Decreased Muscle Strength and Quality in Diabetes-Related Dementia

BACKGROUND/AIMS: Diabetes-related dementia (DrD), a dementia subgroup associated with specific diabetes mellitus (DM)-related metabolic abnormalities, is clinically and pathophysiologically different from Alzheimer disease (AD) and vascular dementia. We determined whether skeletal muscle strength, quality, and mass decrease in individuals with DrD. METHODS: We evaluated grip and knee extension strength, muscle mass, and gait speed in 106 patients with probable AD and without type 2 DM (AD[−DM] group), 74 patients with probable AD and with DM (AD[+DM] group), and 36 patients with DrD (DrD group). Muscle quality was defined as the ratio of muscle strength to muscle mass. RESULTS: Both female and male subjects with DrD showed significantly decreased muscle strength and quality in the upper extremities compared with the subjects with AD[−DM] or AD[+DM]. Female subjects with DrD showed significantly decreased muscle quality in the lower extremities compared with the subjects with AD[−DM]. Both female and male subjects with DrD had a significantly lower gait speed compared with the subjects with AD[−DM]. However, there were no significant differences in muscle mass and the prevalence of sarcopenia between the groups. CONCLUSION: Subjects with DrD showed decreased muscle strength and quality, but not muscle mass, and had a low gait speed.