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)

One of the main determinants of plasma homocysteine in healthy subjects is serum creatinine. In the present study, we therefore investigated the relation between plasma homocysteine concentration, serum creatinine and a new marker for glomerular filtration rate, plasma cystatin C concentration. Cystatin C reflects the glomerular filtration better than serum creatinine and is not related to the muscle mass and formation of creatinine. The study group consisted of 255 healthy subjects from a well-defined area in the southern part of Sweden. The concentration of plasma homocysteine was increased in men compared to women. This difference disappeared when men and women were stratified by serum creatinine values. Statistically significant correlations were noted between plasma homocysteine and age, plasma cystatin C and serum creatinine. It is shown that plasma homocysteine is not only correlated to serum creatinine as a result of renal function but also as a result of the relationship between homocysteine production and creatine-creatinine synthesis. Using linear regression we were able to show that plasma cystatin C had a higher explanatory value than age. Serum creatinine showed a lower explanatory power than age. The findings in the present study might suggest that the increase of plasma homocysteine concentration with age could be partly due to the deterioration of renal function.
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PMID:The increase of plasma homocysteine concentrations with age is partly due to the deterioration of renal function as determined by plasma cystatin C. 958 6

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

Serum creatinine, a surrogate for both renal function and homocysteine generation, is a determinant of fasting plasma total homocysteine levels in coronary artery disease (CAD) patients. We hypothesized that among stable-CAD patients with normal creatinine levels (ie, </=1.4 mg/dL), serum cystatin C, a more sensitive indicator of glomerular filtration rate, would better predict fasting total homocysteine levels in comparison with serum creatinine. Fasting plasma total homocysteine, folate, vitamin B(12), and pyridoxal 5'-phosphate levels, along with serum cystatin C, creatinine, and albumin levels, were determined in 164 consecutive stable-CAD patients (mean+/-SD age, 61+/-9 years; 78.7% men) whose serum creatinine level was </=1.4 mg/dL. All subjects were examined at least 3 to 4 months after the widespread availability of cereal grain flour products fortified with folic acid. General linear modeling with ANCOVA revealed that serum cystatin C (P<0.001), B(12) (P<0.001), age (P=0.002), albumin (P=0.008), and sex (P=0.024) were independent determinants of fasting total homocysteine levels. Cystatin C alone determined over half of the variability (ie, R(2)) in total homocysteine levels accounted for by these 5 independent regressors. In contrast, creatinine, folate, and pyridoxal 5'-phosphate were not independently predictive of fasting total homocysteine levels (P>0.2). Consistent with the impact of folic acid fortification of cereal grain flour in the general population, only 1 of the CAD subjects (0.6%) had a plasma folate level <3 ng/mL. We conclude that serum cystatin C levels may reflect subtle decreases in renal function that independently predict fasting total homocysteine levels among stable-CAD patients with normal serum creatinine.
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PMID:Cystatin C as a determinant of fasting plasma total homocysteine levels in coronary artery disease patients with normal serum creatinine. 1047 68

The aim of this study was to assess parameters of renal function and other determinants of plasma homocysteine in type 2 diabetic patients without coronary heart disease (CHD). Fasting plasma homocysteine, serum cystatin C and serum creatinine were determined in 183 (75 men, 108 women) Type 2 diabetic patients without clinical evidence of CHD. Creatinine clearance was calculated and parameters such as blood pressure, body mass index (BMI), and glycated haemoglobin (HbA(1c)) were assessed. The urine albumin:creatinine ratio was used to classify patients as normo-, micro- or macroalbuminuric. One hundred and ten patients were normoalbuminuric, 67 patients were microalbuminuric and six patients were macroalbuminuric. There was no statistically significant difference in plasma homocysteine concentration between patients with normoalbuminuria and microalbuminuria. There was a trend towards increasing plasma homocysteine with decreasing glomerular filtration rate (GFR) (r=-0.46; P<0.0001). There was statistically significant correlation between plasma homocysteine and age (r=0.37), serum cystatin C (r=0.47), and serum creatinine (r=0.56). Plasma homocysteine concentration was significantly higher in patients with BMI<30 kg/m(2) and showed significant inverse correlation with weight (r=-0.16; P=0.03) and body mass index (r=-0.24; P=0.001). Homocysteine and serum creatinine were significantly higher in males than females and higher in smokers than non smokers but was not associated with glycemic control and duration of diabetes. In conclusion, elevated homocysteine concentration in patients with type 2 DM without CHD is related to age, gender, smoking, BMI and GFR. Follow up studies will provide further information on the association between hyperhomocysteinemia and the development of cardiovascular disease.
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PMID:Homocysteine and endogenous markers of renal function in type 2 diabetic patients without coronary heart disease. 1110 32

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

Fenofibrate increases plasma homocysteine. Because the concentration of plasma homocysteine depends on renal function, we postulate that increases in plasma homocysteine are a result of the known impairment of renal function caused by fenofibrate. Gemfibrozil, another fibrate, does not affect renal function. In a crossover study we tested whether gemfibrozil would raise homocysteine. 22 patients who had hypertriglyceridaemia were given 900 mg gemfibrozil or 200 mg fenofibrate daily for 6 weeks. Lipids were altered similarly, but homocysteine, creatinine, and cystatin C were raised by fenofibrate but not by gemfibrozil (p for differences between treatment effects: 0.007, 0.006, and 0.040, respectively). We propose gemfibrozil should be the fibrate of choice.
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PMID:Effects of fenofibrate and gemfibrozil on plasma homocysteine. 1173 63

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

It has been suggested that hyperhomocysteinemia observed in patients with occlusive vascular disease is caused by reduced renal function secondary to renovascular disease. We have therefore used serum cystatin C, a new sensitive marker for glomerular filtration, in 59 patients with acute coronary syndromes and high plasma homocysteine (tHcy) concentration to measure renal function. Samples were also obtained from 34 patients with low-normal plasma tHcy and 50 control subjects. The patients with low-normal plasma tHcy concentration showed decreased concentrations of serum cystatin C and serum creatinine and increased concentrations of blood folate and serum cobalamin compared to the controls and to the patients with high plasma tHcy. There was a large overlap in cystatin C concentrations between patients with high and low-normal plasma tHcy. None of the parameters investigated except plasma tHcy were significantly different in the group of patients with high plasma tHcy concentration compared to the control group. In order to further demonstrate the importance of renal impairment, a subgroup of the patients with high plasma tHcy was supplemented daily with folic acid 5 mg, pyridoxine 40 mg and cyancobalamin 1 mg for 3 months. Vitamin therapy reduced plasma tHcy from 18.3+/-4.6 pmol/l to 9.6+/-2.2 pmol/l (p<0.0001). However, vitamin treatment did not strengthen the correlation between cystatin C and plasma tHcy concentrations. These findings do not support the hypothesis that subtle renal dysfunction is an important cause of high plasma tHcy concentration in patients with acute coronary syndromes.
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PMID:Renal function exerts only a minor influence on high plasma homocysteine concentrations in patients with acute coronary syndromes. 1193 86

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


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