Plasma folate deficiency increases the risk for abnormal blood pressure in Chinese women of childbearing age

Abstract

In this study, we investigated the association between folate deficiency and abnormal blood pressure (including prehypertension and hypertension) in nonpregnant Chinese women of childbearing age. We hypothesized that lower plasma folate would be positively correlated with a higher risk for abnormal blood pressure. Data were obtained from a national cross-sectional study conducted in 2005-2006 among 3464 nonpregnant women of childbearing age from 9 provinces in China. Sociodemographic characteristics and lifestyle data were obtained from a researcher-designed questionnaire. Dietary folate intake was determined by 24-hour dietary recall. Prehypertension was defined as systolic blood pressure/diastolic blood pressure 120-139/80-89 mmHg, and hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg. Plasma folate concentration was measured with a microbiological assay, and folate deficiency was defined as a plasma folate concentration <10.5 nmol/L. Log-binomial generalized linear modeling was used to examine the association between plasma folate and prehypertension/hypertension after adjustment for confounding factors. The prevalence of prehypertension and hypertension were 20.6% (713/3464) and 3.3% (116/3464), respectively, in Chinese women of childbearing age. The median plasma folate concentration was 14.49 nmol/L (interquartile range: 9.48-22.58), and 30.8% (1067/3464) of women had folate deficiency. Women with folate deficiency were 1.715 times (95% CI, 1.331-2.209) as likely to develop prehypertension or hypertension compared with women with folate sufficiency. In conclusion, a low folate concentration (<10.5 nmol/L) was significantly associated with a higher risk for prehypertension and hypertension in these nonpregnant Chinese women of childbearing age.