Low vitamin B12 levels may predict the risk of ischemic stroke: A cross-sectional study.

BACKGROUND: To examine serum vitamin B12 concentrations in relation to the risk of ischemic stroke among hospitalized patients in the Department of Neurology. METHODS: We performed a cross-sectional study involving 2,212 inpatients discharged from the Department of Neurology of the First Affiliated Hospital of Chongqing Medical University, from January 2020 to January 2022. The results of laboratory assays such as serum vitamin B12, homocysteine, and folate levels were measured. Logistic regression analysis was used to investigate the association between serum vitamin B12 concentrations and ischemic stroke, with adjustment for a number of relevant demographic and lifestyle factors and comorbidities. RESULTS: A total of 961 (43.4%) patients had an ischemic stroke. In the fully adjusted model, logistic regression analysis suggested a positive association between serum vitamin B12 levels<150 pg/mL (aOR: 1.42; 95% CI 1.02-1.97; p = 0.035), serum vitamin B12 150-300 pg/mL (aOR: 1.37; 95% CI 1.11-1.68; p = 0.003) and the prevalence of ischemic stroke. Furthermore, an inverse association was observed between serum vitamin B12 levels ≥ 900 pg/mL (aOR: 0.38; 95% CI: 0.19-0.77; p =0.007) and the prevalence of ischemic stroke. Moreover, the cut-off value of vitamin B12 concentration was 316.4 pg/mL and the discrimination power of the score evaluated by AUC-ROC was 0.71 (95%CI 0.68-0.73, p<0.001) in the vitamin B12 and ischemic stroke. CONCLUSION: Findings suggest that low vitamin B12 levels may predict the risk of ischemic stroke, early and timely supplementation of vitamin B12 can improve the short-term prognosis of ischemic stroke patients.

Vitamin B12 supplementation improves cognitive function in middle aged and elderly patients with cognitive impairment.

Introduction: Objectives: to determine the effects of vitamin B12 supplementation on neuropsychological function and disease progression in middle aged and elderly patients with cognitive impairment. Methods: this was a prospective case-control study. From May 2020 to May 2021, 307 participants clinically diagnosed with cognitive impairment in the Department of Neurology of the First Affiliated Hospital of Chongqing Medical University were enrolled. A total of 115 patients were included in this study. Meanwhile, 115 participants with cognitive impairment were randomly assigned in equal proportions to two groups: vitamin B12 treatment group (n = 58, vitamin B12 500 mg/d intramuscularly for seven days, followed by cobamamide 0.25 mg/d and methylcobalamin 0.50 mg/d) and the control group (n = 57). Demographic characteristics and blood biochemical variables were obtained from all participants. Cognitive performance was measured using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Cognitive performance was measured at baseline and after six months. Results: the vitamin B12 supplementation treatment patients who presented with cognitive impairment showed significant improvement, especially in attention, calculation (p < 0.01) and visual-constructional ability (p < 0.05), in their neuropsychological function compared to their matched group. Conclusion: vitamin B12 supplementation may improve frontal function in patients with cognitive decline. Vitamin B12 levels should be investigated in all patients with cognitive impairment.

Introducción: Objetivos: determinar los efectos de la suplementación con vitamina B12 en la función neuropsicológica y la progresión de la enfermedad en pacientes de mediana edad y adultos mayores con deterioro cognitivo. Métodos: se realizó un estudio prospectivo de casos y controles; se estudiaron 307 participantes, desde mayo de 2020 a mayo de 2021, diagnosticados clínicamente con deterioro cognitivo en el Departamento de Neurología, el Primer Hospital Anexado a la Universidad Médica de Chongqing. En el estudio se incluyeron un total de 115 pacientes con deterioro cognitivo que fueron asignados aleatoriamente en proporciones iguales a dos grupos: un grupo de tratamiento con vitamina B12 (n = 58, vitamina B12 500 mg/d intramuscular durante 7 días, seguido de cobamamida 0,25 mg/d y metilcobalamina 0,50 mg/d) y un grupo de control (n = 57). Se obtuvieron las características demográficas y las variables bioquímicas sanguíneas de todos los participantes. El rendimiento cognitivo se midió mediante el miniexamen del estado mental (MMSE) y la evaluación cognitiva de Montreal (Moca) al inicio del estudio y a los 6 meses. Resultados: los pacientes con deterioro cognitivo que recibieron tratamiento de suplementación con vitamina B12 mostraron una mejora significativa, especialmente en la atención, el cálculo (p < 0,01) y la capacidad visuoespacial (p < 0,05), en su función neuropsicológica en comparación con el grupo control. Conclusión: la suplementación con vitamina B12 puede mejorar la función frontal en pacientes con deterioro cognitivo. Los pacientes con deterioro cognitivo deben conocer sus propios niveles de vitamina B12.

Effects of different legume species and densities on arbuscular mycorrhizal fungal communities in a karst grassland ecosystem.

Legumes can increase nitrogen (N) input to soil via N2 fixation, and arbuscular mycorrhizal fungi (AMF) can colonize legumes, which further promotes the acquisition of nutrients such as phosphorus (P). Nevertheless, little is known about how different legume species or planting densities affect soil AMF communities. We measured soil AMF abundance, diversity, and community composition in two legume species that had been planted at two densities in a karst grassland. Five treatments were used: control (CK), Amorpha fruticosa at 1.5 × 2 m density (AFD1), A. fruticosa at 1 × 1 m density (AFD2), Indigofera atropurpurea at 1.5 × 2 m density (IAD1), and I. atropurpurea at 1 × 1 m density (IAD2). The results showed that A. fruticosa plots were significantly richer in Redeckera spp., while I. atropurpurea plots were richer in Septoglomus. AMF abundance in AFD1, AFD2, and IAD1 was significantly higher than in CK, but AMF abundance in IAD2 was significantly lower than that in the other treatments. AMF richness and Chao1 estimator in AFD1 were significantly higher than in CK. Funneliformis, Septoglomus, and Acaulospora were significantly more abundant in IAD2 than in the other treatments. The interaction between legume species and density had a significant effect on AMF abundance and community composition. AMF abundance and diversity were significantly negatively and positively correlated with available P and microbial biomass N, respectively. These results suggest that different species and densities of legumes may increase available N, which could improve AMF abundance and alleviate soil P deficiencies. Planting A. fruticosa or I. atropurpurea at a low density may be an effective method to increase AMF colonization of roots, and thus, nutrient transport in karst grasslands.