Limited data from cross-sectional studies shows that selenium status is positively associated with musculoskeletal (MSK) function in adults^{(Reference Lauretani F, Bandinelli S and Ray1,Reference Beck, Ferrucci and Sun2)} . However, these associations have not been investigated in a prospective study design and in very old adults. The aims of the study were to examine the relationships between the biomarkers of selenium status and MSK function and disability among participants in The Newcastle 85+ Study at baseline and prospectively up to 5 years.

Biomarkers of selenium status (serum selenium, glutathione peroxidase (GPx3) and selenoprotein P (SePP)) at baseline were measured in 757 participants from The Newcastle 85+ Study. Hand grip strength (HGS) was measured using a hand dynamometer, Timed Up and Go (TUG) was determined as the time to rise from a chair, walk 3 m and return, and sarcopenia prevalence was determined according to EWGSOP cut-offs^{(Reference Cruz-Jentoft3)}. Disability was measured using a self-reported questionnaire focusing on the ability to perform 17 activities of daily living. The relationships between the biomarkers of selenium status and MSK function (HGS, TUG, sarcopenia and disability) were analysed at baseline using linear regression and over 5 years follow-up using linear mixed models adjusting for covariates.

At baseline, in adjusted models, there was no association between biomarkers of selenium status and HGS or TUG. However, there were negative associations between selenium biomarkers and disability; serum selenium (β -0.014 ± 0.06, P = 0.019); and SePP (β -0.15 ± 0.07 P = 0.038). GPx3 activity at baseline was negatively associated with change in prevalence of sarcopenia (β 8.44^E-4 ± 3.88^E-4, P = 0.030) after a 3-year follow-up.

In cross-sectional analysis, selenium status was associated with a lower risk of disability and over time, GPx3 activity was negatively associated with sarcopenia prevalence.