High HbA 1c levels affect motility parameters and overexpress oxidative stress of human mature spermatozoa

The aim of this study is to investigate, by a validated in vitro model, the effect of diabetic plasma on ejaculated human spermatozoa. Plasma of 51 male diabetic patients (mean age 62.28 ± 9.28 years) was selected according to their HbA level: low HBA ≤ 5% (31 mmol/mol), moderate HBA 6%-8% (42-64 mmol/mol) and high HBA ≥ 10% (86 mmol/mol). The plasma was tested on eighteen normal semen samples by analysing gametes motility using a computer Sperm Class Analyzer® and their corresponding oxidative stress (OS) status using thiobarbituric acid-reactive substances assay. The results indicated that diabetic plasma affected all sperm motility parameters with high HbA showing the most important deleterious effects. Low gametes' straight-line velocity was observed in high HbA level, mainly after 20 min of co-incubation (8.78 ± 0.47 µm/s). Also, the highest lipid peroxidation (nmoles MDA/10 SPZ) was observed in high HbA values (0.92 ± 0.09), higher than those in spermatozoa treated with H O (0.85 ± 0.04). Conclusively, a direct impact of diabetic plasma on spermatozoa is revealed with overexpression of OS as the underlying mechanism. These findings suggested that it is strongly recommended to control clinically the glycaemic level and OS in diabetic patients for the maintenance of male fertility.