A recent systematic review of intensive insulin therapy in hospitalized patients published in the Annals of Internal Medicine concluded that intensive insulin therapy (IIT) in hospitalized patients does not improve patient prognosis compared to non-intensive glucose-lowering therapy, but rather increases the risk of hypoglycemia in patients. The authors searched MEDLINE and Cochrane Database of Systematic Reviews for randomized controlled clinical studies comparing intensive insulin therapy with non-intensive glucose-lowering therapy from 1950 to January 2010. A systematic review of the eligible research papers was also conducted. Indicators assessed included short-term mortality (≤28 days), long-term mortality (90 or 180 days), infection rate, days in hospital, and incidence of hypoglycemia. The results confirmed that short-term mortality could not be reduced in critically ill patients with IIT (relative risk of 1.00 [95% CI, 0.94 to 1.07]); there was no consistent evidence that ITT reduced long-term mortality, infection rates, days in hospital, and the proportion of renal transplant patients. There was no evidence that ITT was beneficial in either general inpatients or intensive care patients. Data from 10 clinical studies combined suggest that ITT increases the risk of hypoglycemia in patients (relative risk 6.00 [CI, 4.06 to 8.87],P<0.001). Based on the above analysis, the article concluded that intensive insulin therapy does not improve the prognosis of hospitalized patients, but increases the risk of hypoglycemia in patients.