How Parkinson’s May Affect Sexes Differently Examined in US Study
Male patients in US region found to have worse life quality and more depression
Men with mild-to-moderate Parkinson’s disease may experience greater effects of the disease on certain aspects of their life than women, according to a study of patients living in the southeastern U.S.
Specifically, men were found to have worse motor symptoms, daily life-related impairments, disease-related quality of life, and more depression than women.
This “can contribute to the development of gender-sensitive assessment and rehabilitation policies and protocols for people with PD [Parkinson’s disease],” researchers wrote.
Still, the observed sex differences may not be generalized to patients in other U.S. regions and/or countries, they noted, with prior findings in China suggesting that women with Parkinson’s may have worse disease-related quality of life.
The U.S. study, “Gender differences in motor and non-motor symptoms in individuals with mild-moderate Parkinson’s disease,” was published in the journal PLOS One.
Genetic differences and sex hormones may play role in Parkinson’s progression
Parkinson’s disease is characterized by the death and dysfunction of dopaminergic neurons, nerve cells that communicate by releasing dopamine, a major brain chemical messenger involved in movement control.
Patients experience both motor and non-motor symptoms that impair their ability to perform daily activities, negatively affecting their quality of life and well-being.
Evidence suggests there are differences between men and women with Parkinson’s in disease prevalence, clinical presentation, and response to treatments. These differences may be related to physical and cognitive changes associated with sex and age, sex differences in life expectancy, age at first symptoms (usually later in women), and social interactions.
Genetic differences and the neuroprotective role of certain sex hormones may also contribute to these differences. Estrogen, a hormone responsible for female features and reproduction, is known to increase the levels of dopamine, which may have protective effects in Parkinson’s.
However, the role of a patient’s sex in Parkinson’s symptoms, and how this impacts daily activities and quality of life remains largely unclear.
Now, researchers retrospectively analyzed the motor, cognitive, and psychosocial performance of 127 men and 72 women with mild-to-moderate idiopathic Parkinson’s (of unknown origin) living in a large metro area in the southeastern U.S.
“Sociocultural and demographic factors may affect men and women differently in the southeastern United States,” the researchers wrote, as older adults in this region “have considerable health and health-related quality of life (QoL) challenges” compared with the rest of the country.
The median age of the patients was 69.1 years (68.2 for men and 70.7 for women) and 78.3% were white. Men with Parkinson’s were significantly less likely to live in senior housing than women.
This study appears to support the research that suggests a potential protective impact of estrogens, higher dopaminergic levels, and more intact [nerve cell communication] system in women.
Men found to have worse disease severity and symptoms than women
After adjusting for age, housing, Parkinson’s duration, and the number of falls in the previous year, men were found to have worse disease severity and symptoms than women.
This included a significantly greater impact of both motor and non-motor symptoms on activities of daily living, as well as significantly worse motor problems, as assessed with the corresponding parts of the Movement Disorder Society-Unified Parkinson’s Disease Rating scale.
This “aligns with previous studies suggesting men have greater (i.e., worse) [activities of daily living] and motor symptoms severity,” the researchers wrote.
Men in southeastern U.S. “may be physically sicker than the women, which is true of the general population of older adults, given that women generally outlive men by 5 or more years,” the researchers suggested.
Adjusted analysis of mobility measures showed that women exhibited a significantly slower fast walking speed than men. No sex differences were detected in self-selected walking speed, backward walking speed, or balance.
Fast walking speed “demands maximal performance which may rely more of the ability of fast twitch muscles to generate power. Women tend to lose power in their lower limbs earlier than do men with the aging process,” the researchers wrote.
The only sex differences observed in cognitive function was worse performance of women on serial 3 subtractions, a test to evaluate concentration and memory, by asking the individual to successively subtract 3 from 100.
Disease-specific health-related quality of life was assessed with the self-reported Parkinson’s Disease Quality of Life Questionnaire, which includes eight domains and in which higher scores indicate lower quality of life.
Adjusted analyses showed that men exhibited significantly worse quality of life related to activities of daily living, mobility, communication, cognitive impairment, and emotional well-being relative to women.
Significantly more depressive symptoms found in men with Parkinson’s
Men also experienced significantly more depressive symptoms, as assessed with the Beck Inventory-2.
“This study adds to knowledge on the influence of gender on PD by suggesting that for individuals with mild-moderate PD, at least among this sample residing the Southeastern US, men are more impacted by burden of the disease on both QoL and self-reported motor and non-motor experiences of daily living as measured by PD-specific instruments,” the team wrote.
“Many non-motor and motor variables that are not PD specific show no differences between genders in this [group of patients],” the researchers added.
“This study appears to support the research that suggests a potential protective impact of estrogens, higher dopaminergic levels, and more intact [nerve cell communication] system in women, which others have suggested,” they wrote.
Still, “the current sample derives from a specific geographic area (the southeastern US) and the findings cannot be generalized to the worldwide PD population or perhaps all regions of the US.”