Elevated liver, abdominal fat in obese indicate high cardiac disease risk
MedWire News: Researchers report that obese individuals with raised levels of liver and subcutaneous abdominal fat may be at increased risk for cardiometabolic disease.
"The increased liver and subcutaneous abdominal fat is linked to increased secretion of very-low-density lipoprotein (VLDL) particles," explain Jan Borén (Wallenberg Laboratory, Gothenburg, Sweden) and colleagues.
They add: "These results provide new insights into the pathophysiology of dyslipidemia in obesity."
Borén and team used magnetic resonance imaging to compare the body fat distribution of obese individuals (body mass index [BMI] ≥27 kg/m2) with hypertriglyceridemia (HTG; n=14) and normotriglyceridemia (NTG; n=14).
Participants in the HTG and NTG groups had similar BMIs, of 32.4 and 31.0 kg/m2 respectively. Visceral fat volumes were also comparable between both groups.
In contrast, subcutaneous abdominal fat was significantly higher among HTG individuals than among NTG individuals, with respective mean fat volumes of approximately 4500 and 3500 cm3.
Liver fat content was also significantly higher in HTG than NTG participants, with mean liver fat percentages of 13% and 7%, respectively.
Kinetic studies revealed that participants with HTG secreted VLDL-triglycerides and apolipoprotein B100 (apoB100) at significantly higher rates than did NTG participants and a group of 10 nonobese NTG individuals (controls).
Apo C-III "is a determinant of serum total and VLDL-triglycerides, as well as of the VLDL catabolic rate," explain the researchers. Therefore they measured plasma apo C-III levels in the group and found that obese HTG and non-obese NTG individuals had the highest and lowest C-III levels of all participants, respectively.
Writing in the journal Arteriosclerosis, Thrombosis, and Vascular Biology Borén et al highlight that the increased apo C-III levels seen in obese HTG patients was associated with impaired clearance of the molecule, which they believe provides an insight into the mechanism by which HTG in obesity increases heart disease risk.
The researchers conclude: "The results emphasize the clinical importance of assessing HTG waist to identify obese subjects at high cardiometabolic risk."
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By Lauretta Ihonor