@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 {1286, title = {Chronic kidney disease in octogenarians.}, journal = {Clin J Am Soc Nephrol}, volume = {6}, year = {2011}, month = {2011 Jun}, pages = {1410-7}, abstract = {

BACKGROUND AND OBJECTIVES: There are limited data on the prevalence of chronic kidney disease (CKD) and its clinical importance in the very old. We examined the prevalence of CKD in octogenarians and its association with cardiovascular disease (CVD).

DESIGN, SETTING, PARTICIPANTS, \& MEASUREMENTS: In a cross-sectional analysis of 1028 participants from the Cardiovascular Health Study All Stars, we evaluated association of prevalent CKD with CVD using multivariable logistic regression. CKD was defined as eGFR of <60 ml/min per 1.73 m(2). GFR was estimated using CKD-Epi creatinine and cystatin C equations that incorporate coefficients for age, gender, and race (eGFR(EPI), eGFR(CYS3var)) and the one-variable cystatin C equation (eGFR(CYS1var)). Prevalent CVD was defined as a composite of coronary heart disease, heart failure, and stroke.

RESULTS: Mean age was 86 years, 64\% were women, 86\% were Caucasians, 14\% had diabetes, and 39\% had prevalent CVD. Mean eGFR(EPI), eGFR(CYS3var), and eGFR(CYS1var) were 59, 62, and 70 ml/min per 1.73 m(2), and 51\%, 46\%, and 33\% had CKD, respectively. Associations of CKD with CVD varied by equation in adjusted analyses: CKD(EPI) (OR, 1.53; 95\% CI, 1.15 to 2.03), CKD(CYS3var) (OR, 1.67; 95\% CI, 1.25, 2.23), and CKD(CYS1var) (OR, 2.09; 95\% CI, 1.55, 2.83).

CONCLUSIONS: Reduced eGFR is highly prevalent in octogenarians, and the eGFR(CYS1var) equation yielded the lowest prevalence of CKD but the strongest association with prevalent CVD. Because there are no validated estimating equations in the elderly, estimation of kidney function on the basis of on any one equation should be interpreted with caution.

}, keywords = {Age Factors, Aged, 80 and over, Analysis of Variance, Biomarkers, Cardiovascular Diseases, Chi-Square Distribution, Chronic Disease, Creatinine, Cross-Sectional Studies, Cystatin C, Diabetes Mellitus, Female, Glomerular Filtration Rate, Humans, Kidney, Kidney Diseases, Logistic Models, Male, Models, Biological, Prevalence, Risk Assessment, Risk Factors, United States}, issn = {1555-905X}, doi = {10.2215/CJN.08801010}, author = {Shastri, Shani and Tighiouart, Hocine and Katz, Ronit and Rifkin, Dena E and Fried, Linda F and Shlipak, Michael G and Newman, Anne B and Sarnak, Mark J} } @article {1395, title = {Kidney function and mortality in octogenarians: Cardiovascular Health Study All Stars.}, journal = {J Am Geriatr Soc}, volume = {60}, year = {2012}, month = {2012 Jul}, pages = {1201-7}, abstract = {

OBJECTIVES: To examine the association between kidney function and all-cause mortality in octogenarians.

DESIGN: Retrospective analysis of prospectively collected data.

SETTING: Community.

PARTICIPANTS: Serum creatinine and cystatin C were measured in 1,053 Cardiovascular Health Study (CHS) All Stars participants.

MEASUREMENTS: Estimated glomerular filtration rate (eGFR) was determined using the Chronic Kidney Disease Epidemiology Collaboration creatinine (eGFR(CR) ) and cystatin C one-variable (eGFR(CYS) ) equations. The association between quintiles of kidney function and all-cause mortality was analyzed using unadjusted and adjusted Cox proportional hazards models.

RESULTS: Mean age of the participants was 85, 64\% were female, 66\% had hypertension, 14\% had diabetes mellitus, and 39\% had prevalent cardiovascular disease. There were 154 deaths over a median follow-up of 2.6 years. The association between eGFR(CR) and all-cause mortality was U-shaped. In comparison with the reference quintile (64-75 mL/min per 1.73 m(2) ), the highest (>= 75 mL/min per 1.73 m(2) ) and lowest (<= 43 mL/min per 1.73 m(2) ) quintiles of eGFR(CR) were independently associated with mortality (hazard ratio (HR) = 2.49, 95\% confidence interval (CI) = 1.36-4.55; HR = 2.28, 95\% CI = 1.26-4.10, respectively). The association between eGFR(CYS) and all-cause mortality was linear in those with eGFR(CYS) of less than 60 mL/min per 1.73 m(2) , and in the multivariate analyses, the lowest quintile of eGFR(CYS) (<52 mL/min per 1.73 m(2) ) was significantly associated with mortality (HR = 2.04, 95\% CI = 1.12-3.71) compared with the highest quintile (>0.88 mL/min per 1.73 m(2) ).

CONCLUSION: Moderate reduction in kidney function is a risk factor for all-cause mortality in octogenarians. The association between eGFR(CR) and all-cause mortality differed from that observed with eGFR(CYS) ; the relationship was U-shaped for eGFR(CR) , whereas the risk was primarily present in the lowest quintile for eGFR(CYS) .

}, keywords = {Aged, 80 and over, Analysis of Variance, Cardiovascular Diseases, Chi-Square Distribution, Creatinine, Cystatin C, Diabetes Mellitus, Female, Glomerular Filtration Rate, Humans, Hypertension, Kidney Diseases, Male, Prevalence, Proportional Hazards Models, Retrospective Studies, Risk Factors, United States}, issn = {1532-5415}, doi = {10.1111/j.1532-5415.2012.04046.x}, author = {Shastri, Shani and Katz, Ronit and Rifkin, Dena E and Fried, Linda F and Odden, Michelle C and Peralta, Carmen A and Chonchol, Michel and Siscovick, David and Shlipak, Michael G and Newman, Anne B and Sarnak, Mark J} }