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Topical Area: Energy and Macronutrient Metabolism

Energy and Macronutrient Metabolism (Poster Session)

(P16-017-23) Regulatory Function of microRNA on the Inflammatory Response to Arctic Military Training

Sunday, July 23, 2023
11:45 AM – 12:45 PM ET
Location: Poster Board 181
Disclosure(s):
Adrienne Hatch-McChesney, MS, RD, CSSD: No relevant financial relationship(s) with ineligible companies to disclose.
Jillian T. Allen, MS RD LDN: No relevant financial relationship(s) with ineligible companies to disclose.


Objectives: Circulating microRNA (c-miRNA) are sensitive to exercise, energy status, and macronutrient intake. Whether changes in c-miRNA differ based on macronutrient intake during arctic military training and the function of these changes are unknown. This study aimed to determine if consuming essential amino acid (EAA)-enriched protein, high-fat energy-dense (EN-DENSE), or high-carbohydrate control (CON) supplemental nutrition daily during arctic military training affected c-miRNA.

Methods: Soldiers participating in an 8-day arctic military training were randomly assigned to receive 3 arctic rations plus 4 supplemental EAA (n=27; 31 g protein, 4.2 kcal/g), EN-DENSE (n=22; 35 g fat, 6.7 kcal/g, or CON (n=19; 70 g carbohydrate, 3.4 kcal/g) snack bars providing ~5000 kcal/d. Energy expenditure (D218O) and energy intake (wrapper/food waste collection) were assessed daily. c-miRNA (RT-qPCR microarray) and serum markers of inflammation were measured before (PRE) and after (POST) the training. Bioinformatics and in vitro analysis were used to identify function of the most significant c-miRNA.

Results: Protein, fat, and carbohydrate intakes (g/d) were highest (P < 0.05) in EAA (118±40), EN-DENSE (208±43) and CON (595±88), respectively. Energy expenditure (5341±674 kcal/d), intake (4045±738 kcal/d), and balance (-1257±599 kcal/d) were not different between treatments. Twenty-five c-miRNA changed (23 decreased, 2 increased; all P < 0.05) from PRE to POST, independent of treatment. miR-146a-5p had the most negative fold change from PRE to POST and was identified to target inflammatory signaling. IL6, hepcidin, and ferritin increased (P < 0.05) from PRE to POST, independent of treatment. In vitro overexpression of miR-146a-5p in C2C12 myoblasts decreased (P < 0.05) Il6, Tnfα, and Traf6 gene expression.

Conclusions: These data indicate that changes in c-miRNA are not sensitive to macronutrient intake during arctic military training, and that miR-146a-5p expression may partly explain the systemic inflammatory response.

Funding Sources: DHP JPC-5; author’s views not official Army or DoD policy.