INS and type 2 diabetes mellitus: The small proportion of insulin use in our patients as shown in Table 1, 8.26% among metformin (+) and 6.98% among metformin (−), was consistent with our early study that used a questionnaire to interview patients with T2DM in mid-1990s that showed an insulin using rate of 6.7% among 87,850 patients (Tseng, 2006).