Do men with MS deserve to be offered higher efficacy DMTs earlier than women?
When you do a baseline prognostic profile of someone with MS, being female is a good prognostic factor compared to being a male. Men have a worse outcome. This study below shows men do worse when it comes to poor cognition compared to women (#ThinkCognition).
The question of why women do better cognitively may relate to hormonal factors being neuroprotective, i.e. there is a large body of literature showing that oestrogens are neuroprotective. Another factor that is poorly studies are social factors, i.e. women tend to have larger social networks, which may improve their outcomes (#ThinkSocial).
Another factor is age; men get MS on average 3 years later than women. With ageing, you have less reserve capacity and less ability to repair your brain. Could this explain the poorer outcomes for men with MS?
Finally, men are more likely to have PPMS and hence have had subclinical MS for longer. People with relapsing MS are more likely to get diagnosed and treated earlier in comparison with PPMS, which is typically diagnosed 10 years later than relapsing MS and until recently was not treated. Please note in the NHS PPMS is still not treated with DMTs.
Donaldson et al. Why Sex Matters: A Cognitive Study of People With Multiple Sclerosis. Cogn Behav Neurol. 2019 Mar;32(1):39-45.
BACKGROUND: Cognitive dysfunction affects 40% to 70% of people with multiple sclerosis (MS). Sex may influence a person’s cognition. Although a few studies have reported greater cognitive deficits in men than women, it is unclear whether specific cognitive domains are more vulnerable than others to the effects of sex or whether cognition is influenced by neurologic or psychiatric variables.
METHODS: A chart review was undertaken of 408 people with MS referred to neuropsychological services. Demographic and MS-related variables were extracted from the patients’ records. We used the Minimal Assessment of Cognitive Functioning in Multiple Sclerosis for the neuropsychological assessment. Raw test scores were converted to z scores using Canadian regression-based normative means. A general linear model was conducted on the adjusted scores, controlling for age; years of education; disease course; illness duration; and disability, anxiety, and depression scores.
RESULTS: Men were more likely than women to have primary progressive MS (χ=6.415, P=0.011). There were no other sex differences with respect to demographic, neurologic, or psychiatric data. Women performed significantly better than men on the California Verbal Learning Test-Second Edition Total Learning index (F=7.846, P=0.006).
CONCLUSIONS: An analysis of a large, consecutive sample of people with MS demonstrated that sex, independent of demographic, neurologic, or psychiatric factors, is an important determinant in cognitive impairment, with men being more impaired than women on tests of verbal learning and memory.