Hemoglobin A1c as a Predictor of Incident Diabetes

Abstract

OBJECTIVESeveral studies have suggested that HbA1c levels may predict incident diabetes. With new recommendations for use of HbA1c in diagnosing diabetes, many patients with HbA1c results below the diagnostic threshold will be identified. Clinicians will need to categorize risk for a subsequent diabetic diagnosis in such patients. The objective of this study was to determine the ability of HbA1c to predict the incidence of a diabetic diagnosis.RESEARCH DESIGN AND METHODSWe performed a historical cohort study using electronic medical record data from two Department of Veterans Affairs Medical Centers. Patients (n = 12,589) were identified with a baseline HbA1c <6.5% between January 2000 and December 2001 and without a diagnosis of diabetes. Patients (12,375) had at least one subsequent follow-up visit. These patients were tracked for 8 years for a subsequent diagnosis of diabetes.RESULTSDuring an average follow-up of 4.4 years, 3,329 (26.9%) developed diabetes. HbA1c ≥5.0% carried a significant risk for developing diabetes during follow-up. When compared with the reference group (HbA1c <4.5%), HbA1c increments of 0.5% between 5.0 and 6.4% had adjusted odds ratios of 1.70 (5.0–5.4%), 4.87 (5.5–5.9%), and 16.06 (6.0–6.4%) (P < 0.0001). Estimates of hazard ratios similarly showed significant increases for HbA1c ≥5.0%. A risk model for incident diabetes within 5 years was developed and validated using HbA1c, age, BMI, and systolic blood pressure.CONCLUSIONSThe incidence of diabetes progressively and significantly increased among patients with an HbA1c ≥5.0%, with substantially expanded risk for those with HbA1c 6.0–6.4%.

Point-of-care capillary HbA1c measurement in the emergency department: a useful tool to detect unrecognized and uncontrolled diabetes

“…This finding is consistent with previous studies [7, 18, 19]. HbA1c levels are also an indicator of future DM and may be useful for defining personalized prevention strategies [20]. …”

Association between sleep duration and haemoglobin A1cin young adults

“…Nor can we show that inadequate sleep will lead to long-term adverse effects. However, we found that those who spent less time in bed had a higher risk for prediabetes, which is associated with a greatly increased risk of developing diabetes 20 24. Moreover, even within the non-diabetic range, higher levels of HbA 1c are associated with increased risk of cardiovascular disease 25.…”

Development of a new scoring system for predicting the 5 year incidence of type 2 diabetes in Japan: the Toranomon Hospital Health Management Center Study 6 (TOPICS 6)

“…Results of the EPIC-Potsdam Study also suggested that risk reclassification was improved by adding FPG (IDI 0.0553) or HbA 1c (IDI 0.0974) values using the prediction model by the German Diabetes Risk Score as a reference [14]. Recent prospective studies have examined the utility of introducing HbA 1c testing for predicting diabetes [15,16,[23][24][25][26][27], and some reports have described the development of models to predict future diabetes using blood variables including FPG and HbA 1c [15,25,29]. More recently and concomitantly with the preparation of this manuscript, a risk score that concurrently included measurements of FPG, HbA 1c and other biochemical markers was reported in a Korean population [40].…”

“…Introducing HbA 1c into a prediction model has been suggested to be effective in screening for future diabetes [14][15][16][22][23][24][25][26][27][28], and a few models to predict the development of diabetes have recently been developed that concurrently include measurements of FPG, HbA 1c and other blood markers [15,25,29]. After revising the diagnostic criteria for type 2 diabetes by introducing HbA 1c in 2010 [30], the ADA published guidelines and recommendations for diagnosing diabetes based on published data or derived from expert consensus [31].…”