INS and congestive heart failure: A retrospective cohort study by Yang et al. showed an adjusted HR for pioglitazone versus insulin to be 0.33 (95% CI 0.31-0.36) [16]. Furthermore, the pioglitazone group had significantly lower all-cause mortality rates than the insulin group in each subgroup that was looked at, including sex, age, baseline congestive heart failure status, baseline lipid-altering medication use, and baseline metformin use [16].