Male fertility as an integral reflection of metabolic, endocrine, and musculoskeletal health

A narrative review argues weak muscles and low testosterone track with worse sperm quality, but cites no new data of its own

Journal: Rheumatology International | Published: 2026-07-11 | Type: Journal Article, Review | PMID: 42435059 Authors: Aitbaiuly Batesh (Dept. of Radiology, Khoja Akhmet Yassawi International Kazakh-Turkish University, Shymkent, Kazakhstan); Makhanbetkulova Dinara (Asfendiyarov Kazakh National Medical University, Almaty); Khojakulova Umida (South Kazakhstan Medical Academy, Shymkent); Fedorchenko Yuliya (Ivano-Frankivsk National Medical University, Ukraine); Usen Ahmet (Medipol University, Turkey) Funding/COI: No funding listed. Authors declare no conflicts of interest. Notably, the review's figure was generated using GPT-5.5.

Summary

This is a narrative review, not a study with new data, arguing that male fertility should be understood as part of a broader metabolic-endocrine-musculoskeletal system rather than an isolated reproductive issue. The authors' central claim is that obesity, insulin resistance, chronic inflammation, and sarcopenia (age- or disease-related muscle loss) degrade sperm quality through hormonal disruption and oxidative stress. It runs in Rheumatology International, an unusual home for an andrology topic, which the authors justify through the sarcopenia and musculoskeletal-disease angle.

Claims

• Obesity, insulin resistance, chronic inflammation, and sarcopenia are described as adversely affecting reproductive health via hormonal imbalance, oxidative stress, and impaired cellular homeostasis, though no effect sizes are given in the abstract.
• Testosterone deficiency, reduced muscle strength, and altered myokine signaling are said to act together to compromise spermatogenesis and semen quality.
• Resistance exercise, structured physical activity, nutritional changes, and other lifestyle modifications are described as having "promising effects" on hormones, inflammation, and reproductive function.
• The review calls for integrating reproductive evaluation with metabolic and musculoskeletal assessment for risk stratification, without specifying what that would look like in practice.

Study Quality

This is a narrative literature review, not a systematic review or meta-analysis, despite searching Medline/PubMed, Scopus, and DOAJ. There's no PRISMA flow diagram, no stated inclusion/exclusion criteria, no quality appraisal of the underlying studies, and no reporting of how many papers were screened versus included. That matters because narrative reviews are prone to selective citation, and readers have no way to judge whether the "accumulating evidence" claim reflects a comprehensive literature or a curated one.

The abstract itself is a red flag by this outlet's own citation standards: not a single number, sample size, or effect estimate appears in it, despite covering topics (testosterone deficiency, myokine signaling, sperm quality) where the primary literature does report quantitative findings. The conclusions text supplied also reads as generic boilerplate about genetic testing, seminal proteomics, radiomics, fertility preservation in cancer patients, and AI diagnostics, none of which connect back to the sarcopenia/musculoskeletal framing the abstract promises. That mismatch suggests either recycled text from an unrelated review or a conclusion that doesn't follow from the body of the paper.

Red Flags

• No funding source disclosed, unusual for a journal article of this scope
• Zero quantitative data (no sample sizes, effect sizes, or p-values) anywhere in the abstract
• No PRISMA methodology despite describing a multi-database literature search
• Conclusions section appears disconnected from the review's stated musculoskeletal/sarcopenia focus, reading as generic andrology boilerplate
• A review figure was generated with GPT-5.5, raising questions about how much of the accompanying analysis involved AI assistance
• Published in a rheumatology journal rather than a urology/andrology or endocrinology venue, despite the subject matter sitting outside that journal's usual scope

Strengths

• Draws together a genuinely underexplored angle, sarcopenia and musculoskeletal health, as a lens on male fertility
• Searched three databases (Medline/PubMed, Scopus, DOAJ) rather than one
• Explicit conflict of interest declaration

Verdict

This is a hypothesis-generating narrative review, not evidence, and it reads that way: no numbers, no systematic methodology, and a conclusion that doesn't obviously match its own premise. The underlying idea that systemic metabolic and musculoskeletal health tracks with reproductive function is worth investigating, but this paper doesn't investigate it so much as assert it. Worth a skim for the framing, not worth citing for any specific claim.