The Impact of Light-Dark Cycle Alteration on the Acceleration of Type 1 Diabetes in NOD Mice Model

Amjaad Muhammad Ar Reshaid,1 Yasser Abdulathim Alshawakir,2 Mohammed A Almuayrifi,2 Omar Salem Al-Attas,1 Ahmed S BaHammam,3,4 Reem Abdullah Al Khalifah4– 6 1Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia; 2Experimental Surgery and Animal Lab, College of Medicine, King Saud University, Riyadh, 11451, Saudi Arabia; 3The University Sleep Disorders Centre, Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 4King Saud University Medical City, Riyadh, Saudi Arabia; 5Division of Pediatric Endocrinology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 6University Diabetes Centre, King Saud University Medical City, Riyadh, Saudi ArabiaCorrespondence: Reem Abdullah Al Khalifah, Division of Pediatric Endocrinology, Department of Pediatrics, College of Medicine, P.O Box 2925, Riyadh, 11461, Saudi Arabia, Tel +0118066750, Email [email protected]: We aimed to evaluate the effect of light–dark cycle alteration and soft drink consumption on the acceleration of type 1 diabetes mellitus (T1DM) development among non-obese diabetic (NOD) mice model.Methods: We exposed female NOD and C57BL/6 mice from the age of 5 weeks to either adlib soft drink consumption and/or T20 light–dark cycle alteration until the development of diabetes, or the mice reached the age of 30 weeks. Each group consisted of 7– 15 mice. We monitored weight, length, blood glucose level, and insulin autoantibody (IAA) levels weekly.Results: Out of 75 NOD and 22 C57BL/6 mice, 41 NOD mice developed diabetes, and 6 mice died between 7 and 8 weeks of age. The mean time to development of T1DM among NOD control mice was 20 weeks. The time to development of T1DM was accelerated by two weeks in the NOD mice exposed to light–dark cycle alteration, hazard ratio of 2.65,95th CI (0.70, 10.04) p = 0.15). The other groups developed T1DM, similar to the control group.Conclusion: There was a trend toward earlier development of T1DM among NOD mice exposed to light–dark cycle alteration, but this difference was not statistically significant. Further studies are needed to confirm our findings using larger sample sizes and different animal species.Keywords: type 1 diabetes mellitus, soft drink, sugar, light-dark cycle alteration, NOD/ShiLtJ