Of the 8 studies, 4 (50%) provided diabetes-related complications, including retinopathy, neuropathy, and nephropathy [29,31,33,34]; 6 (75%) reported that 1.6% to 100% of the participants injected insulin [32-37]; and 6 (75%) reported 4.4% to 100% sulfonylureas use [29,33-37]. This evidence concerns the gene INS and neuropathy.