Association between muscle function, cognitive state, depression symptoms and quality of life of older people: evidence from clinical practice

Background: Although low muscle function/strength is an important predictor of poor clinical outcome in older patients, information on its impact on mental health in clinical practice is still lacking. Aims: The aim of this report is to measure the impact of low muscle function measured by handgrip strength on mental health of older people during both acute illness and recovery. Methods: Four hundred and thirty-two randomly selected hospitalized older patients had their baseline demographic and clinical characteristics assessed within 72 h of admission, at 6 weeks and at 6 months. Low muscle strength-handgrip was defined using the European Working Group criteria. Mental health outcome measures including cognitive state, depression symptoms and quality of life were also measured. Results: Among the 432 patients recruited, 308 (79%) had low muscle strength at baseline. Corresponding figures at 6 weeks and at 6 months were 140 (73%) and 158 (75%). Patients with poor muscle strength were significantly older with increased disability and poor nutritional status compared with those with normal muscle strength. After adjustment for age, gender, disability, comorbidity including severity of acute illness and body mass index patients with low muscle strength had worse cognitive function, quality of life and higher depression symptoms compared with those with normal muscle strength over a 6-month period (p < 0.05). Conclusion: Poor muscle strength in older people is associated with poor cognitive state and quality of life and increased depression symptoms during both acute illness and recovery.