Changes in sleep architecture after Type 2 Diabetes Mellitus (T2DM)

Abstract

Introduction Type 2 Diabetes Mellitus (T2DM) is a syndrome in which multiple physiological changes are observed. The pathophysiology of diabetes such as polyphagia, polyuria, polydipsia, weight loss and/or changes in mood, such as depression or less physical activity and stress, contribute to physical and mental deterioration. Epidemiological studies report that the leading cause of death in diabetic patients is due to cardiovascular problems. It has been shown that the decrease in sleep duration combined with T2DM, increases the risk of cardiovascular events in hypertensive patients. Also, chronic sleep deprivation is linked to metabolic and cardiac disorders, and it has been suggested that respiratory conditions, such as obstructive sleep apnea, correlate with cardiovascular disease, diabetes and cancer. In order to explore if there is an association between T2DM and sleep quality, we analyzed through polysomnographic recordings (PSGR), the changes in the macro and micro sleep architecture using a streptozotocin model of T2DM. Materials and methods Six adult male Wistar rats (300–350 g) were implanted with chronic electrodes for PSGR. Rats were adapted to a 12/12 h light/dark cycle (light from 8:00 to 20:00). For T2DM induction, each rat was administered with 45 mg/kg of streptozotocin (SI) i.p. Measures of glucose level were taken on the third or fourth day after SI administration. Rats were selected with a 200 mg/dL minimum blood glucose level. Each rat underwent at least four PSGR which lasted six continuous hours (10:00–16:00). Sleep latency and duration, number of sleep stages, total percentage of Non REM sleep stages I, II and REM sleep, were quantified. Sleep spindles and theta activity were analyzed as well. All PSGR were compared to previous control recordings. Results Our preliminary results show that there is a significant increase in the density and voltage of sleep’s phasic phenomena (e.g. sleep spindles, theta activity, etc.) associated to T2DM induction, as well as a significant decrease in the number and duration of sleep stages. Conclusion Sleep micro architecture in both REM and NREM sleep is particularly enhanced by T2DM induction, whereas sleep stages are diminished. These preliminary results show a possible association between metabolic mechanisms (glucose) and sleep homeostatic processes. Acknowledgements Eva Gonzalez Trujano Carlos Jimenez Rodriguez Carlos Camacho Garcia Raul Cardoso Jose Luis Calderon.