title: Cardiac (82)Rb PET/CT for fast and non-invasive assessment of microvascular function and structure in asymptomatic patients with type 2 diabetes.
abstract: OBJECTIVE
  Coronary flow reserve (CFR) and coronary artery calcium (CAC) represent functional and structural aspects of atherosclerosis. We examined the prevalence of reduced CFR and high CAC scores in three predefined groups of participants without known cardiovascular disease: (1) patients with type 2 diabetes and albuminuria; (2) patients with type 2 diabetes and normoalbuminuria; and (3) non-diabetic controls.
  
  
  METHODS
  In a cross-sectional design, cardiac (82)Rb positron emission tomography/computed tomography was conducted in 60 patients with type 2 diabetes who were free of overt cardiovascular disease and who were stratified by normoalbuminuria (<30 mg/24 h) (n = 30; age [mean ± SD] 60.9 ± 10.1 years) and albuminuria (≥ 30 mg/24 h) (n = 30; age 65.6 ± 4.8 years), and in 30 healthy, non-diabetic controls (age 59.8 ± 9.9 years).
  
  
  RESULTS
  In controls, normoalbuminuric and albuminuric patients, CFR was 3.0 ± 0.8, 2.6 ± 0.8 and 2.0 ± 0.5, respectively. Reduced CFR (<2.5) was observed in 16.7%, 40.0% and 83.3% of participants, respectively, and median (interquartile range) CAC scores were 0 (0-81), 36 (1-325) and 370 (152-1,025), respectively (p for trend <0.01). After adjustment, the difference in CFR and CAC between albuminuric patients and controls remained significant (p ≤ 0.001). There were trends towards lower CFR and higher CAC scores in normoalbuminuric patients vs controls (p ≤ 0.023) and towards higher CAC scores in albuminuric vs normoalbuminuric patients (p = 0.026). In multivariate regression analysis, a higher urinary albumin excretion rate (UAER) tended to predict reduced CFR in the total population (p = 0.045). When the CAC score was added, there was also a trend (p = 0.032) towards an inverse association with reduced CFR.
  
  
  CONCLUSIONS
  Type 2 diabetic patients who were free of overt cardiovascular disease had a high prevalence of coronary microvascular dysfunction, especially with concomitant albuminuria, suggesting a common microvascular impairment occurring in multiple microvascular beds. Prospective studies are needed to show the prognostic significance of this finding.
authors.affiliation: Steno Diabetes Center, Niels Steensens Vej 2, 2820, Gentofte, Denmark. bjos@steno.dk.
authors.forename: Bernt J
authors.initials: BJ
authors.lastname: von Scholten
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Philip
authors.initials: P
authors.lastname: Hasbak
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Christensen
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Adam A
authors.initials: AA
authors.lastname: Ghotbi
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjaer
authors.affiliation: Steno Diabetes Center, Niels Steensens Vej 2, 2820, Gentofte, Denmark.|The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.|Faculty of Health, Aarhus University, Aarhus, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Rossing
authors.affiliation: Steno Diabetes Center, Niels Steensens Vej 2, 2820, Gentofte, Denmark.
authors.forename: Tine W
authors.initials: TW
authors.lastname: Hansen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D049268:Positron-Emission Tomography; D012414:Rubidium Radioisotopes; D014057:Tomography, X-Ray Computed; D061205:Vascular Calcification / Q000000981:diagnostic imaging
chemical_list: D012414:Rubidium Radioisotopes
keywords: Cardiovascular disease; Coronary artery calcium score; Coronary flow reserve; Coronary microcirculation; Microalbuminuria; Microvascular disease; PET/CT; Type 2 diabetes