Comparison of lumbar paraspinal muscle size and density between members of the US Framingham Heart Study and Tsimane forager-horticulturalists of Bolivia
- 1Massachusetts General Hospital
Abstract
Paraspinal muscles support and move the spine, and reduced size and density of these muscles is associated with increased risk of vertebral fracture and back pain. We test the hypothesis that subsistence-oriented forager-horticulturalists (Bolivian Tsimane) have larger and denser paraspinal muscles, and smaller age-related differences in paraspinal muscle size and density, than more sedentary post-industrialized suburbanites (Framingham Heart Study [FHS]). We measured cross-sectional area (CSA) and density of trunk extensors and psoas major at L3 from computed tomography scans of 411 FHS and 330 Tsimane (50% women, aged 50-90 years). Sex-stratified linear regressions determined associations of muscle CSA and density with age and cohort (Tsimane or FHS [ref.]), with and without an age-cohort interaction term. Covariates were height and weight. After adjusting for covariates, Tsimane women had 11-14% larger and denser extensors, and 17-26% smaller and less-dense psoas major, than FHS women. Tsimane men had 8-21% smaller and less-dense psoas major than FHS men. The age-related difference in extensors density was 41% smaller for Tsimane men than for FHS men. There were no other significant age-related cohort differences in muscle CSA or density. We observed a different balance in the size and density of trunk extensors versus psoas major between Tsimane and FHS. A possible explanation for this observation is cohort differences in the amount and types of physical activity, although future work is required to determine the influence of lifestyle and environmental factors on paraspinal muscle size and density.
Related
- Integration-Associated Paraspinal Neoplasm after AAV Gene Therapy.
- Optimizing genomic selection: A comparison of SNP selection strategies for reduced-density panels in beef cattle
- Case Report: Clinical improvement of localized chronic eczema following multisegmental paraspinal electroacupuncture
- Influence of trunk posture on spinal loading and paraspinal muscle forces in adolescent idiopathic scoliosis: a subject-specific musculoskeletal modelling study
- Clinical outcomes after fully visualized transforaminal endoscopic spine surgery in patients with lumbar disc herniation stratified by paraspinal muscle degeneration: A retrospective cohort study
BibTeX
@misc{sibson2026comparison,
title = {{Comparison of lumbar paraspinal muscle size and density between members of the US Framingham Heart Study and Tsimane forager-horticulturalists of Bolivia}},
author = {B. Sibson and B. Allaire and B. Holt and F. Johannesdottir and S. Durga and D. Cummings and M. Gurven and H. Kaplan and B. Trumble and J. Stieglitz and M. Bouxsein},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.25.754176},
url = {https://www.biorxiv.org/content/10.64898/2026.09.25.754176v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Comparison of lumbar paraspinal muscle size and density between members of the US Framingham Heart Study and Tsimane forager-horticulturalists of Bolivia
AU - B. Sibson
AU - B. Allaire
AU - B. Holt
AU - F. Johannesdottir
AU - S. Durga
AU - D. Cummings
AU - M. Gurven
AU - H. Kaplan
AU - B. Trumble
AU - J. Stieglitz
AU - M. Bouxsein
PY - 2026
DA - 2026/09/25
PB - bioRxiv
DO - 10.64898/2026.09.25.754176
UR - https://www.biorxiv.org/content/10.64898/2026.09.25.754176v1
AB - Paraspinal muscles support and move the spine, and reduced size and density of these muscles is associated with increased risk of vertebral fracture and back pain. We test the hypothesis that subsistence-oriented forager-horticulturalists (Bolivian Tsimane) have larger and denser paraspinal muscles, and smaller age-related differences in paraspinal muscle size and density, than more sedentary post-industrialized suburbanites (Framingham Heart Study [FHS]). We measured cross-sectional area (CSA) and density of trunk extensors and psoas major at L3 from computed tomography scans of 411 FHS and 330 Tsimane (50% women, aged 50-90 years). Sex-stratified linear regressions determined associations of muscle CSA and density with age and cohort (Tsimane or FHS [ref.]), with and without an age-cohort interaction term. Covariates were height and weight. After adjusting for covariates, Tsimane women had 11-14% larger and denser extensors, and 17-26% smaller and less-dense psoas major, than FHS women. Tsimane men had 8-21% smaller and less-dense psoas major than FHS men. The age-related difference in extensors density was 41% smaller for Tsimane men than for FHS men. There were no other significant age-related cohort differences in muscle CSA or density. We observed a different balance in the size and density of trunk extensors versus psoas major between Tsimane and FHS. A possible explanation for this observation is cohort differences in the amount and types of physical activity, although future work is required to determine the influence of lifestyle and environmental factors on paraspinal muscle size and density.
ER -