González-Colmenero, Alejandro Díaz

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.

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.

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.