Women who have gestational, or pregnancy-related, diabetes may be more likely to develop a potentially serious build up of fat in the liver later in life, suggests an analysis by researchers at the National Institutes of Health and other institutions. The researchers found that 9 to 16 years after pregnancy, women who had gestational diabetes have high levels of liver enzymes associated with the accumulation of fat, which could place them at risk of liver damage and liver failure. The researchers found a higher risk even for women who, in the years after pregnancy, did not develop prediabetes or type 2 diabetes, conditions that often occur in women who have had gestational diabetes.
The researchers were led by Cuilin Zhang, M.D., of the Epidemiology Branch at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development. The study appears in the Journal of Diabetes.
Gestational diabetes is a type of diabetes occurring only in pregnancy. It results when the level of blood sugar, or glucose, rises too high. Gestational diabetes increases a woman’s risk for high blood pressure disorders of pregnancy, as well as cardiovascular disease and type 2 diabetes later in life.
Fatty liver disease may lead to inflammation and scarring of liver tissue, which may progress to permanent liver damage called cirrhosis. In turn, cirrhosis may progress to liver failure and increase the risk of liver cancer. Type 2 diabetes is associated with an increase in the levels of free fatty acids that can accumulate in the liver and lead to fatty liver disease, the authors write. A few studies have suggested that, because women with gestational diabetes have elevated levels of fatty acids in the liver, they may also have a higher risk of fatty liver disease. However, those studies, the authors wrote, did not account for other factors that might increase a woman’s risk of fatty liver disease, such as obesity before pregnancy.
The researchers analyzed data from the Diabetes & Women’s Health Study, comparing 1,226 pregnant women, 607 of whom had gestational diabetes and 619 of whom did not. At followup examinations 9 to 16 years after birth, researchers took measures of liver enzymes that are elevated in fatty liver disease: alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyl transferase. The researchers used these measurements in combination with others to calculate a liver fat score, fatty liver index, and hepatic steatosis index, all used to estimate the extent of liver fat. The researchers statistically compensated for obesity before pregnancy and other factors known to increase the risk for fatty liver.
Among women with diabetes, ALT was 6.7% higher in women who had gestational diabetes than in women who did not. AST was 4.8% higher in women with gestational diabetes. Measures of gamma glutamyl transferase did not differ significantly between the two groups.
Women with gestational diabetes had more than twice the risk of an elevated liver fat score, nearly 1.6 times the risk of an elevated fatty liver index, and 1.4 times the risk of an elevated hepatic steatosis index.
Based on the study results, the researchers concluded that gestational diabetes could be used to identify women at higher risk of fatty liver disease. They added that future studies are needed to identify strategies to help women with gestational diabetes reduce their risk for liver fat accumulation later in life.
Doneely, SR, et al. Prospective study of gestational diabetes and fatty liver scores 9 to 16 years after pregnancy. Journal of Diabetes.2019. DOI: 10.1111/1753-0407.12934