Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Am J Clin Nutr. 2012 May;95(5):1023-30. doi: 10.3945/ajcn.111.027250. Epub 2012 Apr 4.
Laboratory studies suggest that folate intake may decrease blood pressure (BP) through increasing nitric oxide synthesis in endothelial cells and/or reducing plasma homocysteine concentrations. However, human studies, particularly longitudinal data, are limited.
Our objective was to investigate whether dietary folate intake is associated with the 20-y incidence of hypertension.
We prospectively followed 4400 men and women (African Americans and whites aged 18-30 y) without hypertension at baseline (1985) in the Coronary Artery Risk Development in Young Adults study 6 times, in 1987, 1990, 1992, 1995, 2000, and 2005. Diet was assessed by dietary-history questionnaire at baseline and in 1992 and 2005. Incident hypertension was defined as the first occurrence at any follow-up examination of systolic BP ≥ 140 mm Hg, diastolic BP ≥ 90 mm Hg, or use of antihypertensive medication.
A total of 989 incident cases were identified during the 20-y follow-up. After adjustment for potential confounders, participants in the highest quintile of total folate intake had a significantly lower incidence of hypertension (HR: 0.48; 95% CI: 0.38, 0.62; P-trend < 0.01) than did those in the lowest quintile. The multivariable HRs for the same comparison were 0.33 (95% CI: 0.22, 0.51; P-trend < 0.01) in whites and 0.54 (95% CI: 0.40, 0.75; P-trend < 0.01) in African Americans (P-interaction = 0.047). The inverse associations were confirmed in a subset of the cohort (n = 1445) with serum folate measured at baseline and in 1992 and 2000.
Higher folate intake in young adulthood was longitudinally associated with a lower incidence of hypertension later in life. This inverse association was more pronounced in whites. Additional studies are warranted to establish the causal inference.
实验室研究表明，叶酸摄入可能通过增加内皮细胞中一氧化氮的合成和/或降低血浆同型半胱氨酸浓度来降低血压（BP）。然而，人体研究，特别是纵向数据，是有限的。
我们的目的是调查膳食叶酸摄入是否与 20 年高血压发病率有关。
我们前瞻性地随访了 4400 名男性和女性（18-30 岁的非裔美国人和白人），在基线（1985 年）时没有高血压，在 1987 年、1990 年、1992 年、1995 年、2000 年和 2005 年进行了 6 次随访。饮食通过基线和 1992 年和 2005 年的饮食史问卷进行评估。高血压的发生定义为任何随访检查时收缩压≥140mmHg、舒张压≥90mmHg 或使用抗高血压药物的首次发生。
在 20 年的随访期间，共发现 989 例高血压事件。调整潜在混杂因素后，总叶酸摄入量最高五分位数组的高血压发病率显著降低（HR：0.48；95%CI：0.38，0.62；P-趋势<0.01），而最低五分位数组则没有（HR：0.33；95%CI：0.22，0.51；P-趋势<0.01）。在白人（P 交互=0.047）和非裔美国人（P 交互=0.047）中，相同比较的多变量 HR 分别为 0.33（95%CI：0.22，0.51）和 0.54（95%CI：0.40，0.75）。在基线和 1992 年和 2000 年测量血清叶酸的队列的一个亚组中，也证实了这种反比关系（n=1445）。
年轻时摄入较高的叶酸与以后生活中高血压的发病率较低有关。这种反比关系在白人中更为明显。需要进一步的研究来确定因果关系。
