High glucose levels in pregnancy can affect baby’s heart

By Julie Griffiths on 15 December 2017 Research Diabetes Pregnancy

New research shows how high glucose in pregnancy can keep cardiac cells of fetuses from maturing normally.

The researchers say their findings help explain why babies born to women with diabetes are more likely to develop congenital heart disease.

The study, which was published today in the journal eLife, found that heart cells generate more building blocks of DNA than usual when exposed to high levels of glucose, leading the cells to continue reproducing rather than maturing.

While the researchers highlight that genetics plays a large role in the development of congenital heart disease, the leading non-genetic risk factor for the disease is a mother having diabetes during pregnancy.

Babies born to women with high levels of glucose in their blood during pregnancy are two to five times more likely to develop the disorder than other babies. However, researchers have never been able to define the precise effect of glucose on the developing fetus.

Study lead and UCLA associate professor of molecular, cell, and developmental biology Atsushi Nakano and his colleagues used human embryonic stem cells to grow heart muscle cells (cardiomyocytes) in the lab and then exposed them to varying levels of glucose.

Cells that were exposed to small amounts of glucose matured normally. But cardiomyocytes that had been mixed with high levels of glucose matured late or failed to mature altogether, and instead generated more immature cells.

Atsushi said that high blood sugar levels are not only unhealthy for adults; they’re unhealthy for developing fetuses. He added that understanding the mechanism by which high blood sugar levels cause disease in the fetus may eventually lead to new therapies.

‘More nutrition is generally thought to be better for cells, but here we see the exact opposite,’ Atsushi said. ‘By depleting glucose at the right point in development, we can limit the proliferation of the cells, which coaxes them to mature and makes the heart muscle stronger.’

Access the full study here.