Gastric bypass versus best medical treatment for diabetic kidney disease: 5 years follow up of a single-centre open label randomised controlled trial.

Background: We compared the albuminuria-lowering effects of Roux-en-Y gastric bypass (RYGB) to best medical treatment in patients with diabetic kidney disease and obesity to determine which treatment is better. Methods: A 5 year, open-label, single-centre, randomised trial studied patients with diabetic kidney disease and class I obesity after 1:1 randomization to best medical treatment (n = 49) or RYGB (n = 51). The primary outcome was the proportion of patients achieving remission of microalbuminuria after 5 years. Secondary outcomes included improvements in diabetic kidney disease, glycemic control, quality of life, and safety. For efficacy outcomes, we performed an intention-to-treat (ITT) analysis. This study was registered with ClinicalTrials.gov, NCT01821508. Findings: 88% of patients (44 per arm) completed 5-year follow-up. Remission of albuminuria occurred in 59.6% (95% CI = 45.5-73.8) after best medical treatment and 69.7% (95% CI = 59.6-79.8) after RYGB (risk difference: 10%, 95% CI, -7 to 27, P = 0.25). Patients after RYGB were twice as likely to achieve an HbA1c ≤ 6.5% (60.2% versus 25.4%, risk difference, 34.9%; 95% CI = 15.8-53.9, P < 0.001). Quality of life after five years measured by the 36-Item Short Form Survey questionnaire (standardized to a 0-to-100 scale) was higher in the RYGB group than in the best medical treatment group for several domains. The mean differences were 13.5 (95% CI, 5.5-21.6, P = 0.001) for general health, 19.7 (95% CI, 9.1-30.3, P < 0.001) for pain, 6.1 (95% CI, -4.8 to 17.0, P = 0.27) for social functioning, 8.3 (95% CI, 0.23 to 16.3, P = 0.04) for emotional well-being, 12.2 (95% CI, 3.9-20.4, P = 0.004) for vitality, 16.8 (95% CI, -0.75 to 34.4, P = 0.06) for mental health, 21.8 (95% CI, 4.8-38.7, P = 0.01) for physical health and 11.1 (95% CI, 2.24-19.9, P = 0.01) for physical functioning. Serious adverse events were experienced in 7/46 (15.2%) after best medical treatment and 11/46 patients (24%) after RYGB (P = 0.80). Interpretation: Albuminuria remission was not statistically different between best medical treatment and RYGB after 5 years in participants with diabetic kidney disease and class 1 obesity, with 6-7 in ten patients achieving remission of microalbuminuria (uACR <30 mg/g) in both groups. RYGB was superior in improving glycemia, diastolic blood pressure, lipids, body weight, and quality of life. Funding: The study was supported by research grants from Johnson & Johnson Brasil, Oswaldo Cruz German Hospital, and by grant 12/YI/B2480 from Science Foundation Ireland (Dr le Roux) and grant 2015-02733 from the Swedish Medical Research Council (Dr le Roux). Dr Pereira was funded by the Chevening Scholarship Programme (Foreign and Commonwealth Office, UK).

Sex differences and adverse events of antiretrovirals in people living with HIV/AIDS: a systematic review and meta-analysis protocol.

INTRODUCTION: Antiretroviral therapy (ART) for HIV/AIDS is associated with adverse events (AEs). However, little is known about the differences in the risk of AEs between women and men living with HIV/AIDS. This study aims to determine (1) whether there are sex differences in the risk of AEs in people with HIV/AIDS treated with ART and (2) the prevalence of AEs to the reproductive system and bone mineral density in women. METHODS AND ANALYSIS: This systematic review (SR) will include randomised trials evaluating ART in people living with HIV/AIDS with at least 12 weeks of duration follow-up. Searches will be conducted in Medline, Embase, Cochrane Library, Epistemonikos, Lilacs, trial registries and grey literature databases, without restriction on publication status, year of publication and language. The primary outcome will be the risk of ART discontinuation or drop-outs/withdrawals of ART due to AEs and the number of any treatment-emergent AE. The secondary outcomes are the incidence of serious clinic or laboratory (grade 3 and/or 4) treatment-emergent AEs, hospitalisation, death and AEs specific to the reproductive system and bone mineral density (osteoporosis, osteopenia and fractures) of women. Selection, data extraction and quality assessment will be performed by pairs of reviewers. Cochrane collaboration tools will be used to assess the risk of bias. If appropriate, a meta-analysis will be conducted to synthesise results. The overall quality of the evidence for each outcome will be determined by the Grades of Recommendation, Assessment, Development and Evaluation. ETHICS AND DISSEMINATION: The results of this SR will assist the formulation of public policies aimed at the management and monitoring of AEs of ART in people living with HIV/AIDS. A deliberative dialogue will be scheduled with the Department of Chronic Conditions and Sexually Transmitted Infections of Brazil's Ministry of Health to align the project with policymakers' interests. PROSPERO REGISTRATION NUMBER: CRD42021251051.

Efficacy and costs of nanocrystalline silver dressings versus 1% silver sulfadiazine dressings to treat burns in adults in the outpatient setting: A randomized clinical trial.

BACKGROUND: Nanocrystalline silver dressings can reduce the number of changes, facilitating burn wound management. However, the evidence regarding their efficacy and cost-consequences compared to well-established treatments, such as 1% silver sulfadiazine, is still scarce. OBJECTIVE: To determine the efficacy, safety, and costs of nanocrystalline silver dressings compared to 1% silver sulfadiazine dressings to treat adult patients with burns. STUDY DESIGN AND SETTING: Randomized, single-center, single-blind trial conducted at a referral hospital in São Paulo, Brazil. METHODS: 100 adult patients were randomized 1:1 to nanocrystalline silver (n = 50) or 1% silver sulfadiazine (n = 50). The primary outcome was the proportion of participants with complete re-epithelization at day 15 after randomization. Secondary outcomes included the number of dressing changes, direct medical costs (in international dollars, I$), pain intensity, the incidence of infections, number of patients undergoing surgery, and adverse events. RESULTS: On day 15, the proportion of patients who reached the primary outcome did not differ significantly between participants treated with nanocrystalline silver dressings (24 [48%]) and those treated with 1% silver sulfadiazine dressings (26 [52%]); risk difference of -4.0 percentage points (95% confidence interval [CI], -17 to 9; P = 0.56). The number of patients undergoing surgical intervention was similar between groups (6% vs. 6%), and no local or serious adverse events were reported. The mean (standard deviation, SD) number of dressing changes in the nanocrystalline silver group was 4.1 (2.3), and the corresponding estimate in the 1% silver sulfadiazine group was 9.6 (6.7); mean difference of -5.56 (95% CI), -7.57 to -3.55, P < 0.001). Treatment with nanocrystalline silver dressing incurred significant cost reductions in medical materials, human resources, and administrative labor. However, the mean total cost with nanocrystalline silver dressing was higher compared to 1% silver sulfadiazine dressings: I$496.37 (445.90) vs. I$274.73 (182.76); mean difference = 221.63 (95% CI, 89.04 to 354.23, P = 0.001). The main driver of higher mean total costs among nanocrystalline silver-treated participants was the purchase cost of the dressings, representing 79.3% of the total cost in the nanocrystalline silver group but only 15.2% in the 1% silver sulfadiazine group. CONCLUSION: We found no evidence of a difference between nanocrystalline silver and 1% silver sulfadiazine dressings regarding efficacy and safety outcomes. Nanocrystalline silver dressings were associated with an increase in the total costs, but they could result in important savings for an institution (less changes of dressings, reducing human resources burden), especially if acquisition costs can be decreased. Additional cost-effectiveness studies are warranted. TRIAL REGISTRATION NUMBER: NCT02108535.

A Systematic Review and Meta-Analysis of Enzyme Replacement Therapy in Late-Onset Pompe Disease.

Pompe disease (PD) is a glycogen storage disorder caused by deficient activity of acid alpha-glucosidase (GAA). We sought to review the latest available evidence on the safety and efficacy of recombinant human GAA enzyme replacement therapy (ERT) for late-onset PD (LOPD). METHODS: We systematically searched the MEDLINE (via PubMed), Embase, and Cochrane databases for prospective clinical studies evaluating ERT for LOPD on pre-specified outcomes. A meta-analysis was also performed. RESULTS: Of 1601 articles identified, 22 were included. Studies were heterogeneous and with very low certainty of evidence for most outcomes. The following outcomes showed improvements associated with GAA ERT, over a mean follow-up of 32.5 months: distance walked in the 6-min walking test (6MWT) (mean change 35.7 m (95% confidence interval [CI] 7.78, 63.75)), physical domain of the SF-36 quality of life (QOL) questionnaire (mean change 1.96 (95% CI 0.33, 3.59)), and time on ventilation (TOV) (mean change -2.64 h (95% CI -5.28, 0.00)). There were no differences between the pre- and post-ERT period for functional vital capacity (FVC), Walton and Gardner-Medwin Scale score, upper-limb strength, or total SF-36 QOL score. Adverse events (AEs) after ERT were mild in most cases. CONCLUSION: Considering the limitations imposed by the rarity of PD, our data suggest that GAA ERT improves 6MWT, physical QOL, and TOV in LOPD patients. ERT was safe in the studied population. PROSPERO register: 135102.

Brief interventions for older adults (BIO) delivered by non-specialist community health workers to reduce at-risk drinking in primary care: a study protocol for a randomised controlled trial.

INTRODUCTION: Evidence suggests that brief interventions are effective in reducing alcohol consumption among older adults. However, the effectiveness of these interventions when delivered by community health workers (non-specialists) in a primary healthcare setting is unknown. To our knowledge, this will be the first randomised trial to examine this. METHODS AND ANALYSIS: Two hundred and forty-two individuals considered at-risk drinkers (Alcohol Use Disorders Identification Test-Consumption, AUDIT-C score ≥4) will be recruited and randomly allocated to usual care (waiting-list) or usual care plus an intervention delivered by trained community health workers (non-specialists). Seven primary care units (PCUs) in Sao José dos Campos, Brazil. PCUs are part of the Brazilian public healthcare system (Sistema Único de Saúde).Follow-up6 months.OutcomesThe primary outcome will be the proportion of participants considered at-risk drinkers (AUDIT-C score ≥4). Secondary outcomes will include alcohol consumption in a typical week in the last 30 days (in units per week) assessed by the AUDIT, service use questionnaire, cognitive performance-assessed by The Health and Retirement Study Harmonised Cognitive Assessment, physical activity-assessed by the International Physical Activity Questionnaire, depression-assessed by the Geriatric Depression Scale and quality of life-assessed by the Control, Autonomy, Self-realisation and Pleasure-16 instrument. The analysis will be based on intention-to-treat principle. ETHICS AND DISSEMINATION: This study has been approved by the Ethics Committee of the Universidade Federal de São Paulo, CEP/UNIFESP Project n: 0690/2018; CAAE: 91648618.0.0000.5505. All eligible participants will provide informed consent prior to randomisation. The results of this study will be published in relevant peer-reviewed journals and in conference presentations. TRIAL REGISTRATION NUMBER: RBR-8rcxkk.

Effect of Gastric Bypass vs Best Medical Treatment on Early-Stage Chronic Kidney Disease in Patients With Type 2 Diabetes and Obesity: A Randomized Clinical Trial.

Importance: Early-stage chronic kidney disease (CKD) characterized by microalbuminuria is associated with future cardiovascular events, progression toward end-stage renal disease, and early mortality in patients with type 2 diabetes. Objective: To compare the albuminuria-lowering effects of Roux-en-Y gastric bypass (RYGB) surgery vs best medical treatment in patients with early-stage CKD, type 2 diabetes, and obesity. Design, Setting, and Participants: For this randomized clinical trial, patients with established type 2 diabetes and microalbuminuria were recruited from a single center from April 1, 2013, through March 31, 2016, with a 5-year follow-up, including prespecified intermediate analysis at 24-month follow-up. Intervention: A total of 100 patients with type 2 diabetes, obesity (body mass indexes of 30 to 35 [calculated as weight in kilograms divided by height in meters squared]), and stage G1 to G3 and A2 to A3 CKD (urinary albumin-creatinine ratio [uACR] >30 mg/g and estimated glomerular filtration rate >30 mL/min) were randomized 1:1 to receive best medical treatment (n = 49) or RYGB (n = 51). Main Outcomes and Measures: The primary outcome was remission of albuminuria (uACR <30 mg/g). Secondary outcomes were CKD remission rate, absolute change in uACR, metabolic control, other microvascular complications, quality of life, and safety. Results: A total of 100 patients (mean [SD] age, 51.4 [7.6] years; 55 [55%] male) were randomized: 51 to RYGB and 49 to best medical care. Remission of albuminuria occurred in 55% of patients (95% CI, 39%-70%) after best medical treatment and 82% of patients (95% CI, 72%-93%) after RYGB (P = .006), resulting in CKD remission rates of 48% (95% CI, 32%-64%) after best medical treatment and 82% (95% CI, 72%-92%) after RYGB (P = .002). The geometric mean uACRs were 55% lower after RYGB (10.7 mg/g of creatinine) than after best medical treatment (23.6 mg/g of creatinine) (P < .001). No difference in the rate of serious adverse events was observed. Conclusions and Relevance: After 24 months, RYGB was more effective than best medical treatment for achieving remission of albuminuria and stage G1 to G3 and A2 to A3 CKD in patients with type 2 diabetes and obesity. Trial Registration: ClinicalTrials.gov Identifier: NCT01821508.

Efficacy and safety of intravenous laronidase for mucopolysaccharidosis type I: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the efficacy and safety of IV laronidase for MPS I. METHODS: A systematic literature review was performed by searching the ClinicalTrials.gov, MEDLINE/PubMed, EMBASE, LILACS, and Cochrane Library databases, limited to clinical trials published until December 31, 2016. The first inclusion criterion was being a randomized controlled trial (RCT). If < five RCTs were identified, open-label and nonrandomized trials, controlled or uncontrolled (quasi-experimental), including ≥ five patients, and evaluating relevant outcomes defined a priori, would also be included. For meta-analysis, primary inferences were based on random-effects models. Assessment of article quality was performed in accordance with the GRADE criteria. The Cochrane Risk of Bias tool was used to examine the risk of bias for RCTs. RESULTS: The selection phase retrieved 632 articles. During the first phase of selection, 158 had the abstract or full text read for assessment of eligibility, of which nine (two RCTs) were included for qualitative synthesis. Four papers were included in the meta-analysis, which was performed for the following outcomes: occurrence of treatment-emergent or infusion-related adverse events (65%; 95%CI 53, 76), mild in most cases; development of IgG antibodies to laronidase (88%; 95%CI 67, 100); apnea-hypopnea index (not significant-NS), urinary glycosaminoglycans (GAGs) [mean change -65.5 µg/mg creatinine (95%CI -68.8, -62.3)], liver size [mean change -31.03% (95%CI -36.1, -25.9)], left ventricular mass index (LVMI) [mean change -1.8 (95%CI -2.32, -0.25)], and distance covered in the 6-minute walk test (NS). Among the outcomes not included in meta-analysis, we found evidence for benefit of laronidase only on shoulder flexion. CONCLUSIONS: Our findings suggest that IV laronidase effectively reduces urinary GAGs excretion, hepatomegaly and LVMI, and can improve shoulder flexion in MPS I patients. Laronidase appears to be safe in the studied population.

Microvascular Outcomes after Metabolic Surgery (MOMS) in patients with type 2 diabetes mellitus and class I obesity: rationale and design for a randomised controlled trial.

INTRODUCTION: There are several randomised controlled trials (RCTs) that have already shown that metabolic/bariatric surgery achieves short-term and long-term glycaemic control while there are no level 1A of evidence data regarding the effects of surgery on the microvascular complications of type 2 diabetes mellitus (T2DM). PURPOSE: The aim of this trial is to investigate the long-term efficacy and safety of the Roux-en-Y gastric bypass (RYGB) plus the best medical treatment (BMT) versus the BMT alone to improve microvascular outcomes in patients with T2DM with a body mass index (BMI) of 30-34.9 kg/m2. METHODS AND ANALYSIS: This study design includes a unicentric randomised unblinded controlled trial. 100 patients (BMI from 30 to 34.9 kg/m2) will be randomly allocated to receive either RYGB plus BMT or BMT alone. The primary outcome is the change in the urine albumin-to-creatinine ratio (uACR) captured as the proportion of patients who achieved nephropathy remission (uACR<30 mg/g of albumin/mg of creatinine) in an isolated urine sample over 12, 24 and 60 months. ETHICS AND DISSEMINATION: The study was approved by the local Institutional Review Board. This study represents the first RCT comparing RYGB plus BMT versus BMT alone for patients with T2DM with a BMI below 35 kg/m2. TRIAL REGISTRATION NUMBER: NCT01821508; Pre-results.

Alcohol and tobacco consumption concordance and its correlates in older couples in Latin America.

AIM: As little is known about alcohol and tobacco consumption concordance between older spouses in low- and middle-income countries, the present study aimed to estimate this in older couples from five Latin American countries. METHODS: This study is a secondary analysis of data collected between 2003 and 2007 by the 10/66 Dementia Research Group, from 1451 couples aged over 65 years from Cuba, the Dominican Republic, Peru, Mexico and Puerto Rico. Kappa statistic was used to assess the agreement of the behavior beyond chance, and logistic regression models with meta-analyses were used to estimate the factors associated with concordance. RESULTS: The mean age of the total sample was 74.8 years (SD 6.6). The results showed high levels of agreement rates in relation to drinking and smoking (75.9% and 85% of couples, respectively, did not drink or smoke), which were beyond the agreement expected by chance. Increased age was associated with concordance on both being non-drinkers (OR 1.03, 95% CI 1.01-1.05) and non-smokers (OR 1.05, 95% CI 1.02-1.07); and having a larger social network was associated with less likelihood of the couple being non-drinkers (OR 0.93, 95% CI 0.88-0.98). Attending religious meetings was associated with increased likelihood of the couple being non-smokers (OR 1.19, 95% CI 1.01-1.41). Socioeconomic circumstances were not associated with couples' concordance. CONCLUSIONS: Older Latin American couples have high levels of concordance in drinking and smoking habits, which increases with age, and were not associated with socioeconomic circumstances, but were with social network. This knowledge can assist the development of policies and interventions to promote health among this growing population. Geriatr Gerontol Int 2017; 17: 1849-1857.

Predictive Potential of Twenty-Two Biochemical Biomarkers for Coronary Artery Disease in Type 2 Diabetes Mellitus.

We investigated the potential of a panel of 22 biomarkers to predict the presence of coronary artery disease (CAD) in type 2 diabetes mellitus (DM2) patients. The study enrolled 96 DM2 patients with (n = 75) and without (n = 21) evidence of CAD. We assessed a biochemical profile that included 22 biomarkers: total cholesterol, LDL, HDL, LDL/HDL, triglycerides, glucose, glycated hemoglobin, fructosamine, homocysteine, cysteine, methionine, reduced glutathione, oxidized glutathione, reduced glutathione/oxidized glutathione, L-arginine, asymmetric dimethyl-L-arginine, symmetric dimethyl-L-arginine, asymmetric dimethyl-L-arginine/L-arginine, nitrate plus nitrite, S-nitrosothiols, nitrotyrosine, and n-acetyl-ß-glucosaminidase. Prediction models were built using logistic regression models. We found that eight biomarkers (methionine, nitratate plus nitrite, n-acetyl-ß-glucosaminidase, BMI, LDL, HDL, reduced glutathione, and L-arginine/asymmetric dimethyl-L-arginine) along with gender and BMI were significantly associated with the odds of CAD in DM2. These preliminary findings support the notion that emerging biochemical markers might be used for CAD prediction in patients with DM2. Our findings warrant further investigation with large, well-designed studies.

Predictive Potential of Twenty-Two Biochemical Biomarkers forCoronary Artery Disease in Type 2 Diabetes Mellitus

We investigated the potential of a panel of 22 biomarkers to predict the presence of coronary artery disease (CAD) in type 2diabetes mellitus (DM2) patients. The study enrolled 96 DM2 patients with (n = 75) and without (n = 21) evidence of CAD.We assessed a biochemical profile that included 22 biomarkers: total cholesterol, LDL, HDL, LDL/HDL, triglycerides, glucose,glycated hemoglobin, fructosamine, homocysteine, cysteine, methionine, reduced glutathione, oxidized glutathione, reducedglutathione/oxidized glutathione, L-arginine, asymmetric dimethyl-L-arginine, symmetric dimethyl-L-arginine, asymmetricdimethyl-L-arginine/L-arginine, nitrate plus nitrite, S-nitrosothiols, nitrotyrosine, and n-acetyl-𝛽-glucosaminidase. Predictionmodels were built using logistic regression models.We found that eight biomarkers (methionine, nitratate plus nitrite, n-acetyl-𝛽-glucosaminidase, BMI, LDL, HDL, reduced glutathione, and L-arginine/asymmetric dimethyl-L-arginine) along with gender andBMI were significantly associated with the odds of CAD in DM2. These preliminary findings support the notion that emergingbiochemical markers might be used for CAD prediction in patients with DM2. Our findings warrant further investigation withlarge, well-designed studies.

Biomarkers of oxidative stress and endothelial dysfunction in glucose intolerance and diabetes mellitus.

OBJECTIVES: To evaluate biomarkers of endothelial dysfunction and oxidative stress in glucose intolerance (GI) compared to overt diabetes (DM2). DESIGN AND METHODS: 140 volunteers including 96 with DM2, 32 with GI and 12 controls (C) were studied. (*)NO metabolites, (*)NO synthase inhibitors, thiols and N-acetyl-beta-glucosaminidase (NAGase) activity were analyzed by chemiluminescence, capillary electrophoresis, ELISA and colorimetric assay, respectively. RESULTS: (*)NO metabolites were higher in GI (NOx: p=0.03; S-nitrosothiols: p=0.001) and DM2 (p=0.006; p=0.0006) groups in relation to group C, while nitrotyrosine was higher only in the DM2 group in comparison to the other groups. NAGase activity was elevated in GI (p=0.003) and DM2 (p=0.0004) groups in relation to group C, as well as, ADMA (p=0.01; p=0.003) and GSSG (p=0.01; p=0.002). CONCLUSIONS: (*)NO metabolites, (*)NO synthase inhibitors, thiols and NAGase are biomarkers suitable to indicate endothelial dysfunction and oxidative stress in the early stages of impaired response to insulin.

Meta-analysis of the association of 4 angiotensinogen polymorphisms with essential hypertension: a role beyond M235T?

Angiotensinogen (AGT) gene polymorphisms have been linked to increased risk of hypertension, but the data remain controversial. In this study we review the most commonly investigated polymorphisms at the AGT locus (other than M235T) and provide summary estimates regarding their association with essential hypertension, while addressing heterogeneity, as well as publication biases. Data on 26 818 subjects from 46 studies for the 4 most-studied AGT variants (T174M in exon 2 and 3 promoter variants: A-6G, A-20C, and G-217A) were meta-analyzed. Statistically significant associations with hypertension were identified for the T174M (odds ratio [OR]: 1.19; 95% CI: 1.07 to 1.33; P=0.002) and G-217A (OR: 1.37; 95% CI: 1.17 to 1.59; P=0.00006) polymorphisms. A dual but consistent effect was observed for the -20C allele, which was associated with a decreased risk of hypertension in populations of mixed and European ancestries (OR: 0.64; 95% CI: 0.44 to 0.92; P=0.02 and OR: 0.77; 95% CI: 0.65 to 0.91; P=0.003, respectively), but with a 24% increase in the odds of hypertension in Asian subjects (OR: 1.24; 95% CI: 1.04 to 1.48; P=0.02). No association of the A-6G variant with hypertension was detected. Current studies support the notion that single variants at the AGT might modulate the risk of hypertension but indicate caution in interpreting these results because of the putative presence of publication bias and gene-environment interactions.

5,10-Methylenetetrahydrofolate reductase polymorphisms and acute lymphoblastic leukemia risk: a meta-analysis.

There is evidence supporting a role for 5-10 methylenetetrahydrofolate reductase (MTHFR) gene variants in acute lymphoblastic leukemia (ALL). To provide a more robust estimate of the effect of MTHFR polymorphisms on the risk of ALL, we did a meta-analysis to reevaluate the association between the two most commonly studied MTHFR polymorphisms (C677T and A1298C) and ALL risk. All case-control studies investigating an association between the C677T or A1298C polymorphisms and risk of ALL were included. We applied both fixed-effects and random-effects models to combine odds ratio (OR) and 95% confidence intervals (95% CI). Q-statistic was used to evaluate the homogeneity and both Egger and Begg-Mazumdar tests were used to assess publication bias. The meta-analysis of the C677T polymorphism and risk of childhood ALL included 13 studies with a total of 4,894 individuals. Under a fixed-effects model, the TT genotype failed to be associated with a statistically significant reduction of childhood ALL risk (TT versus CT + CC: OR, 0.88; 95% CI, 0.73-1.06; P = 0.18). However, individuals homozygous for the 677T allele exhibited a 2.2-fold decrease in risk of adult ALL (TT versus CT + CC: OR, 0.45; 95% CI, 0.26-0.77; P = 0.004). In both cases, no evidence of heterogeneity was observed. No association between the A1298C variant and susceptibility to both adult and childhood ALL was disclosed. Our findings support the proposal that the common genetic C677T polymorphism in the MTHFR contributes to the risk of adult ALL, but not to the childhood ALL susceptibility.

Influence of ACE I/D gene polymorphism in the progression of renal failure in autosomal dominant polycystic kidney disease: a meta-analysis.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a renal disease characterized by an important variability in clinical course, which cannot be fully explained by the genetic heterogeneity of the disease. Although the role for the angiotensin I-converting enzyme (ACE) insertion/deletion (I/D) polymorphism as a modifier factor in ADPKD renal deterioration has been suggested, direct evidence from genetic association studies remain inconclusive. To provide a more robust estimate of the putative effect of the ACE I/D polymorphism on the renal progression in ADPKD, we performed a meta-analysis pooling data from all relevant studies in which the role of the ACE I/D variant in ADPKD clinical features was evaluated. METHODS: We applied a random-effects model to combine odds ratio and 95% confidence intervals. Q-statistic was used to evaluate the homogeneity, and both Egger's and Begg-Mazumdar tests were used to assess publication bias. RESULTS: Altogether, three distinct meta-analyses were generated using data from 13 studies. Despite the absence of publication bias and the presence of homogeneity among study results, the DD genotype failed to show an influence on risk of end-stage renal disease (ESRD), mean age at ESRD or risk of hypertension in ADPKD patients when compared with I-allele carriers (DD vs ID+II). Likewise, meta-analyses carried out separately for Caucasian and Asian studies showed no indication of an association between the DD genotype and a faster renal deterioration in ADPKD. CONCLUSION: These findings do not support the hypothesis that the enhanced ACE activity associated with the D allele might promote a significantly worse prognosis in patients with ADPKD.

Do polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene affect the risk of childhood acute lymphoblastic leukemia?

Meta-analysis has become an important statistical tool in genetic association studies, since it may provide more powerful and precise estimates. However, meta-analytic studies are prone to several potential biases not only because the preferential publication of "positive'' studies but also due to difficulties in obtaining all relevant information during the study selection process. In this letter, we point out major problems in meta-analysis that may lead to biased conclusions, illustrating an empirical example of two recent meta-analyses on the relation between MTHFR polymorphisms and risk of acute lymphoblastic leukemia that, despite the similarity in statistical methods and period of study selection, provided partially conflicting results.