Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum creatinine, a surrogate for both renal function and homocysteine generation, is an important determinant of fasting plasma total homocysteine levels in stable renal transplant recipients. In this study, it is hypothesized that among stable renal transplant recipients with normal creatinine levels (i.e., < or = 1.5 mg/dl), serum cystatin C, a more sensitive indicator of GFR, would better predict fasting total homocysteine levels compared with serum creatinine. Fasting plasma total homocysteine, folate, vitamin B12, and pyridoxal 5'-phosphate levels, along with serum cystatin C, creatinine, and albumin levels, were determined in 28 consecutive renal transplant recipients (mean age 47 +/- 14 yr; 60.7% men) with stable allograft function, whose serum creatinine was < or = 1.5 mg/dl. General linear modeling with analysis of covariance revealed that serum cystatin C was independently predictive (partial R = 0.494; P = 0.023) of fasting total homocysteine levels after adjustment for age, gender, vitamin status, albumin, and creatinine levels. In contrast, creatinine levels were not predictive of fasting total homocysteine levels in this model (P = 0.110) or an identical model that excluded cystatin C (P = 0.131). Serum cystatin C levels may reflect subtle decreases in renal function that independently predict fasting total homocysteine levels among stable renal transplant recipients with a normal serum creatinine.
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PMID:Serum cystatin C as a determinant of fasting total homocysteine levels in renal transplant recipients with a normal serum creatinine. 989 Mar 23

Elevated plasma homocysteine is a risk factor for cardiovascular disease and a sensitive marker of inadequate vitamin B12 and folate status. We studied 257 pupils (120 boys, 137 girls, aged 6-17 years) and their parents (88 males, 172 females, aged 26-50 years). Our measurements were part of a national Bavarian health and nutrition examination survey evaluating cardiovascular risk factors. A mild hyperhomocysteinemia (Hcys >15 micromol/l) occurred in 7% of the adults, but in none of the children. Men had significantly higher Hcys levels than women (p<0.0001), boys and girls had comparable concentrations. For adults and children, Hcys correlated inversely with vitamin B12 and folate and positively with the lean body mass and creatinine in serum, but not with cystatin C. Genetic and nutritional factors are determinants of Hcys metabolism. The correlation of Hcys and serum creatinine is dependent on the metabolic link between Hcys production and creatine synthesis.
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PMID:Homocysteine concentrations in a German cohort of 500 individuals: reference ranges and determinants of plasma levels in healthy children and their parents. 1145 84

Glomerular filtration is one of the major determinants of plasma total homocysteine (tHcy). To evaluate the respective roles of residual glomerular filtration (by measuring a specific protein marker, cystatin C), genetic polymorphisms and nutritional status in tHcy blood levels in end-stage renal disease patients (ESRD) under hemodialysis and supplemented with folate, we measured tHcy, folate, vitamin B12 (B12), creatinine, cystatin C, albumin and C-reactive protein and determined the polymorphism of methylenetetrahydrofolate reductase (MTHFR) (C677T and A1289C) and of methionine synthase (MS) (A2756G) in 114 ESRD patients before hemodialysis and 76 control subjects. All patients received a folate supplementation of 700 microg/day. Hyperhomocysteinemia was observed in all patients and exceeded the upper normal limit by 2-fold in 52.4% of the patients. Serum folate was significantly increased and the B12 level was not different from controls. Folate, Cystatin C and creatinine were significantly correlated to tHcy, while no correlation was found between tHcy, albumin and C-reactive protein. No difference in genotype frequency between ESRD patients and controls was found for MTHFR A1289C and MS A2756G. The MTHFR 677TT genotype was less frequent and was associated with a significantly higher tHcy level in patients. Folate and residual glomerular filtration estimated by cystatin C and creatinine levels were two independent determinants of tHcy in ESRD patients. These data suggest that hyperhomocysteinemia is a consequence as well as a complicating factor of renal failure.
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PMID:Hyperhomocysteinemia is related to residual glomerular filtration and folate, but not to methylenetetrahydrofolate-reductase and methionine synthase polymorphisms, in supplemented end-stage renal disease patients undergoing hemodialysis. 1159 45

Homocysteinemia is an independent risk factor for cardiovascular disease, but information on its association with type 2 diabetes and mild renal dysfunction is limited. Plasma total homocysteine (tHcy) concentration is partly determined by renal plasma clearance. Serum cystatin C (Cys C) concentration has been introduced as a marker of renal function, specifically as an indicator of glomerular filtration rate (GFR). The aim of this study was to explore the relationships among tHcy, creatinine clearance (Ccr), serum Cys C, and microalbuminuria in a population with type 2 diabetes. Fasting plasma tHcy, serum homocysteine-related vitamins (folate and vitamin B12), serum Cys C, serum creatinine, urine microalbumin, and creatinine clearance were determined in 75 type 2 diabetic patients and 40 healthy control subjects. The patients were assigned to two groups based on urinary albumin excretion (UAE): normoalbuminuric (NAU, UAE < 30 mg/24 hr, n = 35) and microalbuminuric (MAU, UAE 30-300 mg/24 hr, n = 40). Ccr was calculated using the Cockroft-Gault formula. Plasma Hcy levels were determined by HPLC with fluorescence detection and serum Cys C by automated particle enhanced immunoturbidimetry. Plasma tHcy levels were significantly higher in normoalbuminuric and microalbuminuric patients than in controls (10.64 +/- 0.53, 13.29 +/- 0.78, 6.91 +/- 0.37 mmol/L, respectively). Serum Cys C levels in microalbuminuric diabetics were higher than in normoalbuminurics and controls (1.36 +/- 0.06, 1.12 +/- 0.04, 1.10 +/- 0.06 mg/ L, respectively). Positive correlations were noted between tHcy and Cys C levels in normoalbuminuric and microalbuminuric diabetics (r = 0.72, r = 0.64, respectively). Homocysteine and creatinine concentrations were correlated in both diabetic groups (r = 0.89, r = 0.93, NAU and MAU, respectively). Elevated plasma total homocysteine concentrations in type 2 diabetics suggest an association between homocysteinemia and deterioration of renal function, evidenced by increased serum creatinine and Cys C, Ccr, and microalbuminuria. These findings implicate homocysteinemia in the relationship between diabetic nephropathy and cardiovascular complications of diabetes.
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PMID:Association between homocysteinemia and renal function in patients with type 2 diabetes mellitus. 1217 91

Thiazides and angiotensin-converting enzyme (ACE) inhibitors are first-choice drugs for lowering elevated blood pressure and hence risk of cardiovascular disease. Homocysteine (tHcy) is another and independent cardiovascular risk factor and has been reported to be elevated in patients on antihypertensive therapy. As these studies reported only associations, a preliminary, randomized, prospective treatment study was performed in 40 hypertensive patients. We investigated the major determinants of tHcy concentrations after treatment with hydrochlorothiazide (HCT) or captopril: vitamins B6, B12, folic acid, and creatinine and cystatin C as parameters of renal function. A total of 21 Patients were treated with HCT and 19 with captopril, for, respectively, 31 and 29 days. HCT, but not captopril, raised tHcy by 16% (P =.003) and also creatinine and cystatin C (P =.025 and P =.004, respectively). This tHcy increase may offset the desired cardioprotection conferred by lowering the blood pressure.
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PMID:Antihypertensive treatment and homocysteine concentrations. 1264 60

Hyperhomocysteinemia is a risk factor in obstetrical complications such as pre-eclampsia, 'hemolysis, elevated liver enzymes, low platelet' (HELLP)-syndrome and placental insufficiency. The aim of our study was to investigate the alterations of homocysteine catabolism in these patients in relation to serum B-vitamins and renal function. Maternal fasting serum from pre-eclampsia (n=24), HELLP (n=20) and placental insufficiency (n=25) patients at the time of diagnosis and pregnant controls (n=34) was analyzed for homocysteine and its metabolites cystathionine and methylmalonic acid, the vitamins B6, B12 and folate, renal and additional parameters. Cystathionine, a parameter of homocysteine catabolism, was significantly increased in pre-eclampsia and HELLP compared with controls and placental insufficiency patients (mean concentrations: 343, 324, 248, 227 nmol/l; p=0.001). Homocysteine, folic acid, vitamin B6 and methylmalonic acid, however, did not differ significantly between groups. The main determinants of cystathionine are cystatin C and vitamin B6, whereas the main determinants of homocysteine are folate and uric acid. The strongest dependency of cystathionine on vitamin B6 was observed in pre-eclampsia and HELLP patients. The results suggest that the vitamin B6-dependent trans-sulfuration pathway is activated in pre-eclampsia and HELLP syndrome, probably by oxidative stress. Therefore, the demand for vitamin B6 is increased in these patients. Furthermore, renal dysfunction and low vitamin B6 levels contribute to the increase of cystathionine in pre-eclampsia and HELLP patients.
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PMID:Alteration of homocysteine catabolism in pre-eclampsia, HELLP syndrome and placental insufficiency. 1555 68