Plasma zinc inversely associated with haemorrhagic stroke in hypertension
Hypertensive adults with lower plasma zinc concentration are at increased risk of haemorrhagic stroke, especially those with higher body mass index (BMI) or lower plasma copper levels, a study has found.
The nested case–control study used data from the China Stroke Primary Prevention Trial and included 599 first stroke cases and 599 matched controls. Plasma copper and zinc levels were measured using inductively coupled plasma mass spectrometry.
In the entire population, median plasma zinc concentration at baseline was 104.0 μg/dL. Participants whose zinc concentration was equal to or above vs below the median had higher BMI, triglycerides, estimated glomerular filtration rate, copper, selenium and magnesium levels, higher frequency of antihypertensive medication at baseline, and higher time-averaged blood pressure levels during the treatment period.
Multivariable logistic regression analysis revealed that baseline plasma zinc concentration of ≥104.0 μg/dL was associated with significantly reduced likelihood of first haemorrhagic stroke as compared with <106.9 μg/dL (adjusted odds ratio [aOR], 0.45, 95 percent CI, 0.21–0.94).
The inverse association between plasma zinc and first haemorrhagic stroke was notably stronger among participants with BMI ≥25.0 kg/m2 or plasma copper <100.1 μg/dL at baseline (p-interaction<0.05 for both variables).
There was no significant relationship between plasma zinc and first ischaemic stroke (<103.3 vs ≥103.3 μg/dL; aOR, 1.16, 0.83–1.61).
With further confirmation, the findings may inform clinical and nutritional research on haemorrhagic stroke by considering zinc as a potentially modifiable risk factor, especially for individuals who are obese or with high plasma copper levels, according to researchers.