The role of catecholamines in the etiology of infertility in diabetes mellitus

Single nucleotide polymorphisms in Renalase and KCNQ1 genes and female infertility: A cross-sectional study in Pakistan

A global increase in the incidence of subfertility is observed, and research suggests strong genetic influences that might restrict fertility directly or indirectly. It therefore becomes important to rule out the existence of genetic causes and counsel infertile couples before offering "Advanced Infertility Treatment Techniques." This cross-sectional study aimed to explore the association of KCNQ1 (rs2237895) and Renalase (rs2576178 and rs10887800) single nucleotide polymorphisms with different causes of infertility by analysing 508 fertile and 164 infertile women. Gene variant (AC/CC) of KCNQ1 rs2237895 showed a slight difference in the endometriosis group compared to the fertile group (p = .049), with the C allele showing a significant association with infertility overall (OR = 1.42 [1.100-1.833]; p < .0069). The variant AG/GG of Renalase rs2576178 was significantly associated with overall infertility (OR = 2.266; p < .001), with a strong G allele association with unexplained infertility OR = 2.796 (p = .002) that remained significant after adjusting for age and body mass index. Similarly, Renalase rs10887800 AG/GG and G allele showed significant association with both infertility due to polycystic ovarian syndrome and unexplained infertility. Expression of single nucleotide polymorphism rs2237895 and rs2576178 in both KCNQ1 and Renalase genes might be responsible for altering reproductive potential, hence leading to infertility in women.

Influence of residual insulin secretion and duration of diabetes mellitus on the control of luteinizing hormone secretion in women

BACKGROUND

The aim of the present study was to establish whether the persistence of residual beta-cell activity after long-term diabetes mellitus (DM) exerts a protective role on luteinizing hormone (LH) secretion.

METHODS

The LH responses to stimulation with gonadotropin-releasing hormone (Gn-RH) (100 microg in an i.v. bolus) or naloxone (4 mg injected in an i.v. bolus, followed by the constant infusion of 8 mg in 2 h) were measured in C-peptide-positive (CpP) and C-peptide-negative (CpN) normally menstruating women with short-term (group 1 < 3 years, CpP n = 11, CpN n = 11) or long-term (group 2 > 10 years, CpP n = 11, CpN n = 11) DM and in age-matched normal control subjects (n = 11).

RESULTS

Gn-RH induced significant increments in LH secretion in all groups. Significant LH responses to naloxone were observed in all groups, except in group 2 CpN patients. However, the LH response to either Gn-RH or naloxone was significantly lower in group 1 CpN, group 2 CpP and group 2 CpN patients than in the normal control subjects. Furthermore, the LH response was significantly lower in group 2 CpP than in group 1 CpP patients and in group 2 CpN than in group 1 CpN subjects.

CONCLUSIONS

These results indicate a role for both deficiency in residual endogenous insulin secretion and duration of diabetes in the derangement of LH secretory control. The data suggest that the protective role exerted by residual beta-cell activity on LH secretion during the early years of DM diminishes with time elapsed after the onset of diabetes mellitus.