# Seminal Plasma Metabolomic Profiling Reveals Key Metabolic Signatures Linked to Spermatogenic Potential in Non-Obstructive Azoospermia with Cryptorchidism

## TL;DR

This study identifies unique metabolic patterns in men with cryptorchidism and azoospermia that could help predict the success of sperm retrieval surgery.

## Contribution

The study introduces novel metabolic biomarkers linked to successful sperm retrieval outcomes in non-obstructive azoospermia with cryptorchidism.

## Key findings

- 931 differential metabolites were identified, mainly related to lipid and amino acid metabolism.
- Metabolomic profiles effectively distinguished patients with successful and failed micro-TESE outcomes.
- Four metabolites showed strong predictive value for micro-TESE success.

## Abstract

Background/Objectives: Cryptorchidism is a common cause of male infertility and often results in azoospermia. However, the metabolic perturbations underlying cryptorchidism complicated with azoospermia and their association with surgical sperm retrieval outcomes remain poorly defined. Methods: A total of 35 patients with cryptorchidism and azoospermia, as well as 40 controls with normal semen parameters, were enrolled in the study. Seminal plasma samples from all participants were subjected to metabolomic analysis. Additionally, some patients underwent micro-TESE; the association between metabolomic features and the success or failure of surgical sperm retrieval was further analyzed. Results: A total of 931 differential metabolites were identified between patients and controls, primarily enriched in lipid metabolism and amino acid metabolism pathways. Lipid metabolites were broadly downregulated in patients, while several inflammation-related metabolites, including Prostaglandin E2, were upregulated. Routine clinical parameters showed no significant differences between patients with successful and failed micro-TESE. However, metabolomic profiles effectively distinguished these two subgroups. These differential metabolites between the two subgroups were mainly involved in three key pathways: phenylalanine–tyrosine–tryptophan biosynthesis, aminoacyl-tRNA biosynthesis, and folate biosynthesis. Most metabolites in the first two pathways were downregulated in the successful retrieval group, while those in the folate biosynthesis pathway showed the opposite regulatory trend. Four metabolites, including Leucine, 7,8-Dihydroneopterin, L-Tyrosine and Pterin, exhibited robust predictive value for micro-TESE outcomes. Conclusions: This study reveals distinct metabolic signatures in patients of cryptorchidism with azoospermia. The identified metabolic biomarkers provide valuable references for clinical decision-making regarding micro-TESE, facilitating a personalized assessment of sperm retrieval feasibility.