``We found that the metabolic and endocrine (hormonal system) changes resulting from a significant sleep debt mimic many of the hallmarks of ageing,'' said Eve Van Cauter, who directed the study published in the Lancet, a medical journal. ``We suspect that chronic sleep loss may not only hasten the onset but could also increase the severity of age-related ailments such as diabetes, hypertension, obesity and memory loss,'' she said.