title: Trends in Coronary Atherosclerosis: A Tale of Two Population Subgroups.
abstract: BACKGROUND
  We previously investigated trends in subclinical coronary artery disease and associated risk factors among autopsied non-elderly adults who died from nonnatural causes. Although grade of atherosclerosis declined from 1981 through 2009, the trend was nonlinear, ending in 1995, concurrent with increasing obesity/diabetes in this population. The previous study used linear regression and examined trends for all 4 major epicardial coronary arteries combined. The present investigation of coronary artery disease trends for the period 1995 through 2012 was prompted by a desire for more detailed examination of more recent coronary artery disease trends in light of reports that the epidemics of obesity and diabetes have slowed and are perhaps ending.
  
  
  METHODS
  This population-based series of cross-sectional investigations identified all Olmsted County, Minnesota residents aged 16-64 years who died 1995 through 2012 (N = 2931). For decedents with nonnatural manner of death, pathology reports were reviewed for grade of atherosclerosis assigned each major epicardial coronary artery. Using logistic regression, we estimated calendar-year trends in grade (unadjusted and age- and sex-adjusted) for each artery, initially as an ordinal measure (range, 0-4); then, based on evidence of nonproportional odds, as a dichotomous variable (any atherosclerosis, yes/no) and as an ordinal measure for persons with atherosclerosis (range, 1-4).
  
  
  RESULTS
  Of 474 nonnatural deaths, 453 (96%) were autopsied; 426 (90%) had coronary stenosis graded. In the ordinal-logistic model for trends in coronary artery disease grade (range, 0-4), the proportional odds assumption did not hold. In subsequent analysis as a dichotomous outcome (grades 0 vs 1-4), each artery exhibited a significant temporal decline in the proportion with any atherosclerosis. Conversely, for subjects with coronary artery disease grade 1-4, age- and sex-adjusted ordinal regression revealed no change over time in 2 arteries and statistically significant temporal increases in severity in 2 arteries.
  
  
  CONCLUSIONS
  Findings suggest that efforts to prevent coronary artery disease onset have been relatively successful. However, statistically significant increases in the grade of atherosclerosis in 2 arteries among persons with coronary artery disease may be indicative of a major public health challenge.
authors.affiliation: Centre for Health Services and Policy Research, University of British Columbia, Vancouver, Canada; Department of Health Sciences Research, Mayo Clinic, Rochester, Minn.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Nemetz
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minn.
authors.forename: Carin Y
authors.initials: CY
authors.lastname: Smith
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minn.
authors.forename: Kent R
authors.initials: KR
authors.lastname: Bailey
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minn; Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, Minn.
authors.forename: Veronique L
authors.initials: VL
authors.lastname: Roger
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minn.
authors.forename: William D
authors.initials: WD
authors.lastname: Edwards
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minn. Electronic address: leibson@mayo.edu.
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Leibson
mesh_terms: D000293:Adolescent; D000328:Adult; D001344:Autopsy; D003324:Coronary Artery Disease / Q000145:classification* / Q000453:epidemiology / Q000473:pathology*; D023921:Coronary Stenosis / Q000145:classification / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D058226:Plaque, Atherosclerotic / Q000145:classification / Q000473:pathology*; D012720:Severity of Illness Index; D055815:Young Adult
keywords: Atherosclerosis; Cardiovascular disease; Subclinical coronary artery disease; Time trends