@article {975, title = {Kidney function, electrocardiographic findings, and cardiovascular events among older adults.}, journal = {Clin J Am Soc Nephrol}, volume = {2}, year = {2007}, month = {2007 May}, pages = {501-8}, abstract = {

Chronic kidney disease (CKD) is associated with cardiovascular (CV) disease and mortality. It is not known whether cardiac rhythm disturbances are more prevalent among individuals with CKD or whether resting electrocardiogram findings predict future CV events in the CKD setting. Data were obtained from the Cardiovascular Health Study, a community-based study of adults aged >/=65 yr. After exclusions for prevalent heart disease, atrial fibrillation, implantable pacemaker, or antiarrhythmic medication use, 3238 participants were analyzed. CKD was defined by an estimated GFR <60 ml/min per 1.73 m(2). Outcomes were adjudicated incident heart failure (HF), incident coronary heart disease (CHD), and mortality. Participants with CKD had longer PR and corrected QT intervals compared with those without CKD; however, differences in electrocardiographic markers were explained by traditional CV risk factors and CV medication use. After adjustment for known risk factors, each 10-ms increase in the QRS interval was associated with a 15\% greater risk for incident HF (95\% confidence interval [CI] 1.04 to 1.27), a 13\% greater risk for CHD (95\% CI 1.04 to 1.24), and a 17\% greater risk for mortality (95\% CI 1.09, 1.25) among CKD participants. Each 5\% increase in QTI was associated with a 42\% (95\% CI 1.23 to 1.65), 22\% (95\% CI 1.07 to 1.40), and 10\% (95\% CI 0.98 to 1.22) greater risk for HF, CHD, and mortality, respectively. Associations seemed stronger for participants with CKD; however, no significant interactions were detected. Resting electrocardiographic abnormalities are common in CKD and independently predict future clinical CV events in this setting.

}, keywords = {Aged, Aged, 80 and over, Cardiac Output, Low, Cardiovascular Diseases, Chronic Disease, Coronary Disease, Electrocardiography, Female, Humans, Kidney, Kidney Diseases, Male, Risk Assessment}, issn = {1555-905X}, doi = {10.2215/CJN.04231206}, author = {Kestenbaum, Bryan and Rudser, Kyle D and Shlipak, Michael G and Fried, Linda F and Newman, Anne B and Katz, Ronit and Sarnak, Mark J and Seliger, Stephen and Stehman-Breen, Catherine and Prineas, Ronald and Siscovick, David S} } @article {972, title = {Relationship of uric acid with progression of kidney disease.}, journal = {Am J Kidney Dis}, volume = {50}, year = {2007}, month = {2007 Aug}, pages = {239-47}, abstract = {

BACKGROUND: Uric acid levels are increased in patients with kidney dysfunction. We tested the hypothesis that uric acid may be associated with kidney disease progression.

STUDY DESIGN: Cohort study.

SETTING \& PARTICIPANTS: 5,808 participants of the Cardiovascular Health Study.

PREDICTOR: Uric acid levels.

OUTCOMES \& MEASUREMENTS: Kidney disease progression was defined as a decrease in estimated glomerular filtration rate (GFR) of 3 mL/min/1.73 m(2) per year or greater (>or=0.05 mL/s) and as incident chronic kidney disease (CKD). Measures of kidney function were estimated GFR using the Modification of Diet in Renal Disease Study equation.

RESULTS: Higher quintiles of uric acid levels were associated with greater prevalences of estimated GFR less than 60 mL/min/1.73 m(2) (<1.00 mL/s) of 7\%, 14\%, 12\%, 25\%, and 42\% for quintiles 1 (6.90 mg/dL [>410 micromol/L]), respectively. In comparison, there was only a modest, but significant, association between quintiles of uric acid levels and progression of kidney function decrease, with adjusted odds ratios of 1.0, 0.88 (95\% confidence interval [CI], 0.64 to 1.21), 1.23 (95\% CI, 0.87 to 1.75), 1.47 (95\% CI, 1.04 to 2.07), and 1.49 (95\% CI, 1.00 to 2.22) for quintiles 1 through 5, respectively. No significant association was found between uric acid level and incident CKD (adjusted odds ratio, 1.00; 95\% CI, 0.89 to 1.14).

LIMITATIONS: Measurements of albuminuria were not available.

CONCLUSIONS: Uric acid levels are associated strongly with prevalent CKD. In comparison, greater uric acid levels had a significant, but much weaker, association with progression of kidney disease.

}, keywords = {Aged, Aged, 80 and over, Cohort Studies, Cross-Sectional Studies, Disease Progression, Female, Glomerular Filtration Rate, Humans, Kidney Diseases, Male, Prospective Studies, Uric Acid}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2007.05.013}, author = {Chonchol, Michel and Shlipak, Michael G and Katz, Ronit and Sarnak, Mark J and Newman, Anne B and Siscovick, David S and Kestenbaum, Bryan and Carney, Jan Kirk and Fried, Linda F} } @article {1056, title = {Association of renal function with cardiac calcifications in older adults: the cardiovascular health study.}, journal = {Nephrol Dial Transplant}, volume = {24}, year = {2009}, month = {2009 Mar}, pages = {834-40}, abstract = {

BACKGROUND: Aortic valve sclerosis (AVS) and mitral annulus calcification (MAC) are highly prevalent in patients with end-stage renal disease. It is less well established whether milder kidney disease is associated with cardiac calcifications. We evaluated the relationships between renal function and MAC, aortic annular calcification (AAC) and AVS in the elderly.

METHODS: From the Cardiovascular Health Study, a community-based cohort of ambulatory adults >or= age 65, a total of 3929 individuals (mean +/- SD age 74 +/- 5 years, 60\% women) were evaluated with two-dimensional echocardiography. Renal function was assessed by means of creatinine-based estimated glomerular filtration rate (eGFR) and cystatin C.

RESULTS: The prevalences of MAC and AAC were significantly higher in individuals with an eGFR < 45 mL/ min/1.73 m(2) (P < 0.01 for each), and cystatin C levels were significantly higher in individuals with MAC or AAC compared to individuals without these cardiac calcifications (P < 0.001 for each). After multivariate-adjustment, an eGFR <45 mL/min/1.73 m(2) was significantly associated with MAC [odds ratio 1.54 (95\% CI 1.16-2.06), P = 0.003] and not associated with AAC [1.30 (0.97-1.74), P = 0.085] and AVS [1.15 (0.86-1.53), P = 0.355]. In addition, cystatin C levels were independently associated with MAC [odds ratio per SD 1.12 (1.05-1.21), P = 0.001] and not associated with AAC [1.07 (1.00-1.15), P = 0.054] and AVS [0.99 (0.93-1.06), P = 0.82]. Furthermore, the prevalence of multiple cardiac calcifications was higher in subjects with an eGFR < 45 mL/ min/1.73 m(2) and increased per quartile of cystatin C (P-values < 0.001). In addition, a significant trend was observed between an eGFR < 45 mL/min/1.73 m(2), increasing levels of cystatin C and the number of cardiac calcifications (P < 0.05).

CONCLUSIONS: In a community-based cohort of the elderly, moderate kidney disease as defined by an eGFR <45 mL/min/1.73m(2) and elevated levels of cystatin C was associated with prevalent MAC. In addition, a significant trend was observed between an eGFR <45 mL/min/1.73m(2), increasing levels of cystatin C and the number of cardiac calcifications. No associations were found between renal function and AAC or AVS.

}, keywords = {Aged, Aortic Valve, Calcinosis, Case-Control Studies, Cohort Studies, Creatinine, Cystatin C, Female, Glomerular Filtration Rate, Heart Valve Diseases, Humans, Kidney Diseases, Male, Mitral Valve, Risk Factors}, issn = {1460-2385}, doi = {10.1093/ndt/gfn544}, author = {Asselbergs, Folkert W and Mozaffarian, Dariush and Katz, Ronit and Kestenbaum, Bryan and Fried, Linda F and Gottdiener, John S and Shlipak, Michael G and Siscovick, David S} } @article {1057, title = {Clinical and subclinical cardiovascular disease and kidney function decline in the elderly.}, journal = {Atherosclerosis}, volume = {204}, year = {2009}, month = {2009 May}, pages = {298-303}, abstract = {

OBJECTIVE: Kidney function decline in elderly persons may be the result of microvascular atherosclerosis. As a proxy for the renovascular system, we evaluated the association of clinical and subclinical cardiovascular disease (CVD) with kidney function decline.

METHODS: This study included 4380 subjects from the Cardiovascular Health Study, a longitudinal, community-based cohort of persons aged >or=65 from 4 U.S. communities. Creatinine and cystatin C were measured at baseline, year 3, and year 7; eligible subjects had at least two measures. Creatinine-based estimated glomerular filtration rate (eGFR(creat)) was calculated using the MDRD equation. Rapid kidney function decline was defined as an annual eGFR loss >3 mL/min/1.73 m(2). Predictors of rapid kidney decline included prevalent and subclinical measures of CVD.

RESULTS: Mean decline in eGFR(creat) was 0.4+/-2.6/year; 714 (16\%) had rapid progression. In multivariate models adjusted for demographics, cardiovascular risk factors, and inflammation, prevalent stroke (OR, 95\% CI: 1.55, 1.16-2.08) and heart failure (OR, 95\% CI: 1.80, 1.40-2.31) were independent predictors of rapid kidney decline. Among persons without clinical CV, the subclinical disease measures ankle-arm index <0.9 (OR, 95\% CI: 1.67, 1.25-2.24), common carotid intima-media thickness (>or=1.14 mm) (OR, 95\% CI: 1.52, 1.12-2.06) and internal carotid intima-media thickness (>1.82 mm) (OR, 95\% CI: 1.50, 1.12-2.02) had independent associations with rapid kidney function decline. Results were similar using cystatin C.

CONCLUSION: Clinical atherosclerosis and heart failure and subclinical measures of CVD have independent associations with kidney function decline progression in the elderly, suggesting an underlying role of renal atherosclerosis.

}, keywords = {Age Factors, Aged, Atherosclerosis, Cardiovascular Diseases, Creatinine, Cystatin C, Female, Glomerular Filtration Rate, Heart Failure, Humans, Kidney, Kidney Diseases, Linear Models, Longitudinal Studies, Male, Odds Ratio, Risk Assessment, Risk Factors, Time Factors, United States}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2008.08.016}, author = {Shlipak, Michael G and Katz, Ronit and Kestenbaum, Bryan and Fried, Linda F and Siscovick, David and Sarnak, Mark J} } @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 {1089, title = {Rate of kidney function decline in older adults: a comparison using creatinine and cystatin C.}, journal = {Am J Nephrol}, volume = {30}, year = {2009}, month = {2009}, pages = {171-8}, abstract = {

BACKGROUND/AIMS: The aim of this study was to determine the decline in the estimated glomerular filtration rate (eGFR) in elderly persons and to compare estimates based on creatinine and cystatin C.

METHODS: In the Cardiovascular Health Study, GFR changes in an elderly cohort were estimated from serum creatinine and cystatin C measured at baseline, year 3 and year 7 in 4,380 participants (age 72 +/- 5 years at entry). Outcomes were mean eGFR decline, incident chronic kidney disease (CKD) and rapid decline in eGFR (annual loss >3 ml/min/1.73 m(2)).

RESULTS: Mean annual eGFR loss as estimated from creatinine was 0.4 +/- 3.6 ml/min/1.73 m(2), with 16\% of the participants experiencing a rapid decline. Mean eGFR loss as estimated from cystatin C was 1.8 +/- 2.6, with 25\% of the participants experiencing a rapid decline (p < 0.001 for both). Among participants without baseline CKD, incident CKD was detected at year 7 in 10\% (n = 263) using creatinine and 19\% (n = 544) using cystatin C (p < 0.001). Increasing age was the strongest predictor of rapid decline; adjusted odds ratios were 1.38 (1.16-1.65), 1.62 (1.31-1.99) and 2.96 (2.28-3.84) for participants aged 70-74, 75-79 and 80+ at baseline, compared with those aged 65-69.

CONCLUSION: In elderly persons, cystatin C estimated substantially larger declines in kidney function than creatinine did. Defining the optimal measurement of kidney function in elderly persons should be a high priority for future research.

}, keywords = {Age Factors, Aged, Creatinine, Cystatin C, Disease Progression, Female, Glomerular Filtration Rate, Humans, Kidney, Kidney Diseases, Male, Risk Factors}, issn = {1421-9670}, doi = {10.1159/000212381}, author = {Shlipak, Michael G and Katz, Ronit and Kestenbaum, Bryan and Fried, Linda F and Newman, Anne B and Siscovick, David S and Stevens, Lesley and Sarnak, Mark J} } @article {1186, title = {Alcohol consumption and kidney function decline in the elderly: alcohol and kidney disease.}, journal = {Nephrol Dial Transplant}, volume = {25}, year = {2010}, month = {2010 Oct}, pages = {3301-7}, abstract = {

BACKGROUND: Alcohol consumption appears to be protective for cardiovascular disease; however, its relationship with kidney disease is unclear.

METHODS: This prospective cohort study included 4343 subjects from the Cardiovascular Health Study, a longitudinal, community-based cohort of persons aged >=65 from four US communities. We used previously defined categories based on weekly alcohol consumption: none, former, <1 drink, 1-6 drinks, 7-13 drinks and >=14 drinks. Cystatin C was measured at baseline, year 3 and year 7; eligible subjects had at least two measures. Estimated GFR(cys) was calculated from cystatin C. The primary outcome was rapid kidney function as an annual estimated GFR (eGFR(cys)) loss >3 mL/min/1.73 m(2)/year.

RESULTS: Eight percent of the cohort reported former alcohol use and 52\% reported current alcohol consumption. During a mean follow-up of 5.6 years, 1075 (25\%) participants had rapid kidney function decline. In adjusted logistic regression models, there was no association between alcohol use and kidney function decline (odds ratio, 95\% confidence interval: none = reference; former = 1.18, 0.89-1.56; <1 drink = 1.20, 0.99-1.47; 1-6 = 1.18, 0.95-1.45; 7-13 = 1.10, 0.80-1.53; >14 = 0.89, 0.61-1.13). Results were similar with kidney function decline as a continuous outcome.

CONCLUSIONS: Our results suggest that moderate alcohol consumption has neither adverse nor beneficial effects on kidney function. Although clinicians will need to consider the potential deleterious effects associated with alcohol consumption, there does not appear to be a basis for recommending that older adults discontinue or initiate light to moderate alcohol consumption to protect against kidney disease.

}, keywords = {Aged, Aging, Alcohol Drinking, Cohort Studies, Cystatin C, Female, Glomerular Filtration Rate, Humans, Kidney, Kidney Diseases, Male, Prospective Studies}, issn = {1460-2385}, doi = {10.1093/ndt/gfq188}, author = {Menon, Vandana and Katz, Ronit and Mukamal, Kenneth and Kestenbaum, Bryan and de Boer, Ian H and Siscovick, David S and Sarnak, Mark J and Shlipak, Michael G} } @article {1177, title = {Cystatin C and sudden cardiac death risk in the elderly.}, journal = {Circ Cardiovasc Qual Outcomes}, volume = {3}, year = {2010}, month = {2010 Mar}, pages = {159-64}, abstract = {

BACKGROUND: Recent studies have demonstrated an association between moderate kidney dysfunction and sudden cardiac death in people with cardiovascular disease.

METHODS AND RESULTS: The study was a longitudinal analysis among 4465 participants from the Cardiovascular Health Study without prevalent cardiovascular disease at baseline. Cystatin C and creatinine were measured from baseline sera. Sudden cardiac death (SCD) was defined as a sudden pulseless condition from a cardiac origin in a previously stable individual that occurred out of the hospital or in the emergency room. The association between cystatin C tertiles and SCD was determined with multivariate Cox proportional hazards. A similar analysis compared SCD incidence across creatinine-based estimated glomerular filtration rate (eGFR) tertiles. Over a median follow-up of 11.2 years, 91 adjudicated SCD events occurred. The annual incidence of SCD events increased across cystatin C tertiles: 10 events per 10 000 person years in tertile 1, 25 events per 10 000 person years in tertile 2, and 32 events per 10 000 person-years in the highest cystatin C tertile. These associations persisted after multivariate adjustment: hazards ratio=2.72; 95\% confidence interval, 1.44 to 5.16 in tertile 2 and hazards ratio=2.67; 95\% confidence interval, 1.33 to 5.35 in tertile 3. After multivariate adjustment, the rate of SCD also increased in a linear distribution across creatinine-based eGFR tertiles: 15 events per 10 000 person-years in tertile 1, 22 events per 10 000 person-years in tertile 2, and 27 events per 10 000 person-years in tertile 3. No significant associations, however, remained between creatinine-based eGFR and SCD after multivariable adjustment.

CONCLUSIONS: Impaired kidney function, as measured by cystatin C, has an independent association with SCD risk among elderly persons without clinical cardiovascular disease.

}, keywords = {Age Factors, Aged, Biomarkers, Chi-Square Distribution, Creatinine, Cystatin C, Death, Sudden, Cardiac, Female, Glomerular Filtration Rate, Humans, Incidence, Kidney Diseases, Longitudinal Studies, Male, Proportional Hazards Models, Risk Assessment, Risk Factors, Time Factors, United States, Up-Regulation}, issn = {1941-7705}, doi = {10.1161/CIRCOUTCOMES.109.875369}, author = {Deo, Rajat and Sotoodehnia, Nona and Katz, Ronit and Sarnak, Mark J and Fried, Linda F and Chonchol, Michel and Kestenbaum, Bryan and Psaty, Bruce M and Siscovick, David S and Shlipak, Michael G} } @article {1166, title = {Impaired kidney function and atrial fibrillation in elderly subjects.}, journal = {J Card Fail}, volume = {16}, year = {2010}, month = {2010 Jan}, pages = {55-60}, abstract = {

BACKGROUND: Impaired kidney function is associated with increased risk for cardiovascular events. We evaluated whether kidney function is associated with atrial fibrillation (AF) risk in elderly persons.

METHODS AND RESULTS: Subjects were participants in the Cardiovascular Health Study (CHS), a population-based cohort of ambulatory elderly. Measures of kidney function were cystatin C and creatinine-based estimated glomerular filtration rate (eGFR). Among the 4663 participants, 342 (7\%) had AF at baseline and 579 (13\%) developed incident AF during follow-up (mean 7.4 years). In unadjusted analyses, cystatin C quartiles were strongly associated with prevalent AF with a nearly 3-fold odds in the highest quartile compared with the lowest (HR=1.19, 95\% CI [0.80-1.76] in quartile 2; HR=2.00, 95\% CI [1.38-2.88] in quartile 3; and HR=2.87, 95\% CI [2.03-4.07] in quartile 4). This increased risk for prevalent AF remained significant after multivariate adjustment. The risk for incident AF increased across cystatin C quartiles in the unadjusted analysis (HR=1.37, 95\% CI [1.07-1.75] in quartile 2; HR=1.43, 95\% CI [1.11-1.84] in quartile 3; and HR=1.88, 95\% CI [1.47-2.41] in quartile 4); however, after multivariate adjustment, these findings were no longer significant. An estimated GFR <60 mL.min.1.73m(2) was associated with prevalent and incident AF in unadjusted, but not multivariate analyses.

CONCLUSIONS: Impaired kidney function, as measured by cystatin C, is an independent marker of prevalent AF; however, neither cystatin C nor eGFR are predictors of incident AF.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Atrial Fibrillation, Cohort Studies, Cross-Sectional Studies, Female, Follow-Up Studies, Glomerular Filtration Rate, Humans, Kidney Diseases, Kidney Function Tests, Male}, issn = {1532-8414}, doi = {10.1016/j.cardfail.2009.07.002}, author = {Deo, Rajat and Katz, Ronit and Kestenbaum, Bryan and Fried, Linda and Sarnak, Mark J and Psaty, Bruce M and Siscovick, David S and Shlipak, Michael G} } @article {1349, title = {Kidney function decline in the elderly: impact of lipoprotein-associated phospholipase A(2).}, journal = {Am J Nephrol}, volume = {34}, year = {2011}, month = {2011}, pages = {512-8}, abstract = {

BACKGROUND: Whether lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) levels are associated with kidney function decline has not been well studied.

METHODS: We investigated associations of Lp-PLA(2) antigen and activity with kidney function decline and rapid decline over 5.7 years in the Cardiovascular Health Study (n = 4,359). We estimated kidney function by cystatin C (eGFRcys) in repeated measures, and defined rapid decline as >=3 ml/min/1.73 m(2) per year. We stratified by baseline preserved GFR (>=60 ml/min/1.73 m(2)).

RESULTS: Mean age was 72 {\textpm} 5 years. Average eGFRcys decline was -1.79 ml/min/1.73 m(2) (SD = 2.60) per year. Among persons with preserved GFR, compared to the lowest quartile of Lp-PLA(2) antigen, eGFRcys decline was faster among persons in the second, β -0.31 (95\% CI -0.52, -0.10), third -0.19 (-0.41, 0.02) and fourth quartiles -0.26 (-0.48, -0.04) after full adjustment. Persons in the highest quartile of Lp-PLA(2) antigen had increased odds of rapid decline 1.34 (1.03, 1.75), compared to the lowest. There was no significant association between levels of Lp-PLA(2) activity and eGFRcys decline or rapid decline. Associations were not statistically significant among persons with low eGFR (<60 ml/min/1.73 m(2)) at baseline.

CONCLUSION: Higher levels of Lp-PLA(2) antigen but not activity were significantly associated with faster rates of kidney function decline. These findings may suggest a novel vascular pathway for kidney disease progression.

}, keywords = {Aged, Cardiovascular Diseases, Creatinine, Cystatin C, Disease Progression, Female, Geriatrics, Glomerular Filtration Rate, Humans, Kidney, Kidney Diseases, Male, Middle Aged, Phospholipases A2, Risk Factors, Treatment Outcome}, issn = {1421-9670}, doi = {10.1159/000333045}, author = {Peralta, Carmen A and Katz, Ronit and Shlipak, Michael and Dubin, Ruth and DeBoer, Ian and Jenny, Nancy and Fitzpatrick, Annette and Koro, Carol and Kestenbaum, Bryan and Ix, Joachim and Sarnak, Mark and Cushman, Mary} } @article {1312, title = {Serum 25-hydroxyvitamin D and change in estimated glomerular filtration rate.}, journal = {Clin J Am Soc Nephrol}, volume = {6}, year = {2011}, month = {2011 Sep}, pages = {2141-9}, abstract = {

BACKGROUND AND OBJECTIVES: Mounting evidence suggests that 1,25-dihydroxyvitamin D prevents the progression of chronic kidney disease (CKD). It is not clear whether "nutritional" forms of vitamin D affect GFR.

DESIGN, SETTING, PARTICIPANTS, \& MEASUREMENTS: We tested whether serum 25-hydroxyvitamin D concentration (25(OH)D), a measure of total vitamin D intake from cutaneous synthesis and dietary consumption, is associated with loss of estimated GFR among 1705 older adults with predominantly normal baseline kidney function participating in the Cardiovascular Health Study. Baseline 25(OH)D was measured by HPLC-tandem mass spectrometry. GFR was estimated at baseline and 4 years later using the CKD-EPI formula, with rapid GFR loss defined as 12 ml/min per 1.73 m(2) or more over 4 years.

RESULTS: Rapid GFR loss was observed for 207 participants (12\%). Each 10 ng/ml lower 25(OH)D was associated with a 25\% greater risk of rapid GFR loss (95\% confidence interval [CI] 5\%, 49\%, P = 0.01), adjusting for potential confounding characteristics. Compared with 25(OH)D >=30 ng/ml, 25(OH)D concentrations 15 to 29 ng/ml and <15 ng/ml were associated with 29\% (95\% CI -13\%, 91\%) and 68\% (95\% CI 1\%, 177\%) greater adjusted risks of rapid GFR loss, respectively. Magnitudes of association were largest among participants with diabetes.

RESULTS: were similar evaluating a composite outcome of rapid GFR loss, end stage renal disease, and death. Conclusions Insufficient 25(OH)D may be a modifiable risk factor for early GFR loss. We recommend clinical trials to determine whether vitamin D supplementation prevents the development and progression of CKD.

}, keywords = {Aged, Female, Glomerular Filtration Rate, Humans, Kidney Diseases, Male, Prospective Studies, Vitamin D}, issn = {1555-905X}, doi = {10.2215/CJN.02640311}, author = {de Boer, Ian H and Katz, Ronit and Chonchol, Michel and Ix, Joachim H 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} }