Low, high serum folate up risk of cardiovascular deaths among hypertensive adults

Both low and high folate among hypertensive adults appear to increase the risk of dying from cardiovascular disease (CVD) compared with moderate serum folate concentration, suggests a recent study.

A total of 1,298 deaths were recorded after 33,627 person-years (PYs) of follow-up. Of these, 638 were from CVD (109 strokes and 529 heart diseases). A U-shaped association was seen after multivariable adjustment for heart disease, acute myocardial infarction, and overall CVD deaths.

The corresponding mortality rate for heart disease in patients with low, moderate, and high folate were 12.18 per 1,000 PYs (HR, 1.79, 95 percent confidence interval [CI], 1.63–1.98), 14.12 per 1,000 PYs (HR, 1.00 (reference), and 23.80 per 1,000 PYs (HR, 1.31, 95 percent CI, 1.17–1.46). For acute myocardial infarction, the HRs were 2.28 (95 percent CI, 1.80–2.88), 1.00 (reference), and 1.77 (95 percent CI, 1.42–2.20) for hypertensive patients with serum folate in the low, inter-, and high quartile, respectively.

The investigators obtained and analysed data of 3,116 hypertensive adults aged ≥19 years who participated in the Third National Health and Nutrition Examination Survey (1991–1994). Vital status was followed until 31 December 2010. Hazard ratios (HRs) of cardiovascular deaths were estimated using Cox regression for those with serum folate in the first and fourth quartiles compared with patients with interquartile folate.

“A significant shift toward high folate concentrations has been taking place following the mandatory folate fortification,” the investigators noted. “Yet the relationship between folate and health outcomes beyond neural tube defects remains understudied.”