Factors related to functional independence in females with Parkinson's disease: A systematic review

Males and females may exhibit diverse expressions of Parkinson's disease (PD) as a result of biological and social differences. In general, a higher incidence of PD is found among males (RR = 1.5) compared to females. However, rigidity, postural instability and levodopa-induced dyskinesia are more prevalent in females with PD. These fluctuations affect motor performance and impact functional ability. This systematic review suggests that there is minimal research literature with respect to females living with PD. Specifically, the influence of physical ability in females with PD is underemphasized, considering its contribution to functional daily living and quality of life. Three intervention and nine functional assessment studies met inclusion criteria (n = 302; mean age = 65.5 ± 8.3 years, 44% female). Reports suggest that females with PD have different gait patterns compared to 'healthy' age-matched females and males with PD. Females with PD experience increased freezing of gait as compared to males with PD. Dynamic balance was reduced in females compared to males with PD. Differences in cardiorespiratory fitness compared to healthy age-matched females was inconclusive. Studies were rated to be of moderate quality (20 ± 5.4/32) and future studies should focus on improving sex-matched recruitment, randomized group allocation, and blinding of evaluators to ensure unbiased results. Regardless, the specific impact of PD on females warrants further investigation.