@article {1130, title = {Association of chronic kidney disease with the spectrum of ankle brachial index the CHS (Cardiovascular Health Study).}, journal = {J Am Coll Cardiol}, volume = {54}, year = {2009}, month = {2009 Sep 22}, pages = {1176-84}, abstract = {

OBJECTIVES: This study sought to determine the association of chronic kidney disease (CKD) with high ankle brachial index (ABI) measurement and to compare its strength with that of CKD with a low ABI.

BACKGROUND: CKD is an important risk factor for cardiovascular disease (CVD) events. A high ABI, a marker of lower extremity arterial stiffness, is associated with CVD events and mortality. The association between CKD and high ABI is unknown.

METHODS: The CHS (Cardiovascular Health Study) enrolled community-living people >65 years of age and measured kidney function and ABI. Glomerular filtration rate (GFR) was estimated using equations that incorporated either cystatin C or creatinine, and CKD was defined by estimated GFR <60 ml/min/1.73 m(2). The ABI was categorized as low (<0.90), low-normal (0.90 to 1.09), normal (1.10 to 1.40), and high (>1.40 or incompressible). Multinomial logistic regression was used to evaluate the associations of CKD with ABI categories.

RESULTS: Among 4,513 participants, 23\% had CKD, 13\% had a low ABI, and 3\% had a high ABI. In models adjusted for age, sex, race, hypertension, diabetes, smoking, body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and C-reactive protein, cystatin C-based CKD was associated with both low ABI (relative risk [RR]: 2.0; 95\% confidence interval [CI]: 1.6 to 2.5; p <0.001) and high ABI (RR: 1.6; 95\% CI: 1.0 to 2.3; p = 0.03). Results were similar when CKD was defined by creatinine.

CONCLUSIONS: CKD is associated with both the high and the low extremes of ABI in community-living older people. Future studies should evaluate whether arterial stiffness is an important mechanism leading to CVD in people with CKD.

}, keywords = {Aged, Aged, 80 and over, Ankle Brachial Index, C-Reactive Protein, Cardiovascular Diseases, Chronic Disease, Cohort Studies, Cross-Sectional Studies, Female, Glomerular Filtration Rate, Humans, Kidney Diseases, Lipids, Male, Risk Factors}, issn = {1558-3597}, doi = {10.1016/j.jacc.2009.06.017}, author = {Ix, Joachim H and Katz, Ronit and de Boer, Ian H and Kestenbaum, Brian R and Allison, Matthew A and Siscovick, David S and Newman, Anne B and Sarnak, Mark J and Shlipak, Michael G and Criqui, Michael H} } @article {1131, title = {Obesity and change in estimated GFR among older adults.}, journal = {Am J Kidney Dis}, volume = {54}, year = {2009}, month = {2009 Dec}, pages = {1043-51}, abstract = {

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.

STUDY DESIGN: Cohort study.

SETTING \& PARTICIPANTS: 4,295 participants in the community-based Cardiovascular Health Study, aged >or= 65 years.

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

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

MEASUREMENTS: 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.

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

CONCLUSION: Obesity may be a modifiable risk factor for the development and progression of kidney disease in older adults.

}, keywords = {Aged, Aging, Body Composition, Body Mass Index, Chronic Disease, Cohort Studies, Creatinine, Cystatin C, Female, Glomerular Filtration Rate, Humans, Kidney, Kidney Diseases, Longitudinal Studies, Male, Obesity, Risk Factors}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2009.07.018}, author = {de Boer, Ian H and Katz, Ronit and Fried, Linda F and Ix, Joachim H and Luchsinger, Jose and Sarnak, Mark J and Shlipak, Michael G and Siscovick, David S and Kestenbaum, Bryan} } @article {1368, title = {Chronic kidney disease, insulin resistance, and incident diabetes in older adults.}, journal = {Clin J Am Soc Nephrol}, volume = {7}, year = {2012}, month = {2012 Apr}, pages = {588-94}, abstract = {

BACKGROUND AND OBJECTIVES: Insulin resistance is a complication of advanced CKD. Insulin resistance is less well characterized in earlier stages of CKD. The response of the pancreatic β cell, effects on glucose tolerance, and risk of diabetes are not clear.

DESIGN, SETTING, PARTICIPANTS, \& MEASUREMENTS: The Cardiovascular Health Study included 4680 adults without baseline diabetes. The Chronic Kidney Disease Epidemiology Collaboration creatinine equation was used to obtain the estimated GFR (eGFR). Insulin resistance was evaluated as fasting insulin concentration. The insulin sensitivity index, β cell function, and glucose tolerance were assessed by oral glucose tolerance testing. Incident diabetes was defined as fasting glucose >=126 mg/dl, nonfasting glucose >=200 mg/dl, or use of glucose-lowering medications.

RESULTS: Mean age was 72.5 years (range, 65-98 years). Mean eGFR was 72.2 (SD 17.1) ml/min per 1.73 m(2). After adjustment, each 10 ml/min per 1.73 m(2) lower eGFR was associated with a 2.2\% higher fasting insulin concentration (95\% confidence interval [CI], 1.4\%, 2.9\%; P<0.001) and a 1.1\% lower insulin sensitivity index (95\% CI, 0.03\%, 2.2\%; P=0.04). Surprisingly, eGFR was associated with an augmented β cell function index (P<0.001), lower 2-hour glucose concentration (P=0.002), and decreased risk of glucose intolerance (P=0.006). Over a median 12 years{\textquoteright} follow-up, 437 participants (9.3\%) developed diabetes. eGFR was not associated with the risk of incident diabetes.

CONCLUSIONS: Among older adults, lower eGFR was associated with insulin resistance. However, with lower eGFR, β cell function was appropriately augmented and risks of impaired glucose tolerance and incident diabetes were not increased.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Biomarkers, Chronic Disease, Creatinine, Diabetes Mellitus, Female, Glomerular Filtration Rate, Glucose Tolerance Test, Health Surveys, Humans, Hypoglycemic Agents, Incidence, Insulin, Insulin Resistance, Insulin-Secreting Cells, Kidney, Kidney Diseases, Linear Models, Male, Proportional Hazards Models, Risk Assessment, Risk Factors, United States}, issn = {1555-905X}, doi = {10.2215/CJN.11861111}, author = {Pham, Hien and Robinson-Cohen, Cassianne and Biggs, Mary L and Ix, Joachim H and Mukamal, Kenneth J and Fried, Linda F and Kestenbaum, Bryan and Siscovick, David S and de Boer, Ian H} }