Total homocysteine as a risk factor for vascular disease in renal transplant recipients

Protocol for the IMPACT Trial: Improving Healthcare Outcomes in American Transplant Recipients Using Culturally-Tailored Novel Technology

Kidney transplant (KT) recipients face post-transplant health issues. Immunosuppressive agents can cause hyperlipidemia, hypertension, post-transplant diabetes, and glomerulopathy. Post-transplant weight gain and decreased activity are associated with poor quality of life, sleep, and cardiometabolic outcomes. This study will test the feasibility and acceptability of a culturally tailored diet and exercise intervention for KT patients delivered immediately post-transplant using novel technology. A registered dietitian nutritionist (RDN) and physical rehabilitation therapist will examine participants' cultural background, preferences, and health-related obstacles (with consultation from the transplant team) to create an individualized exercise and meal plan. The RDN will provide medical nutrition therapy via the nutrition care process throughout the course of the intervention. The Twistle Patient Engagement Platform will be used to deliver and collect survey data, communicate with participants, and promote retention. Outcomes to be assessed include intervention feasibility and acceptability and intervention efficacy on patients' adherence, medical, quality of life, and occupational outcomes.

Individual and Joint Associations of Methylenetetrahydrofolate Reductase C677T Genotype and Plasma Homocysteine With Dyslipidemia in a Chinese Population With Hypertension

We aimed to examine the cross-sectional associations of plasma total homocysteine (tHcy) concentrations and methylenetetrahydrofolate reductase ( MTHFR) C677T genotype with dyslipidemia. A total of 231 patients with mild-to-moderate essential hypertension were enrolled from the Huoqiu and Yuexi communities in Anhui Province, China. Plasma tHcy levels were measured by high-performance liquid chromatography. Genotyping was performed by TaqMan allelic discrimination technique. Compared with MTHFR 677 CC + CT genotype carriers, TT genotype carriers had higher odds of hypercholesterolemia (adjusted odds ratio [OR] [95% confidence interval (CI)]: 2.7 [1.4-5.2]; P = .004) and higher odds of abnormal low-density lipoprotein cholesterol (adjusted OR [95% CI]: 2.3 [1.1-4.8]; P = .030). The individuals with the TT genotype had higher concentrations of log(tHcy) than those with the 677 CC + CT genotype (adjusted β [standard error]: .2 [0.03]; P < .001). Patients with tHcy ≥ 10 μmol/L had significantly higher odds of hypercholesterolemia (adjusted OR [95% CI]: 2.4 [1.2-4.7]; P = .010). Furthermore, patients with both the TT genotype and the tHcy ≥ 10 μmol/L had the highest odds of hypercholesterolemia (adjusted OR [95% CI]: 4.1 [1.8-9.4]; P = .001) and low-density lipoprotein cholesterol (adjusted OR [95% CI]: 2.4 [1.0-6.0]; P = .064). This study suggests that both tHcy and the MTHFR C677T gene polymorphism may be important determinants of the incidence of dyslipidemia in Chinese patients with essential hypertension. Further studies are needed to confirm the role of tHcy and the MTHFR C677T mutation in the development of dyslipidemia in a larger sample.

Effect of simvastatin on plasma homocysteine levels and its modification by MTHFR C677T polymorphism in Chinese patients with primary hyperlipidemia

OBJECTIVE

We investigate the effect of simvastatin on plasma homocysteine (Hcy) levels and whether genetic factor affects the effect of simvastatin.

METHODS

A total of 338 patients with hyperlipidemia were enrolled. Simvastatin was orally administered at a dose of 20 mg/day for 8 weeks. Plasma Hcy levels were measured by high-performance liquid chromatography at baseline and after 8 weeks of treatment. Genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism was performed by TaqMan probe technique.

RESULTS

Serum total Hcy levels were positively correlated with serum creatinine (r = 0.332, P < 0.001). Among total subjects, simvastatin treatment resulted in a significant reduction in serum Hcy levels after 8 weeks (-0.37 ± 2.21 μmol/L, P = 0.003), and this effect was dependent on the initial levels of serum Hcy. The individuals with 677TT genotype had a significantly higher baseline Hcy level and a greater change in Hcy levels. After stratification by body mass index (BMI), we observed a significant increase in Hcy levels among the TT genotype group in adjusted model (beta±SE: 2.64 ± 0.84 μmol/L; P = 0.002) among patients with BMI ≥ 25 (kg/m(2) ).

CONCLUSIONS

Simvastatin can cause a marked decrease in plasma Hcy levels. MTHFR C677T genetic variant contributes to simvastatin's effects among Chinese subjects with primary hyperlipidemia.

Cardiovascular Biomarkers in CKD: Pathophysiology and Implications for Clinical Management of Cardiac Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with all forms of chronic kidney disease (CKD). The underlying pathological state is caused by a complex interplay of traditional and nontraditional risk factors that results in atherosclerosis, arteriosclerosis, and altered cardiac morphological characteristics. This multifactorial disease introduces new challenges in predicting and treating patients with CVD sufficiently early in the course of CKD to positively alter patient outcome. Asymptomatic individuals with progressive CVD are a group of patients that deserve focused attention because early detection and intervention may provide the best opportunity for improved outcome. However, identifying CVD in asymptomatic patients with CKD or end-stage renal disease remains a significant hurdle in the management of these patients. Recently, a number of cardiovascular biomarkers were identified as predictors of patient outcome in individuals with CVD and, with additional research, may be used to guide the early diagnosis of and therapy for CVD in patients with CKD. This review examines the pathophysiological characteristics and potential clinical role of these novel cardiovascular biomarkers in risk stratification, risk monitoring, and selection of preventive therapies for patients with CKD.

Physical rehabilitation and risk of atherosclerosis after successful kidney transplantation

Regular physical activity is usually associated with significant health benefits, but therapeutic exercise is seldom routine in renal transplant recipients. We report a randomized clinical trial of exercise training after renal transplantation. Sixty-nine patients were randomly recruited on the first or second day after kidney transplantation into two groups: exercise intervention (PT) and standard care (CT) as controls. The exercise training program consisted of tailored exercises to be performed under a physiotherapist's supervision for 15 to 30 minutes every second hospital day. At that time, biochemical markers of graft function were assessed including specific tests for atherosclerosis. Repeated measures analysis of variance was performed to determine differences between the two groups. We found an inverse correlation between total homocysteine as well as interleukin-18 (IL:18) levels and muscle strength of the upper limbs (r = -.78, P < .0001). There was a positive correlation between muscle strength and improved graft function in the PT group versus CT groups (r = .05; P < .05). Hyperhomocysteinemia and high IL-18 expression in renal allograft recipients may be independent markers of early atherosclerosis development.

Is there additional effect of MTHFR C677T mutation on lipid abnormalities in renal allograft recipients?

BACKGROUND

The MTHFR C677T mutation and elevated atherogenic lipoprotein levels are known as cardiovascular risk factors in patients with renal transplantation treated with cyclosporine (CsA). The aim of the present study was to eveluate the contribution of MTHFR C677T mutation to the risk of dyslipidemia in renal transplant recipients. We also studied the effect of the MTHFR-C677 T genotype on transplant survival.

METHODS

The study included 29 nondiabetic renal transplant recipients and 27 healthy controls. MTHFR C677T genotypes were determined by PCR and RFLP techniques. Biochemical parameters were measured in a computerized autoanalyzer.

RESULTS

In the patient group, the distribution of the CC, CT, and TT genotypes was 44.8% (n = 13), 37.9% (n = 11), and 17.2% (n = 5), respectively. The frequencies of the C and T alleles were 0.64 and 0.36, respectively. Subjects with the T allele had the highest levels of TC (P <.05) and LDL-C (P <.05); subjects with the CC genotype had the lowest.

CONCLUSIONS

We observed that the MTHFR T allele has an unfavorable effect on serum lipid profile, leading to a rise in the total and LDL cholesterol concentrations. Thus, we believe that MTHFR C allele has a protective effect and MTHFR T allele has a detrimental effect on the serum lipid profile.