A Chinese study has shown that there is a significant negative association between plasma selenium concentrations and the risk of a first stroke in males but not in females. This is not the first time that sex differences have been reported relative to selenium metabolism. More on that later.
Plasma Selenium Levels and the Risk of a First Stroke
The Chinese researchers analyzed the results from a nested case-control study with 1255 first stroke cases and 1255 matched controls [Hu 2021].
- They found that males (but not females) with plasma selenium concentrations above 94 micrograms per liter had significantly less risk of a first stroke of any kind and significantly less risk of a first ischemic stroke.
- There was also a stronger negative association between plasma selenium levels and first strokes of all kinds — ischemic, hemorrhagic, or unidentified — in males with higher vitamin E levels.
- There was no significant association between plasma selenium levels and first hemorrhagic stroke risk in either males or females.
N.B. In this study, there were many more cases of first ischemic stroke (n=1079) than there are cases of first hemorrhagic stroke (n=171). Five cases were of uncertain origin.
Evidence from Other Studies of Selenium Level and Stroke Risk
The results from studies of selenium level and stroke risk have been somewhat confusing to date: