Aims/hypothesis
To complete a comparative analysis of studies that have examined the relationship between glycaemia and cardiovascular disease
(CVD)/coronary artery disease (CAD) and perform a prospective analysis of the effect of change in glycosylated Hb level on
CAD risk in the Pittsburgh Epidemiology of Diabetes Complications Study (EDC) of childhood-onset type 1 diabetes mellitus
(n = 469) over 16 years of two yearly follow-up.
Methods
Measured values for HbA1 and HbA1c from the EDC were converted to the DCCT-standard HbA1c for change analyses and the change in HbA1c was calculated (final HbA1c minus baseline HbA1c). CAD was defined as EDC-diagnosed angina, myocardial infarction, ischaemia, revascularisation or fatal CAD after medical
record review.
Results
The comparative analysis suggested that glycaemia may have a stronger effect on CAD in patients without, than in those with,
albuminuria. In EDC, the change in HbA1c differed significantly between CAD cases (+0.62 ± 1.8%) and non-cases (−0.09 ± 1.9%) and was an independent predictor of
CAD.
Conclusions/interpretation
Discrepant study results regarding the relationship of glycaemia with CVD/CAD may, in part, be related to the prevalence of
renal disease. Measures of HbA1c change over time show a stronger association with CAD than baseline values.
Keywords Childhood-onset diabetes - Coronary heart disease - Epidemiology - Glycaemic control - HbA1c
- Macrovascular complications - Type 1 diabetes