There’s a link between insufficient sleep and the development of insulin resistance, one of the factors that cause type 2 diabetes, and now, a team of researchers has discovered a biological reason for this relationship, at least in men, reports Deccan Chronicle.

“Our highly controlled sleep study showed that even one night of restricted sleep can cause insulin resistance and that we can dampen this effect by controlling levels of these two important hormones,” said senior investigator Peter Y. Liu of Los Angeles Biomedical (LA BioMed) Research Institute at Harbor-UCLA Medical Center, Torrance, Calif.

Insulin resistance occurs when the body does not properly use the hormone insulin. Testosterone is the main anabolic, or muscle-building, hormone, whereas cortisol–often called the “stress hormone”–helps catabolism, or breaking down energy and fat stores for use, Liu explained. Past research shows that sleep loss reduces a man’s testosterone levels and increases cortisol levels.