Relationship between iodine nutritional status and low handgrip strength in a Northwestern Chinese cohort: construction of a predictive nomogram model

Background: Grip strength is a key marker for sarcopenia screening, yet the influence of iodine nutritional status on low grip strength (LGS) remains poorly understood. Methods: = 242) cohorts. Logistic regression analyses identified factors associated with LGS. A nomogram integrating urinary iodine concentration (UIC), systolic blood pressure (SP), and routine clinical variables was constructed. Model performance was evaluated using ROC curves, Hosmer-Lemeshow test, and Brier scores. Restricted cubic spline (RCS) analysis assessed the dose-response relationship between UIC and LGS, with subgroup analyses by thyroid function. Results: > 0.05). RCS analysis revealed a U-shaped association between UIC and LGS in unadjusted analyses, with the inverse associations most evident among euthyroid participants. Conclusion: The nomogram provides a practical, objective tool for early identification of individuals at high probability of LGS. Moderate-to-high UIC is associated with LGS odds, particularly in euthyroid adults. This model may guide targeted screening and interventions in community settings. In the cross-sectional design, causal inferences cannot be drawn; Further research is warranted to elucidate these complex relationships.