Biomedical subjects

Linda F Fried

Publications and source records attributed to Linda F Fried.

At least 19 recordsLinked to original sources

PubMed2006

Association of kidney function with incident hip fracture in older adults.

Kidney dysfunction is associated with bone loss, and patients with ESRD have an increased risk for hip fracture. However, the association of mild to moderate kidney disease with hip fracture has not been studied previously. The association of kidney function with incident hip fracture was examined among participants in the Cardiovascular Health Study, a community-based cohort of older individuals. The primary measure of kidney function was serum cystatin C, a measure that does not depend on lean mass. Hip fractures were identified using International Classification of Diseases, Ninth Revision codes for hospitalizations. A total of 4699 individuals had cystatin C measured in 1992 to 1993 and did not have a hip fracture before cystatin C measurement. The association of kidney function with hip fracture was analyzed with Cox proportional hazards models. Analyses were conducted separately for men and women. After a mean follow-up of 7.1 yr, 195 incident hip fractures occurred in women and 79 occurred in men. Higher cystatin C levels were associated with a higher risk for fracture in women (hazard ratio [HR] 1.26; 95% confidence interval [CI] 1.14 to 1.38 per SD) and in men (HR 1.27; 95% CI 1.11 to 1.46). After multivariable adjustment, higher cystatin C levels were significantly associated with hip fracture in women (HR 1.16; 95% CI 1.01, 1.33) but not in men (HR 1.14; 95% CI 0.86 to 1.52), although the magnitude of the association was similar. Kidney dysfunction, as assessed by cystatin C, is associated with an increased risk for hip fracture. Further studies are needed to evaluate potential mediators of this relationship and to assess whether interventions can decrease this risk.

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PubMed2006

Cystatin C and measures of physical function in elderly adults: the Health, Aging, and Body Composition (HABC) Study.

Most studies of the relation between kidney function and physical function have been conducted in persons with advanced kidney disease and have used creatinine-based measures of kidney function. Cystatin C concentration is a measure of kidney function that is independent of muscle mass, unlike creatinine. Using baseline data on 3,043 elderly adults from the Health, Aging, and Body Composition Study (Blacks and Whites recruited from Pittsburgh, Pennsylvania, and Memphis, Tennessee, in 1997-1998), the authors examined the cross-sectional association between cystatin C level and performance on several tests of physical function. After adjustment for demographic and lifestyle variables, chronic health conditions, and inflammation, each standard-deviation (0.34 mg/liter) increase in cystatin C concentration was associated with 1.32 odds (95% confidence interval (CI): 1.20, 1.46) of not completing a 400-m walk, a 10.9-second (95% CI: 8.1, 13.8) slower 400-m walk time, a 0.11-point (95% CI: 0.09, 0.13) reduction in lower extremity performance score, a 1.12-kg (95% CI: 0.83, 1.40) lower grip strength, and a 4.7-nm (95% CI: 3.5, 5.9) lower knee extension strength. In contrast, when kidney function was measured by estimated glomerular filtration rate, the association of kidney function with physical function was only evident below 60 ml/minute/1.73 m2. In these older adults, mild decrements in kidney function, as measured by cystatin C concentration, were associated with poorer physical function.

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PubMed2006

Associations of race with depression and symptoms in patients on maintenance haemodialysis.

BACKGROUND: Although studies have shown that African American haemodialysis patients report better overall quality of life than Whites, racial differences in depression and symptom burden remain less well characterized. The aim of this study was to compare these domains between African American and White patients on chronic haemodialysis. METHODS: We surveyed African American and White maintenance haemodialysis patients. Depression was assessed using the Beck Depression Inventory (BDI) and Cognitive Depression Index (CDI). Symptoms were evaluated using the Dialysis Symptom Index (DSI). RESULTS: Among the 82 Whites and 78 African Americans enrolled, there were no racial differences in the prevalence of depression (27% in African Americans vs 27% in Whites, P = 1.0), BDI Scores (11.2 vs 10.9, P = 0.6) or CDI scores (6.0 vs 6.0, P = 0.9). Symptom burden was substantial in both African Americans and Whites (median number of symptoms 8.5 and 9.0, respectively) with no racial differences in the overall burden or severity of symptoms. However, based on a single item, African Americans were more likely to describe their religious/spiritual beliefs as "very important". Adjustment for demographic and treatment characteristics had no impact on the associations of race with depression or symptoms. CONCLUSIONS: Depression and symptoms are highly prevalent in both African American and White haemodialysis patients, without racial differences in these health-related domains. In exploratory analyses, spiritual/religious beliefs appear to be of greater importance to African Americans. The relevance of these observations to the advantages in quality of life and survival among African Americans on haemodialysis warrants further investigation.

Black or African American↗

PubMed2006

Cystatin C and prognosis for cardiovascular and kidney outcomes in elderly persons without chronic kidney disease.

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.

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PubMed2006

Renal function and heart failure risk in older black and white individuals: the Health, Aging, and Body Composition Study.

BACKGROUND: Chronic kidney disease is a risk factor for heart failure, an association that may be particularly important in blacks who are disproportionately affected by both processes. Our objective was to determine whether the association of chronic kidney disease with incident heart failure differs between blacks and whites. METHODS: The study population comprised participants in the Health, Aging, and Body Composition Study without a diagnosis of heart failure (1124 black and 1676 white community-dwelling older persons). The main predictors were quintiles of cystatin C and creatinine concentrations and estimated glomerular filtration rate. The main outcome measure was incident heart failure. RESULTS: Over a mean 5.7 years, 200 participants developed heart failure. High concentrations of cystatin C and low estimated glomerular filtration rate were each associated with heart failure, but the magnitude was greater for blacks than for whites (cystatin C concentration: adjusted hazard ratio for quintile 5 [> or =1.18 mg/dL] vs quintile 1 [<0.84 mg/dL] was 3.0 [95% confidence interval 1.4-6.5] in blacks and 1.4 [95% confidence interval, 0.8-2.5] in whites; estimated glomerular filtration rate: adjusted hazard ratio for quintile 5 (<59.2 mL/min) vs quintile 1 (>86.7 mL/min) was 2.7 [95% confidence interval, 1.4-4.9] in blacks and 1.8 [95% confidence interval, 0.9-3.6] in whites). For cystatin C, this association was observed at more modest decrements in kidney function among blacks as well. The population attributable risk of heart failure was 47% for blacks with moderate or high concentrations of cystatin C (> or =0.94 mg/dL) (56% prevalence) but only 5% among whites (64% prevalence). CONCLUSION: The association of kidney dysfunction with heart failure appears stronger in blacks than for whites, particularly when cystatin C is used to measure kidney function.

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PubMed2006

Statins for improving renal outcomes: a meta-analysis.

Statins frequently are used to prevent cardiovascular events. Several recent studies suggest that statins also may have renal benefits, although this is controversial. This systematic review and meta-analysis were performed to assess the effect of statins on change in kidney function and urinary protein excretion. Medline, EMBASE, the Cochrane Central Register of Controlled Trials, conference proceedings, and the authors' personal files were searched. Published or unpublished randomized, controlled trials or crossover trials of statins that reported assessment of kidney function or proteinuria were included, and studies of individuals with ESRD were excluded. Data were extracted for study design, subject characteristics, type of statin and dose, baseline/change in cholesterol levels, and outcomes (change in measured or estimated GFR [eGFR] and/or urinary protein excretion). Weighted mean differences were calculated for the change in GFR between statin and control groups using a random-effects model. A random-effects model also was used to calculate the standardized mean difference for the change in urinary protein excretion between groups. Twenty-seven eligible studies with 39,704 participants (21 with data for eGFR and 20 for proteinuria or albuminuria) were identified. Overall, the change in the weighted mean differences for eGFR was statistically significant (1.22 ml/min per yr slower in statin recipients; 95% confidence interval [CI] 0.44 to 2.00). In subgroup analysis, the benefit of statin therapy was statistically significant in studies of participants with cardiovascular disease (0.93 ml/min per yr slower than control subjects; 95% CI 0.10 to 1.76) but was NS for studies of participants with diabetic or hypertensive kidney disease or glomerulonephritis. The standardized mean difference for the reduction in albuminuria or proteinuria as a result of statin therapy was statistically significant (0.58 units of SD greater in statin recipients; 95% CI 0.17 to 0.98). Statin therapy seems to reduce proteinuria modestly and results in a small reduction in the rate of kidney function loss, especially in populations with cardiovascular disease.

Albuminuria↗

PubMed2006

Kidney function predicts the rate of bone loss in older individuals: the Cardiovascular Health Study.

BACKGROUND: Results of cross-sectional analyses of the association of kidney function with bone mineral density (BMD) have been conflicting. We examined the association of cystatin-C, a new marker of kidney function that is unrelated to lean mass, with initial and follow-up BMD, in an ancillary study of the Cardiovascular Health Study, a population-based cohort of individuals > or = 65 years old. METHODS: Two years after measurement of cystatin-C and other covariates, the first BMD was measured in Pittsburgh, Pennsylvania and Davis, California, by using dual energy x-ray absorptiometry. Follow-up BMD was measured in Pittsburgh 4 years later. Associations of cystatin-C with initial BMD and the change in BMD (%/y) at the hip were examined with linear regression. Analyses were conducted separately for men and women. RESULTS: In 1519 participants who had cystatin-C and initial BMD assessed, 614 had follow-up BMD. The percent annual change in BMD at the total hip by cystatin-C quartiles was -0.24, -0.13, -0.40, and -0.66%/y (first to fourth quartile) in women and -0.02, -0.30, -0.18, and -0.94%/y in men. After adjusting for potential confounders, cystatin-C was marginally associated with initial BMD in men but not women. Cystatin-C was associated with bone loss in men; after adjustment for weight loss, cystatin-C was not associated with bone loss in women. CONCLUSION: Kidney dysfunction, as assessed by cystatin-C, is associated with a more rapid loss of BMD at the hip, especially in men. Further studies are needed to confirm these findings and to determine whether this loss leads to an elevated risk of fracture.

Absorptiometry, Photon↗

PubMed2006

Chronic kidney disease and functional limitation in older people: health, aging and body composition study.

OBJECTIVES: To assess whether chronic kidney disease (CKD) is independently associated with incident physical-function limitation. DESIGN: Prospective cohort study. SETTING: Two sites: Pittsburgh, Pennsylvania, and Memphis, Tennessee. PARTICIPANTS: Two thousand one hundred thirty-five men and women aged 70 to 79 without functional limitation at baseline from the Health, Aging and Body Composition Study. MEASUREMENTS: Functional limitation was defined as difficulty in walking one-quarter of a mile or climbing 10 steps on two consecutive reports 6 months apart (in the same function). Kidney function was measured using serum cystatin C. Estimated glomerular filtration rate (eGFR), using the Modification of Diet in Renal Disease formula (<60 versus > or =60 mL/min per 1.73 m(2)), was a secondary predictor. Muscle strength, lean body mass according to dual energy x-ray absorptiometry, comorbidity, medication use, and inflammatory markers were evaluated as covariates. RESULTS: Persons in the highest (> or =1.13 mg/L) quartile of cystatin C experienced a significantly higher risk of developing functional limitation than those in the lowest (<0.86 mg/L) quartile (hazard ratio (HR)=1.70, 95% confidence interval (CI)=1.40-2.07). The association between the fourth cystatin C quartile and functional limitation remained after adjustment for demographics, lean body mass, comorbidity, muscle strength, and gait speed (HR=1.41, 95% CI=1.13-1.75), although the association was attenuated after adjustment for markers of inflammation (HR=1.15, 95% CI=0.90-1.46). Similar results were found for eGFR less than 60 mL/min per 1.73 m(2), although the association with functional limitation remained after adjustment for inflammatory markers (HR=1.30, 95% CI=1.08-1.56). CONCLUSION: CKD is associated with the development of functional impairment independent of comorbidity, body composition, and tests of strength and physical performance. The mechanism may be related to a heightened inflammatory state in CKD.

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PubMed2005

Cystatin C and mortality risk in the elderly: the health, aging, and body composition study.

Kidney dysfunction is known to decrease life expectancy in the elderly. Cystatin C is a novel biomarker of kidney function that may have prognostic utility in older adults. The association of cystatin C with mortality was evaluated in a biracial cohort of black and white ambulatory elderly and compared with that of serum creatinine concentrations. The Health, Aging and Body Composition study is a cohort of well-functioning elderly that was designed to evaluate longitudinal changes in weight, body composition, and function. A total of 3075 participants who were aged 70 to 79 yr and had no disability were recruited at sites in Memphis, TN, and Pittsburgh, PA, between April 1997 and June 1998 with a follow-up of 6 yr. At entry, the mean cystatin C was 1.05 mg/L and the mean creatinine was 1.06 mg/dl. After 6 yr of follow-up, 557 participants had died. The mortality rates in each ascending cystatin C quintile were 1.7, 2.7, 2.9, 3.1, and 5.4%/yr. After adjustment for demographic risk factors, comorbid health conditions, and inflammatory biomarkers (C-reactive protein, IL-6. and TNF-alpha), each quintile of cystatin C was significantly associated with increased mortality risk compared with the lowest: Hazard ratios (HR; 95% confidence intervals) quintile 1, -1.0 (referent); quintile 2, -1.74 (1.21 to 2.50); quintile 3, -1.51 (1.05 to 2.18); quintile 4, -1.49 (1.04 to 2.13); and quintile 5, -2.18 (1.53 to 3.10). These associations did not differ by gender or race. Results were consistent for cardiovascular and other-cause mortality, but not cancer mortality. Creatinine quintiles were not associated with mortality after multivariate adjustment (HR: 1.0 [referent], 1.00 [0.72 to 1.39], 0.95 [0.68 to 1.32], 1.11 [0.79 to 1.57], 1.16 [0.86 to 1.58]). Cystatin C is a strong, independent risk factor for mortality in the elderly. Future studies should investigate whether cystatin C has a role in clinical medicine.

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PubMed2005

Kidney function as a predictor of noncardiovascular mortality.

Chronic kidney disease is associated with a higher risk for cardiovascular mortality, as well as all-cause mortality. Whether chronic kidney disease is a predictor of noncardiovascular mortality is less clear. To further explore the latter, the association of kidney function with total noncardiovascular mortality and cause-specific mortality was assessed in the Cardiovascular Health Study, a community-based cohort of older individuals. Kidney disease was assessed using cystatin C and estimated GFR in 4637 participants in 1992 to 1993. Participants were followed until June 30, 2001. Deaths were adjudicated as cardiovascular or noncardiovascular disease by committee, and an underlying cause of death was assigned. The associations of kidney function with total noncardiovascular mortality and cause-specific mortality were analyzed by proportional hazards regression. Noncardiovascular mortality rates increased with higher cystatin C quartiles (16.8, 17.1, 21.6, and 50.0 per 1000 person-years). The association of cystatin C with noncardiovascular mortality persisted after adjustment for demographic factors; the presence of diabetes, C-reactive protein, hemoglobin, and prevalent cardiovascular disease; and measures of atherosclerosis (hazard ratio 1.69; 95% confidence interval 1.33 to 2.15, for the fourth quartile versus the first quartile). Results for estimated GFR were similar. The risk for noncardiac deaths attributed to pulmonary disease, infection, cancer, and other causes was similarly associated with cystatin C levels. Kidney function predicts noncardiovascular mortality from multiple causes in the elderly. Further research is needed to understand the mechanisms and evaluate interventions to reduce the high mortality rate in chronic kidney disease.

Age Factors↗

PubMed2005

Cystatin C and subclinical brain infarction.

Subclinical brain infarcts (SBI) are common in the elderly and are associated with covert neurologic and cognitive impairment. Although renal impairment is associated with accelerated cerebrovascular disease and an increased risk for clinically apparent brain infarct, few studies have examined the relationship between renal function and SBI, and these may have been limited by the inaccuracy of creatinine as a renal function marker. A cross-sectional study was performed among older adults in the Cardiovascular Health Study to examine associations between SBI and two serum markers of renal function: Serum creatinine (SCr) and cystatin C (CysC). Patients had cranial magnetic resonance imaging and renal markers measured in 1992 to 1993. Logistic regression was used to estimate the associations between renal function (estimated by 1/SCr and 1/CysC) and SBI, controlling for potential confounding factors. SBI were present in 789 (28.7%) of 2784 participants. A linear association with SBI was observed for 1/CysC (per 1-SD decrement; odds ratio [OR] 1.20; 95% confidence interval [CI] 1.09 to 1.32; P < 0.001) but not for 1/SCr (OR 1.08; 95% CI 0.98 to 1.19; P = 0.14), for which a quadratic U-shaped association was suggested (P = 0.004). In a model with both markers, 1/CysC was linearly associated with SBI (OR 1.26; P < 0.001), whereas 1/SCr was not (OR 1.06; P = 0.3). The prevalence of SBI was directly associated with quintile of CysC, whereas the association between SCr and SBI was U-shaped, with greater prevalence at high and low levels. Compared with creatinine, CysC, a novel marker of renal function, has a stronger and more direct association with SBI in the elderly.

Age Factors↗

PubMed2005

Prevalence, severity, and importance of physical and emotional symptoms in chronic hemodialysis patients.

The prevalence, severity, and clinical significance of physical and emotional symptoms in patients who are on maintenance hemodialysis remain incompletely characterized. This study sought to assess symptoms and their relationship to quality of life and depression. The recently developed Dialysis Symptom Index was used to assess the presence and the severity of 30 symptoms. The Illness Effects Questionnaire and Beck Depression Inventory were used to evaluate quality of life and depression, respectively. Correlations among symptom burden, symptom severity, quality of life, and depression were assessed using Spearman correlation coefficient. A total of 162 patients from three dialysis units were enrolled. Mean age was 62 y, 48% were black, 62% were men, and 48% had diabetes. The median number of symptoms was 9.0 (interquartile range 6 to 13). Dry skin, fatigue, itching, and bone/joint pain each were reported by > or =50% of patients. Seven additional symptoms were reported by >33% of patients. Sixteen individual symptoms were described as being more than "somewhat bothersome." Overall symptom burden and severity each were correlated directly with impaired quality of life and depression. In multivariable analyses adjusting for demographic and clinical variables including depression, associations between symptoms and quality of life remained robust. Physical and emotional symptoms are prevalent, can be severe, and are correlated directly with impaired quality of life and depression in maintenance hemodialysis patients. Incorporating a standard assessment of symptoms into the care provided to maintenance hemodialysis patients may provide a means to improve quality of life in this patient population.

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PubMed2005

Cystatin C and the risk of death and cardiovascular events among elderly persons.

BACKGROUND: Cystatin C is a serum measure of renal function that appears to be independent of age, sex, and lean muscle mass. We compared creatinine and cystatin C levels as predictors of mortality from cardiovascular causes and from all causes in the Cardiovascular Health Study, a cohort study of elderly persons living in the community. METHODS: Creatinine and cystatin C were measured in serum samples collected from 4637 participants at the study visit in 1992 or 1993; follow-up continued until June 30, 2001. For each measure, the study population was divided into quintiles, with the fifth quintile subdivided into thirds (designated 5a, 5b, and 5c). RESULTS: Higher cystatin C levels were directly associated, in a dose-response manner, with a higher risk of death from all causes. As compared with the first quintile, the hazard ratios (and 95 percent confidence intervals) for death were as follows: second quintile, 1.08 (0.86 to 1.35); third quintile, 1.23 (1.00 to 1.53); fourth quintile, 1.34 (1.09 to 1.66); quintile 5a, 1.77 (1.34 to 2.26); 5b, 2.18 (1.72 to 2.78); and 5c, 2.58 (2.03 to 3.27). In contrast, the association of creatinine categories with mortality from all causes appeared to be J-shaped. As compared with the two lowest quintiles combined (cystatin C level, < or =0.99 mg per liter), the highest quintile of cystatin C (> or =1.29 mg per liter) was associated with a significantly elevated risk of death from cardiovascular causes (hazard ratio, 2.27 [1.73 to 2.97]), myocardial infarction (hazard ratio, 1.48 [1.08 to 2.02]), and stroke (hazard ratio, 1.47 [ 1.09 to 1.96]) after multivariate adjustment. The fifth quintile of creatinine, as compared with the first quintile, was not independently associated with any of these three outcomes. CONCLUSIONS: Cystatin C, a serum measure of renal function, is a stronger predictor of the risk of death and cardiovascular events in elderly persons than is creatinine.

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PubMed2005

Chronic kidney disease and cognitive impairment in the elderly: the health, aging, and body composition study.

Previous studies suggest a link between chronic kidney disease (CKD) and cognitive impairment. Whether the longitudinal course of cognitive impairment differs among people with or without CKD is unknown. Data collected in 3034 elderly individuals who participated in the Health, Aging, and Body Composition study were analyzed. Cognitive function was assessed with the Modified Mini-Mental State Exam (3MS) at baseline and then 2 and 4 yr after baseline. Cognitive impairment was defined as a 3MS score <80 or a decline in 3MS >5 points after 2 or 4 yr of follow-up among participants with baseline 3MS scores > or =80. Participants with CKD, defined as an estimated GFR (eGFR) <60 ml/min per 1.73 m2, were further divided into two eGFR strata. Unadjusted mean baseline 3MS scores and mean declines in 3MS scores over 4 yr were significantly more pronounced for participants with lower baseline eGFR. More advanced stages of CKD were associated with an increased risk for cognitive impairment: Odds ratio (OR) 1.32 (95% confidence interval [CI] 1.03 to 1.69) and OR 2.43 (95% CI, 1.38 to 4.29) for eGFR 45 to 59 ml/min per 1.73 m2 and <45 ml/min per 1.73 m2, respectively, adjusted for case mix, baseline 3MS scores, and other potential confounders. CKD is associated with an increased risk for cognitive impairment in the elderly that cannot be fully explained by other well-established risk factors. Studies aimed at understanding the mechanism(s) responsible for cognitive impairment in CKD and efforts to interrupt this decline are warranted.

Age Factors↗

PubMed2005

Cardiovascular mortality risk in chronic kidney disease: comparison of traditional and novel risk factors.

CONTEXT: Elderly persons with chronic kidney disease have substantial risk for cardiovascular mortality, but the relative importance of traditional and novel risk factors is unknown. OBJECTIVE: To compare traditional and novel risk factors as predictors of cardiovascular mortality. DESIGN, SETTING, AND PATIENTS: A total of 5808 community-dwelling persons aged 65 years or older living in 4 communities in the United States participated in the Cardiovascular Health Study cohort. Participants were initially recruited from 1989 to June 1990; an additional 687 black participants were recruited in 1992-1993. The average length of follow-up in this longitudinal study was 8.6 years. MAIN OUTCOME MEASURES: Cardiovascular mortality among those with and without chronic kidney disease. Chronic kidney disease was defined as an estimated glomerular filtration rate of less than 60 mL/min per 1.73 m2. RESULTS: Among the participants, 1249 (22%) had chronic kidney disease at baseline. The cardiovascular mortality risk rate was 32 deaths/1000 person-years among those with chronic kidney disease vs 16/1000 person-years among those without it. In multivariate analyses, diabetes, systolic hypertension, smoking, low physical activity, nonuse of alcohol, and left ventricular hypertrophy were predictors of cardiovascular mortality in persons with chronic kidney disease (all P values <.05). Among the novel risk factors, only log C-reactive protein (P = .05) and log interleukin 6 (P<.001) were associated with the outcome as linear predictors. Traditional risk factors were associated with the largest absolute increases in risks for cardiovascular deaths among persons with chronic kidney disease: for left ventricular hypertrophy, there were 25 deaths per 1000 person-years; current smoking, 20 per 1000 person-years; physical inactivity, 15 per 1000 person-years; systolic hypertension, 14 per 1000 person-years; diabetes, 14 per 1000 person-years; and nonuse of alcohol, 11 per 1000 person-years vs 5 deaths per 1000 person-years for those with increased C-reactive protein and 5 per 1000 person-years for those with increased interleukin 6 levels. A receiver operating characteristic analysis found that traditional risk factors had an area under the curve of 0.73 (95% confidence interval, 0.70-0.77) among those with chronic kidney disease. Adding novel risk factors only increased the area under the curve to 0.74 (95% confidence interval, 0.71-0.78; P for difference = .15). CONCLUSIONS: Traditional cardiovascular risk factors had larger associations with cardiovascular mortality than novel risk factors in elderly persons with chronic kidney disease. Future research should investigate whether aggressive lifestyle intervention in patients with chronic kidney disease can reduce their substantial cardiovascular risk.

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PubMed2005

Cystatin C concentration as a risk factor for heart failure in older adults.

BACKGROUND: Previous studies that evaluated the association of kidney function with incident heart failure may be limited by the insensitivity of serum creatinine concentration for detecting abnormal kidney function. OBJECTIVE: To compare serum concentrations of cystatin C (a novel marker of kidney function) and creatinine as predictors of incident heart failure. DESIGN: Observational study based on measurement of serum cystatin C from frozen sera obtained at the 1992-1993 visit of the Cardiovascular Health Study. Follow-up occurred every 6 months. SETTING: Adults 65 years of age or older from 4 communities in the United States. PARTICIPANTS: 4384 persons without previous heart failure who had measurements of serum cystatin C and serum creatinine. MEASUREMENTS: Incident heart failure. RESULTS: The mean (+/-SD) serum concentrations of cystatin C and creatinine were 82 +/- 25 nmol/L (1.10 +/- 0.33 mg/L) and 89 +/- 34 micromol/L (1.01 +/- 0.39 mg/dL), respectively. During a median follow-up of 8.3 years (maximum, 9.1 years), 763 (17%) participants developed heart failure. After adjustment for demographic factors, traditional and novel cardiovascular risk factors, cardiovascular disease status, and medication use, sequential quintiles of cystatin C concentration were associated with a stepwise increased risk for heart failure in Cox proportional hazards models (hazard ratios, 1.0 [reference], 1.30 [95% CI, 0.96 to 1.75], 1.44 [CI, 1.07 to 1.94], 1.58 [CI, 1.18 to 2.12], and 2.16 [CI, 1.61 to 2.91]). In contrast, quintiles of serum creatinine concentration were not associated with risk for heart failure in adjusted analysis (hazard ratios, 1.0 [reference], 0.77 [CI, 0.59 to 1.01], 0.85 [CI, 0.64 to 1.13], 0.97 [CI, 0.72 to 1.29], and 1.14 [CI, 0.87 to 1.49]). LIMITATIONS: The mechanism by which cystatin C concentration predicts risk for heart failure remains unclear. CONCLUSIONS: The cystatin C concentration is an independent risk factor for heart failure in older adults and appears to provide a better measure of risk assessment than the serum creatinine concentration. *For a full list of participating Cardiovascular Health Study investigators and institutions, see http://www.chs-nhlbi.org.

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PubMed2005

Cystatin-C and mortality in elderly persons with heart failure.

OBJECTIVES: We sought to evaluate cystatin-C, a novel measure of renal function, as a predictor of mortality in elderly persons with heart failure (HF) and to compare it with creatinine. BACKGROUND: Renal function is an important prognostic factor in patients with HF, but creatinine levels, which partly reflect muscle mass, may be insensitive for detecting renal insufficiency. METHODS: A total of 279 Cardiovascular Health Study participants with prevalent HF and measures of serum cystatin-C and creatinine were followed for mortality outcomes over a median of 6.5 years. RESULTS: Median creatinine and cystatin-C levels were 1.05 mg/dl and 1.26 mg/l. Each standard deviation increase in cystatin-C (0.35 mg/l) was associated with a 31% greater adjusted mortality risk (95% confidence interval [CI] 20% to 43%, p < 0.001), whereas each standard deviation increase in creatinine (0.39 mg/dl) was associated with a 17% greater adjusted mortality risk (95% CI 1% to 36%, p = 0.04). When both measures were combined in a single adjusted model, cystatin-C remained associated with elevated mortality risk (hazard ratio 1.60, 95% CI 1.32 to 1.94), whereas creatinine levels appeared associated with lower risk (hazard ratio 0.73, 95% CI 0.57 to 0.95). CONCLUSIONS: Cystatin-C is a stronger predictor of mortality than creatinine in elderly persons with HF. If confirmed in future studies, this new marker of renal function could improve risk stratification in patients with HF.

Age Factors↗

PubMed2005

Associations between retinal microvascular abnormalities and declining renal function in the elderly population: the Cardiovascular Health Study.

BACKGROUND: Microvascular abnormalities in the kidney are common histopathologic findings in individuals with chronic kidney disease or renal failure. These abnormalities may represent one manifestation of ongoing systemic microvascular damage. We hypothesized that retinal microvascular abnormalities, when present, would be associated with progressive renal dysfunction in elderly individuals. METHODS: The Cardiovascular Health Study (CHS) is a prospective, multicenter, cohort study initiated in 1989 designed to examine cardiovascular risk factors, morbidity, and mortality in elderly Americans. As part of an ancillary study, CHS participants underwent retinal photography in 1997 and 1998. Retinal microvascular abnormalities were assessed and graded by using standardized measures. Retinal microvascular abnormalities were defined as retinopathy (hard and soft exudates, hemorrhages, or microaneurysms) and/or retinal arteriolar abnormalities (arteriovenous nicking, focal arteriolar narrowing, or lowest quartile arteriole-venule ratio). Associations between these abnormalities and observed 4-year changes in serum creatinine levels and estimated glomerular filtration rates (eGFRs) from study years 5 to 9 (encompassing years 1994 to 2001) were examined by using regression modeling. RESULTS: A total of 1,394 CHS participants had retinal and serum creatinine data. After adjustments for age, race, sex, weight, diabetes, hypertension, angiotensin-converting enzyme inhibitor use, and proteinuria, participants with retinopathy showed a significant increase in serum creatinine level and decline in eGFR compared with those without retinopathy during the 4-year study period (+0.24 mg/dL [+21 micromol/L] versus -0.21 mg/dL [-19 micromol/L] and -0.48 mL/min/1.73 m2 [-0.01 mL/s/1.73 m2] versus +1.74 mL/min/1.73 m2 [+0.03 mL/s/1.73 m2], respectively). Participants with retinopathy also were significantly more likely to have an observed significant deterioration in renal function, defined as a 0.3-mg/dL (27-micromol/L) increase in serum creatinine level or 20% or greater decline in eGFR (odds ratio, 3.20; 95% confidence interval, 1.58 to 6.50; and odds ratio, 2.84; 95% confidence interval, 1.56 to 5.16, respectively). These associations remained in separate stratified analyses of patients with and without diabetes. The presence of retinal arteriolar abnormalities was not associated with deteriorating renal function. CONCLUSION: Retinal microvascular abnormalities defined as retinopathy were significantly associated with renal function deterioration. The observed findings were independent of effects of any associated diabetes or hypertension. These findings suggest that systemic microvascular disease may be associated with progressive renal dysfunction in the elderly population.

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