Abstract 12719: The Association of High Vitamin B12 With Mortality Risks and Related Metabolisms Among Hypertensive Population

Abstract

Background: The association of high serum vitamin B12 (B12) with mortality risks is not well studied, and its independence from related metabolites needs to be disentangled. This study aims to explore the association of high serum B12 levels with all-cause mortality and its interaction with serum folate and plasma total homocysteine (tHcy) among Chinese adults with hypertension. Methods: This large observational study obtained data from the China Stroke Primary Prevention Trial (CSPPT), a multi-center RCT. The study sample consisted of 9,695 hypertensive adults who were not exposed to B vitamin supplements at baseline and during follow-up. The primary outcome was all-cause mortality, and the secondary outcome was cardiovascular mortality. Patients were stratified by B12 tertiles, and previously published cutoffs: B12 < 299.52 pg/ml included patients with circulating B12 deficiency and sub-optimal deficiency; B12 < 349.69 pg/ml with concomitant elevated tHcy determines B12 metabolic deficiency; B12 ≥ 349.69 ng/ml refers to those who are free from both circulating and metabolic B12 deficiency. Results: During the median follow-up time of 4.5 years, 284 deaths occurred. Compared to individuals with lower B12 levels, those with elevated B12 showed increased risk of all-cause mortality (hazard ratio (HR), 1.41 95%CI 1.07-1.85) and cardiovascular mortality (HR, 3.01; 95% CI 1.30-7.01). The association between elevated B12 and all-cause mortality risk appears robust in all tested subgroups. After excluding those with potential B12 metabolic deficiency, elevated B12 remains significantly and independently associated with all-cause mortality (HR, 1.36 95%CI 1.05, 1.76) and cardiovascular mortality (HR, 2.44 95%CI 1.15, 5.18). The Bayesian kernel machine regression results showed that higher B12 is associated with increased all-cause mortality risk independent of baseline folate and tHcy. Conclusion: Among Chinese adults with hypertension, elevated B12 levels is associated with increased risk of all-cause mortality, independent of baseline folate, tHcy, and other traditional risk factors. These findings, if further confirmed, have important implications for nutritional counseling and clinical recommendations on B vitamin therapy.