June 20, 2014
April P. Carson, PhD, MSPH, assistant professor in the Department of Epidemiology, recently investigated secular changes in coronary heart disease (CHD) incidence and mortality among adults with and without diabetes and the effect of increased lipid-lowering medication use and reductions in low-density lipoprotein cholesterol (LDL-C) levels on these changes. Co-investigators include department colleagues Rikki M. Tanner, MPH, student assistant; Huifeng Yun, MD, PhD, research assistant professor; Emily B. Levitan, ScD, assistant professor; and Paul Muntner, PhD, professor; in addition to George Howard, DrPH, professor in the Department of Biostatistics; Todd M. Brown, MD, MSPH, assistant professor in the Division of Cardiovascular Disease; and Stephen P. Glasser, MD, and Monika M. Safford, MD, professors in the Division of Preventive Medicine.
The researchers analyzed data on participants ages 45 through 64 years from the Atherosclerosis Risk in Communities Study in 1987 to 1996 (early time period) and the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study in 2003 to 2009 (late time period). Hazard ratios for the association of diabetes and time period with incident CHD and CHD mortality were obtained after adjustment for socio-demographics, cardiovascular risk factors, lipid-lowering medication use, and LDL-C.
After multivariable adjustment, diabetes was found to be associated with an increased CHD risk during the early and late time periods. CHD incidence and mortality declined between the early and late time periods for individuals with and without diabetes. Increased use of lipid-lowering medication and lower LDL-C explained 33.6 percent and 27.2 percent of the decline in CHD incidence and CHD mortality, respectively, for those with diabetes.
The team concluded that, although rates have declined, diabetes remains associated with an increased risk of CHD incidence and mortality, highlighting the need for continuing diabetes prevention and cardiovascular risk factor management.