I thought that title
would get your attention. It will be interesting to see how many hits this
particular blog post gets over the coming months.
But I am being a bit
disingenuous. What I really want to talk about is the role of gender in
Parkinson’s.
It turns out that
Parkinson’s is slightly different between men and women. There are three main
differences:
- More men than women have Parkinson’s, by a ratio of about 2:1
- Women on average have later onset: the average age at diagnosis is about 62 for women and 60 for men
- The initial symptoms are different. Women are more likely to have tremor as one of their first symptoms whereas men are more likely to get rigidity of movement.
Why are there these differences
between men and women?
The short answer is
nobody knows, but it is thought that the female hormone oestrogen plays a role.
A few studies have
indicated neuroprotective effects of oestrogen on nigrostriatal dopaminergic
cells (the ones that are dying in my brain).
The oestrogen hypothesis is further backed up by the fact that the number
of children, age at menopause, and duration of fertile life are all correlated
with later age at onset in women. My mother had six children, so perhaps this
goes some way to explaining why her onset was so much later than mine.
Other studies have
proved inconclusive however, and if oestrogen is neuroprotective, the exact
mechanism for this is unknown.
Could oestrogen, or
something similar be used to treat Parkinson’s?
Well, probably not. It
seems that although onset of Parkinson’s is a little different between the
sexes, once a person has confirmed Parkinson’s, the progression is much the
same. In other words, by the time you’re diagnosed it’s too late. Perhaps 90%
of the dopaminergic cells are already gone so a treatment that slightly slows
down depletion of the remaining cells would only have a small effect.
This is borne out by
my own observations. For example, I went to a coffee morning with my local
Parkinson’s group last weekend: there were five men and three women (so roughly
2:1) but there was just as much variation in the range and severity of symptoms
across the two genders.
There is clearly
something significant in the difference between men and women. If you were
known to be at risk of Parkinson’s due to a genetic factor then a treatment
that could significantly delay onset might be well worth taking. Though it’s
not a simple case of men swallowing oestrogen tablets to protect themselves.
For one thing, that has side effects of shrinking testes and growing breasts…
Nevertheless, it seems
to me that the gender question could be a fruitful line of research, but there
have been relatively few studies on the topic.
As for the impact of
Parkinson’s on one’s sex life (which, go on, admit it, is the real reason you
clicked on this post), well… some things are best left private. But I’m sure if
you go back to Google or Bing, you will find plenty of other references to that
particular topic…
