In detail, patients receiving insulin monotherapy (OR: 2.07, CI: 1.54–2.79, p < 0.001), insulin + statins (OR:2.24, CI: 1.68–3.00, p < 0.001), insulin + DPP-IV inhibitors + statins (OR: 4.31, CI: 1.80–10.33, p = 0.001), insulin + metformin + statins (OR:2.27, CI: 1.55–3.31, p < 0.001) or a combination therapy of sulfonylureas + metformin (OR:1.70, CI: 1.08–2.69, p = 0.02) were at increased risk of being diagnosed with pneumonia during the observational period. The gene discussed is INS; the disease is susceptibility to pneumonia measurement.