Gender plays a role in many diseases, including diabetes and metabolic disorders. “Men’s and women’s bodies function differently—and they also develop metabolic disorders differently,” explains Prof. Dr. Susanna Hofmann of DZD partner Helmholtz Munich. One reason for this is the different distribution of fat. Women store energy as fat under the skin of the abdomen, hips, and thighs. Men store excess energy as fat in the abdominal cavity, which is more easily converted into energy.
Differences in muscle metabolism between women and men
Skeletal muscle plays an important role in glucose metabolism and thus also in the development of type 2 diabetes. Studies by the DZD show that women and men differ in this regard: women’s muscles rely more on fatty acids for energy production and more often contain endurance-oriented muscle fibers, whereas in men, glucose utilization and fast-twitch muscle fibers are more prominent.
The sexes also respond differently to physical exertion. Women adapt their muscle metabolism efficiently after a short period and improve aerobic energy production. Men, in contrast, tend to show stress responses in their muscles initially. However, with regular training, these differences gradually diminish, and both sexes benefit from improved endurance and glucose utilization.
Insulin acts differently in the brain
Studies by the DZD partner in Tübingen further show that the brain responds differently to insulin in women and men. The action of the hormone insulin in the brain plays an important role in the human body. It influences, among other things, overall metabolism, fat distribution, and eating behavior. Studies in men have shown that individuals whose brains respond little or not at all to insulin are more likely to gain weight and accumulate more abdominal fat.
Age and cycle influence insulin action in women
As women age, the effect of insulin in the female brain declines. “The hippocampus is particularly striking: in women, reduced insulin action becomes evident from around the age of 50, whereas in men it remains largely stable between ages 20 and 70,” explains DZD researcher Prof. Dr. Stephanie Kullmann, deputy head of the Metabolic Neuroimaging Department at the Institute for Diabetes Research and Metabolic Diseases (IDM) in Tübingen.
In women, insulin action also fluctuates over the course of the menstrual cycle. Before ovulation, insulin sensitivity in the brain is higher than afterward—a possible explanation for the sometimes pronounced blood glucose fluctuations in women with type 1 diabetes. This is suggested by a study involving 11 young women. Many affected individuals already take these changes into account in everyday life and adjust their insulin dose according to their cycle. The results now provide a plausible explanation: cycle-dependent changes in insulin sensitivity in the brain.
Female hormones influence metabolism
However, insulin is not the only factor that plays a central role in the development of metabolic diseases. Sex-specific hormones also influence metabolism. Up to menopause, women develop metabolic diseases less frequently than men. This may indicate a protective role of estrogens, the female sex hormones. After menopause, when hormone production declines, the risk of obesity increases. Studies, including those from the DZD, show that estrogens, for example, regulate satiety signals in the brain. Although the exact mechanisms are not yet fully understood, these findings help explain sex-specific differences and support the development of new, more individualized therapies for obesity.
Goal: more personalized therapies
These research findings make it clear: sex is an important factor in effective diabetes prevention and treatment. A better understanding of these differences can help tailor therapies more precisely to individuals—and thus improve care for both women and men.
