Black women with pregnancy-induced
high blood pressure have more homocysteine (an amino acid linked with
atherosclerosis) and less
folic acid in their blood than white women, according to a study published in the rapid access issue of
Hypertension: Journal of the American Heart Association.
This difference may contribute to the higher rates of the hypertension condition known as preeclampsia among black women and indicate future risk for cardiovascular disease, said lead author Thelma E. Patrick, Ph.D., R.N., an assistant professor at the University of Pittsburgh School of Nursing and an assistant investigator at Magee-Womens Research Institute.
“There is a higher incidence of preeclampsia in black women and we know that when black women experience the disorder they are more likely to have a more severe form that shows up as early as six months into pregnancy,” Patrick said.
It’s unclear if the differences are due to diet, lifestyle or heredity. But, since high homocysteine levels have been linked to diets low in folic acid and vitamins B6 and B12, Patrick said the finding suggests that it may be necessary to increase folic acid intake among blacks.
Epidemiological studies of non-pregnant populations have shown that too much homocysteine in the blood is related to a higher risk of coronary heart disease and stroke, though no causal link has been established, she said.
Blood homocysteine levels are strongly influenced by diet and genetic factors. Folic acid and vitamins B6 and B12 help break down homocysteine. Folic acid is found in green, leafy vegetables such as spinach, turnip greens and kale, while B6 and B12 come from grains and other types of food. Folic acid, B6 and B12 can be found in prenatal vitamins. Because low folic acid is also associated with birth defects in the nervous system, the United States requires cereal and bread to be fortified with folic acid.
Preeclampsia affects an estimated 3 to 5 percent of U.S. pregnancies. The onset of the disorder is detected by an increase in blood pressure and can cause protein in the urine — a sign of potential kidney damage and severe water retention resulting in swelling in the hands and feet. The condition can also affect circulation in the small vessels of the brain and the liver, causing headaches, double vision or abdominal pain. Preeclampsia can endanger the lives of mothers and babies, and is a common reason for premature birth, Patrick said.
Researchers examined 85 white women and 78 black women who gave birth at Magee-Womens Hospital. Thirty-four white women and 26 black women had preeclampsia.