Presentation Type
Poster Presentation
Category
STEM (science, technology, engineering, mathematics)
Abstract/Artist Statement
Load carriage transiently stimulates bone metabolism biomarkers, but impact by sex is unclear. Males (M) generally exhibit higher circulating bone metabolism biomarkers than females (F). Sclerostin (SOST) inhibits a key formation pathway. Human procollagen type 1 N-terminal propetide (P1NP) is a formation byproduct. C-Terminal Telopeptide of Type 1 Collagen (CTX1) is a resorption byproduct.
PURPOSE: Investigate sex differences in bone metabolism following 5 days of load carriage.
METHODS: 12M (29±9 y, 54.6±8.2 mL∙kg-1∙min-1) and 20F (27±5 y, 43.4±4.9 mL∙kg-1∙min-1) completed the protocol. Each day consisted of two 1-hour ascents separated by a 15-minute rest. Ascents were paced at 70% of age-predicted heart rate max (121±8 bpm), descents were self-paced. Packs weighed 30% of lean body mass determined by dual-energy X-ray absorptiometry (M 19.1±3.0 kg and F 12.8±1.6 kg). Blood was sampled before and after the intervention for biomarker analysis.
RESULTS: SOST overall was higher in M (12.8±4.0 pg∙mL-1) than F (8.3±4.3 pg∙mL-1, p=0.005). There was no change in SOST for either sex (p>0.05) from pre–post hike. CTX1 overall was lower in M (270.8±196.0 pg∙mL-1) than F (517.8±315.7 pg∙mL-1, p=0.016). There was no change in CTX1 for either sex (p>0.05) from pre–post hike. P1NP was higher in M (pre- 50.2±15.6 ng∙mL-1, post- 44.4±10.7 ng∙mL-1) than F (pre- 23.1±12.9 ng∙mL-1, post- 24.4±14.5 ng∙mL-1, p< 0.001) across timepoints. P1NP decreased from pre–post hike in M (p=0.022) with no change in F (p>0.05).
CONCLUSION: Biomarkers indicate bone metabolism may vary by sex following daily load carriage. Total bone metabolism in M appears higher than F, but less resilient to daily load carriage. Breakdown itself appears resilient to load carriage between sexes. While reduced formation in M, but not F, may indicate a shift toward net breakdown after daily load carriage. Indicating daily load carriage may weaken bone in M but not F.
Mentor Name
Dustin Slivka
SEX DIFFERENCES IN BONE METABOLISM BIOMARKERS DUE TO PROLONGED DAILY LOAD CARRIAGE
UC North Ballroom
Load carriage transiently stimulates bone metabolism biomarkers, but impact by sex is unclear. Males (M) generally exhibit higher circulating bone metabolism biomarkers than females (F). Sclerostin (SOST) inhibits a key formation pathway. Human procollagen type 1 N-terminal propetide (P1NP) is a formation byproduct. C-Terminal Telopeptide of Type 1 Collagen (CTX1) is a resorption byproduct.
PURPOSE: Investigate sex differences in bone metabolism following 5 days of load carriage.
METHODS: 12M (29±9 y, 54.6±8.2 mL∙kg-1∙min-1) and 20F (27±5 y, 43.4±4.9 mL∙kg-1∙min-1) completed the protocol. Each day consisted of two 1-hour ascents separated by a 15-minute rest. Ascents were paced at 70% of age-predicted heart rate max (121±8 bpm), descents were self-paced. Packs weighed 30% of lean body mass determined by dual-energy X-ray absorptiometry (M 19.1±3.0 kg and F 12.8±1.6 kg). Blood was sampled before and after the intervention for biomarker analysis.
RESULTS: SOST overall was higher in M (12.8±4.0 pg∙mL-1) than F (8.3±4.3 pg∙mL-1, p=0.005). There was no change in SOST for either sex (p>0.05) from pre–post hike. CTX1 overall was lower in M (270.8±196.0 pg∙mL-1) than F (517.8±315.7 pg∙mL-1, p=0.016). There was no change in CTX1 for either sex (p>0.05) from pre–post hike. P1NP was higher in M (pre- 50.2±15.6 ng∙mL-1, post- 44.4±10.7 ng∙mL-1) than F (pre- 23.1±12.9 ng∙mL-1, post- 24.4±14.5 ng∙mL-1, p< 0.001) across timepoints. P1NP decreased from pre–post hike in M (p=0.022) with no change in F (p>0.05).
CONCLUSION: Biomarkers indicate bone metabolism may vary by sex following daily load carriage. Total bone metabolism in M appears higher than F, but less resilient to daily load carriage. Breakdown itself appears resilient to load carriage between sexes. While reduced formation in M, but not F, may indicate a shift toward net breakdown after daily load carriage. Indicating daily load carriage may weaken bone in M but not F.