AIMS/HYPOTHESIS: There is conflicting evidence regarding appropriate glycaemic targets for patients with type 2 diabetes. Here, we investigate the relationship between HbA(1c) and the risks of vascular complications and death in such patients. METHODS: Eleven thousand one hundred and forty patients were randomised to intensive or standard glucose control in the Action in Diabetes and Vascular disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial. Glycaemic exposure was assessed as the mean of HbA(1c) measurements during follow-up and prior to the first event. Adjusted risks for each HbA(1c) decile were estimated using Cox models. Possible differences in the association between HbA(1c) and risks at different levels of HbA(1c) were explored using linear spline models. RESULTS: There was a non-linear relationship between mean HbA(1c) during follow-up and the risks of macrovascular events, microvascular events and death. Within the range of HbA(1c) studied (5.5-10.5%), there was evidence of 'thresholds', such that below HbA(1c) levels of 7.0% for macrovascular events and death, and 6.5% for microvascular events, there was no significant change in risks (all p > 0.8). Above these thresholds, the risks increased significantly: every 1% higher HbA(1c) level was associated with a 38% higher risk of a macrovascular event, a 40% higher risk of a microvascular event and a 38% higher risk of death (all p < 0.0001). CONCLUSIONS/INTERPRETATION: In patients with type 2 diabetes, HbA(1c) levels were associated with lower risks of macrovascular events and death down to a threshold of 7.0% and microvascular events down to a threshold of 6.5%. There was no evidence of lower risks below these levels but neither was there clear evidence of harm. TRIAL REGISTRATION: ClinicalTrial.gov NCT00145925 FUNDING: Servier and the National Health and Medical Research Council of Australia (project grant ID 211086 and programme grant IDs 358395 and 571281).
AD - The George Institute for Global Health, PO Box M201, Missenden Road, Camperdown, NSW 2050, Sydney, NSW, Australia, szoungas@georgeinstitute.org.au. AN - 22186981 BT - Diabetologia DA - 204169516252 ET - 2011/12/22 LA - Eng M1 - 3 N1 - for the ADVANCE Collaborative GroupDiabetologiaDiabetologia. 2012 Mar;55(3):636-643. Epub 2011 Dec 21. N2 -AIMS/HYPOTHESIS: There is conflicting evidence regarding appropriate glycaemic targets for patients with type 2 diabetes. Here, we investigate the relationship between HbA(1c) and the risks of vascular complications and death in such patients. METHODS: Eleven thousand one hundred and forty patients were randomised to intensive or standard glucose control in the Action in Diabetes and Vascular disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial. Glycaemic exposure was assessed as the mean of HbA(1c) measurements during follow-up and prior to the first event. Adjusted risks for each HbA(1c) decile were estimated using Cox models. Possible differences in the association between HbA(1c) and risks at different levels of HbA(1c) were explored using linear spline models. RESULTS: There was a non-linear relationship between mean HbA(1c) during follow-up and the risks of macrovascular events, microvascular events and death. Within the range of HbA(1c) studied (5.5-10.5%), there was evidence of 'thresholds', such that below HbA(1c) levels of 7.0% for macrovascular events and death, and 6.5% for microvascular events, there was no significant change in risks (all p > 0.8). Above these thresholds, the risks increased significantly: every 1% higher HbA(1c) level was associated with a 38% higher risk of a macrovascular event, a 40% higher risk of a microvascular event and a 38% higher risk of death (all p < 0.0001). CONCLUSIONS/INTERPRETATION: In patients with type 2 diabetes, HbA(1c) levels were associated with lower risks of macrovascular events and death down to a threshold of 7.0% and microvascular events down to a threshold of 6.5%. There was no evidence of lower risks below these levels but neither was there clear evidence of harm. TRIAL REGISTRATION: ClinicalTrial.gov NCT00145925 FUNDING: Servier and the National Health and Medical Research Council of Australia (project grant ID 211086 and programme grant IDs 358395 and 571281).
PY - 2012 SN - 1432-0428 (Electronic)0012-186X (Linking) SP - 636 EP - 643 ST - T2 - Diabetologia TI - Association of HbA(1c) levels with vascular complications and death in patients with type 2 diabetes: evidence of glycaemic thresholds VL - 55 ER -