Objectives: Alzheimer's disease (AD) impairs cognitive functions, subsequently decreasing activity of daily living (ADL), and is frequently accompanied by lower limb fracture including hip fracture in the elderly. However, there have been few studies on what kinds of physical functions are affected or what degrees of dysfunction are produced by this combination. This study aims to clarify the relationship between decreased ADL and the combination of AD and lower limb fracture.
Methods: We examined present illness and ADL in 4340 elderly aged 82.8 ± 9.36 years [average ± standard deviation (SD)] requiring nursing care and compared ADL between elderly with and without AD or lower limb fracture treated with surgery or conservatively using analysis of covariance (ANCOVA), with age and sex as covariants.
Results: We recognized that activities of cognitive function (p < 0.001), eating (dysphagia) (p < 0.001), eating (feeding) (p < 0.001), and toilet use (p < 0.001) in the elderly with AD were significantly lower than in those without the disease, even after adjusting for sex and age. Activities of bed mobility (p < 0.05), transfer and locomotion (p < 0.001), and bathing (p < 0.05) in the elderly with a fracture treated with surgery were significantly lower, which differed from the results of AD. Significant interactions of AD and fracture treated with surgery on the ADL scores for bed mobility (p < 0.001), dysphagia (p < 0.01), feeding (p < 0.001), and toilet use (p < 0.05) show that the combination had a much more profound influence on the ADL scores than AD or fracture alone. We obtained almost the same results for fractures treated conservatively as for fractures treated with surgery.
Conclusions: These results demonstrated that the combined effects of AD and lower limb fracture were significantly greater than expected additive effects of AD and fracture, suggesting that the combination of AD and lower limb fracture has synergistic effects on almost all types of ADL except cognitive functions.