Is left ventricular longitudinal function related to metabolic abnormalities and fat distribution?

BackgroundMorbid obesity is associated with impaired long-term survival. Visceral and pericardial fat have been implicated in the pathogenesis of obesity-related cardiovascular disease. However, the impact of fat regional distribution on left ventricular (LV) longitudinal function remains unexplored.Method and resultsWe prospectively compared 20 obese patients to 20 age- and sex-matched normoweight control subjects. Patients with diabetes were excluded. Abdominal and pericardial fat (PF) were measured using multidetector computed tomography. Comprehensive echocardiography was performed to assess LV volumes, systolic and diastolic functions and global longitudinal strain (GLS). There was no significant difference between the 2 groups with regard to demographic and clinical data. Obese patients had significant worse metabolic profile (p<0.05) and higher waist circumference (134±3 vs. 84±9cm, p<0.01), insulin level (37±22 vs. 11±11μU/ml, p<0.01) and subcutaneous (19±5 vs. 6±2L, p<0.01), visceral (8±4 vs. 3±2L, p<0.01) and PF (0.17±0.1 vs. 0.09±0.05L, p=0.005) volumes. Although LV dimensions were higher in obese group (p<0.05), there was no significant difference between groups regarding to LV systolic and diastolic functions (LV ejection fraction: 62±7% vs. 63±6%, p=0.3; E/Ea: 6.3±1.8 vs. 6.2±1.9, p=0.9). Nonetheless, obese patients had lower GLS (17±3 vs. 19±2%, p=0.03) suggesting the presence of subclinical LV systolic dysfunction. In the whole cohort, there were significant correlations between GLS and triglyceride (r=-0.33, p=0.03), HDL level (r=0.36, p=0.02), waist circumference (r=-0.4, p=0.01), insulin level (r=-0.45, p=0.004), PF (r=-0.42, p=0.01), subcutaneous (r=-0.45, p=0.008) and visceral (r=-0.52, p=0.002) volumes.ConclusionThese results show that morbid obese patients have subclinical LV myocardial alteration, even in presence of preserved systolic and diastolic functions. LV dysfunction may be related to metabolic abnormalities and regional fat distributions including PF