The categories were Normal (2,882 participants), Obese (9,393), PreSarc (634), and PreSarc-Obese (1,670).

Over 92,431.5 person-years of prospective follow-up, the presarcopenic phenotype was suggestively associated with a higher risk of incident osteoporosis, with a hazard ratio of 1.87 and a 95 percent confidence interval of 1.00 to 3.48, yielding a p-value of 0.049. The confidence interval touching 1.00 and the borderline p-value mean the association should be interpreted cautiously, and the authors themselves describe it as suggestive rather than definitive.

Obesity alone, by contrast, was not significantly associated with osteoporosis risk in this cohort. The hazard ratio for the Obese group was 0.79, with a 95 percent confidence interval of 0.53 to 1.18 and a p-value of 0.251.

Beyond the epidemiological cohort, the study included a proteomic component. In a subset of 196 participants, the researchers profiled circulating proteins and identified three that showed consistent negative associations with both muscle-related traits and bone mineral density: interleukin-18 receptor 1 (IL-18R1), insulin-like growth factor-binding protein 7 (IGFBP7), and vanin-2 (VNN2). In other words, higher circulating levels of these proteins were linked to lower measures of both muscle and bone health.

IL-18R1 was the most specifically quantified of the three. It was negatively associated with muscle mass, with a beta coefficient of -0.403 and a p-value below 0.001, and negatively associated with bone mineral density, with a beta of -0.050 and a p-value below 0.05. These are observational associations from a proteomic subset, not proof of a causal relationship.

In mice fed a high-fat diet, the three candidate proteins were upregulated in parallel with lower normalized grip strength and reduced trabecular bone volume fraction, with p-values below 0.01. This parallelism in the mouse model is consistent with the human proteomic findings, but it remains a model observation and does not establish that the proteins drive bone loss in humans.

Preliminary in silico molecular docking generated a hypothesis-generating structural model predicting a putative IL-18R1/RANKL interface stabilized by a salt bridge at a distance of 2.8 angstroms. The authors are explicit that this is a predicted structural model; direct physical binding kinetics and causal signaling cascades have not been demonstrated and require rigorous biochemical and functional validation.

Taken together, the findings position presarcopenic phenotypes as prospective predictors of incident osteoporosis in older adults, while the circulating proteins IL-18R1, IGFBP7, and VNN2 are offered as complementary, hypothesis-generating biological clues linking integrated muscle and bone deterioration. The authors caution that further validation is needed before these proteins can be considered causal mediators or clinical targets.

Subject of Research: The association of presarcopenic body-composition phenotypes with incident osteoporosis risk in older UK Biobank adults, with proteomic markers of muscle and bone deterioration.

Article Title: Association of presarcopenic phenotypes with incident osteoporosis: a prospective UK biobank cohort and proteomic study

Article References: Xia, D., Zhai, L., Gong, W., Kou, Y., Cao, G., Bao, Y., Li, Z., Zhang, X., Gao, T., & Dai, S. (2026). Association of presarcopenic phenotypes with incident osteoporosis: a prospective UK biobank cohort and proteomic study. BMC Geriatrics. https://doi.org/10.1186/s12877-026-08570-9

Image Credits: AI Generated

DOI: 10.1186/s12877-026-08570-9

Keywords: osteoporosis, presarcopenia, sarcopenia, UK Biobank, body composition, handgrip strength, IL-18R1, IGFBP7, VNN2, proteomics, bone mineral density, cohort study