For exam- ple, long-term follow-up from the UKPDS indicates that patients receiving metformin, particularly those who were overweight, had a lower incidence of diabetic complications, MI, and death than those who received insulin plus a sulfonylurea.588 In addition, available information suggests that certain agents lack an acceptable safety profile. The FDA, for example, has imposed restrictions on use of rosiglitazone, a thiazolidinedione, because of data that sug- gest an increased risk of cardiovascular complications. Pre- scriptions for rosiglitazone should not be initiated for patients with SIHD. Patients who are already receiving this agent and whose blood glucose is well controlled should be counseled about the potential hazards, and switching to a different agent should be strongly considered. In this light, when deciding whether to prescribe newer hypoglycemic agents, providers should bear in mind the potential for safety concerns that could emerge when these drugs are adopted into wider use. 4.4.1.4. Physical Activity Class I 1. For all patients, the clinician should encourage 30 to 60 minutes of moderate-intensity aerobic activity, such as brisk walking, at least 5 days and preferably 7 days per week, supplemented by an increase in daily lifestyle activities (eg, walking breaks at work, gardening, household work) to improve cardiorespi- ratory fitness and move patients out of the least-fit, least-active, high-risk cohort (bottom 20%).602 604 (Level of Evidence: B) 2. For all patients, risk assessment with a physical activity history and/or an exercise test is recom- mended to guide prognosis and prescription.605 608 (Level of Evidence: B) 3. Medically supervised programs (cardiac rehabilita- tion) and physician-directed, home-based programs are recommended for at-risk patients at first diag- nosis.602,609,610 (Level of Evidence: A) Class IIa 1. 