Experts: Risk of stroke may start in the womb
Last Updated: 2003-06-19 16:43:50 -0400 (Reuters Health)
By Alison McCook
NEW YORK (Reuters Health) – Researchers have long struggled to explain why some people living in certain regions of the U.S. and UK are more likely to develop stroke than others. Now, two experts are looking to the womb to explain this uneven pattern. They found that UK regions marked by high stroke rates also showed high rates of death among mothers and infants in the early 20th century, the years when many stroke patients were born. This trend suggests that the mysterious variations in stroke rates may be the result of historical, regional differences in maternal health, they write in a report released Thursday. If this theory proves correct, study author Dr. David J. P. Barker of the University of Southampton in the UK told Reuters Health that, in the next generation, stroke prevention may lie “in good nutrition among mothers at conception and beyond.”
In the U.S., the southeast is known as the “stroke belt,” a region where stroke rates and the risk of death from stroke are significantly higher than in the rest of the country. In England and Wales, researchers have found that stroke rates tend to spike in northern towns, where they are accompanied by similar increases in the rates of high blood pressure and death from heart disease. Researchers who have investigated the potential reasons behind the patchwork distribution of stroke rates in the U.S. have shown they bear no relationship to inequalities in medical care, and have uncovered no explanation for why they occur.
Now, in the journal Stroke: Journal of the American Heart Association, Barker and co-author Dr. Daniel T. Lackland of the Medical University of South Carolina in Charleston propose that the differences in stroke rates may stem from previous geographical variations in overall prenatal health. In the report, Barker and Lackland compare stroke-related death rates in different regions of England and Wales between 1968 and 1978 to the rate of maternal and infant deaths during the first part of the 20th century, approximately the time when many stroke patients were born. In an interview, Barker said that places in the UK that are characterized by high rates of stroke had historically high rates of death among mothers and babies. “It’s a very strong relationship,” he explained.
As further evidence that the risk of stroke may begin before birth, Barker said that people with low birth weights — a sign of poor prenatal nutrition — are more likely to eventually develop stroke. He added that the phenomenon of the U.S. stroke belt and other regions with high stroke rates applies to people who were born in these areas, and not those who moved there later in life. “The place where you’re born is a strong determinant of your stroke risk,” he said.
In an accompanying editorial, Dr. Larry B. Goldstein of Duke University in Durham, North Carolina cautions that the current report only links stroke risk to in utero health, and does not show that one causes the other. “Despite this inherent limitation … the data provide another compelling argument to ensure adequate prenatal care and maternal nutrition,” Goldstein writes.
Source: Stroke 2003;10.1161/01.STR.0000077257.27430.7E