Sleep Debt and Insulin Resistance: What's Worse, Sleep Deprivation or Sleep Restriction?

Objective  To evaluate which condition of sleep debt has a greater negative impact on insulin resistance: sleep deprivation for 24 hours or 4 hours of sleep restriction for 4 nights. Materials and Methods  In total, 28 healthy male subjects aged 18 to 40 years were recruited and randomly allocated to two groups: sleep deprivation (SD) and sleep restriction (SR). Each group underwent two conditions: regular sleep (11 pm to 7 am ) and total sleep deprivation for 24 hours (SD); regular sleep (11 pm to 7 am ) and 4 nights of sleep restriction (SR) (1 am to 5 am ). The oral glucose tolerance test (OGTT) was performed, and baseline glucose, insulin, free fatty acids (FFAs), and cortisol were measured. In addition, the area under the curve (AUC) for glucose and insulin, the homeostasis model assessment of insulin resistance (HOMA-IR), and the Matsuda Index (Insulin Sensitivity Index, ISI) were calculated. Results  Glucose and insulin had a similar pattern between groups, except at the baseline, when insulin was higher in the sleep debt condition of the SR when compared with the SD ( p  < 0.01). In the comparison between regular sleep and sleep debt, the SD had a higher insulin AUC ( p  < 0.01) and FFAs ( p  = 0.03) after sleep deprivation, and insulin and the insulin AUC increased ( p  < 0.01 for both), while the ISI decreased ( p  = 0.02) after sleep restriction in the SR. In baseline parameters covariate by the condition of regular sleep, insulin ( p  = 0.02) and the HOMA-IR ( p  < 0.01) were higher, and cortisol ( p  = 0.04) was lower after sleep restriction when compared with sleep deprivation. Conclusion  Sleep restriction for 4 consecutive nights is more detrimental to energy metabolism because of the higher insulin values and insulin resistance compared with an acute period of sleep deprivation of 24 hours.