Patients who experienced weight loss as an outcome of bariatric surgery saw a decrease in abdominal and pericardial fat, with a higher relative decrease of visceral and paracardial fat volumes, according to a study published in the journalClinical Endocrinology.
However, the researchers did not see an improvement in cardiovascular function or myocardial triglyceride content after Roux en-Y gastric bypass (RYGB) surgery.
The researchers, led by Dr Linda D van Schinkel, of the departments of general internal medicine, endocrinology and metabolism, Leiden University Medical Center in the Netherlands, note that cardiac ectopic fat depositions are thought to play a role in the pathogenesis of cardiovascular disease (CVD), the main cause of death in type 2 diabetes patients. Although diet-induced weight loss results in a decrease in cardiac ectopic fat stores, it is not known if this is the same for surgically-induced weight loss is less clear.
As a result, the researchers assessed myocardial triglyceride (TG) content, pericardial fat and cardiac function in obese, in ten insulin-dependent type 2 diabetes patients before and 16 weeks after RYGB surgery.
Forty percent of the patients were men and their mean age was 53.7 years. Ectopic fat accumulation and cardiovascular function and were assessed with magnetic resonance (MR) imaging and myocardial TG content with MR spectroscopy before and 16 weeks after RYGB surgery.
They report that BMI decreased from 41.3±4.3 at baseline to 34.1±2.8 (p<0.001) after 16 weeks and glycaemic control improved as well (HbA1c: 7.8±1.1 to 6.8±1.3% (62±12 to 51±14 mmol/l) (p<0.05)).
They did not observe an effect of the RYGB surgery on myocardial TG content, cardiac function or pulse wave velocity., although there was a greater relative decrease in visceral (-35.5±9.6%), compared to subcutaneous fat volume (-25.0±6.3%) and in paracardial (-17.3±17.2%), compared to epicardial fat volume (-6.4±6.0%).
“These findings contribute to the existing evidence suggesting tissue-specific changes in body fat distribution after weight loss and exercise interventions. However, the decrease in pericardial fat did not lead to improved cardiovascular function after the RYGB surgery,” they conclude. “Our study was successful in showing substantial changes of bariatric surgery on ectopic fat accumulation and in particular provided new data on fat distribution in epi- and paracardial fat.”
This study received funding from the Netherlands Heart Foundation and was performed with an unrestricted grant from the Dutch Obesity Clinic.