DIABETICMedicine DOI: 10.1111/dme.12459
Research: Epidemiology Aging is associated with increased HbA1c levels, independently of glucose levels and insulin resistance, and also with decreased HbA1c diagnostic specificity N. Dubowitz1,2, W. Xue5, Q. Long5, J. G. Ownby1,3, D. E. Olson1,3, D. Barb1,3, M. K. Rhee1,3, A. V. Mohan4, P. I. Watson-Williams1,4, S. L. Jackson1,6, A. M. Tomolo1,4, T. M. Johnson II1,2 and L. S. Phillips1,3 1 Atlanta VA Medical Center, Decatur, 2Division of Geriatrics, 3Division of Endocrinology and Metabolism, 4Division of General Internal Medicine and Geriatrics, Department of Medicine, Emory University School of Medicine, Atlanta, 5Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta and 6Nutrition and Health Sciences, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA, USA
Accepted 28 March 2014
Abstract To determine whether using HbA1c for screening and management could be confounded by age differences, whether age effects can be explained by unrecognized diabetes and prediabetes, insulin resistance or postprandial hyperglycaemia, and whether the effects of aging have an impact on diagnostic accuracy.
Aim
Methods We conducted a cross-sectional analysis in adults without known diabetes in the Screening for Impaired Glucose Tolerance (SIGT) study 2005–2008 (n=1573) and the National Health and Nutrition Examination Survey (NHANES) 2005–2006 (n=1184).
Both glucose intolerance and HbA1c levels increased with age. In univariate analyses including all subjects, HbA1c levels increased by 0.93 mmol/mol (0.085%) per 10 years of age in the SIGT study and by 1.03 mmol/mol (0.094%) per 10 years in the NHANES; in both datasets, the HbA1c increase was 0.87 mmol/mol (0.08%) per 10 years in subjects without diabetes, and 0.76 mmol/mol (0.07%) per 10 years in subjects with normal glucose tolerance, all P
