Impact of type 2 diabetes and duration of type 2 diabetes on cardiac structure and function

BACKGROUND: Contemporary treatment of type 2 diabetes (T2D) has improved patient outcome and may also have affected myocardial structure and function. We aimed to describe the effect of T2D and T2D duration on cardiac structure and function in a large outpatient population.

METHODS: We performed comprehensive echocardiography on a representative sample of 1004 persons including a representative sample of 770 patients with T2D without known heart disease and 234 age- and sex-matched controls.

RESULTS: T2D was associated with increased left ventricular (LV) wall thicknesses and decreased LV internal diameter and the changes were pronounced with increasing diabetes duration (P<0.01 for all) but not with increased LV mass (P=0.74). It was also significantly associated with the prevalence of diastolic dysfunction (16.5% vs. 4.0%; P<0.001), with indices of LV relaxation and elevated filling pressures expressed as e'septal (mean: 6.9 (SD: 1.9) cm/s vs. 7.5 (2.4); P<0.001) and E/e'septal (median: 10.8 (interquartile range (IQR): 9.1-13.3) vs. 9.1 (7.2-11.1); P<0.001) and global longitudinal strain (mean: -14.1 (SD: 2.4) vs. -15.0 (2.0), P<0.001) but not with LV ejection fraction (median: 60.8 (IQR: 56.5-65.1) vs. 62.1 (57.9-65.4), P=0.28). With the exception of global longitudinal strain, this was pronounced with increasing diabetes duration for all measures including increasing diastolic dysfunction (<10years: 10.8%, 10-20years: 18.5%, >20years: 24.8%; P<0.001). The increased risk of diastolic dysfunction persisted after multivariable adjustment (P=0.013).

CONCLUSIONS: In patients with T2D, LV structural and functional alterations persist and are accentuated with increasing diabetes duration despite reductions in overall risk of cardiovascular disease in this patient population.