Ageing of human myofibres in the Vastus Lateralis muscle: A narrative review.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic search or quantitative synthesis
PubMed 41506604 · doi:10.1016/j.arr.2026.103022
What was done
This narrative review synthesized published evidence on age-related structural and phenotypic alterations in the human vastus lateralis muscle, examining changes across organ, tissue, and cellular levels with a focus on myofibre types, extracellular matrix, and cellular components.
What was found
The abstract reports no numerical data or effect sizes. It qualitatively describes that ageing and sarcopenia disproportionately affect type II (fast-twitch/glycolytic) myofibres through selective fibre loss, atrophy, and redistribution, driven by multifactorial mechanisms including dysregulated nutrient sensing, altered protein turnover, neuromuscular junction deterioration, satellite cell and mitochondrial dysfunction, and extracellular matrix changes.
Why it matters
The review organizes current understanding of why fast-twitch muscle fibres are selectively vulnerable during human ageing, which is central to defining targets for mitigating sarcopenia and locomotor decline.
Limits
As a narrative review, it lacks a systematic search protocol, explicit inclusion criteria, and formal risk-of-bias assessment. Findings rely on underlying histomorphometric studies that show conflicting results, and no new empirical data or quantitative pooled estimates are provided.
Cited by
- supports Humans experience a progressive loss of type II muscle fibers starting after the fourth decade of life.