The impact of genetic makeup on blood insulin levels in men and women was first identified in the largest international study ever designed for this type of problem.
By publishing their findings in the journal Nature Communications, researchers from the University of Surrey, VIB-KU Leuven, the University of Lille and several other institutions, as part of the MAGIC consortium (Meta-analysis of Glucose and Insulin-related Traits Consortium), examined variations in the DNA of 151,188 Europeans without diabetes, to determine whether genetics influence the observed gender differences in the body’s ability to manage blood sugar levels and insulin in the blood.
High blood sugar (glucose) levels are seen when the pancreas is unable to produce sufficient amounts of the hormone insulin. When such disturbances in sugar levels occur, especially when associated with increased body weight or obesity, cells in other tissues in the body may not respond to insulin and become resistant to it. ‘insulin.
Professor Inga Prokopenko, University of Surrey, who is leading the study, said: ‘It is important to understand the causes of gender differences in fasting glucose and insulin, as both of these indicate how our body naturally reacts to sugar in the blood. Impaired glucose metabolism can lead to type 2 diabetes and other preventable diseases. “
Previous research has shown that more men than women have higher blood sugar levels when fasting. Women, on the other hand, are more likely to have problems with glucose tolerance, which means their bodies are not processing enough blood sugar after eating. However, it is not known whether genetic factors play a role in these differences.
“We have identified DNA variants that differ in their effect on fasting insulin levels by gender. For example, variants of the IRS1 gene have a greater impact in men than in women, while other variants of the ZNF12 gene have a large effect on insulin resistance in women, and no detectable effect in women. men ”, explains Dr Vasiliki Lagou, researcher at VIB and KU Leuven.
Prof. Prokopenko stresses “This is an excellent international effort in its analytical approaches and results, which paves the way for future studies on gender differences in human characteristics and diseases. “
Statistics and human big data
Dr Marika Kaakinen of the University of Surrey highlights the methodology applied to the study, reusable for posteriority: “If this study provides clues at the genetic level on the differences in glucose and insulin levels between men and women, its methodology also guides future studies that may apply a similar process. An even larger sample size would be desirable, this is becoming less and less complicated with the increasing availability of data from large biobanks “.
Researchers have also found that a higher waist-to-hip ratio in women, also known as belly fat accumulation, makes them resistant to insulin, which can lead to the development of type 2 diabetes.
The results of this study also led researchers to believe that abdominal obesity in women could contribute to the development of other diseases of which insulin resistance is a symptom, such as Stein-Leventhal syndrome (polycystic ovaries) or fatty liver disease (fatty liver disease).
It has also been found that severe leanness (anorexia) is genetically inversely correlated with fasting insulin levels and, again, this relationship is stronger in women than in men.
Dr Lagou continues: “This study adds to the growing body of evidence that genetics contribute to differences between the sexes in normal physiological processes and in changes leading to chronic diseases, beyond those caused. by sex hormones and environmental exposures. “
Prof. Inga Prokopenko says: “Rather than taking a one-size-fits-all approach to designing treatment plans and preventative measures taken to stop the development of a disease, gender and individual genetic makeup should be taken into consideration. “
Read the article in the journal Nature Communications