Cancer Signaling Transcriptome Is Upregulated in Type 2 Diabetes Mellitus

Overview of Transcriptomic Research on Type 2 Diabetes: Challenges and Perspectives

Type 2 diabetes (T2D) is a common chronic disease whose etiology is known to have a strong genetic component. Standard genetic approaches, although allowing for the detection of a number of gene variants associated with the disease as well as differentially expressed genes, cannot fully explain the hereditary factor in T2D. The explosive growth in the genomic sequencing technologies over the last decades provided an exceptional impetus for transcriptomic studies and new approaches to gene expression measurement, such as RNA-sequencing (RNA-seq) and single-cell technologies. The transcriptomic analysis has the potential to find new biomarkers to identify risk groups for developing T2D and its microvascular and macrovascular complications, which will significantly affect the strategies for early diagnosis, treatment, and preventing the development of complications. In this article, we focused on transcriptomic studies conducted using expression arrays, RNA-seq, and single-cell sequencing to highlight recent findings related to T2D and challenges associated with transcriptome experiments.

Polyunsaturated fatty acid intake and incidence of type 2 diabetes in adults: a dose response meta-analysis of cohort studies

BACKGROUND

To evaluate the association and dose-response relationship between polyunsaturated fatty acid (PUFA) intake and incidence of type 2 diabetes (T2D) in adults.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched for cohort studies that examined the association between PUFA and T2D incidence published up to September 6, 2021. Relative risk (RR) or hazard ratio (HR) was used as the effect indicator, each effect size was expressed by 95% confidence interval (CI). The presence of heterogeneity of effect size between studies was assessed by the Q-test and I² statistics. If I² ≥ 50%, the random-effects model was applied, otherwise the fixed effects model was used. Sensitivity analysis was performed for all models. Potential publication bias was assessed. We conducted linear and nonlinear dose-response meta-analyses, calculated summary relative risk (SRR).

RESULTS

Twenty-five articles were selected including 54,000 patients in this study. Our estimates observed no linear associations between total PUFA and the incidence of T2D. However, the summary dose-response curve of T2D risk increased in a nonlinear pattern with the consumption of omega-3 PUFA (P_nonlinearity < 0.001) and docosahexaenoic acid (DHA) (P_nonlinearity = 0.040). Our subgroup analysis showed that total PUFA intake was associated with increased incidence of T2D in Europe (RR: 1.040, 95% CI 1.009 to 1.072), and Australia (RR: 1.188, 95% CI 1.113 to 1.269). However, total PUFA intake was associated with decreased T2D incidence in Asia (RR: 0.897, 95% CI 0.860 to 0.936). Subgroup analysis based on PUFA types showed that DHA intake was associated with decreased T2D incidence (RR: 1.164, 95% CI 1.048 to 1.294) while linoleic acid (LA) decreased T2D incidence (RR: 0.956, 95% CI 0.930 to 0.983). Regarding the sex subgroup, women's intake of total PUFA would increase the risk of T2D (RR: 1.049, 95% CI 1.019 to 1.079) while total PUFA intake decreased the risk of T2D in men (RR: 0.955, 95% CI 0.913 to 0.999).

CONCLUSION

For specific PUFA, dose-response curves show nonlinear significant associations between PUFA intakes and T2D. It may be necessary to pay attention to the effects of PUFA and type of intake on T2D. Trial registration Not applicable.