Evaluation of left ventricular function in obese patients with obstructive sleep apnea by three-dimensional speckle tracking echocardiography

Both obstructive sleep apnea(OSA) and obesity can cause myocardial remodeling and cardiac insufficiency via corresponding pathophysiological pathways. Therefore, it is speculated that the superposition of OSA and obesity may cause more severe impairment of cardiac function. The objective of our study was to evaluate the early changes of left ventricular systolic function in obese patients with OSA with three-dimensional speckle tracking echocardiography(3D-STE). This study was conducted with 33 obese OSA, 46 non-obese OSA, and 20 healthy subjects. Demographic, biochemical, and Polysomnography(PSG) data were collected, and their relation with the left ventricular strain was measured and analyzed with 3D-STE. The left ventricular strain was significantly worse in the OSA group compared to the control group(P < 0.05). The global longitudinal strain(GLS) was significantly worse obese group compared to non-obese OSA group (P < 0.05). The GLS value positively correlated with body mass index(BMI)(r = 0.406, P < 0.001), apnea–hypopnea index(AHI)(r = 0.610, P < 0.001)and homeostasis model assessment of insulin resistance(HOME-IR)(r = 0.431, P < 0.001) in patients with OSA, as well as high sensitivity C-reactive protein(hs-CRP)(r = 0.394, P < 0.001). Multiple linear regression analysis showed BMI and AHI were predictors of GLS. In OSA patients, the myocardial strain was impaired before the damages in left ventricular ejection fraction, suggesting that the left ventricular systolic function is damaged early. The coexistence of obesity and OSA can lead to severe impairment of cardiac function through mechanisms such as hypoxia and insulin resistance.