The relationship between glycaemic control and heart failure in 83,021 patients with type 2 diabetes.
OBJECTIVE
The aim of this study was to examine the relationship between glycaemic control and hospitalisation for heart failure in patients with type 2 diabetes.


METHODS
Patients included in the Swedish National Diabetes Register (NDR) during 1998-2003 were followed until hospitalisation for heart failure, death or 31 December 2009. Unadjusted and adjusted incidence rates for heart failure were estimated by Poisson regression and relative risk was estimated by Cox regression.


RESULTS
In 83,021 patients with type 2 diabetes, 10,969 (13.2%) were hospitalised with a primary or secondary diagnosis of heart failure during a mean follow-up of 7.2 years. The incidence increased by male sex (p < 0.001), older age (p < 0.001) and longer diabetes duration (p < 0.001). In Cox regression adjusting for risk factors of heart failure the HR per each percentage unit higher HbA(1c) (10 mmol/mol) for heart-failure hospitalisation was 1.12 (95% CI 1.10, 1.14). By category of HbA(1c) the HR for heart failure hospitalisation was: HbA(1c) 6.0 to <7.0% (42 to <53 mmol/mol), 0.91 (95% CI 0.84, 0.98); HbA(1c) 7.0 to <8.0% (53 to <64 mmol/mol), 0.99 (95% CI 0.91, 1.07); HbA(1c) 8.0 to <9.0% (64 to < 75 mmol/mol), 1.10 (95% CI 1.01, 1.20); HbA(1c) 9.0 to <10.0% (75 to <86 mmol/mol), 1.27 (95% CI 1.15, 1.41); HbA(1c) ≥ 10.0 % (≥ 86 mmol/mol), 1.71 (1.51, 1.93) (reference HbA(1c) <6% [42 mmol/mol]). The HR for patients with HbA(1c) 7.0 to <8.0% (53 to < 64 mmol/mol) compared with patients with HbA(1c) 6.0 to <7.0% (42 to <53 mmol/mol) was 1.09 (95% CI 1.03, 1.14).


CONCLUSIONS
Poor glycaemic control (HbA(1c) >7% [53 mmol/mol]) is associated with an increased risk of hospitalisation for heart failure in patients with type 2 diabetes.
Department of Medicine, Uddevalla Hospital, 451 80 Uddevalla, Sweden. lind.marcus@telia.com
M
M
Lind
M
M
Olsson
A
A
Rosengren
A-M
AM
Svensson
I
I
Bounias
S
S
Gudbjörnsdottir
D017677:Age Distribution; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism; D006333:Heart Failure / Q000453:epidemiology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D006943:Hyperglycemia / Q000453:epidemiology* / Q000378:metabolism; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012042:Registries / Q000706:statistics & numerical data; D012307:Risk Factors; D017678:Sex Distribution; D013548:Sweden / Q000453:epidemiology
D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human