In vivo triglyceride synthesis in subcutaneous adipose tissue of humans correlates with plasma HDL parameters.
Low concentrations of plasma HDL-C are associated with the development of atherosclerotic cardiovascular diseases and type 2 diabetes. Here we aimed to explore the relationship between the in vivo fractional synthesis of triglycerides (fTG) in subcutaneous (s.q.) abdominal adipose tissue (AT), HDL-C concentrations and HDL particle size composition in non-diabetic humans.



The fTG in s.q. abdominal AT was measured in 16 non-diabetic volunteers (7 women, 9 men; Age: 49 ± 20 years; BMI: 31 ± 5 kg/m; Fasting Plasma Glucose: 90 ± 10 mg/dl) after (2)H2O labeling. HDL-C concentration and subclasses, large (L-HDL), intermediate (I-HDL) and small (S-HDL) were measured.



Linear regression analyses demonstrated significant associations of fTG with plasma concentration of HDL-C (r = 0.625,p = 0.009) and percent contribution of L-HDL (r = 0.798,p < 0.001), I-HDL (r = -0.765,p < 0.001) and S-HDL (r = -0.629, p = 0.009). When analyses were performed by gender, the associations remained significant in women (HDL-C: r = 0.822,p = 0.023; L-HDL: r = 0.892,p = 0.007; I-HDL: r = -0.927,p = 0.003) but not men.



Our study demonstrated an in vivo association between subcutaneous abdominal adipose tissue lipid dynamics and HDL parameters in humans, but this was true for women not men. Positive association with L-HDL and negative with I-HDL suggest that subcutaneous abdominal adipose tissue lipid dynamics may play an important role in production of mature functional HDL particles. Further studies evaluating the mechanism responsible for these associations and the observed gender differences are important and warranted to identify potential novel targets of intervention to increase the production of atheroprotective subclasses of HDL-Cs and thus decreasing the risks of development of atherosclerotic conditions.
Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA. Electronic address: detuvden@utmb.edu.
Demidmaa
D
Tuvdendorj
Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA.
Alejandro O
AO
Munoz
University of California in San Francisco, San Francisco, CA, USA.
Viviana
V
Ruiz-Barros
University of California in San Francisco, San Francisco, CA, USA.
Jean-Marc
JM
Schwarz
Biomedical Department of Internal Medicine and Medical Specialties, University of Palermo, Palermo, Italy.
Giuseppe
G
Montalto
Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA.
Manisha
M
Chandalia
Pharmacology & Toxicology, University of Texas Medical Branch, Galveston, TX, USA.
Lawrence C
LC
Sowers
Biomedical Department of Internal Medicine and Medical Specialties, University of Palermo, Palermo, Italy; Euro-Mediterranean Institute of Science and Technology, Palermo, Italy.
Manfredi
M
Rizzo
University of California in San Francisco, San Francisco, CA, USA.
Elizabeth J
EJ
Murphy
Departments of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA.
Nicola
N
Abate
D000368:Aged; D050197:Atherosclerosis / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood*; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D050155:Lipogenesis; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D050507:Subcutaneous Fat, Abdominal / Q000378:metabolism*; D014280:Triglycerides / Q000097:blood / Q000378:metabolism*
D001786:Blood Glucose; D008076:Cholesterol, HDL; D008055:Lipids; D014280:Triglycerides
Adipocyte; Atheroprotective; Gender-related; HDL-C metabolism; Mass spectrometry; Stable isotope tracer kinetics; Triglycerides