Abstract
OBJECTIVE: We aimed to compare muscle strength, physical performance, and muscle parameters in non-diabetic and type 2 diabetes mellitus (T2DM) older adults and to determine the association of the duration of diabetes with these outcomes. DESIGN: A cross-sectional study. SETTING: The China Action on Spine and Hip Status study (CASH). PARTICIPANTS: 301 participants enrolled from a subcohort of CASH, of which 114 were diagnosed with well-controlled type 2 diabetes mellitus, MEASUREMENTS: We measured physical performance and muscle strength with the timed up-and-go test (TUG) and handgrip strength (HGS) and measured the area and density of the thigh, gluteus and trunk muscles (core muscles) using quantitative CT scans. RESULTS: Participants with long-term (≥10 years) diabetes had a longer TUG (β coefficient: 0.64 [95% CI, 0.06, 1.22]; P = 0.030) and a lower HGS (-2.29 [-4.48, -0.10]; P = 0.041) as well as a lower muscle area of the thigh (-7.10 [-13.44, -0.76]; P = 0.028). The lower HGS among patients with long-term (≥10 years) diabetes was largely mediated by muscle area of the thigh (compared with non-diabetic controls: percentage mediated, 38.3%; P = 0.023; compared with <10 years diabetes: percentage mediated, 51.8%; P = 0.039). CONCLUSIONS: Older adults with long-term (≥10 years) diabetes had lower TUG and HGS than either non-diabetic participants, and the difference in HGS was largely mediated by a decrease in muscle area of the thigh muscles. Our finding suggested that long duration of diabetes, even in well-controlled subjects, may be associated with poor physical functions.