The contribution of musculoskeletal factors to physical frailty: a cross-sectional study

Monica C Tembo,James Gaston,Lana J Williams,Mohammadreza Mohebbi,Sharon L Brennan-Olsen,Kara L Holloway-Kew,Sophia X Sui,Mark A Kotowicz,Julie A Pasco

doi:10.1186/s12891-021-04795-4

Abstract

BackgroundMusculoskeletal conditions and physical frailty have overlapping constructs. We aimed to quantify individual contributions of musculoskeletal factors to frailty.MethodsParticipants included 347 men and 360 women aged ≥60 yr (median ages; 70.8 (66.1–78.6) and 71.0 (65.2–77.5), respectively) from the Geelong Osteoporosis Study. Frailty was defined as ≥3, pre-frail 1–2, and robust 0, of the following; unintentional weight loss, weakness, low physical activity, exhaustion, and slowness. Measures were made of femoral neck BMD, appendicular lean mass index (ALMI, kg/m2) and whole-body fat mass index (FMI, kg/m2) by DXA (Lunar), SOS, BUA and SI at the calcaneus (Lunar Achilles Insight) and handgrip strength by dynamometers. Binary and ordinal logistic regression models and AUROC curves were used to quantify the contribution of musculoskeletal parameters to frailty. Potential confounders included anthropometry, smoking, alcohol, prior fracture, FMI, SES and comorbidities.ResultsOverall, 54(15.6%) men and 62(17.2%) women were frail. In adjusted-binary logistic models, SI, ALMI and HGS were associated with frailty in men (OR = 0.73, 95%CI 0.53–1.01; OR=0.48, 0.34–0.68; and OR = 0.11, 0.06–0.22; respectively). Muscle measures (ALMI and HGS) contributed more to this association than did bone (SI) (AUROCs 0.77, 0.85 vs 0.71, respectively). In women, only HGS was associated with frailty in adjusted models (OR = 0.30 95%CI 0.20–0.45, AUROC = 0.83). In adjusted ordinal models, similar results were observed in men; for women, HGS and ALMI were associated with frailty (ordered OR = 0.30 95%CI 0.20–0.45; OR = 0.56, 0.40–0.80, respectively).ConclusionMuscle deficits appeared to contribute more than bone deficits to frailty. This may have implications for identifying potential musculoskeletal targets for preventing or managing the progression of frailty.

Highlights

Musculoskeletal conditions and physical frailty have overlapping constructs
Research has shown that musculoskeletal conditions are a major cause of functional impairment and disability [11, 12] and that frailty is associated with lower bone mineral density (BMD), muscle or lean mass and handgrip strength (HGS) [6, 13,14,15]
The association was sustained after adjustments for relevant characteristics, where men with higher measures were less likely to be frail; stiffness index (SI), Appendicular lean mass index (ALMI) and HGS (Fig. 2)

Summary

Introduction

We aimed to quantify individual contributions of musculoskeletal factors to frailty. Research has shown that musculoskeletal conditions are a major cause of functional impairment and disability [11, 12] and that frailty is associated with lower bone mineral density (BMD), muscle or lean mass and handgrip strength (HGS) [6, 13,14,15]. To our knowledge, to date, no study has quantified the contribution of musculoskeletal components to frailty. This is pertinent to the understanding the condition and highlighting potential targets for interventions. The aim of this study was to investigate the association between musculoskeletal factors and frailty, defined using the Fried frailty phenotype, and quantify their contributions to frailty

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Conclusion