In cooperation with colleagues at universities in England and Belgium, Reedik Mägi, a professor at the University of Tartu Institute of Genomics, studied how genes influence the blood sugar levels of men and women.
“Earlier studies have shown that impaired fasting glycemia is more common in men than in women, but impaired glucose tolerance is more common in women,” said Mägi. He says that both are pre-diabetes conditions, where blood sugar levels are higher than normal. So far, it has been unknown whether such gender differences in the levels of blood sugar and insulin are also reflected in the genetic background of these characteristics.
According to Mägi, they have also studied other characteristics in a similar way. “For example, one of the characteristics with gender-dependent genetics, is the waist to hip circumference ratio that evaluates body fat deposition. The genetic factors determining the so-called apple- and pear-shaped obesity mostly only affect women,” added Mägi.
By studying more than 150,000 Europeans, the scientists identified several gene variants, which affect the fasting blood sugar and insulin levels differently in men and women. For example, it was found that the gene variant, which has previously been associated to schizophrenia, multiple sclerosis (i.e., sclerosis multiplex) and breast cancer, also affects the fasting blood sugar level.
“Such genetic links also explain why the probability of the co-existence of certain diseases is higher – for example, people with breast cancer have a higher risk of developing type 2 diabetes,” said Mägi.
Furthermore, the scientists found that in women, insulin resistance, i.e., one of the symptoms of pre-diabetes, where the organism’s ability to regulate the blood sugar levels is impaired, is also affected by the waist to hip circumference ratio and a higher body mass index. According to the authors of the study, this finding indicates that abdominal fat is an important risk factor for several diseases in women. In women, abdominal fat may also cause polycystic ovary syndrome and fatty liver disease, where insulin resistance is often the occurring concomitant symptom.
“Such studies help identify the gender-dependent impact of genes and indicate the differences between the developmental mechanisms of diseases in men and women. Taking these differences into account, physicians could develop more accurate treatment plans for male and female patients,” Mägi explained the importance of the study.
The authors noted that, in the future, similar studies should be even larger, because studying the characteristics of different groups requires larger data volumes.
The study was published in the Nature Communications journal.
The translation of this article from Estonian Public Broadcasting science news portal Novaator was funded by the European Regional Development Fund through Estonian Research Council.