Type II DM as a Cardiovascular Risk Equivalent: A Systematic Review of the Literature
Creators: name: Miller-Fitzwater, Anna
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: Context: The incidence of Type II Diabetes Mellitus (DM) is rapidly expanding in the United States. Cardiovascular disease (CVD) remains the leading cause of death for people with DM. Since a systematic review had not be done to assess if DM is a CVD or coronary heart disease (CHD) risk equivalent for future CHD events the most recent guidelines from the National Cholesterol Education Panel, the Adult Treatment Panel III (ATP-III) were made based on a series of three studies. The ATP-III recommended that all people with DM be treated as (CHD) risk equivalents. Objective: To review the literature systematically to answer the question Is DM a substantial CHD risk equivalent for hard CVD events? and to further analyze this question by answering a series of sub-questions. Data Sources: We searched MEDLINE including the clinical queries option through December 17,2007 for English language articles containing the MESH phrases Arterioscleorsis or Myocardial Ischemia/epidemiology or Myocardial Ischemia/prevention and control AND Diabetes Mellitus. We also hand searched bibliographies of relevant articles and files of experts in the field. Study Selection: Studies were included if they were in conducted in western populations, had at least a 5 year follow-up period, measured clinical outcomes of CVD (not intermediate factors), and answered our primary question or one of our sub-questions of the primary question by allowing direct comparison of patients with DM and no CVD to those with CVD but no DM. Admissible study designs included cohort studies, systematic reviews, meta-analyses, and controlled trials. Studies were independently critically appraised by two reviewers with discrepancies adjudicated by a third reviewer. Studies that were of adequate internal and external validity were included in the results. Data extraction: Two reviewers independently abstracted the relevant data from the included studies and entered them into evidence tables. These tables were checked against each other and combined into a single table. Data synthesis: There is little data comparing the risk of nonfatal CHD events between DM and prior CHD/CVD. Mixed effects were noted when answering the question of whether or not DM is a CHD risk equivalent for future CHD mortality or CVD mortality. Most studies suggested that prior MI conferred a higher risk for future CVD events than did DM. When compared to men, DM seemed to confer a higher risk in women for future CHD than did prior MI. DM also seemed to confer higher risks for CHD mortality in relation to the risk ofMI as a women aged and in people with a long duration ofDM. Equivalent risk factors in populations of people with DM compared to those with prior MI did not seem to change the risk equivalency for future CHD morality when compared to the overall unstratified analysis. We also found that there is inadequate research to show how the presence of other markers of CVD in people with DM changes their risk for future CHD events in relation to those with DM but without CVD or those without DM but with prior CHD Conclusion: DM is not a universal CHD risk equivalent for future CHD mortality. All patients with DM should not be treated to the stringent LDL cutoffs used for people with prior CHD. Those at low risk (young, short duration of diabetes, few other risk factors, etc.) should be treated based on their absolute risk calculation for future CHD which takes into account an individual's clinical scenario.