Background Adipokines are reported to participate in many common pathologic processes of glucose dysregulation, such as insulin resistance, β-cell dysfunction, and chronic inflammation. Objective To detect the concentrations of plasma asprosin in subjects with impaired glucose regulation (IGR) and newly diagnosed type 2 diabetes (nT2DM) and its relationship to parameters of glucose and lipid metabolism, insulin resistance, and pancreatic β-cell function. Methods 143 eligible participants were included and were divided into three groups including normal glucose regulation (NGR, n = 52), IGR (n = 40), and nT2DM group (n = 51). The intravenous glucose tolerance test (IVGTT) and clinical and biochemical parameters were measured in all participants. Results Plasma asprosin levels were higher in IGR (82.40 ± 91.06 ng/mL, P < 0.001) and nT2DM (73.25 ± 91.69 ng/mL, P < 0.001) groups compared with those in the NGR (16.22 ± 9.27 ng/mL) group, especially in IGR subjects. Correlation analysis showed that plasma asprosin levels were positively correlated with waist circumference (Wc), fasting plasma glucose (FPG), postchallenge plasma glucose (2hPG), HbA1c, triglyceride (TG), and homeostasis model assessment for insulin resistance (HOMA-IR) and negatively correlated with homeostasis model assessment for β-cell function (HOMA-β), area under the curve of the first-phase (0–10 min) insulin secretion (AUC), acute insulin response (AIR), and glucose disposition index (GDI) (all P < 0.05). Multiple logistical regression analyses revealed that plasma asprosin concentrations were significantly correlated with IGR and nT2DM after controlling for age, sex, BMI, and WHR. Conclusions Circulating asprosin might be a predictor of early diagnosis in DM and might be a potential therapeutic target for prediabetes and T2DM.

Background Increasing evidence indicates that the gut microbiota contributes to the occurrence and development of metabolic diseases. However, little is known about the effects of commonly used antidiabetic agents on the gut microbiota. In this study, we investigated the roles of dipeptidyl peptidase-4 inhibitors (DPP-4i) and α-glucosidase inhibitor in modulating the gut microbiota. Methods 16S-rDNA sequencing was performed to analyse the effects of DPP-4i and acarbose on the gut microbiota in mice fed a high-fat diet (HFD). Fecal microbiota transplantation (FMT) from type 2 diabetes patients to germ-free mice was performed to investigate the contribution of the altered microbiome to antidiabetic effects of the drugs. Fecal metabolomics was also analysed by untargeted and targeted GC–MS systems. Findings Although DPP-4i and α-glucosidase inhibitor both altered the gut microbial composition, only the microbiome modulation of DPP-4i contributed to its hypoglycemic effect. Specifically, the changes of 68.6% genera induced by HFD were rescued by DPP-4i. FMT showed that the DPP-4i-altered microbiome improved glucose tolerance in colonized mice, while acarbose did not. Moreover, DPP-4i increased the abundance of Bacteroidetes, and also promoted a functional shift in the gut microbiome, especially increasing the production of succinate. Interpretation Our findings demonstrate an important effect of DPP-4i on the gut microbiota, revealing a new hypoglycemic mechanism and an additional benefit of it. Furthermore, modulating the microbial composition, and the functional shift arising from changes in the microbiome, might be a potential strategy for improving glucose homeostasis. Fund This work was supported by grants from the National Natural Science Foundation of China (No. 81700757, No. 81471039, No. 81700714 and No. 81770434), the National Key R&D Program of China (No. 2017YFC1309602, No. 2016YFC1101100, No. 2017YFD0500503 and No. 2017YFD0501001), and the Natural Science Foundation of Chongqing (No. cstc2014jcyjjq10006, No. cstc2016jcyjA0093 and No. cstc2016jcyjA0518).

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