@article {876, title = {Cystatin-C and inflammatory markers in the ambulatory elderly.}, journal = {Am J Med}, volume = {118}, year = {2005}, month = {2005 Dec}, pages = {1416}, abstract = {

PURPOSE: Inflammatory factors are elevated in persons with severe renal dysfunction, but their association across all levels of renal function is unclear. We compared cystatin-C, a novel marker of renal function, with creatinine and estimated glomerular filtration rate (eGFR) as predictors of C-reactive protein and fibrinogen levels.

METHODS: This study is a cross-sectional analysis to evaluate cystatin-C, creatinine, and eGFR as predictors of the inflammatory markers C-reactive protein and fibrinogen. Participants included 4637 ambulatory elderly patients from the Cardiovascular Health Study. Multivariate linear regression was used to determine the independent associations of each renal function measurement with the inflammatory marker outcomes.

RESULTS: After adjustment for confounding factors, cystatin-C was correlated with both C-reactive protein (coefficient = 0.13; 95\% confidence interval: 0.10-1.16, P <.0001) and fibrinogen levels (0.15; 0.13-0.18, P <.0001). Associations were larger than those for creatinine and C-reactive protein (0.05; 0.02-0.07, P = .003) or fibrinogen (0.07; 0.04-0.10, P <.0001). Adjusted levels of C-reactive protein increased incrementally across quintiles of cystatin-C, from a median of 2.2 mg/L in quintile 1 to 3.7 mg/L in quintile 5. In contrast, both C-reactive protein and fibrinogen had U-shaped associations with quintiles of creatinine and eGFR, because the inflammatory markers were equivalently elevated in quintiles 1 and 5.

CONCLUSIONS: The finding of a significant linear association of cystatin-C and inflammation markers suggests that even small reductions in renal function may be associated with adverse pathophysiologic consequences.

}, keywords = {Age Factors, Aged, Biomarkers, C-Reactive Protein, Cross-Sectional Studies, Cystatin C, Cystatins, Female, Fibrinogen, Glomerular Filtration Rate, Humans, Kidney Diseases, Male, Predictive Value of Tests, Sensitivity and Specificity}, issn = {1555-7162}, doi = {10.1016/j.amjmed.2005.07.060}, author = {Shlipak, Michael G and Katz, Ronit and Cushman, Mary and Sarnak, Mark J and Stehman-Breen, Catherine and Psaty, Bruce M and Siscovick, David and Tracy, Russell P and Newman, Anne and Fried, Linda} } @article {912, title = {Cystatin C and prognosis for cardiovascular and kidney outcomes in elderly persons without chronic kidney disease.}, journal = {Ann Intern Med}, volume = {145}, year = {2006}, month = {2006 Aug 15}, pages = {237-46}, abstract = {

BACKGROUND: Cystatin C is an alternative measure of kidney function that may have prognostic importance among elderly persons who do not meet standard criteria for chronic kidney disease (estimated glomerular filtration rate [GFR] > or =60 mL/min per 1.73 m2).

OBJECTIVE: To evaluate cystatin C as a prognostic biomarker for death, cardiovascular disease, and incident chronic kidney disease among elderly persons without chronic kidney disease.

DESIGN: Cohort study.

SETTING: The Cardiovascular Health Study, a population-based cohort recruited from 4 communities in the United States.

PARTICIPANTS: 4663 elderly persons.

MEASUREMENTS: Measures of kidney function were creatinine-based estimated GFR by using the Modification of Diet in Renal Disease equation and cystatin C concentration. Outcomes were death, cardiovascular death, noncardiovascular death, heart failure, stroke, myocardial infarction, and incident chronic kidney disease during follow-up (median, 9.3 years).

RESULTS: At baseline, 78\% of participants did not have chronic kidney disease (estimated GFR > or =60 mL/min per 1.73 m2) and mean cystatin C concentration, creatinine concentration, and estimated GFR were 1.0 mg/L, 79.6 micromol/L (0.9 mg/dL), and 83 mL/min per 1.73 m2, respectively. Cystatin C concentrations (per SD, 0.18 mg/L) had strong associations with death (hazard ratio, 1.33 [95\% CI, 1.25 to 1.40]), cardiovascular death (hazard ratio, 1.42 [CI, 1.30 to 1.54]), noncardiovascular death (hazard ratio, 1.26 [CI, 1.17 to 1.36]), incident heart failure (hazard ratio, 1.28 [CI, 1.17 to 1.40]), stroke (hazard ratio, 1.22 [CI, 1.08 to 1.38]), and myocardial infarction (hazard ratio, 1.20 [CI, 1.06 to 1.36]) among these participants. Serum creatinine concentrations had much weaker associations with each outcome and only predicted cardiovascular death. Participants without chronic kidney disease who had elevated cystatin C concentrations (> or =1.0 mg/L) had a 4-fold risk for progressing to chronic kidney disease after 4 years of follow-up compared with those with cystatin C concentrations less than 1.0 mg/L.

LIMITATIONS: Because this study did not directly measure GFR or albuminuria, the extent to which cystatin C may be influenced by nonrenal factors was not determined and participants with albuminuria might have been misclassified as having no kidney disease.

CONCLUSIONS: Among elderly persons without chronic kidney disease, cystatin C is a prognostic biomarker of risk for death, cardiovascular disease, and chronic kidney disease. In this setting, cystatin C seems to identify a "preclinical" state of kidney dysfunction that is not detected with serum creatinine or estimated GFR.

}, keywords = {Aged, Biomarkers, Cardiovascular Diseases, Creatinine, Cystatin C, Cystatins, Glomerular Filtration Rate, Humans, Kidney, Longitudinal Studies, Prognosis, Proportional Hazards Models, Renal Insufficiency, Chronic, Risk Factors}, issn = {1539-3704}, doi = {10.7326/0003-4819-145-4-200608150-00003}, author = {Shlipak, Michael G and Katz, Ronit and Sarnak, Mark J and Fried, Linda F and Newman, Anne B and Stehman-Breen, Catherine and Seliger, Stephen L and Kestenbaum, Brian and Psaty, Bruce and Tracy, Russell P and Siscovick, David S} } @article {1565, title = {Fatty acid-binding protein 4 and incident heart failure: the Cardiovascular Health Study.}, journal = {Eur J Heart Fail}, volume = {15}, year = {2013}, month = {2013 Apr}, pages = {394-9}, chapter = {394}, abstract = {

AIM: To examine the association of plasma fatty acid-binding protein 4 (FABP4) with incident heart failure.

METHODS AND RESULTS: In a prospective study of 4179 participants from the Cardiovascular Health Study, we measured plasma FABP4 on blood specimens collected between 1992 and 1993. Incident heart failure was adjudicated by an endpoint committee and we used a Cox proportional hazards model to calculate hazard ratios (HRs) of heart failure. The average age at baseline was 75 years. During a median follow-up of 10.7 years, 1182 cases of incident heart failure occurred. We observed a positive association between FABP4 and heart failure in the minimally adjusted models [HR 1.32, 95\% confidence interval (CI) 1.25-1.38 per 1 SD higher FABP4] that was attenuated upon adjustment for potential confounders, mostly kidney function and body mass index (corresponding HR 1.09, 95\% CI 1.01-1.17). In a subsample of heart failure cases with available data on LV systolic function, FABP4 was not associated with heart failure with or without preserved LV systolic function. Exclusion of people with unintentional weight loss and self-reported fair/poor health status did not alter the conclusion.

CONCLUSION: An elevated plasma concentration of FABP4 was associated with a modestly higher risk of heart failure in older adults in the USA after adjustment for confounding factors.

}, keywords = {Aged, Aged, 80 and over, Body Mass Index, Cohort Studies, Fatty Acid-Binding Proteins, Female, Follow-Up Studies, Glomerular Filtration Rate, Heart Failure, Humans, Male, Proportional Hazards Models, Prospective Studies, Risk Factors, United States, Ventricular Function, Left}, issn = {1879-0844}, doi = {10.1093/eurjhf/hfs196}, author = {Djouss{\'e}, Luc and Bartz, Traci M and Ix, Joachim H and Kochar, Jinesh and Kizer, Jorge R and Gottdiener, John S and Tracy, Russell P and Mozaffarian, Dariush and Siscovick, David S and Mukamal, Kenneth J and Zieman, Susan J} } @article {6576, title = {Advanced glycation/glycoxidation endproduct carboxymethyl-lysine and incidence of coronary heart disease and stroke in older adults.}, journal = {Atherosclerosis}, volume = {235}, year = {2014}, month = {2014 Jul}, pages = {116-21}, abstract = {

BACKGROUND: Advanced glycation/glycoxidation endproducts (AGEs) accumulate in settings of increased oxidative stress--such as diabetes, chronic kidney disease and aging--where they promote vascular stiffness and atherogenesis, but the prospective association between AGEs and cardiovascular events in elders has not been previously examined.

METHODS: To test the hypothesis that circulating levels of N(ɛ)-carboxymethyl-lysine (CML), a major AGE, increase the risk of incident coronary heart disease and stroke in older adults, we measured serum CML by immunoassay in 2111 individuals free of prevalent cardiovascular disease participating in a population-based study of U.S. adults ages 65 and older.

RESULTS: During median follow-up of 9.1 years, 625 cardiovascular events occurred. CML was positively associated with incident cardiovascular events after adjustment for age, sex, race, systolic blood pressure, anti-hypertensive treatment, diabetes, smoking status, triglycerides, albumin, and self-reported health status (hazard ratio [HR] per SD [0.99 pmol/l] increase=1.11, 95\% confidence interval [CI]=1.03-1.19). This association was not materially attenuated by additional adjustment for C-reactive protein, estimated glomerular filtration rate (eGFR), and urine albumin/creatinine ratio. Findings were similar for the component endpoints of coronary heart disease and stroke.

CONCLUSIONS: In this large older cohort, CML was associated with an increased risk of cardiovascular events independent of a wide array of potential confounders and mediators. Although the moderate association limits CML{\textquoteright}s value for risk prediction, these community-based findings provide support for clinical trials to test AGE-lowering therapies for cardiovascular prevention in this population.

}, keywords = {Aged, Albumins, Antihypertensive Agents, Blood Pressure, Cardiovascular Diseases, Cohort Studies, Coronary Disease, Creatinine, Female, Glomerular Filtration Rate, Glycation End Products, Advanced, Humans, Immunoassay, Incidence, Lysine, Male, Oxidative Stress, Proportional Hazards Models, Stroke, Treatment Outcome}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2014.04.013}, author = {Kizer, Jorge R and Benkeser, David and Arnold, Alice M and Ix, Joachim H and Mukamal, Kenneth J and Djouss{\'e}, Luc and Tracy, Russell P and Siscovick, David S and Psaty, Bruce M and Zieman, Susan J} } @article {6340, title = {Estimated GFR and circulating 24,25-dihydroxyvitamin D3 concentration: a participant-level analysis of 5 cohort studies and clinical trials.}, journal = {Am J Kidney Dis}, volume = {64}, year = {2014}, month = {2014 Aug}, pages = {187-97}, abstract = {

BACKGROUND: Decreased glomerular filtration rate (GFR) leads to reduced production of 1,25-dihydroxyvitamin D3 from 25-hydroxyvitamin D3 (25[OH]D3). Effects of low GFR on vitamin D catabolism are less well understood. We tested associations of estimated GFR (eGFR) with the circulating concentration of 24,25-dihydroxyvitamin D3 (24,25[OH]2D3), the most abundant product of 25(OH)D3 catabolism, across populations with a wide range of GFRs.

STUDY DESIGN: Cross-sectional study.

SETTING \& PARTICIPANTS: 9,596 participants in 5 cohort studies and clinical trials: the Diabetes Control and Complications Trial (N=1,193), Multi-Ethnic Study of Atherosclerosis (N=6,470), Cardiovascular Health Study (N=932), Seattle Kidney Study (N=289), and Hemodialysis Study (N=712).

PREDICTOR: eGFR.

OUTCOME: Circulating 24,25(OH)2D3 concentration.

MEASUREMENTS: GFR was estimated from serum creatinine using the Chronic Kidney Disease Epidemiology Collaboration equation. Vitamin D metabolites were measured by mass spectrometry.

RESULTS: Circulating 24,25(OH)2D3 concentration was correlated with circulating 25(OH)D3 concentration (Pearson r range, 0.64-0.88). This correlation was weaker with lower eGFRs. Moreover, the increment in 24,25(OH)2D3 concentration associated with higher 25(OH)D3 concentration (slope) was lower with lower eGFRs: 2.06 (95\% CI, 2.01-2.10), 1.77 (95\% CI, 1.74-1.81), 1.55 (95\% CI, 1.48-1.62), 1.17 (95\% CI, 1.05-1.29), 0.92 (95\% CI, 0.74-1.10), 0.61 (95\% CI, 0.22-1.00), and 0.37 (95\% CI, 0.35-0.39) ng/mL of 24,25(OH)2D3 per 10 ng/mL of 25(OH)D3 for eGFRs>=90, 60-89, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m2 and end-stage renal disease treated with hemodialysis, respectively. As a result, at a 25(OH)D3 concentration of 20 ng/mL, mean 24,25(OH)2D3 concentrations were 2.92 (95\% CI, 2.87-2.96), 2.68 (95\% CI, 2.64-2.72), 2.35 (95\% CI, 2.26-2.45), 1.92 (95\% CI, 1.74-2.10), 1.69 (95\% CI, 1.43-1.95), 1.14 (95\% CI, 0.62-1.66), and 1.04 (95\% CI,1.02-1.07) ng/mL for each category, respectively. This interaction was independent of other relevant clinical characteristics. Race, diabetes, urine albumin excretion, and circulating parathyroid hormone and fibroblast growth factor 23 concentrations more modestly modified the association of 24,25(OH)2D3 with 25(OH)D3.

LIMITATIONS: Lack of direct pharmacokinetic measurements of vitamin D catabolism.

CONCLUSIONS: Lower eGFR is associated strongly with reduced vitamin D catabolism, as measured by circulating 24,25(OH)2D3 concentration.

}, keywords = {24,25-Dihydroxyvitamin D 3, Adult, Aged, Aged, 80 and over, Biomarkers, Cohort Studies, Cross-Sectional Studies, Diabetes Mellitus, Female, Glomerular Filtration Rate, Humans, Kidney Failure, Chronic, Male, Middle Aged, Observational Studies as Topic, Randomized Controlled Trials as Topic, Young Adult}, issn = {1523-6838}, doi = {10.1053/j.ajkd.2014.02.015}, author = {de Boer, Ian H and Sachs, Michael C and Chonchol, Michel and Himmelfarb, Jonathan and Hoofnagle, Andrew N and Ix, Joachim H and Kremsdorf, Robin A and Lin, Yvonne S and Mehrotra, Rajnish and Robinson-Cohen, Cassianne and Siscovick, David S and Steffes, Michael W and Thummel, Kenneth E and Tracy, Russell P and Wang, Zhican and Kestenbaum, Bryan} } @article {8539, title = {Metabolic Clusters and Outcomes in Older Adults: The Cardiovascular Health Study.}, journal = {J Am Geriatr Soc}, volume = {66}, year = {2018}, month = {2018 02}, pages = {289-296}, abstract = {

BACKGROUND/OBJECTIVES: Few studies have the requisite phenotypic information to define metabolic patterns that may inform our understanding of the pathophysiology and consequences of diabetes in older adults. We sought to characterize clusters of older adults on the basis of shared metabolic features.

DESIGN: Population-based prospective cohort study.

SETTING: Four U.S. Cardiovascular Health Study field centers.

PARTICIPANTS: Individuals aged 65 and older taking no glucose-lowering agents (N~=~2,231).

MEASUREMENTS: K-means cluster analysis of 11 metabolic parameters (fasting and postload serum glucose and plasma insulin, fasting C-peptide, body mass index, C-reactive protein (CRP), estimated glomerular filtration rate (eGFR), albuminuria, carboxymethyl lysine (an advanced glycation end-product), procollagen III N-terminal propeptide (a fibrotic marker)) and their associations with incident cardiovascular disease, diabetes, disability, and mortality over 8 to 14.5~years of follow-up and with measures of subclinical cardiovascular disease.

RESULTS: A 6-cluster solution provided robust differentiation into distinct, identifiable clusters. Cluster A (n~=~739) had the lowest glucose and insulin and highest eGFR and the lowest rates of all outcomes. Cluster B (n~=~419) had high glucose and insulin and intermediate rates of most outcomes. Cluster C (n~=~118) had the highest insulin. Cluster D (n~=~129) had the highest glucose with much lower insulin. Cluster E (n~=~314) had the lowest eGFR and highest albuminuria. Cluster F (n~=~512) had the highest CRP. Rates of CVD, mortality, and subclinical atherosclerosis were highest in clusters C, D, and E and were similar to rates in participants with treated diabetes. Incidence of disability was highest in Cluster C.

CONCLUSION: Clustering according to metabolic parameters identifies distinct phenotypes that are strongly associated with clinical and functional outcomes, even at advanced age.

}, keywords = {Aged, Aged, 80 and over, Blood Glucose, C-Reactive Protein, Cardiovascular Diseases, Diabetes Mellitus, Female, Glomerular Filtration Rate, Humans, Incidence, Insulin, Longitudinal Studies, Male, Prospective Studies, Risk Factors, United States}, issn = {1532-5415}, doi = {10.1111/jgs.15205}, author = {Mukamal, Kenneth J and Siscovick, David S and de Boer, Ian H and Ix, Joachim H and Kizer, Jorge R and Djouss{\'e}, Luc and Fitzpatrick, Annette L and Tracy, Russell P and Boyko, Edward J and Kahn, Steven E and Arnold, Alice M} }