Impact of sleep deprivation and high-fat feeding on insulin sensitivity and beta cell function in dogs

Abstract

Aims/hypothesis: Insufficient sleep is increasingly recognised as a major risk factor for the development of obesity and diabetes, and short-term sleep loss in clinical studies leads to a reduction in insulin sensitivity. Sleep loss-induced metabolic impairments are clinically relevant, since reductions in insulin sensitivity after sleep loss are comparable to insulin sensitivity differences between healthy individuals and those with impaired glucose tolerance. However, the relative effects of sleep loss vs high-fat feeding in the same individual have not been assessed. In addition, to our knowledge no diurnal (active during the daytime) non-human mammalian model of sleep loss-induced metabolic impairment exists, which limits our ability to study links between sleep and metabolism.

Methods: This study examined the effects of one night of total sleep deprivation on insulin sensitivity and beta cell function, as assessed by an IVGTT, before and after 9 months of high-fat feeding in a canine model.

Results: One night of total sleep deprivation in lean dogs impaired insulin sensitivity to a similar degree as a chronic high-fat diet (HFD)(normal sleep: 4.95 ± 0.45 mU^-1 l^-1 min^-1; sleep deprivation: 3.14 ± 0.21 mU^-1 l^-1 min^-1; HFD: 3.74 ± 0.48 mU^-1 l^-1 min^-1; mean ± SEM). Hyperinsulinaemic compensation was induced by the chronic HFD, suggesting adequate beta cell response to high-fat feeding. In contrast, there was no beta cell compensation after one night of sleep deprivation, suggesting that there was metabolic dysregulation with acute sleep loss that, if sustained during chronic sleep loss, could contribute to the risk of type 2 diabetes. After chronic high-fat feeding, acute total sleep deprivation did not cause further impairments in insulin sensitivity (sleep deprivation + chronic HFD: 3.28 mU^-1 l^-1 min^-1).

Conclusions/interpretation: Our findings provide further evidence that sleep is important for metabolic health and establish a diurnal animal model of metabolic disruption during insufficient sleep.

Keywords: Canine; Diabetes; Diet; Dog; Fat; Glucose; Insulin; Obesity; Sleep.

Fig. 1

Schematic representation of experimental conditions and experimental protocol. IVGTTs were conducted following one night of normal sleep (dark period) and one night of total sleep deprivation (dim-light period), assigned in random order in24animals and separated by18 ± 3 days (mean ± SEM). A subset of eight animals then went on to receive an HFD for approximately 9 months, after which IVGTTs were conducted following one night of normal sleep and one night of total sleep deprivation, assigned in random order

Fig. 2

Effects of one night of sleep deprivation vs a chronic HFD. IVGTTs were used to assess insulin sensitivity (as S_I) (a), beta cell response (as AIR_G) (b) and DI (c) in eight animals following one night of normal sleep and one night of total sleep deprivation, assigned in random order, before and after approximately 9 months on an HFD. Data are represented as mean + SEM with individual animals represented by coloured data points. To convert S_I values to SI units, multiply by 0.167 *p < 0.05