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Serine modulates insulin resistance during short-term bed rest
Alja Ivetac1, Teresa Cannito1, Alessio Nunnari1
1Department of Medical, Surgical and Health Sciences, Cattinara Hospital, University of Trieste, Trieste, Italy.
Nutrition (Burbank, Los Angeles County, Calif.)
|February 24, 2026
Summary
Maintaining serine levels during inactivity may protect against insulin resistance (IR). This study found that serine impacts IR, but IR does not affect serine levels, suggesting a protective role for serine.
Area of Science:
- Exercise Physiology
- Metabolic Health
- Nutritional Biochemistry
Background:
- Muscle unloading during inactivity is linked to insulin resistance (IR) and altered amino acid (AA) profiles.
- Investigating the role of AAs in IR during periods of inactivity is crucial for understanding metabolic changes.
Purpose of the Study:
- To assess the potential impact of amino acids (AAs) on insulin resistance (IR) during inactivity.
- To determine the relationship between specific AA profiles and IR markers.
Main Methods:
- Retrospective analysis of plasmatic AA, glucose, and insulin from three bed rest studies.
- Multivariate imputation used for missing AA values to evaluate trends in relation to HOMA IR during 9 days of inactivity.
- Generalized linear mixed model (GLMM) fitted to examine the effect of selected AAs on HOMA IR.
Main Results:
- Serine demonstrated a significant negative fixed effect on HOMA IR, indicating a protective role.
- A unidirectional relationship was observed, with serine impacting HOMA IR but not vice versa.
- Serine levels fluctuated during bed rest, and drops in serine availability correlated with rising HOMA IR.
Conclusions:
- Serine levels appear to inversely impact insulin resistance (IR) during inactivity.
- Maintaining adequate serine levels during short-term bed rest may play a protective role against the development of IR.
- Further research into serine supplementation or strategies to uphold its levels during inactivity is warranted.
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