The diverse impact of the genetic makeup in men and women on levels of fasting blood insulin has been identified for the first time in the largest international study of its kind. Researchers from the University of Surrey, VIB-KU Leuven, University of Lille, and a number of other institutions, as part of the Meta-analysis of Glucose and Insulin- related traits Consortium (MAGIC), examined DNA variations in 151,188 Europeans without diabetes, to determine whether genetic differences can explain the known gender differences in how well the body is able to manage blood sugar and insulin levels.
We have high blood sugar (glucose) levels when the pancreas does not produce sufficient insulin. Such changes in blood sugar levels, especially when associated with higher body weight or obesity, may make cells in other tissues unresponsive to insulin.
Professor Inga Prokopenko from the University of Surrey and senior author of the study explains, “It is important to understand what causes gender differences in fasting glucose and fasting insulin levels, as both indicate how well our bodies naturally cope with sugar in the blood. A disturbed glucose metabolism can lead to type 2 diabetes and other preventable illnesses.”
Previous research has shown that more men have a higher level of blood sugar when fasting compared to women. Women, in turn, are more likely to have problems with glucose tolerance, which means their bodies do not process blood sugar actively enough after food intake. However, whether genetic factors play a role in such differences has been unclear.
“We identified DNA variants that differ in their effect on fasting insulin levels by gender,” says Dr Vasiliki Lagou, researcher at the VIB and KU Leuven.
Professor Prokopenko highlights “This is an excellent international effort in its analytical approaches
Researchers also discovered that a higher waist to hip ratio in women, also called apple-shaped fat distribution, causes them to be insulin resistant, potentially leading to the development of type 2 diabetes. Findings from this study have also led researchers to believe that abdominal obesity in women might contribute to the development of other illnesses where insulin resistance is a symptom, such as polycystic ovary syndrome and fatty liver disease.
Dr Lagou continues: “This study adds to the evidence that genetics contributes to differences between the two genders in normal physiological processes and in changes leading to chronic conditions beyond those contributed by sex hormones and environmental exposures.”
Professor Inga Prokopenko: “Rather than a ‘one size fits all’ approach in designing treatment plans and preventative measures taken to stop the development of an illness, gender and individual genetic makeup should be taken into consideration.”