The Effects of Simulated Jet-lag and Running-Wheel Access on the Symptoms of Type-2 Diabetes in TallyHo/JngJ Mice

Type 2 Diabetes mellitus (T2DM) is the most common form of human diabetes, accounting for about 90% of all cases and affecting about 27.85 million Americans. It is often accompanied by hyperglycemia and obesity. Diabetes has been linked to circadian rhythms (a 24-hour long daily biological clock) as it can affect critical clock genes and disruptions in the rhythm can lead to increased possibility of developing the disorder. Despite the connections between T2DM and the biological clock, there is still a gap of knowledge concerning how biological clock disruptions specifically affect body weight, blood glucose, and insulin levels in T2DM individuals or if there are ways to alleviate the clock stress that can lead to symptoms of T2DM. This study looked at the effects of voluntary exercise on common symptoms of diabetes, such as hyperglycemia and hyperinsulinemia, during jet lag. Two groups of five-week old C57BL/6J (B6; control) and TallyHo/JngJ (TH; diabetic) mice were kept in either a 12:12 LD cycle or a 6-hour advance simulated jet lag, and given standard chow and water ad libitum. Half of each strain received access to a running wheel while the other half were placed into a cage, which can monitor home cage locomotor activity, but without a running wheel. Weekly measurements of body weight, food and water consumption were recorded. In addition, a 12-hour fasting glucose tolerance test with 30, 60, and 120 min time-points was conducted every four weeks starting at age-week eight. Although diabetic animals seemed to benefit from access to a running wheel with increased insulin sensitivity, they did not show reduced severity of diabetic symptoms due to the exercise during the shifting conditions. Further research should explore other assets to alleviate circadian stressors