Clinical Implication of Plasma Hydrogen Sulfide Levels in Japanese Patients with Type 2 Diabetes

Abstract

Objective The goal of the present study was to investigate the plasma hydrogen sulfide (H₂S) levels in patients with type 2 diabetes, as the plasma H₂S levels in Japanese patients with type 2 diabetes remain unclear. Methods The plasma H₂S levels were measured in 154 outpatients with type 2 diabetes and 66 outpatients without diabetes. All blood samples were collected in the outpatient department from 09:00 to 10:00. The patients had fasted from 21:00 the previous evening and had not consumed alcohol or caffeine or smoked until sample collection. The plasma H₂S levels were measured using the methylene blue assay. The plasma H₂S levels were determined in triplicate, and the average concentrations were calculated against a calibration curve of sodium sulfide. Results The patients with type 2 diabetes showed a progressive reduction in the plasma H₂S levels (45.115.5 M versus 54.026.4 M, p<0.05), which paralleled poor glycemic control. There was a significant correlation between a reduction in the plasma H₂S levels and the HbA1c levels (=-0.505, p<0.01), Furthermore, a reduction in the plasma H₂S levels was found to be related to a history of cardiovascular diseases in patients with type 2 diabetes (39.913.8 M versus 47.515.9 M, p<0.01). Conclusion Collectively, the plasma H₂S levels were reduced in patients with type 2 diabetes, which may have implications in the pathophysiology of cardiovascular disease in diabetic patients. The trial was registered with the University Hospital Medical Information Network (UMIN no. #000020549).