Reduced kidney function as a risk factor for incident heart failure: the atherosclerosis risk in communities (ARIC) study

Reduced kidney function is a risk factor for cardiovascular morbidity and mortality, and both heart failure (HF) and kidney failure incidences are increasing. This study therefore sought to determine the effect of decreased kidney function on HF incidence in a population-based study of middle-aged adults. From 1987 through 2002, 14,857 participants of the Atherosclerosis Risk in Communities (ARIC) study who were free of prevalent HF at baseline were followed for incident HF hospitalization or death (International Classification of Diseases, Ninth Revision/10th Revision 428/I50). Estimated GFR (eGFR) was calculated using the abbreviated Modification of Diet in Renal Disease (MDRD) Study equation, and kidney function was categorized as normal (eGFR > or =90 ml/min per 1.73 m(2); n = 7143), mildly reduced (eGFR 60 to 89 ml/min per 1.73 m(2); n = 7311), and moderately/severely reduced (eGFR <60 ml/min per 1.73 m(2); n = 403). Cox proportional hazards models were used to control for demographic and cardiovascular risk factors; analyses were stratified by the presence of coronary heart disease at baseline. During a mean follow-up of 13.2 yr, 1193 participants developed HF. The incidence of HF was three-fold higher for individuals with eGFR <60 ml/min per 1.73 m(2) compared to the reference group with eGFR > or =90 ml/min per 1.73 m(2) (18 versus 6 per 1000 person-years). The overall adjusted relative hazard of developing HF was 1.94 (1.49 to 2.53) for individuals with eGFR <60 ml/min per 1.73 m(2) compared to the reference group and was significantly increased for individuals with and without prevalent coronary heart disease at baseline. A substantially greater decline in kidney function occurred in individuals concomitant with HF hospitalization/death compared to those who did not develop HF. In summary, middle-aged adults with moderately/severely reduced kidney function are at high risk for developing HF.     

Lower heart rate variability is associated with the development of coronary heart disease in individuals with diabetes: the atherosclerosis risk in communities (ARIC) study

The objective of this study was to test prospectively in a population sample whether individuals with impaired heart rate variability (HRV) are at increased risk of developing coronary heart disease (CHD) and of non-CHD mortality and to test whether this relationship is more pronounced among individuals with diabetes. We examined the association between HRV and incident CHD and non-CHD mortality in a cohort of 11,654 men and women aged 45-64 years at intake, from the biracial, population-based Atherosclerosis Risk in Communities Study. Supine, resting, 2-min beat-to-beat heart rate data were collected at the baseline examination. High frequency (HF; 0.15-0.40 Hz) and low frequency (LF; 0.04-0.15 Hz) spectral powers, LF/HF ratio, normalized HF and LF, the standard deviation of all normal R-R intervals (SDNN), and the mean of the sum of the squared differences between adjacent normal R-R intervals (MSSD) were used as the conventional indexes of HRV to measure cardiac autonomic control. From this cohort, 635 cases of incident CHD (including 346 cases of incident myocardial infarction [MI] and 82 cases of fatal CHD), and 623 non-CHD deaths were identified and validated after an average of 8 years of follow-up. Among individuals with diabetes, the multivariable adjusted proportional hazards ratios (95% CI) were 2.03 (1.28-3.23), 1.60 (1.12-2.27), 1.50 (0.65-3.42), and 1.27 (0.84-1.91) for incident MI, incident CHD, fatal CHD, and non-CHD deaths, respectively, comparing the lowest quartile to the upper most three quartiles of HF. A similar pattern of associations was found for LF, SDNN, and MSSD. By contrast, there was no consistent pattern of associations among individuals without diabetes. At the population level, a lower HRV (reflective of impaired cardiac autonomic control) is statistically significantly related to the development of CHD among individuals with diabetes, independent of markers of the duration/severity of the glucose metabolism impairment. These data suggest a contribution of an impaired cardiac autonomic control to the risk of CHD among individuals with diabetes.     

Traditional and nontraditional risk factors predict coronary heart disease in chronic kidney disease: results from the atherosclerosis risk in communities study

Some risk factors for coronary heart disease (CHD) incidence in the general population are not associated with CHD incidence among patients with ESRD but have not been well characterized in chronic kidney disease (CKD). The association of several risk factors with CHD incidence was studied among participants with CKD in the population-based Atherosclerosis Risk in Communities (ARIC) Study. CHD risk factors and estimated GFR using serum creatinine were measured among 807 ARIC participants with CKD (estimated GFR between 15 and 59 ml/min per 1.73 m(2)). The incidence of CHD during 10.5 yr of follow-up was 6.3, 8.5, and 14.4 per 1000 person-years among ARIC participants with an estimated GFR of >/=90, 60 to 89, and 15 to 59 ml/min per 1.73 m(2), respectively. After adjustment for age, race, gender, and ARIC field center, among those with CKD, the relative risk (95% confidence interval) of CHD was 1.65 (1.01 to 2.67) for current smoking, 2.02 (1.27 to 3.22) for hypertension, 3.06 (2.01 to 4.67) for diabetes, and 1.96 (1.14 to 3.36) for anemia. The comparably adjusted relative risks of CHD for each standard deviation higher total and HDL cholesterol were 1.50 (1.25 to 1.71) and 0.79 (0.62 to 1.01), respectively, and 1.38 (1.13 to 1.69), 1.24 (1.06 to 1.46), 0.65 (0.54 to 0.79), and 1.38 (1.19 to 1.59) for waist circumference, leukocyte count, serum albumin, and fibrinogen, respectively. CHD risk factors in the general population remain predictive among patients with CKD. Given the high risk for CHD among patients with CKD, control of these risk factors may have a substantial impact on their excess burden of CHD.     

Association of a fasting glucose genetic risk score with subclinical atherosclerosis: The Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE

Elevated fasting glucose level is associated with increased carotid intima-media thickness (IMT), a measure of subclinical atherosclerosis. It is unclear if this association is causal. Using the principle of Mendelian randomization, we sought to explore the causal association between circulating glucose and IMT by examining the association of a genetic risk score with IMT.

RESEARCH DESIGN AND METHODS

The sample was drawn from the Atherosclerosis Risk in Communities (ARIC) study and included 7,260 nondiabetic Caucasian individuals with IMT measurements and relevant genotyping. Components of the fasting glucose genetic risk score (FGGRS) were selected from a fasting glucose genome-wide association study in ARIC. The score was created by combining five single nucleotide polymorphisms (SNPs) (rs780094 [GCKR], rs560887 [G6PC2], rs4607517 [GCK], rs13266634 [SLC30A8], and rs10830963 [MTNR1B]) and weighting each SNP by its strength of association with fasting glucose. IMT was measured through bilateral carotid ultrasound. Mean IMT was regressed on the FGGRS and on the component SNPs, individually.

RESULTS

The FGGRS was significantly associated (P = 0.009) with mean IMT. The difference in IMT predicted by a 1 SD increment in the FGGRS (0.0048 mm) was not clinically relevant but was larger than would have been predicted based on observed associations between the FFGRS, fasting glucose, and IMT. Additional adjustment for baseline measured glucose in regression models attenuated the association by about one third.

CONCLUSIONS

The significant association of the FGGRS with IMT suggests a possible causal association of elevated fasting glucose with atherosclerosis, although it may be that these loci influence IMT through nonglucose pathways.Elevated fasting glucose level is associated with increased carotid intima-media thickness (IMT) (1,2), a measure of subclinical atherosclerosis. However, it is still unclear if this relation is causal, due to unmeasured confounding by other cardiovascular risk factors, or due to the metabolic derangements of diabetes—a disease defined by fasting glucose level.Several recent fasting glucose genome-wide association studies (GWAS) (3–5) and a large GWAS meta-analysis (6) have identified multiple genetic variants with strong associations to fasting plasma glucose level. A recent GWAS in the Atherosclerosis Risk in Communities (ARIC) study found five variants significantly associated with fasting glucose after correction for genome-wide testing (7). Consistent associations for all five of the variants have been reported in other fasting glucose GWAS (6). We demonstrated that these variants are much more strongly associated with fasting glucose in the normal or prediabetic range than in the diabetic range (7).The discovery of genetic variants reproducibly associated with fasting glucose provides the opportunity to investigate a causal association between fasting glucose and cardiovascular disease (CVD) using the theory of Mendelian randomization. Because of random assortment of alleles at the time of gamete formation, genetic variants should not be associated with known and unknown confounders in association analyses. Genetic variants can also be measured very accurately and are thus subject to little measurement error. Finally, genetic variants are also not susceptible to issues of reverse causality (8). Therefore, the proxy use of single nucleotide polymorphisms (SNPs) significantly associated with a trait instead of the trait itself in association analyses can help to explore a causal association between a trait and disease (9). This technique was recently used in a meta-analysis to examine the causal relationship of C-reactive protein to heart disease (10). In this paper, we applied principles of Mendelian randomization to explore whether there is a causal relation between fasting glucose in the nondiabetic range and subclinical atherosclerosis. In order to reduce problems with multiple testing, to create a genetic variable that accounted for a substantive amount of variation in fasting glucose, and to attempt to account for pleiotropic effects of individual SNPs, a composite genetic risk score was used. However, Mendelian randomization results from single SNPs associated with fasting glucose are also presented in the online appendix available at http://diabetes.diabetesjournals.org/cgi/content/full/db10-0839/DC1.     

Kidney function and risk of peripheral arterial disease: results from the Atherosclerosis Risk in Communities (ARIC) Study

Chronic kidney disease (CKD) is associated with an increased risk for cardiovascular disease, but its association with peripheral arterial disease (PAD) is unclear. With the use of data from the Atherosclerosis Risk in Communities (ARIC) Study, 14,280 middle-aged adults were categorized on the basis of estimated GFR >/=90, 60 to 89, and 15 to 59 ml/min per 1.73 m(2) for normal kidney function, mildly decreased kidney function, and stages 3 to 4 CKD, respectively. Incident PAD was defined as a new onset of ankle-brachial index <0.9 assessed at regular examinations, new intermittent claudication assessed by annual surveillance, or PAD-related hospital discharges. Incidence rates and relative risks (RR) for PAD were compared across these categories. During a mean follow-up time of 13.1 yr (186,616 person-years), 1016 participants developed PAD. The incidence rates per 1000 person-years were 4.7, 4.9, and 8.6 for the normal kidney function, mildly decreased kidney function, and CKD groups, respectively. Compared with participants with normal kidney function, the age-, gender-, race-, and ARIC field center-adjusted RR for PAD was 1.04 (95% confidence interval [CI] 0.91 to 1.18) for those with mildly decreased kidney function and 1.82 (95% CI 1.34 to 2.47) for those with CKD. After additional adjustment for cardiovascular disease risk factors, an increase in risk for incident PAD still was observed in participants with CKD, with a multivariable adjusted RR of 1.56 (95% CI 1.13 to 2.14). Patients with CKD are at increased risk for incident PAD. Development of strategies for screening and prevention of PAD in this high-risk population seems warranted.     

Plasma lipids and risk of developing renal dysfunction: the atherosclerosis risk in communities study

BACKGROUND: Animal and in vitro data suggest that dyslipidemia plays an important role in the initiation and progression of chronic renal disease, but few prospective studies have been conducted in humans. METHODS: We studied the relationship of plasma lipids to a rise in serum creatinine of 0.4 mg/dL or greater in 12,728 Atherosclerosis Risk in Communities (ARIC) participants with baseline serum creatinine that was less than 2.0 mg/dL in men and less than 1.8 mg/dL in women. RESULTS: During a mean follow-up of 2.9 years, 191 persons had a rise in creatinine of 0.4 mg/dL or greater, yielding an incidence rate of 5.1 per 1000 person years. Individuals with higher triglycerides and lower high-density lipoprotein (HDL) and HDL-2 cholesterol at baseline were at increased risk for a rise in creatinine after adjustment for race, gender, baseline age, diabetes, serum creatinine, systolic blood pressure, and antihypertensive medication use (all P trends 相似文献   

Retinal microvascular abnormalities and renal dysfunction: the atherosclerosis risk in communities study

Microvascular disease has been linked with renal dysfunction in patients with diabetes. The aim of this study was to examine the association of retinal microvascular abnormalities to renal dysfunction among participants of the Atherosclerosis Risk in Communities Study, a population-based investigation in four U.S. communities. At the third examination (1993 to 1995), retinal photography was performed and the presence of retinal microvascular abnormalities was documented using a standard grading protocol. Renal dysfunction was defined as an increase in serum creatinine of at least 0.4 mg/dl or a death or hospitalization as a result of chronic kidney disease between the second (1990 to 1992) and fourth (1996 to 1998) examinations. Among 10,056 people who were included in the study, 270 (2.7%) developed renal dysfunction. After controlling for age, gender, race, diabetes, BP, and other risk factors, individuals with retinopathy (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.4 to 2.8), microaneurysms (OR, 2.0; 95% CI, 1.3 to 3.1), retinal hemorrhages (OR, 2.6; 95% CI, 1.6 to 4.0), soft exudates (OR, 2.7; 95% CI, 1.6 to 4.8), and arteriovenous nicking (OR, 1.4; 95% CI, 1.0 to 1.9) were more likely to develop renal dysfunction than individuals without these abnormalities. Retinal microvascular abnormalities are associated with renal dysfunction, suggesting that common systemic microvascular processes may underlie the development of microvascular damage in the eye and kidneys.     

Adiponectin and the development of type 2 diabetes: the atherosclerosis risk in communities study

Adipocyte-derived secretory proteins have been increasingly linked to diabetes. To investigate whether adiponectin, a major adipocyte secretory protein, predicts diabetes, we conducted a case-cohort study representing the approximately 9-year experience of the 10,275 middle-aged, U.S. African-American and white participants of the Atherosclerosis Risk in Communities (ARIC) study. Adiponectin was measured on stored plasma of 581 incident diabetes case subjects and 572 noncase subjects. Overall hazard ratios (95% CIs) for developing diabetes, for those in the second, third, and fourth (versus the first) quartile of adiponectin were 0.57 (0.41-0.78), 0.39 (0.27-0.56), and 0.18 (0.11-0.27), respectively, after adjustment for age, sex, ethnicity, study center, parental history of diabetes, and hypertension and 0.72 (0.48-1.09), 0.67 (0.43-1.04), and 0.58 (0.34-0.99), respectively, after additional adjustment for BMI, waist-to-hip ratio, fasting glucose, insulin, and a score composed of six inflammation markers. The association was of similar magnitude in men and women and in whites and African Americans, but was absent in smokers and in those with a greater inflammation score (interaction P < 0.01 for each). In conclusion, in this community-based sample of U.S. adults, higher adiponectin levels were associated with a lower incidence of diabetes.     

Chronic kidney disease,anemia, and incident stroke in a middle-aged,community-based population: the ARIC Study

BACKGROUND: Chronic kidney disease (CKD) has been linked to higher stroke risk. Anemia is a common consequence of CKD, and recent evidence suggests anemia may increase risk of cardiovascular events. The combined effect of CKD and anemia on stroke risk, however, has not been investigated thoroughly. We analyzed data from a middle-aged, community-based cohort to determine if CKD and anemia interacted to affect stroke risk. METHODS: Data on 13,716 participants in the prospective Atherosclerosis Risk in Communities (ARIC) Study were analyzed to assess the joint effect of CKD and anemia on risk of incident stroke during a 9-year follow-up period. CKD was defined as a creatinine clearance of <60 mL/min. Anemia was defined as hemoglobin levels of <13 g/dL for men or <12 g/dL for women. RESULTS: Overall, CKD was associated with an increase in stroke risk after adjustment for other factors [hazard ratio HR) 1.81; 95% CI 1.26 to 2.02]. However, this association was modified substantially by anemia. In the presence of anemia, CKD was associated with a substantially higher risk of stroke compared to no CKD (HR 5.43; 95% CI 2.04 to 14.41). In contrast, when anemia was not present, CKD was associated with only a modest, nonsignificant elevation in stroke risk (HR 1.41; 95% CI 0.93 to 2.14). The interaction between CKD and anemia on risk of stroke was statistically significant (P < 0.01). CONCLUSION: Among middle-aged, community-based persons, the combination of CKD and anemia was associated with a substantial increase in stroke risk, independent of other known risk factors for stroke.     

Associations of increases in serum creatinine with mortality and length of hospital stay after coronary angiography

The absence of a universally accepted definition of radiocontrast nephropathy (RCN) has hampered efforts to characterize effectively the incidence and the clinical significance of this condition. The objective of this study was to identify a clinically relevant definition of RCN by assessment of the relationships between increases in serum creatinine (Scr) of varying magnitude after coronary angiography and clinical outcomes. An electronic medical database was used to identify all patients who underwent coronary angiography at the University of Pittsburgh Medical Center during a 12-yr period and abstract Scr levels before and after angiography, as well as demographic characteristics and comorbid conditions. Changes in Scr after angiography were categorized into mutually exclusive categories on the basis of absolute and relative changes from baseline levels, with a separate category denoting "unknown" change. Discrete proportional odds models were used to examine the association between increases in Scr and 30-d in-hospital mortality and length of stay. A total of 27,608 patients who underwent coronary angiography were evaluated. Small absolute (0.25 to 0.5 mg/dl) and relative (25 to 50%) increases in Scr were associated with risk-adjusted odds ratios for in-hospital mortality of 1.83 and 1.39, respectively. Larger increases in Scr generally were associated with greater risks for these clinical outcomes. Small increases in Scr after the administration of intravascular radiocontrast are associated with adverse patient outcomes. This observation will help guide the post-procedure care of patients who undergo coronary angiography and has important implications for future studies that investigate RCN.     

Low-grade systemic inflammation and the development of type 2 diabetes: the atherosclerosis risk in communities study

To examine the association of low-grade systemic inflammation with diabetes, as well as its heterogeneity across subgroups, we designed a case-cohort study representing the approximately 9-year experience of 10,275 Atherosclerosis Risk in Communities Study participants. Analytes were measured on stored plasma of 581 incident cases of diabetes and 572 noncases. Statistically significant hazard ratios of developing diabetes for those in the fourth (versus first) quartile of inflammation markers, adjusted for age, sex, ethnicity, study center, parental history of diabetes, and hypertension, ranged from 1.9 to 2.8 for sialic acid, orosomucoid, interleukin-6, and C-reactive protein. After additional adjustment for BMI, waist-to-hip ratio, and fasting glucose and insulin, only the interleukin-6 association remained statistically significant (HR = 1.6, 1.01-2.7). Exclusion of GAD antibody-positive individuals changed associations minimally. An overall inflammation score based on these four markers plus white cell count and fibrinogen predicted diabetes in whites but not African Americans (interaction P = 0.005) and in nonsmokers but not smokers (interaction P = 0.13). The fully adjusted hazard ratio comparing white nonsmokers with score extremes was 3.7 (P for linear trend = 0.008). In conclusion, a low-grade inflammation predicts incident type 2 diabetes. The association is absent in smokers and African-Americans.     

Predictive value of HLA antibodies and serum creatinine in chronic rejection: results of a 2-year prospective trial

In this large collaborative study, 2,231 transplanted patients with functioning kidneys were tested for HLA antibodies, then examined 2 years later for graft survival. Among 478 patients with antibodies, 15.1% failed in 2 years, compared to 6.8% failure in 1,753 patients without antibodies (P=0.00000002). Cytotoxicity testing correlated better with outcome than flow cytometry or ELISA testing on HLA coated beads, possibly because it detected non-HLA antigens. When the patients were further broken down into those with serum creatinine at the time of testing of 0.5-1.9, 4.4% of antibody patients failed at 2 years, compared to 4.3% of patients without antibodies. This 0.1% difference increased among patients with serum creatinine values of 2.0-2.9 to 17.9%, and among those with 3.0-3.9 to 16.3%. We conclude that HLA antibodies posttransplantation is predictive of subsequent graft failure, and its predictive value can be enhanced among patients with higher serum creatinine values.     

Genomewide linkage analysis to serum creatinine, GFR, and creatinine clearance in a community-based population: the Framingham Heart Study

Kidney disease is a risk factor for the development of cardiovascular disease, all-cause mortality, and ESRD. It is not known to what extent genetic factors play a role in the development of kidney disease in the general population. Multipoint variance components linkage analysis was performed using Genehunter on 330 families from the Framingham Heart Study offspring cohort, using a 10-cM genomewide scan for serum creatinine, GFR, and creatinine clearance (CRCL) measured from 1998 to 2001. GFR was estimated using the simplified Modification of Diet in Renal Disease Study equation, and CRCL was estimated using the Cockcroft-Gault equation. Covariates in the adjustment included age, gender, body mass index, diabetes, systolic BP, hypertension treatment, tobacco use, and HDL cholesterol. Overall, 1224 subjects (52% women), mean age 59, were available for analysis. Mean creatinine was 0.87 mg/dl, mean GFR was 87 ml/min per 1.73 m(2), and mean creatinine clearance was 100 ml/min. The multivariable-adjusted heritability estimates for creatinine, GFR, and CRCL were 0.29, 0.33, and 0.46, respectively. The peak log of the odds ratio (LOD) scores for serum creatinine, GFR, and CRCL were 2.28 at 176 cM on chromosome 4, 2.19 at 78 cM on chromosome 4, and 1.91 at 103 cM on chromosome 3, respectively. In a community-based sample, measures of serum creatinine, GFR, and CRCL are heritable, suggesting an underlying genetic component. These results also provide suggestive evidence for linkage to measures of kidney function. Further research is necessary to identify the genes involved in the development of kidney disease and to understand their roles in this complex process.     

Iron overload in haemodialysis patients increases the risk of bacteraemia: a prospective study

The incidence of bacteraemia in relation to the degree of transfusional iron overload was studied prospectively in patients from one haemodialysis unit over a 2-year period, with a total follow-up of 181.3 patient-years in 158 patients. Every 3 months, the patients were classified according to the serum ferritin in one of three groups: less than 500, 500-1000 or greater than 1000 micrograms/l. Twenty-nine episodes of bacteraemia were recorded over 181.3 patient-years (yearly incidence of 0.160). The yearly incidence of bacteraemia was 0.1173 and 0.1101 for ferritin less than 500 and 500-1000 micrograms/l (no significant difference), with a cumulative incidence for both groups of 0.1164. In the ferritin greater than 1000 micrograms/l group, the incidence was 0.3404 (P less than or equal to 0.005 versus the ferritin less than or equal to 1000 micrograms/l group). After stratification for patient's age (at inclusion in the study) and duration of haemodialysis therapy, the higher incidence of bacteraemia in the ferritin greater than 1000 versus less than or equal to 1000 micrograms/l groups persisted (P less than or equal to 0.005). This prospective study confirms previous retrospective studies in showing that acquired transfusional iron overload in haemodialysis is associated with a greater risk of bacteraemia.     

Risk factor groupings related to insulin resistance and their synergistic effects on subclinical atherosclerosis: the atherosclerosis risk in communities study

The extent to which groupings of insulin resistance-related cardiovascular risk factors synergize to produce atherosclerosis beyond what is expected from their additive effects is uncertain. The objective of this study was to measure interactions among groupings of the features of the insulin resistance syndrome (IRS) on carotid intimal-medial thickness (IMT). This cross-sectional study used baseline data from the Atherosclerosis Risk in Communities Study on 11,790 adults aged 45-64 years without diagnosed diabetes, treated dyslipidemia, or coronary heart disease. The main outcome was carotid IMT, assessed using B-mode ultrasound. The excess carotid IMT attributable to each IRS grouping was determined using multiple linear regression models. There were 57 possible combinations of six IRS components (hypertension, hyperinsulinemia, obesity, hypertriglyceridemia, low HDL cholesterol, and hyperglycemia). In multivariate analysis, 29 of the 57 groupings were associated with excess carotid IMT. Individuals with all six IRS components had the greatest excess IMT compared with those without this grouping (71 micro m; 95% CI 40-102 micro m). The groupings most strongly associated with excess carotid IMT included hypertension and hypertriglyceridemia. Interventions aimed at ameliorating the IRS may produce reductions in atherosclerotic risk beyond that predicted by treatment of individual IRS-related risk factors.     

Neutrophil gelatinase-associated lipocalin (NGAL) correlations with cystatin C, serum creatinine and eGFR in patients with normal serum creatinine undergoing coronary angiography.

Sir, Neutrophil gelatinase-associated lipocalin (NGAL), a memberof the lipocalin family, is readily excreted and detected inurine, due to its small molecular size (25 kDa) and resistanceto degradation. NGAL is highly accumulated in the human kidneycortical tubules, blood and urine, after nephrotoxic and ischaemicinjuries [1]. Thus, NGAL might represent an early, sensitive,non-invasive biomarker for acute renal injury [2], and urinaryNGAL might serve as an early marker for ischaemic renal injuryin children after cardiopulmonary bypass [3]. On the other hand,serum cystatin C was proposed as a new marker of glomerularfiltration rate (GFR), even in chronic kidney disease [4]. CystatinC has a low molecular weight (13 kDa) and is freely filtered     

Vasectomy, inflammation, atherosclerosis and long-term followup for cardiovascular diseases: no associations in the atherosclerosis risk in communities study.

PURPOSE: Although human studies have failed to reveal an increased risk of clinical cardiovascular disease in men who undergo vasectomy, the possibility exists that an association may be detectable only after a long followup, or it may be more evident for subclinical than clinical disease. We assessed the association of vasectomy with inflammation and coagulation factors, carotid intimal-medial thickness, carotid plaque, prevalent peripheral arterial disease, and incident coronary heart disease and stroke in the Atherosclerosis Risk in Communities cohort. MATERIALS AND METHODS: Included in the study were 3,957 white men 45 to 64 years old who were free of coronary heart disease at the Atherosclerosis Risk in Communities (ARIC) baseline examination in 1987 to 1989. Data on vasectomy was collected at baseline by self-reporting. High resolution B-mode ultrasound was done to assess carotid intimal-medial thickness and carotid plaque. The cohort was followed an average of 9 years for incident cardiovascular events. RESULTS: Average time since vasectomy was 16 years. Approximately 20% of the population had undergone vasectomy 20 years or more ago at baseline. Multivariate analysis showed no association of vasectomy status with inflammation or coagulation factors, peripheral arterial disease, carotid plaque, carotid far wall thickness, incident coronary heart disease or stroke. Associations were unaffected by the time since vasectomy. CONCLUSIONS: There is no evidence in this population based sample of men indicating that vasectomy is related to atherosclerosis even after more than 20 years of followup.     

Minimal changes of serum creatinine predict prognosis in patients after cardiothoracic surgery: a prospective cohort study

Acute renal failure increases risk of death after cardiac surgery. However, it is not known whether more subtle changes in renal function might have an impact on outcome. Thus, the association between small serum creatinine changes after surgery and mortality, independent of other established perioperative risk indicators, was analyzed. In a prospective cohort study in 4118 patients who underwent cardiac and thoracic aortic surgery, the effect of changes in serum creatinine within 48 h postoperatively on 30-d mortality was analyzed. Cox regression was used to correct for various established demographic preoperative risk indicators, intraoperative parameters, and postoperative complications. In the 2441 patients in whom serum creatinine decreased, early mortality was 2.6% in contrast to 8.9% in patients with increased postoperative serum creatinine values. Patients with large decreases (DeltaCrea <-0.3 mg/dl) showed a progressively increasing 30-d mortality (16 of 199 [8%]). Mortality was lowest (47 of 2195 [2.1%]) in patients in whom serum creatinine decreased to a maximum of -0.3 mg/dl; mortality increased to 6% in patients in whom serum creatinine remained unchanged or increased up to 0.5 mg/dl. Mortality (65 of 200 [32.5%]) was highest in patients in whom creatinine increased > or =0.5 mg/dl. For all groups, increases in mortality remained significant in multivariate analyses, including postoperative renal replacement therapy. After cardiac and thoracic aortic surgery, 30-d mortality was lowest in patients with a slight postoperative decrease in serum creatinine. Any even minimal increase or profound decrease of serum creatinine was associated with a substantial decrease in survival.