@article {1149, title = {Albuminuria, impaired kidney function and cardiovascular outcomes or mortality in the elderly.}, journal = {Nephrol Dial Transplant}, volume = {25}, year = {2010}, month = {2010 May}, pages = {1560-7}, abstract = {

BACKGROUND: Kidney disease is a risk factor for mortality and cardiovascular disease in older adults, but the separate and combined effects of albuminuria and cystatin C, a novel marker of glomerular filtration, are not known.

METHODS: We examined associations of these markers with mortality and cardiovascular outcomes during a median follow-up of 8.3 years in 3291 older adults in the Cardiovascular Health Study. Kidney disease was assessed using urinary albumin/creatinine ratio (ACR), cystatin C and Modification of Diet in Renal Disease estimated glomerular filtration rate (eGFR). We defined subgroups based on presence of microalbuminuria (MA, ACR > 30 mg/g) and categories of normal kidney function (cystatin C < 1.0 mg/L and eGFR > 60 mL/min/1.73 m(2)); preclinical kidney disease (cystatin C level > 1.0 mg/l but eGFR > 60 mL/min/1.73 m(2)); and chronic kidney disease (CKD) (eGFR < 60 mL/min/1.73 m(2)). Cox proportional hazards models were used to examine associations between these six subgroups and all-cause or cardiovascular mortality, myocardial infarction and heart failure.

RESULTS: One thousand one hundred fifty (34.9\%) had normal kidney function (12.2\% with MA), 1518 (46.1\%) had preclinical kidney disease (17.9\% with MA) and 622 (18.9\%) had CKD (47\% with MA). After adjustment, the presence of either preclinical kidney disease or MA was associated with an over 50\% increase in mortality risk; the presence of both was associated with a 2.4-fold mortality risk. Those with CKD and MA were at highest risk, with a nearly 4-fold mortality risk.

CONCLUSION: Elevated cystatin C and albuminuria are common, identify different subsets of the older population, and are independent, graded risk factors for cardiovascular disease and mortality.

}, keywords = {Aged, Albuminuria, Cardiovascular Diseases, Creatinine, Cystatin C, Female, Glomerular Filtration Rate, Heart Failure, Humans, Male, Myocardial Infarction, Risk Factors}, issn = {1460-2385}, doi = {10.1093/ndt/gfp646}, author = {Rifkin, Dena E and Katz, Ronit and Chonchol, Michel and Fried, Linda F and Cao, Jie and de Boer, Ian H and Siscovick, David S and Shlipak, Michael G and Sarnak, Mark J} } @article {1190, title = {Association between baseline kidney function and change in CRP: an analysis of the cardiovascular health study.}, journal = {Nephron Clin Pract}, volume = {115}, year = {2010}, month = {2010}, pages = {c114-21}, abstract = {

BACKGROUND: In cross-sectional analyses, C-reactive protein (CRP) levels are inversely related to levels of kidney function. The relationship between kidney function and subsequent changes in CRP is unknown.

METHODS: We studied 4,364 individuals from the Cardiovascular Health Study, a longitudinal cohort of community-dwelling older adults. Baseline eGFRcys was estimated using cystatin C. CRP was measured at baseline and after 3 and 7 years of follow-up; slopes of change in CRP were calculated.

RESULTS: The mean (SD) age of the cohort was 72 (5.2) years; mean (SD) eGFRcys was 78.9 (18.4) ml/min/1.73 m(2). The median (interquartile range IQR) baseline CRP was 2.39 (1.22, 4.33) mg/l; the median (IQR) yearly change in CRP was -0.0051 (-0.020 to 0.27) mg/l/year. After adjustment for demographic characteristics and the initial level of CRP, each standard deviation lower baseline eGFR was associated with a small and non-significant yearly increase in CRP (0.032 mg/l/year; 95\% CI: -0.005 to 0.070, p = 0.094).

CONCLUSIONS: We did not find a relationship between eGFR and subsequent changes in CRP. The association between kidney function and CRP in cross-sectional analyses may reflect unmeasured confounding by atherosclerosis; alternatively, the burden of comorbidity and interval mortality in this population may have masked a stronger longitudinal association between kidney function and change in CRP. Further study in younger populations may clarify whether impaired kidney function leads to change in inflammation over time.

}, keywords = {Aged, Biomarkers, C-Reactive Protein, Cardiovascular Diseases, Cohort Studies, Cross-Sectional Studies, Female, Follow-Up Studies, Glomerular Filtration Rate, Humans, Kidney Function Tests, Longitudinal Studies, Male, Residence Characteristics}, issn = {1660-2110}, doi = {10.1159/000312874}, author = {Rifkin, Dena E and Katz, Ronit and Fried, Linda F and Kestenbaum, Bryan and Jenny, Nancy Swords and Newman, Anne B and Siscovick, David S and Shlipak, Michael G and Sarnak, Mark J} } @article {5862, title = {Apolipoprotein E and kidney function in older adults.}, journal = {Clin Nephrol}, volume = {78}, year = {2012}, month = {2012 Sep}, pages = {174-80}, abstract = {

BACKGROUND: Previous studies suggest that the ε4 and ε2 alleles of apolipoprotein E (APOE) may be associated with decreased and increased risks of CKD, respectively, but there are limited data in older adults. We evaluated the associations of apolipoprotein E alleles with kidney function among older adults in the cardiovascular health study (CHS).

METHODS: Caucasian participants had APOE allelic analysis and serum creatinine and cystatin C measured at baseline (n = 3,844 for cross sectional analysis) and in follow up (n = 3,226 for longitudinal analysis). APOE variation was evaluated as an additive model with number of ε2, ε3 and ε4 alleles. GFR was estimated using the CKD epidemiology equation (eGFRcreat) and the cystatin C demographic equation (eGFRcys). The primary outcome was CKD defined by eGFR < 60 ml/min/1.73 m2. The secondary outcome was rapid progression defined by annual loss of eGFR > 3 ml/min/1.73 m2.

RESULTS: Mean eGFRcreat was 72 ml/min/1.73 m2 (25\% CKD). Compared with the ε3 allele, the APOE ε4 allele was associated with reduced risk of CKD by eGFRcreat: unadjusted odds ratio (OR) and 95\% confidence interval (CI) 0.79 (0.67 - 0.93) per allele, fully adjusted OR (95\% CI) 0.80 (0.68 - 0.96) per allele. Results were consistent using eGFRcys. There was no association of the ε2 allele with CKD or between the apolipoprotein E gene with rapid progression.

CONCLUSIONS: The apolipoprotein ε4 allele was associated with lower odds of CKD in elderly Caucasian individuals. Future research should confirm these findings in other races and explore mechanisms to explain these results.

}, keywords = {Aged, Aged, 80 and over, Alleles, Apolipoproteins E, Confidence Intervals, Creatinine, Cross-Sectional Studies, Cystatin C, Disease Progression, European Continental Ancestry Group, Female, Gene Frequency, Genotype, Glomerular Filtration Rate, Humans, Kidney, Male, Odds Ratio, Renal Insufficiency, Chronic, Risk Factors}, issn = {0301-0430}, author = {Seshasai, Rebecca Kurnik and Katz, Ronit and de Boer, Ian H and Siscovick, David and Shlipak, Michael G and Rifkin, Dena E and Sarnak, Mark J} }