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.