Muscle weakness, cognitive impairment and their interaction on altered balance in elderly outpatients: results from the TRIP observational study

BACKGROUND: The determinants of altered balance in older subjects and, particularly, the contribution of muscle strength and cognitive impairment are still uncertain. We hypothesized that both these conditions and their interactions could affect balance in older persons. To address this hypothesis, we studied the cross-sectional association between handgrip strength and balance performance in subjects with and without cognitive impairment. METHODS: Two hundred and sixty-three elderly outpatients (104 men and 159 women, aged 81.44 ± 7.36 years) were evaluated for the comprehensive geriatric assessment. The patients were enrolled from the cross-sectional observational Traumatic Risk Identikit Parma study that was aimed at identifying risk factors for falling in older outpatients. RESULTS: Balance deficit, defined as an inability to maintain tandem position for at least 10 seconds, was present in 185 patients (70.34%). The mean mini-mental state examination score was 20.79 ± 6.5, the median short physical performance battery score was 5.0 and the mean grip strength was 18.54 ± 9.14 kg. After dividing the subjects into four categories according to the presence of low grip strength and/or cognitive impairment, we found that the mini nutritional assessment short-form scale score was negatively and independently (β: -0.02 ± 0.01; p=0.04) associated with balance deficit in the group with low grip strength and cognitive impairment. In the other three categories, grip strength was negatively and significantly associated with balance deficit. CONCLUSION: The loss of muscle strength, presence of cognitive impairment and their interaction, influenced probably by malnutrition, could affect balance in older persons.