INS and diabetes mellitus: Another nationwide population-based study from Taiwan found that patients with diabetes mellitus had an increased risk of gastric cancer (HR 1.49; 95% CI: 1.16–1.92, p = 0,002) and may be affected by the use of different categories of glucose-lowering therapies: insignificant effect on gastric cancer risk in diabetes treatment with sulfonylurea use (HR 1.13; 95% CI: 0.68–1.86), with metformin use (HR – 1.28; 95% CI: 0.72–2.08), or with insulin use (HR 0.53; 95% CI: 0.27–1.04), but gastric cancer risk significantly decreased with thiazolidinedione use (HR 0.11; 95% CI: 0.02–0.82) [24].