Effect of metformin on microvascular outcomes in patients with type 2 diabetes: A systematic review and meta-analysis.

AIMS: Examine the efficacy of metformin compared to placebo or other glucose-lowering medications on microvascular outcomes in patients with Type 2 Diabetes Mellitus (T2DM). METHODS: MEDLINE, EMBASE, Web of Science, and Scopus were searched from database inception to March 2020. We included randomized clinical trials of patients with T2DM receiving metformin compared with another active glucose-lowering treatment or placebo in which a microvascular outcome was assessed. The risk of bias was assessed using the Cochrane Risk of Bias tool. Microvascular complications included kidney-related outcomes, retinopathy, and peripheral neuropathy. An inverse-weighted variance random-effect meta-analysis was performed to estimate drugs effect over microvascular disease. PROSPERO (CRD42019120365). RESULTS: Nineteen RCTs (n = 18,181) were included. Metformin increased estimated glomerular filtration rate (eGFR) by a mean difference (MD) of 1.08 (95% CI 0.84 to 1.33 ml/min/1.73 m2) after 24 weeks. No effect was found on urinary albumin-creatinine ratio, serum creatinine, and end-stage kidney disease; Patient-important outcomes regarding kidney disease, retinal outcomes, peripheral neuropathy or quality of life were not assessed by any of the included studies and could not be analyzed. CONCLUSIONS: There is no evidence of clinically significant beneficial effect of metformin therapy as compared to other glucose-lowering medications or placebo on the examined microvascular complications.

Values, preferences and burden of treatment for the initiation of GLP-1 receptor agonists and SGLT-2 inhibitors in adult patients with type 2 diabetes: a systematic review.

OBJECTIVES: Assess values, preferences and burden of treatment that patients with type 2 diabetes consider when initiating glucagon-like peptide-1 receptor agonists (GLP-1 RA) or sodium-glucose cotransporter-2 inhibitors (SGLT-2i) compared with other glucose-lowering options. METHODS: Paired reviewers independently included studies reporting quantitative or qualitative methods to assess values, preferences and burden of treatment reported by patients with type 2 diabetes regarding the initiation of GLP-1 RA or SGLT-2i over other alternatives. A systematic search in MEDLINE, Scopus, EMBASE, Web of Science and Cochrane Central Register of Controlled Trials from inception until May 2020 was performed by an experienced librarian. Risk of bias was assessed with a specifically designed tool for values and preferences studies. RESULTS: 17 studies (7296 patients) proved eligible. Studies fulfilling criteria for SGLT-2i were not identified. Five studies (2662 patients) evaluated preferences for GLP-1 RA compared with other glucose-lowering medications. 12 studies (4634 patients) evaluated preferences between, at least, two kinds of GLP-1 RA or their injection devices based on the following attributes: efficacy, dose, application frequency, device characteristics. Among studies comparing GLP-1 RA to other glucose-lowering medications, some preferences were observed for dypeptil peptidase-4 inhibitors compared with once daily liraglutide. Comparing different attributes of GLP-1 RA drugs and devices, cardiovascular risk reduction, glucose lowering potential, once weekly and simple administered regimens were the most preferred. CONCLUSIONS: As no evidence for preferences on SGLT-2i was available, only preferences for GLP-1 RA were assessed; however, evidence is still limited for the latter. Studies comparing preferences for GLP1-RA to other glucose-lowering alternatives only included twice daily or once daily injection regimens of GLP-1 RA drugs. According to our findings, once weekly alternatives are widely preferred than the formers. The extent to which patients with type 2 diabetes value reduced adverse cardiovascular and kidney outcomes, weighed benefits against harms and burden of treatment is limited and with very low certainty. PROSPERO REGISTRATION NUMBER: CRD42020159284.

Diagnostic Accuracy of the Triglyceride and Glucose Index for Insulin Resistance: A Systematic Review.

Introduction. The triglyceride and glucose (TyG) index has been described as a biochemical marker of insulin resistance (IR); however, its diagnostic accuracy remains uncertain. OBJECTIVE: To summarize the evidence assessing the diagnostic accuracy of the TyG index regarding IR. METHODS: A comprehensive search in MEDLINE, EMBASE, Web of Science, and Scopus was performed without any language restriction. Studies assessing the diagnostic accuracy of the TyG index against the hyperinsulinemic-euglycemic clamp (HIEC) or any other IR biochemical were assessed independently and in duplicate. Diagnostic accuracy measures (sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratios) were extracted independently and in duplicate. The QUADAS-2 tool was used to assess the risk of bias of independent studies. RESULTS: We identified 15 eligible studies with 69,922 participants and an overall quality of low to moderate. The TyG index was evaluated by HIEC and HOMA as reference tests. The highest achieved sensitivity was 96% using HIEC, and the highest specificity was of 99% using HOMA-IR, with a cutoff value of 4.68. AUC values varied from 0.59 to 0.88. Cutoff values for IR were variable between studies, limiting its comparability. CONCLUSION: In this systematic review, we found moderate-to-low quality evidence about the usefulness of the TyG index as a surrogate biochemical marker of IR. Due to the lack of a standardized IR definition and heterogeneity between studies, further validation and standardized cutoff values are needed to be used in clinical practice.

Hypertriglyceridemia and Its Association with HbA1c Test: A Prospective In Vivo Controlled Study.

BACKGROUND: Hypertriglyceridemia and hyperglycemia coexist in 30-60% of patients with diabetes. The impact of hypertriglyceridemia regarding HbA1c assay reliability remains uncertain. Therefore, we conducted a prospective in vivo controlled study with the aim of defining the association between triglyceride levels and HbA1c. METHODS: A total of 44 patients with an index-hospital admission diagnosis of diabetic ketoacidosis or hypertriglyceridemia-induced pancreatitis, as a model for acute elevation of triglycerides, were recruited. Blood samples were drawn for the measurement of HbA1c, triglycerides, glucose, and hemoglobin at baseline and subsequently 24 and 48 hours after admission. HbA1c analysis was performed with high-performance liquid chromatography Bio-Rad D10 (NGSP approved). RESULTS: All patients completed the study protocol. A difference between mean triglycerides from day 0 (baseline) to day 2 of 1567.2 mg/dL was observed. We found a difference between mean serum HbA1c from days 0 to 2 of 0.09% [1 mmol/mol] (p = 0.004). Moreover, a weak correlation between the mean difference of HbA1c and triglycerides from baseline to day 2 was found to be statistically significant (r = 0.256, p = 0.015). None of these findings, however, are clinically significant. CONCLUSION: Triglycerides do not impair the interpretation of HbA1c assay. Patients and clinicians can now be confident that hypertriglyceridemia is not an important factor when interpreting HbA1c results.

Trustworthiness of randomized trials in endocrinology-A systematic survey.

BACKGROUND: Trustworthy (i.e. low risk of bias) randomized clinical trials (RCTs) play an important role in evidence-based decision making. We aimed to systematically assess the risk of bias of trials published in high-impact endocrinology journals. METHODS: We searched the MEDLINE/PubMed database between 2014 and 2016 for phase 2-4 RCTs evaluating endocrine-related therapies. Reviewers working independently and in duplicate used the Cochrane Risk of Bias Tool (CCRBT) to determine the extent to which the methods reported protected the results of each RCT from bias. RESULTS: We assessed 292 eligible RCTs, of which 40% (116) were judged to be at low risk, 43% (126) at moderate, and 17% (50) at high risk of bias. Blinding of outcome assessment was the least common domain reported 43% (125), while selective reporting of outcomes was the most common 97% (282). In multivariable analysis, RCTs with a parallel design (OR 2.4; 95% CI; 1.2-4.6) and funded by for-profit sources (OR 2.2; 95% CI; 1.3-3.6) were more likely to be at low risk of bias. CONCLUSIONS: Trustworthy evidence should ultimately shape care to improve the likelihood of desirable patient outcomes. Six out-of 10 RCTs published in top endocrine journals are at moderate/high-risk of bias. Improving this should be a priority in endocrine research.

Systematic review and meta-analysis of the effect of SGLT-2 inhibitors on microvascular outcomes in patients with type 2 diabetes: a review protocol.

INTRODUCTION: Sodium glucose cotransporter 2 (SGLT-2) inhibitors are a relatively new drug-class of glucose-lowering medications. Several trials and systematic reviews have demonstrated their beneficial effect on some macrovascular outcomes. Their effect on microvascular outcomes has been reported as positive in several trials, however, their effect remains uncertain. Therefore, we report the protocol of a systematic review and meta-analysis aimed at determining the effect of SGLT-2 inhibitors regarding patient-important and surrogate microvascular outcomes in patients with type 2 diabetes. METHODS AND ANALYSIS: A comprehensive search will be conducted to find eligible articles from each database's earliest inception to November 2017. These databases will include Ovid, MEDLINE, EMBASE, Web of Science, and Scopus. We will search for randomized controlled trials (RCTs) that compare any of the SGLT-2 inhibitors with any other active treatment or placebo assessing microvascular outcomes in either their primary or secondary outcomes. Reviewers working independently and in duplicate will review all abstracts, and full-text manuscripts for eligibility, and will systematically extract the data and will assess the risk of bias in the included studies. Random-effects models will also be used. ETHICS AND DISSEMINATION: The results of the systematic review will be disseminated via publication in a peer-reviewed journal regardless of outcome and will be presented at relevant conferences. The data we will use do not include individual patient data, so ethical approval is not required PROSPERO REGISTRATION NUMBER: CRD42017076460.

Perineural spread-susceptible structures: a non-pathological evaluation of the skull base.

Perineural spread adenoid cystic carcinoma can alter the dimension of foramina and canals of the skull base. The objective of this study was to determine the range of normal variation of the foramina and canals of both hemicranium. We analyzed 200 individuals with no alterations of the skull base in a retrospective manner using high-resolution computed tomography. We measured the short and long axis diameters of the foramen rotundum (FR), foramen ovale (FO), stylomastoid foramen (SMF), pterygoid canal (PTC), internal auditory canal (IAC), and the facial nerve canal in its labyrinthine portion (LPFC) to calculate the area in each hemicranium, compare them and obtain the normal range of asymmetry. Parametric and non-parametric comparison tests were realized. The structures that had the lowest range of asymmetry were the LPFC (0.00-0.79 mm2) and the FR (0.00-2.12 mm2). The one that had the highest asymmetry range was the FO (0.00-9.16 mm2). Significant differences were found in the FO (p = 0.01) and the IAC (p = 0.00) in the gender comparison. We determined a normal asymmetry range of the susceptible foramina and canals of the skull base. This study reports a useful and objective measure to differentiate anatomical from pathological variations of the foramina and canals of the skull base by age and gender. Our results establish a basis for future studies that evaluate this range as a diagnostic tool of metastasis in the skull base as a complement of other imaging techniques.