Insulin dependant diabetes mellitus: implications for male reproductive function

BACKGROUND: Diabetes mellitus (DM) is increasing in men of reproductive age. Despite this, the prevalence of dia-betes in men attending fertility clinics is largely unknown. Furthermore, studies examining the effects of DM on sperm fertility potential have been limited to conventional semen analysis. METHODS: Conventional semen analysis (semen volume, sperm count, motility and morphology) was performed for 27 diabetic (mean age 34+ 2 years) and 29 non-diabetic subjects (control group, men undergoing routine infertility investigations, mean age 33+ 1 years). Nuclear DNA (nDNA) fragmentation was assessed using the alkaline Comet assay and mitochondrial DNA (mtDNA) deletions by Long-PCR. RESULTS: Other than a small, but significant, reduction in semen volume in diabetic men (2.6 versus 3.3 ml; P < 0.05), conventional semen parameters did not differ significantly from control subjects. Diabetic subjects had significantly higher mean nDNA fragmentation (53 versus 32%; P < 0.0001) and median number of mtDNA deletions (4 versus 3; P < 0.05) compared with control subjects. CONCLUSIONS: Diabetes is associated with increased sperm nuclear and mtDNA damage that may impair the reproductive capability of these men