Case Control Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Biol Chem. Nov 27, 2022; 13(5): 83-94
Published online Nov 27, 2022. doi: 10.4331/wjbc.v13.i5.83
Serum leptin level in Sudanese women with unexplained infertility and its relationship with some reproductive hormones
Abdullah Abdulslam Abdullah, Musa Ahmed, Adesina Oladokun, Nasir Adam Ibrahim, Shahd Nourain Adam
Abdullah Abdulslam Abdullah, Musa Ahmed, Department of Reproductive Health Sciences, Pan African University Life and Earth Sciences Institute, University of Ibadan, Ibadan 119, Oyo, Nigeria
Abdullah Abdulslam Abdullah, Musa Ahmed, Adesina Oladokun, Department of Obstetrics and Gynecology, College of Medicine, University of Ibadan, Ibadan 119, Oyo, Nigeria
Abdullah Abdulslam Abdullah, Department of Biomedical Sciences, Faculty of Veterinary Sciences, University of Gadarif, Gadarif 208, Sudan
Musa Ahmed, Department of Veterinary Surgery, Faculty of Veterinary Medicine, AL-Salam University, Al-fula 120, West Kordofan, Sudan
Nasir Adam Ibrahim, Department of Biology, Faculty of Science, Imam Mohammed Ibn Saud Islamic University, Riyadh 13318, Saudi Arabia
Nasir Adam Ibrahim, Department of Biochemistry and Physiology, Faculty of Veterinary Medicine, University of Al-butana, Ruffaa 210, Sudan
Shahd Nourain Adam, College of Nursing, University of Bahri, Khartoum 12217, Sudan
Author contributions: Abdulslam Abdullah A, Ahmed M, Oladokun A, Ibrahim NA, and Adam SN analyzed and interpreted the data, and drafted the manuscript; Abdulslam Abdullah A and Oladokun A designed the study and directed implementation and data collection; Abdulslam Abdullah A, Ahmed M, Oladokun A, Ibrahim NA, and Adam SN edited the manuscript for intellectual content and provided critical comments on the manuscript; and all authors gave final approval of the version to be published, have agreed on the journal to which the article has been submitted, and agreed to be accountable for all aspects of the work.
Institutional review board statement: The study protocol and procedures were approved by the University of Ibadan/University College Hospital Ethics Committee (Ref. No. UI/EC/20/0438), and the Federal Ministry of Health Republic of Sudan (Ref. No. 4-12-20).
Informed consent statement: Informed consent was obtained from all the study participants, and all necessary information regarding the study (objectives, requirements of the participants, and duration of the study) were given to the prospective study participants on an information sheet in Arabic to ensure an informed decision to participate in the study. Then, the full case history of the participants was taken through clinical examinations and laboratory investigations. Ethical notions such as discretion/confidentiality, free consent of the interviewees as well as beneficence and non-maleficence to participants were scrupulously respected.
Conflict-of-interest statement: All the authors report having no relevant conflicts of interest for this article.
Data sharing statement: The datasets used during this study are available from the principal investigator upon reasonable request.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Abdullah Abdulslam Abdullah, MSc, Academic Researcher, Department of Reproductive Health Sciences, Pan African University Life and Earth Sciences Institute, University of Ibadan, Ajibode Road, 200132, Ibadan 119, Oyo, Nigeria.
Received: August 22, 2022
Peer-review started: August 22, 2022
First decision: September 26, 2022
Revised: September 30, 2022
Accepted: November 23, 2022
Article in press: November 23, 2022
Published online: November 27, 2022
Research background

The current knowledge and practices in infertility treatment proved suitable for almost all infertility types and their etiologies, except for unexplained infertility (UI) which is when standard-approved infertility tests have not found a clear cause for the couple’s inability to achieve pregnancy. Adipokines such as leptin were found to have a positive relationship with UI in females and they can be used as reliable predictive biomarkers for UI in women.

Research motivation

Despite the established relationship between leptin and female reproduction, the exact role of leptin in women’s infertility is not clear enough and the reasonable conclusion is that “we need further investigations to fill this diagnostic gap”. Where some studies reported high levels of serum leptin in infertile women, other studies reported increased leptin levels in both fertile and infertile women, thus, high serum leptin levels in these patients were not a contributing factor to infertility.

Research objectives

The objective of this study was to evaluate the serum leptin levels in Sudanese women and to ascertain the relationship between serum leptin levels and UI.

Research methods

A matched (age and body mass index) case-control study was conducted from March 2021 to February 2022. The study samples were 210 women with UI and 190 fertile women of reproductive age who were attending the maternity hospitals and fertility clinics in Khartoum state Sudan. The serum concentration of leptin and other serum biomarkers were determined using enzyme-linked immunosorbent assays.

Research results

The results showed that there was a highly statistically significant difference between the two groups (P < 0.001) for all examined eight biomarkers. Whereby, leptin, luteinizing hormone/follicular stimulating hormone (FSH) ratio, prolactin hormone and testosterone (T) were significantly higher in the UI group compared with the control group, in contrast, FSH and estradiol/T ratio were significantly lower in the UI group than in the control group.

Research conclusions

This study reveals that leptin could be a potential biomarker for UI in Sudanese women and it may be useful for identifying women with a high risk of infertility.

Research perspectives

Further studies need to be carried out to clarify the exact association between leptin levels and UI in women.