Women who develop diabetes while pregnant may be at elevated risk of also developing a dangerous build up of fat in their livers when they reach middle age, according to a new analysis.
The common risk factor for both gestational diabetes and non-alcoholic fatty liver disease, researchers say, is trouble making or using the hormone insulin to manage blood sugar, known as insulin resistance.
"We hope that early identification can promote healthy lifestyle changes that prevent or slow disease progression," said lead author Dr. Veeral Ajmera of the University of California, San Francisco.
"Pregnancy stresses the body in many ways, one of which is the ability to manage blood sugar," Ajmera said by email. "During pregnancy a woman's body becomes more resistant to insulin, which is the hormone required to decrease the blood sugar."
Insulin resistance is also "central to development of non-alcoholic fatty liver disease," which affects 20 per cent to 30 per cent of adults in the western world, the study team writes in The American Journal of Gastroenterology. Non-alcoholic fatty liver disease is the most common chronic liver disease in the United States.
Fatty liver disease is often diagnosed later in life, Ajmera told Reuters Health. So the researchers used long-term data to see if diabetes during pregnancy made a woman more likely to develop fatty liver disease 25 years later.
The researchers analysed information about 1,115 black and white women recruited between 1985-1986 in four cities across the United States who gave birth to at least one child.
The participants did not have diabetes before becoming pregnant and the study excluded people who had liver issues related to alcohol, HIV, hepatitis or medications.
At the start of the study, women reported on whether they first experienced diabetes during pregnancy, and researchers confirmed the diagnosis with blood test results. Twenty-five years later, the women received more blood tests as well as CT scans of their livers to check if they had fatty liver disease.
At the beginning of the study, 124 women reported that they developed diabetes while they were pregnant. These women were more likely than those who did not experience gestational diabetes to be overweight. They also had higher degrees of insulin resistance when they were younger as well as at the 25-year follow up.
The women who experienced diabetes during pregnancy were also more likely to have developed diabetes again at some point in the following 25 years.
Overall, 75 women were diagnosed with non-alcoholic fatty liver disease when they were middle aged. Women who had diabetes during pregnancy were more than twice as likely as those who didn't to later develop fatty liver disease.
After researchers adjusted for diabetes that some women experienced outside of pregnancy, the risk of non-alcoholic fatty liver disease was still 50 per cent higher for women who had gestational diabetes compared to those who didn't.
Fatty liver disease can have grave health effects and can even lead to cirrhosis, a condition that causes liver damage and possible failure, said Simon Taylor-Robinson, a professor of medicine at Imperial College London in the UK who wasn't involved in the study.
He advocates changes in diet to avoid the insulin resistance that leads to diabetes and fatty liver disease. "Many women are obese - so it is a matter of reducing weight and eating sensibly," he said.
Taylor-Robinson recommends eating fewer carbohydrates, more proteins and vegetables, and in particular, avoiding large amounts of fruit juice, which can contain a lot of sugar.
Ajmera also advised lifestyle changes, especially adding exercise. "We recommend either aerobic or resistance training for 30 minutes five times per week," he said.
"There are consequences to obesity and this includes cirrhosis, liver cancer and heart disease," Taylor-Robinson said. "Those people who become diabetic during pregnancy have strong risks of developing these complications later in life if attention isn't given to weight, diet and exercise."