Abstract
Purpose :
The constant demand for around the clock services, rapid industrialization, sedentary lifestyle and other environmental factors are contributing to the circadian rhythm disruption (CRD) and increasing the risk of type 2 diabetes (T2D). Indeed, a functional clock is protective against insulin resistance and T2D. However, the consequences of CRD on the retinal structure and glucose uptake are not yet known. Therefore, the purpose of this study was to determine the effect of CRD on the retinal structure and glucose uptake.
Methods :
The C57BL6/J male mice were exposed to two different lighting conditions 10 hr light: 10 hr dark cycle (T20) or 12 hr light: 12 hr dark cycle (T24) for 10 weeks. At study termination, retinal thickness was evaluated using a spectral-domain optical coherence tomography (SD-OCT). Simultaneously, the insulin resistance was evaluated using hyperinsulinemic and euglycemic clamp. The body composition, glucose turnover rate, and tissue glucose uptake were evaluated.
Results :
The CRD resulted in a decrease in overall retinal thickness. The animals on a shorter cycle (T20) demonstrated an increase in total body fat and a decrease in lean mass. The glucose turnover rate exhibited a modest and insignificant reduction in the T20 group. The glucose uptake was reduced significantly in the retina along with a decrease in glucose uptake in gastrocnemius muscle, visceral fat brown adipose tissue, and subcutaneous fat. The glycolysis was decreased in a T20 group in comparison to a T24 group.
Conclusions :
CRD affects the normal retinal structure and alters overall metabolism as exhibited by a decrease in tissue glucose uptake, glycolysis, and an increase in body fat mass. Thus, our studies have broader implications for understanding the consequences of CRD, similar to those observed in shift workers on normal vision function.
This is a 2020 ARVO Annual Meeting abstract.