Defects in postabsorptive plasma homeostasis of fatty acids in sickle cell disease.
BACKGROUND
The chronic hemolytic anemia experienced by sickle cell disease (SCD) patients leads to adverse effects on oxygen transport by the blood and to a decrease in oxygen availability for peripheral tissues. Limited tissue oxygen availability has the potential to modify events of intracellular metabolism and, thus, alter lipid homeostasis.


METHODS
The impact of SCD on plasma fatty acid homeostasis was determined in 8 African American SCD patients and in 6 healthy African American control subjects under postabsorptive conditions and during a 3-hour IV infusion of a nutrient solution containing lipid, glucose, and amino acids.


RESULTS
SCD patients had higher fasting levels of plasma nonesterified fatty acids (NEFA), triglycerides, and phospholipids than healthy controls. Similarly, SCD patients had higher fasting levels of fatty acids in plasma triglycerides and phospholipids than healthy controls. Infusion of nutrients resulted in equivalent plasma NEFA profiles, total NEFA, and triglycerides in SCD patients and controls. However, the plasma phospholipid concentrations and fatty acid composition of plasma triglycerides and phospholipids were significantly higher in SCD patients; in particular, plasma pools of oleic acid were consistently increased in SCD. Plasma free oleic acid levels were elevated basally, leading to increased oleic acid content in triglycerides and phospholipids both post absorptively and during nutrient infusion.


CONCLUSIONS
There is an underlying defect in lipid metabolism associated with SCD best manifested during the fasting state. This abnormality in lipid homeostasis has the potential to alter red blood cell (RBC) membrane fluidity and function in SCD patients.
Buchowski
Maciej S
MS
Center for Nutrition and Department of Family and Community Medicine, Meharry Medical College, Nashville, Tennessee 37208, USA. maciej.buchowski@vanderbilt.edu
Swift
Larry L
LL
Akohoue
Sylvie A
SA
Shankar
Sadhna M
SM
Flakoll
Paul J
PJ
Abumrad
Naji
N
D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood / Q000378:metabolism*; D016022:Case-Control Studies; D004910:Erythrocyte Membrane / Q000737:chemistry* / Q000378:metabolism; D005215:Fasting / Q000097:blood / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood / Q000737:chemistry; D005260:Female; D006801:Humans; D007263:Infusions, Parenteral; D050356:Lipid Metabolism / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood / Q000737:chemistry; D019518:Postprandial Period / Q000502:physiology; D014280:Triglycerides / Q000097:blood / Q000737:chemistry
D005230:Fatty Acids, Nonesterified; D010743:Phospholipids; D014280:Triglycerides