Background: Understanding the determinants associated with prediabetes and type 2 diabetes in coronary patients may help to individualize treatment and modelling interventions. We sought to identify sociodemographic, medical and psychosocial factors associated with normal blood glucose (HbA1c < 5.7%), prediabetes (HbA1c 5.7-6.4%), and type 2 diabetes.
Methods: A cross-sectional explorative study applied regression analyses to investigate the factors associated with glycaemic status and control (HbA1c level) in 1083 patients with myocardial infarction and/or a coronary revascularization procedure. Data were collected from hospital records at the index event and from a self-report questionnaire and clinical examination with blood samples at 2-36 months follow-up.
Results: In all, 23% had type 2 diabetes, 44% had prediabetes, and 33% had normal blood glucose at follow-up. In adjusted analyses, type 2 diabetes was associated with larger waist circumference (Odds Ratio 1.03 per 1.0 cm, p = 0.001), hypertension (Odds Ratio 2.7, p < 0.001), lower high-density lipoprotein cholesterol (Odds Ratio 0.3 per1.0 mmol/L, p = 0.002) and insomnia (Odds Ratio 2.0, p = 0.002). In adjusted analyses, prediabetes was associated with smoking (Odds Ratio 3.3, p = 0.001), hypertension (Odds Ratio 1.5, p = 0.03), and non-participation in cardiac rehabilitation (Odds Ratio 1.7, p = 0.003). In patients with type 2 diabetes, a higher HbA1c level was associated with ethnic minority background (standardized beta [β] 0.19, p = 0.005) and low drug adherence (β 0.17, p = 0.01). In patients with prediabetes or normal blood glucose, a higher HbA1c was associated with larger waist circumference (β 0.13, p < 0.001), smoking (β 0.18, p < 0.001), hypertension (β 0.08, p = 0.04), older age (β 0.16, p < 0.001), and non-participation in cardiac rehabilitation (β 0.11, p = 0.005).
Conclusions: Along with obesity and hypertension, insomnia and low drug adherence were the major modifiable factors associated with type 2 diabetes, whereas smoking and non-participation in cardiac rehabilitation were the factors associated with prediabetes. Further research on the effect of individual tailoring, addressing the reported significant predictors of failure, is needed to improve glycaemic control.
Trial registration: Retrospectively registered at ClinicalTrials.gov: NCT02309255 , December 5th 2014.
Keywords: Coronary heart disease; Glycaemic control; HbA1c; Prediabetes; Psychosocial factors; Risk factor control; Secondary prevention; Type 2 diabetes.