05-1.24) per 10 kg after adjustment for age, sex, race, and smoking. The magnitude of increased risk was larger for participants with estimated GFR < 60 mL/min/1.73 m(2) at baseline (P for interaction < 0.05). Associations were substantially attenuated by further adjustment for diabetes, hypertension, and C-reactive protein level. Obesity measurements were not associated with change in GFR estimated using serum cystatin C level.


CONCLUSIONS
Few participants with advanced chronic kidney disease at baseline, no direct GFR measurements.


CONCLUSIONS
Obesity may be a modifiable risk factor for the development and progression of kidney disease in older adults.
de Boer
Ian H
IH
Division of Nephrology, University of Washington, Seattle, WA 98195, USA. deboer@u.washington.edu
Katz
Ronit
R
Fried
Linda F
LF
Ix
Joachim H
JH
Luchsinger
Jose
J
Sarnak
Mark J
MJ
Shlipak
Michael G
MG
Siscovick
David S
DS
Kestenbaum
Bryan
B
D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D002908:Chronic Disease; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D007674:Kidney Diseases / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D012307:Risk Factors
D055316:Cystatin C; D003404:Creatinine