Nearly 1 billion adults aged around 30-69 years worldwide were estimated to have obstructive sleep apnoea, with and without symptoms, based on an apnoea-hypopnoea index. Both obstructive sleep apnea (OSA)and obesity is said to 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.

A recent study in The International journal of Cardiovascular Imaging reports that OSA patients,had 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 hypoxia and insulin resistance.
The objective of the 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).
The study was conducted in 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 results of the study were
• 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 in the OSA 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.
• Multiple linear regression analysis showed BMI as a predictor of GLS and global circumferential strain(GCS), AHI as a predictor of GLS, and HOME-IR as a predictor of global area strain(GAS) and global radial strain(GRS).
Researchers concluded that "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 hypoxia and insulin resistance."
Reference: 10.21203/rs.3.rs-1331917/v1