Kisspeptin System and Menarcheal Age as Predictors of Primary Female Infertility: A Case-Control Study Among Nigerian Women

Background The Kisspeptin system plays a critical regulatory role in female reproductive functions. However, its role is not yet investigated in primary female infertility (PFI). Materials and Methods This is a case-control study of consenting primarily infertile (54) and fertile (50) Nigerian females aged between 20 and 44 years who sought consult at University College Hospital, Ibadan. Basic clinical and demographic data were obtained from the participants using a clinical proforma. Five ml of blood were collected by venepuncture for kisspeptin, KISS1, and KISS1R gene expression analysis within the plasma using ELISA and RT-qPCR techniques. The menarcheal age and BMI of the cases and controls were also investigated as possible predictors of PFI. Result There was no significant change in the relative expression of Kisspeptin, KISS1, and KISS1R genes (p>0.05) in the plasma of the primarily infertile women (PIW) compared to the fertile women (FW). PIW with early menarche showed a significantly lower level of Kisspeptin compared to PIW with normal menarche (p=0.03). Plasma Kisspeptin levels in PIW showed a weak negative correlation (r = −.305; p=0.039) and a good predictive model for KISS1 gene expression (p=0.001; r=0.458). There was a significant difference in KISS1 gene expression in PIW when compared based on their menarcheal age categories (p=0.04). Conclusion Kisspeptin levels, KISS1, and KISS1R gene expression levels in the blood may not be useful for diagnosing PFI. However, menarcheal age should be investigated as an additional diagnostic indicator for PFI.