I'm still very much a novice when it comes to nutrition, but perhaps the bigger question is knowing what other effects insulin may have on your body.
After "Googling" sucralose and insulin, the first few results that popped up included the spiking of insulin secretion.
My understanding (which may be completely incorrect) is that sucralose, a corn derived sweetener, is not digested by our body. HOWEVER, my assumption is our body still recognizes the sugar for being a sugar and in turn releases insulin. Sucralose is more potent as a sweetner than regular sugar (600x). My assumption is there is very likely a psychosomatic effect here.