Plasma NEFA storage in adipose tissue in the postprandial state: sex-related and regional differences.
OBJECTIVE
We recently reported that a small fraction of circulating NEFA is stored through direct uptake in subcutaneous fat in postabsorptive humans in vivo and that this pathway may favour lower-body fat distribution in women. Here, we examined sex-related and regional differences in storage of plasma NEFA in subcutaneous adipose tissue during postprandial conditions.


METHODS
At 1 h after lunch, men and women of normal weight received an intravenous bolus of approximately 1.66 MBq [1-(14)C]oleate followed by timed subcutaneous fat biopsies. The preceding breakfast was either a normal- or high-fat meal; the high-fat breakfast was used to create postprandial oleate concentrations in the postabsorptive range.


RESULTS
Storage of the NEFA tracer in adipose tissue (dpm/g lipid) was greater in women; in both sexes abdominal fat stored tracer more avidly than femoral fat. A greater fraction of the administered tracer was stored in whole body subcutaneous fat of women than in that of men (27 +/- 3 vs 8 +/- 1%, respectively, p < 0.0001). No significant differences in tracer storage were observed between participants consuming the high- vs normal-fat breakfast.


CONCLUSIONS
Postprandial NEFA storage in subcutaneous fat through direct uptake accounts for approximately 25% of NEFA disposal in women, but for <10% in men in a wide range of circulating NEFA concentrations. It is greater in the upper- than lower-body subcutaneous fat, favouring upper-body fat accumulation in both sexes.
Koutsari
C
C
Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Snozek
C L H
CL
Jensen
M D
MD
D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002149:Energy Intake; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D008079:Lipoproteins, VLDL / Q000378:metabolism; D008297:Male; D019518:Postprandial Period; D017697:Premenopause; D012016:Reference Values; D012727:Sex Characteristics
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D008079:Lipoproteins, VLDL