Serum Amyloid A, C-Reactive Protein, and Retinal Microvascular Changes in Hypertensive Diabetic and Nondiabetic Individuals

Serum Amyloid A, C-Reactive Protein, and Retinal Microvascular Changes in Hypertensive Diabetic and Nondiabetic Individuals An Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) substudy Christoph Stettler , MD 1 , 2 , 3 , Nicholas Witt , PHD 2 , Robyn J. Tapp , PHD 2 , 4 , Simon Thom , FRCP 2 , Sabin Allemann , PHD 1 , 3 , Therese Tillin , MSC 2 , Alice Stanton , PHD 5 , Eoin O'Brien , PHD 6 , Neil Poulter , FRCP 2 , J. Ruth Gallimore , 7 , Alun D. Hughes , PHD 2 and Nish Chaturvedi , MD 2 1 Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital and University of Bern, Bern, Switzerland; 2 International Center for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, U.K.; 3 Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland; 4 International Public Health Unit, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia; 5 Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland Research Institute, Dublin, Ireland; 6 Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland; 7 Division of Medicine, Centre for Amyloidosis and Acute Phase Proteins, University College London, London, U.K. Corresponding author: Christoph Stettler, christoph.stettler{at}insel.ch . Abstract OBJECTIVE To study the association of the inflammatory markers serum amyloid A (SAA) and C-reactive protein (CRP) with retinal microvascular parameters in hypertensive individuals with and without type 2 diabetes. RESEARCH DESIGN AND METHODS This cross-sectional analysis was a substudy in 711 patients (159 with and 552 without diabetes) of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) based on digital 30-degree images of superior and inferior temporal retinal fields. RESULTS SAA was associated with arteriolar length-to-diameter ratio positively in nondiabetic patients ( P trend = 0.028) but negatively in diabetic patients ( P trend = 0.005). The difference was unlikely to be a chance finding ( P = 0.007 for interaction). Similar results were found for the association of SAA with arteriolar tortuosity ( P = 0.05 for interaction). Associations were less pronounced for CRP and retinal parameters. CONCLUSIONS Inflammatory processes are differentially involved in retinal microvascular disease in diabetic compared with nondiabetic hypertensive individuals. Footnotes The costs of publication of this article were de