Insulin-like Peptide-6 Levels in Non-obstructive Azoospermia

J Coll Physicians Surg Pak. 2022 Oct;32(10):1238-1241. doi: 10.29271/jcpsp.2022.10.1238.


Objective: To investigate the serum versus insulin-like peptide-6 (INSL-6) levels in men with non-obstructive azoospermia (NOA) and normospermia.

Study design: Descriptive study.

Place and duration of study: Department of Urology, Balikligol State Hospital and Harran University, Sanliurfa, Turkey, between July and October 2020.

Methodology: The serum and seminal levels of INSL-6 were measured in men with NOA, and normospermia using a commercially available enzyme-linked immunosorbent assay. Age, body mass index (BMI), hormone profile, testicular volumes and seminal and serum INSL-6 levels were compared between the study groups.

Results: In total, 80 men were included in the study, 40 of whom have NOA and 40 have normospermia. No significant difference was found in the mean age and BMI between the groups (p >0.05). Seminal INSL-6 levels were higher in the normospermia group, although serum and seminal INSL-6 levels were not significantly different in this group (p >0.05). No significant correlation was observed between serum INSL-6 levels and age, BMI,testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and varicocele presence (p >0.05). No significant association was found between seminal INSL-6 levels and age, BMI, FSH, LH, and testosterone levels (p >0.05). However, a significant negative association observed between seminal INSL-6 levels and testicular volume (p <0.05).

Conclusion: The seminal INSL-6 levels were approximately 5.5 times higher than the serum INSL-6 levels and survival level of INSL-6 were higher in the normospermia. This suggests that INSL-6 plays an active role in the male reproductive system. However, the mechanism and extent of this effect remain to be elucidated.

Key words: Infertility, Non-obstructive azoospermia, Insulin-like peptide-6.

MeSH terms

  • Azoospermia*
  • Follicle Stimulating Hormone
  • Humans
  • Insulins*
  • Luteinizing Hormone
  • Male
  • Testis
  • Testosterone


  • Insulins
  • Testosterone
  • Luteinizing Hormone
  • Follicle Stimulating Hormone

Supplementary concepts

  • Azoospermia, Nonobstructive