Research Paper Title

Comparative Trends in the Incidence of Hospitalised Myocardial Infarction and Coronary Heart Disease in Adults With and Without Diabetes Mellitus in Western Australia From 1998 to 2010.

Background

The risk of myocardial infarction (MI) is elevated in people with diabetes mellitus (DM) compared with non-DM counterparts. The aim of this study was to compare population trends in the incidence of hospitalised MI and coronary heart disease (CHD) in adults with and without DM.

Methods

All incident hospitalised MI and CHD events were identified from whole-population hospital data in Western Australia for 1998 to 2010. Annual age-standardised MI and CHD incidence rates were calculated for people with and without DM aged 35 to 84 years and age-adjusted trends estimated from Poisson regression.

Results

There were 26 610 incident MI and 56 142 incident CHD cases during the study period. MI incidence rates fell in men (−2.9%/y; 95% confidence interval [CI], −3.7 to −2.1) and women (−3.8%/y; 95% CI, −4.8 to −2.1) with DM, representing overall reductions of 35% and 43% respectively, with comparable reductions in incident CHD. Downward trends in MI incidence in those with DM were most apparent in 55- to 84-year olds. In adults without DM, there was no decline in MI incidence but a small significant decrease in incident CHD (men, −1.5%/y; 95% CI, −1.8 to −1.2 and women, −1.3%/y; 95% CI, −1.8 to −0.9). Incidence rate ratios for MI in men with versus without DM declined from 4.5 (95% CI, 4.2–4.8) to 3.1 (95% CI, 2.9–3.3) and from 6.0 (95% CI, 5.4–6.6) to 3.8 (95% CI, 3.5–4.1) in women between 1998 and 2010.

Conclusions

There have been significant reductions in incidence rates of MI and CHD in adults with DM between 1998 and 2010; however, the excess risk of MI incidence remains 3 to 4× greater in people with DM.

Reference

Nedkoff, L., Knuiman, M., Hung, J. & Briffa, T.G. (2014) Comparative Trends in the Incidence of Hospitalized Myocardial Infarction and Coronary Heart Disease in Adults With and Without Diabetes Mellitus in Western Australia From 1998 to 2010. Circulation: Cardiovascular Quality and Outcomes. Published online before print August 26, 2014, doi: 10.1161/CIRCOUTCOMES.114.000952.