Sleep Disturbances and Glucose Homeostasis

Abstract

Sleep disturbances, induced by either lifestyle, shift work or sleeping disorders, have become more prevalent in our 24/7 Western society.Sleep disturbances are associated with impaired health including metabolic diseases such as obesity and type 2 diabetes. The question remains whether there is a direct effect of disturbed sleep on glucose homeostasis. Experimental studies under controlled laboratory conditions in both humans and experimental animals revealed that there are differences between the effects of acute or chronic sleep disturbance. Acute sleep restriction clearly leads to glucose intolerance, often combined with insulin resistance. Although glucose intolerance does also occur after chronic sleep disturbance, the changes in insulin can vary, dependent on the body weight changes in the various studies. The underlying mechanism that might cause the changes in glucose homeostasis after sleep disturbance remains unclear, but both the biological clock located in the nucleus suprachiasmaticus as well as orexinergic mechanisms in brain and periphery seem to be involved. KeywordsSleep restriction, sleep deprivation, shift work, glucose homeostasis, hyperglycaemia, type 2 diabetes, rats, obstructive sleep apnoea Metabolic Consequences of Sleep DisturbancesSleep disturbances are also linked to metabolic dysfunctioning.Studies in shift workers provided the first (indirect) evidence for a relationship between sleep disturbances and impaired metabolism.Shift work has become more prevalent during the past decades and shows clear negative effects on sleep timing, length and quality. There is also a direct correlation between disturbed sleep and obesity, the main risk factor for developing cardiovascular diseases and type 2 diabetes. Evidence for this comes from several epidemiological studies, including those described by Caput and Van Cauter. 17,18 In addition, the group of Gottlieb and co-workers show that there is a relation between OSA and obesity, type 2 diabetes and cardiovascular disease. In fact, there is a bidirectional relationship: OSA leads to obesity, but obesity also directly affects OSA: weight gain or weight loss leads to a significant worsening or improvement, respectively, of sleep apnoea in adults. 23,24 OSA is also directly associated with insulin resistance and glucose intolerance, independent of changes in weight.