A new review from Italian scientists adds to the growing body of evidence describing how Parkinson’s disease (PD) affects women and men differently.
In the study, published in the Journal of Parkinson’s Disease, researchers present the most recent knowledge about these gender differences and highlight the significance of estrogens, which appear to play an important role in the sex differences in PD.
PD is a slowly progressive disorder that affects movement, muscle control, and balance. It is the second most common age-related, neurodegenerative disorder, affecting about 3% of the population by the age of 65 and up to 5% of individuals over 85 years of age.
The risk of developing PD is twice as high in men than women, but women experience a more rapid disease progression and a lower survival rate.
“It is becoming increasingly evident that PD differs in women and men,” said lead author Fabio Blandini, M.D., scientific director of the IRCCS Mondino Foundation, National Institute of Neurology, Pavia, Italy. “Recent research findings suggest that biological sex also impacts on disease risk factors and, potentially, on molecular mechanisms involved in the pathogenesis of PD.”
This review looked at the most recent knowledge concerning differences between women and men with PD including quality of life, genetic and environmental risk factors, drug therapies for motor and non-motor symptoms, surgical procedures, steroids and the impact of gender on disease progression.
Recent research has shown that women and men have distinctive motor and non-motor symptoms as their PD progresses.
For example, motor symptoms tend to emerge later in women; tremor is a common first presenting symptom associated with recurrent falls and more severe pain syndromes with specific characteristics such as reduced rigidity and a higher likelihood of developing postural instability (unstable while standing).
Conversely, male PD patients show more serious postural problems and have worse general cognitive abilities. In addition, “freezing of gait” — the most disabling motor complication of PD, in which people get “stuck” in place and temporarily have a hard time moving their feet forward — develops later in men. But men have a higher risk of developing camptocormia (abnormal severe forward flexion of the trunk when standing or walking).
Non-motor symptoms have been the subject of a study of more than 950 PD patients, which concluded that symptoms such as fatigue, depression, restless legs, constipation, pain, loss of taste or smell, weight change and excessive sweating are more common and severe in women.
Other studies have shown that male PD patients have worse general cognitive abilities and being male is the main risk factor for mild cognitive impairment and its more rapid progression in the severe stage of the disease.
A diagnosis of PD with dementia has a greater impact on life expectancy of women than men; in addition, women show distinctive symptoms as well as differences in the response to drug therapies and deep brain stimulation, and in their personal evaluation of the quality of life compared to men.
The authors highlight the significance of estrogens, which play an important role in the sex differences in PD, providing disease protection as demonstrated by the similar incidence of the disease in men and post-menopausal women.
“Sex hormones act throughout the entire brain of both males and females and sex differences are now highlighted in brain regions and functions not previously considered as subjected to such differences, opening the way to a better understanding of sex-related behavior and functions,” added Silvia Cerri, Ph.D., head of the Laboratory of Cellular and Molecular Neurobiology of the IRCCS Mondino Foundation and first author of the article.
“Neuroinflammation is an important piece of the pathogenic puzzle of PD. Current evidence suggests that the physiological role exerted by microglial and astrocytic cells could become compromised during aging, thus contributing to PD onset and progression.
“Since estrogens have anti-inflammatory properties, their actions throughout the lifespan could partially account for sex-related risk and manifestation of PD.”
Source: IOS Press