The study suggests mothers who binge drink before they become pregnant may be more likely to have children with high blood sugar and other changes in glucose function that increase their risk of developing diabetes as adults.
Principal investigator Prof Dipak Sarkar said: “The effects of alcohol use during pregnancy on an unborn child are well known, including possible birth defects and learning and behaviour problems.
“However, it is not known whether a mother’s alcohol use before conception also could have negative effects on her child’s health and disease susceptibility during adulthood,”
For women, binge drinking is defined as the equivalent of four or more drinks in about two hours.
Prof Sarkar and his colleagues conducted the study in rats, whose basic processes of glucose function are similar to those in humans.
For four weeks, they gave female rats a diet containing 6.7 per cent alcohol, which raised their blood alcohol levels to those of binge drinking in humans.
Alcohol was then removed from the rats’ diet, and they were bred three weeks later, equal to several months in humans.
Adult offspring of these rats were compared with the offspring of rats that didn’t receive alcohol before conception.
After the rats’ offspring reached adulthood, the researchers used standard lab techniques to monitor their levels of blood glucose and insulin and two other important hormones, glucagon and leptin.
Glucagon stimulates the liver to convert glycogen into glucose to move to the blood, making blood glucose levels higher. Although the main function of leptin is inhibiting appetite, it also reduces the glucose-stimulated insulin production by the pancreas.
The researchers found that the offspring of rats exposed to alcohol before conception had several signs of abnormal glucose function.
Altered glucose function included increased blood glucose levels, decreased insulin levels in the blood and pancreatic tissue, reduced glucagon levels in the blood while being increased in pancreatic tissue, and raised blood levels of leptin.
The researchers said they also found evidence that preconception alcohol exposure increased the expression of some inflammatory markers in pancreatic tissue.
Study co-author Ali Al-Yasari, a doctoral candidate, said this might lower insulin production and action on the liver that increases blood glucose levels.
He said the overexpression of inflammatory markers may be how pre-pregnancy alcohol use altered normal glucose function in the offspring.
He added: “These findings suggest that the effects of a mother’s alcohol misuse before conception may be passed on to her offspring.
“These changes could have lifelong effects on the offspring’s glucose function and possibly increase their susceptibility to diabetes.”