Serum 25-hydroxyvitamin D deficiency predicts long-term poor prognosis among ischemic stroke patients without hyperglycaemia.

BACKGROUND: It is unclear whether 25-hydroxyvitamin D [25(OH)D] has a protective effect on long-term prognosis of ischemic stroke and whether it is affected by blood glucose levels. We aim to examine the effect of serum vitamin D especially its deficiency on 1-year poor outcome of ischemic stroke patients in total patients and by blood glucose subgroups. METHODS: A total of 3041 ischemic patients from China Antihypertensive Trial in Acute Ischemic Stroke were included. The serum concentrations of 25(OH)D were measured at baseline. All subjects were followed up for death and vascular events at 1year after acute ischemic stroke. RESULTS: Among total ischemic stroke patients and those with hyperglycemia, 25(OH)D deficiency was not associated with the risk of vascular events and death. In the normoglycemic subgroup, 25(OH)D deficiency subjects had a significantly higher risk of poor prognosis compared with those with 25(OH)D≥20ng/ml. The hazard ratio (95% confidence interval) was 1.58(1.04-2.41) in the multivariable adjusted model (P for linear trend=0.02). CONCLUSION: Serum 25(OH)D deficiency may be merely an independent risk factor of 1-year poor prognosis in ischemic stroke patients without hyperglycemia. Future studies about improving long-term prognosis of ischemic stroke by vitamin D supplementation could be first applied to these patients.

Induction of cytochrome P450 2B6 activity by the herbal medicine baicalin as measured by bupropion hydroxylation.

PURPOSE: This study investigated the effect of the herbal medicine baicalin on bupropion hydroxylation, a probe reaction for CYP2B6 activity related to different CYP2B6 genotype groups. METHOD: Seventeen healthy male volunteers (6 CYP2B6*1/*1, 6 CYP2B6*1/*6, and 5 CYP2B6*6/*6) received orally administered bupropion alone and during daily treatment with baicalin. Blood samples were taken up to 72 h after each bupropion dose, and pharmacokinetics profiles were determined on days 1 and 25 for bupropion and hydroxybupropion. RESULT: Baicalin administration increased hydroxybupropion maximum plasma concentration (C(max)) by 73% [90% confidence interval (CI), 44-108%; P < 0.01] and the area under the concentration time curve extrapolated to infinity (AUC(0-infinity)) of hydroxybupropion by 87% (90% CI, 48-137%; P < 0.01), with no change in the elimination half-life of hydroxybupropion. Baicalin increased the AUC(0-infinity) ratio of hydroxybupropion to bupropion by 63% (90% CI, 38-92%; P < 0.01). CONCLUSION: Baicalin significantly induced CYP2B6-catalyzed bupropion hydroxylation, and the effects of baicalin on other CYP2B6 substrate drugs deserve further investigation.