Solis-Pacheco, Ricardo Cesar

Evidence has raised concerns regarding the association between funding sources and doubtful data. Our main outcome was to analyze trends on funding sources in articles published from 1990 to 2020 in the more influential journals of internal and general medicine. In this meta-epidemiological study, we included peer-reviewed studies from the 10 highest impact journals in general and internal medicine published between January 1990 and February 2020 based on published original research according to the 2018 InCites Journal of Citation Reports, these consisted of the following: The New England Journal of Medicine, The Lancet, JAMA, BMJ, JAMA Internal Medicine, Annals of Internal Medicine, PLOS Medicine, Cachexia, BMC Medicine, and Mayo Clinic Proceedings. Two reviewers working in duplicate extracted data regarding year of publication, study design, and sources of funding. In total, 496 articles were found; of these, 311 (62.7%) were observational studies, 167 (33.7%) were experimental, and 16 (3.2%) were secondary analyses. Percentages of grant sources through the years were predominantly from government (60%), industry (23.83%), and non-governmental (16.06%) organizations. The percentage of industry subsidies tended to decrease, but this was not significant in a linear regression model (r=0.02, p≥0.05). Government and non-government funding sources showed a trend to decrease in the same univariate analysis with both significant associations (r=0.21, p ≤0.001 and r=0.10, p≤0.001, respectively). The main funding source in medical research has consistently been government aid. Despite previous reported data, no association was found between the source of funding and statistically significant results favoring study authors’ hypothesis.

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.