From:http://jdrf.org/2015/02/the-serious-side-of-the-flu-for-people-with-t1d/
The flu can increase the risk of diabetic ketoacidosis (DKA), a serious acute complication of type 1 diabetes (T1D) that results from too little insulin
DKA is normally seen in states of prolonged fasting or starvation. The body shifts metabolism from primarily using glucose to using an alternate fuel pathway, ketones, derived from fatty acids. A key signal for this shift is very low insulin levels. However, in T1D this shift can happen within a few hours when too little insulin is administered, often in the setting of another illness such as an infection or flu (the basal insulin in a basal/bolus insulin regimen typically blocks the production of ketones). The ketones build up in the blood stream and make the blood more acidic and can be associated with dangerous shifts in many of the essential electrolytes.
More andSeven things that you can you do:http://jdrf.org/2015/02/the-serious-side-of-the-flu-for-people-with-t1d/