Efficacy and Safety Study of Linagliptin in Brittle Diabetes Mellitus Combined with Early Diabetic Nephropathy Treated with Dendrobium Polysaccharide Extracts

Objectives: Linagliptin reduces blood glucose levels, but its efficacy in brittle diabetes mellitus with early diabetic nephropathy (BDM-EDN) remains unclear. Therefore, this study investigated the efficacy and safety of linagliptin in BDM-EDN treated with Dendrobium polysaccharide extract. Materials and Methods: From January 2020 to December 2022, 90 BDM-EDN patients admitted to the endocrinology department of our hospital were selected and equally divided into a control group, a Dendrobium polysaccharide (10 mg/d) group, and a Dendrobium polysaccharide (10 mg/d) + linagliptin (5 mg/d) group using a random number table method. After 12 weeks of continuous treatment, serum indicators were measured, and an enzyme-linked immunosorbent assay (ELISA) was used to examine the levels of inflammatory factors. Polymerase chain reaction (PCR) detected HMGN1 and toll-like receptor 4 (TLR4) expressions. Fifteen BDM-EDN model mice were constructed and equally divided into Dendrobium polysaccharide (10 mg/d) + CRX-527 (an agonist of the HMGN1/TLR4 pathway, 0.1 mg) group and Dendrobium polysaccharide (10 mg/d) + TAK-242 (inhibitor of HMGN1/TLR4 pathway) group. The expression differences of the HMGN1/TLR4 pathway in mice were observed in the 0.1 mg group and the Dendrobium polysaccharide (10 mg/d) + linagliptin (5 mg/d) + TAK-242 (0.1 mg) group. Results: Compared with the control group, the biochemical indexes were significantly reduced in the Dendrobium polysaccharide group, while the anti-inflammatory factor interleukin (IL)-10 was elevated (p < .05). Compared with the Dendrobium polysaccharide group, biochemical indexes, renal function indexes, and inflammatory factors were all reduced in the Dendrobium polysaccharide + linagliptin group (p < .05). Both Dendrobium polysaccharide and linagliptin had inhibitory effects on HMGN1/TLR4 levels. In comparison with the Dendrobium polysaccharide group, FPG and 2hPBG decreased; urinary albumin excretion rate (UAER), Cys-C, and C-reactive protein (CRP) decreased; and IL-10 increased in the Dendrobium polysaccharide + TAK-242 group (p < .05). Conclusion: Linagliptin combined with Dendrobium polysaccharide extract can modulate the blood glucose level of BDM- EDN patients, improve UAER by decreasing inflammatory response, and protect renal function.