Marion T Guerrero-Wyss, Stuart Johnston, Carla M Prado, Bhautesh D Jani, Frederick K Ho, Stuart R Gray, Carlos A Celis-Morales
Multimorbidity and greater cumulative LTC burden were prospectively associated with incident sarcopenia in both females and males. The graded association across LTC burden and the estimated population-level burden suggest that multimorbidity is an important marker of subsequent sarcopenia risk. Further research should determine whether incorporating muscle health assessment into the care of people with multimorbidity improves prediction or clinical outcomes.
OBJECTIVE: To examine sex-specific prospective associations of multimorbidity, cumulative long-term condition (LTC) burden, and individual LTCs with incident sarcopenia.
METHODS: This prospective cohort study included 47,417 UK Biobank participants without sarcopenia at baseline. Multimorbidity was defined as ≥2 LTCs, and cumulative LTC burden was categorised as 0, 1, 2, 3, 4, or ≥ 5 conditions. Incident sarcopenia was defined using an adapted European Working Group on Sarcopenia in Older People 2 framework incorporating low muscle strength and low muscle mass. Sex-stratified Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs). Standardised 10-year risks and multimorbidity-specific population attributable fractions (PAFs) were also estimated.
RESULTS: During a median follow-up of 11.5 years, 1065 participants developed incident sarcopenia. Multimorbidity was associated with a higher hazard of sarcopenia in females (HR 1.85, 95% CI 1.52-2.24) and males (HR 2.02, 1.57-2.60), with no evidence of multiplicative effect modification by sex. Each increase in LTC-count category was associated with a higher hazard in females (HR 1.24, 95% CI 1.17-1.33) and males (HR 1.29, 1.18-1.40). Standardised 10-year risks increased from 1.73% to 3.15% in females and from 0.88% to 1.76% in males comparing 0 LTCs with multimorbidity. The multimorbidity-specific 10-year PAF was 17.1% (95% CI 10.4-23.8) in females and 18.8% (13.7-27.6) in males.
CONCLUSIONS: Multimorbidity and greater cumulative LTC burden were prospectively associated with incident sarcopenia in both females and males. The graded association across LTC burden and the estimated population-level burden suggest that multimorbidity is an important marker of subsequent sarcopenia risk. Further research should determine whether incorporating muscle health assessment into the care of people with multimorbidity improves prediction or clinical outcomes.