Resistive index of renal artery and blood pressure in postmenopausal women

Relationship of MTHFR gene polymorphisms with renal and cardiac disease

AIM: To investigate the effects of different methylenetetrahydrofolate reductase (MTHFR) 677C>T gene polymorphism and hyperhomocysteinemia for the development of renal failure and cardiovascular events, which are controversial.

METHODS: We challenged the relationship, if any, of MTHFR 677C>T and MTHFR 1298A>C polymorphisms with renal and heart function. The present article is a reappraisal of these concepts, investigating within a larger population, and including a subgroup of dialysis patients, if the two most common MTHFR polymorphisms, C677T and A1298C, as homozygous, heterozygous or with a compound heterozygous state, show different association with chronic renal failure requiring hemodialysis. MTHFR polymorphism could be a favorable evolutionary factor, i.e., a protective factor for many ominous conditions, like cancer and renal failure. A similar finding was reported in fatty liver disease in which it is suggested that MTHFR polymorphisms could have maintained and maintain their persistence by an heterozygosis advantage mechanism. We studied a total of 630 Italian Caucasian subject aged 54.60 ± 16.35 years, addressing to the increased hazard of hemodialysis, if any, according to the studied MTHFR genetic polymorphisms.

RESULTS: A favorable association with normal renal function of MTHFR polymorphisms, and notably of MTHFR C677T is present independently of the negative effects of left ventricular hypertrophy, increased Intra-Renal arterial Resistance and hyperparathyroidism.

CONCLUSION: MTHFR gene polymorphisms could have a protective role on renal function as suggested by their lower frequency among our dialysis patients in end-stage renal failure; differently, the association with left ventricular hypertrophy and reduced left ventricular relaxation suggest some type of indirect, or concurrent mechanism.

Sustainable medical research by effective and comprehensive medical skills: overcoming the frontiers by predictive, preventive and personalized medicine

Background

Clinical research and practice require affordable objectives, sustainable tools, rewarding training strategies and meaningful collaboration.

Method

Our unit delivers courses on project design and management promoting ideas, useful skills, teaching and exploring implementation of networks and existing collaborations. We investigated the effectiveness of a sustainable approach of comprehensive diagnosis and care and its usefulness within concrete models of research project teaching methodology.

Results

The model of predictive, preventive and personalized medicine (PPPM) of adolescent hypertension, developed since 1976 and still active, was displayed. This is a paradigm of comprehensive PPPM aimed at the management of a recognized, but actually neglected, societal and clinical problem. The second model was addressed to the analysis of performance of an outpatient diagnostic and therapy unit and its relationship with the emergency department. Part of the patients, 4,057 cancer patients presenting at the emergency care, were addressed to the outpatient diagnostic and therapy unit for further assessment, treatment and follow-up. The stay in DH was 6.3 ± 2.1 non-consecutive days, with shortage of costs, vs. in-hospital stays. Research planning courses, based on these models, ensued in an increase of competitive project submission and successful funding.

Discussion

Active promotion of interdisciplinary knowledge and skills is warranted. Misleading messages and information are detrimental not only to healthy and sick people but, equally, to all health professionals: efforts for basing on evidence by research any statement are needed. The actual pre-requisite of personalized medicine is the coherent and articulated promotion of the professional quality of staff. Health professionals should and can be skilled in sustainable non-invasive diagnostic procedures, in non-pharmacological intervention, in translational research (from epidemiology to personalized therapy) and in timely dissemination of the information.

Conclusion

Recommendations are provided according to PPPM: proposed models are based on financial sustainability and patient's satisfaction criteria and are addressed to research projects and dissemination also by e-learning. The guidelines of the EU calls in personalized medicine are able to provide a critical added value by accurate planning, transparency of assessment and unbiased reports, dissemination and exploitation.

Renal insufficiency in non-diabetic subjects: relationship of MTHFR C677t gene polymorphism and left ventricular hypertrophy

BACKGROUND

Association of methylenetetrahydrofolate reductase (MTHFR) 677C>T gene polymorphism with hyperhomocysteinemia, renal failure, and cardiovascular events is controversial. We investigated the relationship of MTHFR 677C>T polymorphisms with left ventricular hypertrophy (LVH) and renal insufficiency.

METHODS

Glomerular filtration rate (GFR) and left myocardial ventricular mass/m2 were assessed in 138 non-diabetic subjects (age, 50.93 ± 14.85 years; body mass index, 27.95 ± 5.98 kg/m(2)), 38 no-mutation wild MTHFR C677CC, 52 heterozygous MTHFR C677CT, and 48 homozygous MTHFR C677TT, all with adequate adherence to current international healthy dietary guidelines. Serum homocysteine, insulin resistance, high-sensitivity C-reactive-protein (hsCRP), parathyroid hormone, and renal artery resistive index (RRI) were challenged by odds ratio analysis and multiple linear regression models.

RESULTS

MTHFR 677C>T polymorphism showed higher GFR (73.8 ± 27.99 vs. 58.64 ± 29.95; p= 0.001) and lower renal failure odds (OR, 0.443; 95% confidence interval, 0.141-1.387) in comparison with wild MTHFR genotype. A favorable effect on GFR of MTHFR polymorphism is presented independently by the negative effects of LVH, increased intra-renal arterial resistance, and hyperparathyroidism; GFR is the significant predictive factor to LVH.

CONCLUSIONS

Renal insufficiency in non-diabetic subjects is explained by interactions of MTHFR C677T polymorphism mutation with LVH, hsCRP, intact parathyroid hormone (iPTH), and RRI. Sign of these predictive effects is opposite: subjects with MTHFR 677C>T polymorphism have lower likelihood of renal insufficiency; differently, wild-type MTHFR genotype subjects have lower GFR and greater hsCRP, iPTH, RRI, and LVH.

Renal resistive index and parathyroid hormone relationship with renal function in nondiabetic patients

INTRODUCTION

The renal resistive index (RRI) reflects intrarenal vascular resistance and stiffness, which are associated with chronic kidney disease. The links connecting renal function, intrarenal arterial resistance, and parathyroid hormone (PTH) with hypertension and metabolic factors remain elusive. The aim of this study is to investigate the possible relationship of RRI with glomerular filtration rate, PTH, hypertension, obesity (body mass index and waist-to-hip ratio), bioelectrical impedance analysis in body composition assessment, serum lipids, and insulin resistance assessed by homoeostasis model insulin resistance index.

PATIENTS AND METHODS

This study was carried out on 387 (246 women, 141 men) nondiabetic patients, between >25 and <75 years, referred to an Internal Medicine Clinic and Day Hospital for essential hypertension, overweightness-obesity, and/or dyslipidemia. Lower salt/lower calorie Mediterranean diet, physical activity increase, smoking withdrawal, and lifestyle counseling, provided by a health psychologist support, were prescribed.

RESULTS

Higher hypertension risk, present in 42.5% of the overall group of eligible patients (164/387), is associated with high PTH and high RRI, along with greater renal insufficiency, insulin resistance, and obesity. There is a straight linear relationship of RRI to PTH (0.202; p=0.009) in arterial hypertension, which is not observed in normal blood pressure patients. By gender-adjusted multiple linear regression analysis, it was found that fat mass, waist-to-hip ratio, and PTH account significantly for 62.3% of the variance to RRI in hypertensive patients.

CONCLUSION

Increased arterial stiffness and intrarenal arterial resistance are associated with higher PTH in arterial hypertension; obesity (defined by greater fat mass and waist-to-hip ratio) and PTH are the independent conditions that account significantly for higher RRI.

Renal function and severity of bright liver. Relationship with insulin resistance, intrarenal resistive index, and glomerular filtration rate

AIMS

Relationships of renal function and liver disease are described in acute and chronic liver failure. The aim of the study is to investigate which relationship, if any, is present between severity of non-alcoholic fatty liver disease (NAFLD), assessed by bright liver score (BLS) versus mild-moderate renal insufficiency assessed by glomerular filtration rate (GFR) and by ultrasound intra-renal arterial resistive index (RRI). Moreover, which difference, if any, can be found in NAFLD patients with normal versus increased transaminases.

PATIENTS

The study enrolled 323 NAFLD and 176 non-NAFLD consecutive patients, comparable for age, gender distribution, GFR, and RRI referred to a university clinical day hospital after an ultrasound diagnosis of bright liver, for clinical-nutritional counselling. Personalized computerized mediterranean diet, physical activity increase, and smoking withdrawal integrated counselling were provided.

RESULTS

In NAFLD patients, homoeostasis model (HOMA) has a significant correlation with BLS. According to the severity of BLS, grade II-III versus grade I patients have significantly higher values of HOMA, body mass index (BMI), triglycerides, and longitudinal right liver length. By odds ratio, more severe BLS, increased HOMA, and transaminases are associated with lower GFR. Increased transaminases are associated with higher grades of BLS, HOMA, and BMI. By multiple linear regression waist-to-hip ratio, RRI, and BLS, as significant independent factors (p < 0.0001), explain significantly variance to GFR. This is not observed in normal control group, in which only RRI is a factor explaining GFR.

CONCLUSION

Greater RRI, abdominal obesity, and greater BLS account for a lower GFR in NAFLD patients suggesting the hypothesis that inter-related factors can be operating early in the natural history of obesity-related kidney and liver disease.

Lifestyle interventions, insulin resistance, and renal artery stiffness in essential hypertension

The study investigates lifestyle and effective anti-hypertensive intervention in overweight-obese patients can influence insulin-resistance (HOMA-IR) and US Renal-Resistive-Index (RRI). After a 1-year interventional program (including a personalized Mediterranean diet, physical activity increase, smoking withdrawal counseling), 156 Essential Hypertension (EH) patients still have abnormal HOMA-IR, significantly higher in comparison to 159 control group patients. Body mass index (BMI) and cholesterol-high-density-lipoprotein improvement are the best predictors of a HOMA-IR decrease; RRI improves in EH according to lifestyle interventions, but no predictor to RRI is identified. Persistence of IR can be tentatively assumed as a steady sign, persistent also after extended lifestyle intervention in EH, further warranting more intensive dietary interventions.

Long-term effects of percutaneous nephrolithotomy on renal morphology and arterial vascular resistance as evaluated by color Doppler ultrasonography: preliminary report

We evaluated the long-term effects of percutaneous nephrolithotomy (PNL) on renal morphology and vascular resistance. Parenchyma thickness, echogenicity and resistive index (RI) of upper, middle and lower poles of operated and contralateral kidneys of 41 patients with 82 renal units who underwent unilateral PNL with single pole access between 2000 and 2002 were examined separately by color Doppler ultrasonography. Mean patient age and duration between PNL and evaluation time were 38.29+/-11.53 years and 46.44+/-10.9 months, respectively. In operated kidney, mean RI, parenchyma thickness and echogenicity of the access pole were not statistically different than those of the adjacent two poles (0.608+/-0.053 vs. 0.608+/-0.052 for RI, P=0.895; 11.46+/-2.58 vs. 11.41+/-2.68 mm for parenchyma thickness, P=0.838; 0.049+/-0.31 vs. 0.073+/-0.33 for parenchyma echogenicity, P=0.160, respectively). Although mean RI and parenchyma thickness of access pole were statistically significantly different than the mean values of contralateral kidney (0.562+/-0.032 and 14.31+/-1.37 mm, respectively), no statistical difference was found between mean parenchyma echogenicities of both of them (echogenicity of contralateral kidney was 0, P=0.317). No significant difference was found between the average echogenicities of the three poles of the operated and contralateral kidneys (0.063+/-0.32 vs. 0, P=0.080). In 14 patients RI decreased from 0.694+/-0.058 to 0.602+/-0.056 in operated kidney (P=0.001) and from 0.604+/-0.06 to 0.559+/-0.031 in contralateral kidney (P=0.018) following PNL. It seems that PNL does not cause renal scarring, renal parenchymal loss or increase in renal vascular resistance in the long term. However, prospective studies must be performed for more definitive conclusions.

An association between the methylenetetrahydrofolate reductase (MTHFR) C677T mutation and inflammation markers related to cardiovascular disease

BACKGROUND

Prospective studies have identified many markers of systemic inflammation that are powerful predictors of future cardiovascular events. The methylenetetrahydrofolate reductase (MTHFR) C677T genotype, a common polymorphism that induces hyperhomocysteinaemia, has been proposed as a genetic risk factor for cardiovascular disease. In this work, we evaluated the relationship between the levels of inflammation markers and MTHFR genotype among cardiovascular disease free subjects of the ATTICA study.

METHODS

During 2001-2002, we randomly enrolled for genetic evaluation 574 subjects from Attica region, Greece. In this work, we investigated demographic, lifestyle, clinical, biochemical and genetic information from 322 men (46+/-13 years) and 252 women (45+/-14 years). Among other characteristics, we measured various inflammatory markers levels in relation to C677T MTHFR genotype distribution.

RESULTS

The MTHFR genotypes distribution was: homozygous normal (CC) genotype, 41%; heterozygous (CT), 48%; and homozygous mutant (TT) genotype, 11%. C-reactive protein (CRA), fibrinogen, white blood cell (WBC) counts and amyloid-a levels were higher in TT compared to CC and CT genotypes (p<0.01), in both genders, even after controlling for various potential confounders.

CONCLUSION

The observed association between markers of systemic inflammation with MTHFR genotype may state a hypothesis for a common pathobiological mechanism between inflammation process and MTHFR, which is a key enzyme in homocysteine (Hcy) metabolism.

Color Doppler sonography examination of partially obstructed kidneys associated with ureteropelvic junction stone before and after percutaneous nephrolithotripsy: Preliminary report

AIM

To evaluate resistive index (RI) changes before and after unilateral percutaneous nephrolithotripsy in chronic partially obstructed kidneys due to ureteropelvic junction (UPJ) stones.

METHODS

Intrarenal RI of obstructed and contralateral normal kidneys of 18 patients were recorded immediately before the operations and at postoperative days 1, 7 and 30. Postoperative RI measurements were compared with baseline values for all patients without grouping and separately for different groups according to the preoperative RI value of the obstructed kidney.

RESULTS

Mean age and symptom duration were 27.5 years and 43.8 weeks, respectively. Preoperatively and at all postoperative controls, kidney diameters and renal parenchyma thicknesses were normal in all patients. Mean RI of obstructed kidneys decreased from 0.68 to 0.63 for all patients (P=0.032), from 0.64 to 0.63 for those with preoperative RI<0.70 (P=0.850) and from 0.73 to 0.62 for those with preoperative RI>or=0.70 (P=0.001). In patients with preoperative RI>or=0.70 in obstructed kidney, significant RI decreases were recorded at postoperative day 7 and RI differences between obstructed and contralateral kidneys disappeared after then. No difference was present pre- and postoperatively between the mean RI of obstructed and contralateral kidneys of the patients with RI<0.70. Mean RI of contralateral kidneys were normal preoperatively and showed no significant change postoperatively.

CONCLUSIONS

Preoperative RI levels may indirectly reflect the presence of functionally significant obstruction in chronic obstructed kidneys related to UPJ stones. Patients with RI>or=0.70 may have a good indication for a surgical approach. Normalization of high RI occurs rapidly after percutaneous nephrolithotripsy.

Estrogen neuroprotection against the neurotoxic effects of ethanol withdrawal: potential mechanisms

Ethanol withdrawal (EW) produces substantial neurotoxic effects, whereas estrogen is neuroprotective. Given observations that both human and nonhuman female subjects often show less impairment following EW, it is reasonable to hypothesize that estrogens may protect females from the neurotoxic effects of ethanol. This article is based on the assumption that the behavioral deficits seen following EW are produced in part by neuronal death triggered by oxidative insults produced by EW. The EW leads to activation of protein kinase C, especially PKCepsilon, which subsequently triggers apoptotic downstream events such as phosphorylation of nuclear factor-kappaB (NFkappaB) complex. On phosphorylation, active NFkappaB translocates to the nucleus, binds to DNA, and activates caspases, which trigger DNA fragmentation and apoptosis. In contrast, estrogens are antioxidant, inhibit overexpression of PKCepsilon, and suppress expression of NFkappaB and caspases. Estrogen treatment reduces the behavioral deficits seen during EW and attenuates molecular signals of apoptosis. The effects of ethanol and estrogen on each step in the signaling cascade from ethanol exposure to apoptosis are reviewed, and potential mechanisms by which estrogen could produce neuronal protection against the neurotoxicity produced by EW are identified. These studies serve as a guide for continuing research into the mechanisms of the neuroprotective effects of estrogen during EW and for the development of potential estrogen-based treatments for male and female alcoholics.