Vitamin A in hypercholesterolemia.
This study evaluated the relationship between plasma vitamin A and cholesterol in 48 patients with hypercholesterolemia studied before and after treatment with a cholesterol-lowering diet, with or without lipid-lowering medication. Plasma vitamin A levels were higher in hypercholesterolemic subjects than in healthy controls (2.58 +/- 0.15 vs. 1.82 +/- 0.14 mmol/L, p = 0.025) despite similar values for retinol binding protein (RBP). Successful cholesterol lowering, defined as greater than 25% reduction in low density lipoprotein cholesterol, was achieved in 16 patients. In this subset, plasma vitamin A declined from 3.00 +/- 0.32 (pretreatment) to 2.34 +/- 0.15 mmol/L (post treatment; p = 0.018). A nonsignificant increase in RBP was observed, resulting in a significant decrease in the molar ratio of vitamin A to RBP (1.05 +/- 0.06 vs. 0.80 +/- 0.05, p = 0.013). These data suggest an interaction between vitamin A and cholesterol that is independent of the transport mechanisms for vitamin A in association with chylomicrons (post absorptive) and with RBP. Further examinations of the form or forms of vitamin A (retinol, retinyl ester), its distribution within the plasma lipoproteins, and the mechanisms of origin and removal are warranted to explain these findings.
Smith
D K
DK
Department of Medicine, Medical College of Georgia, Augusta 30912.
Greene
J M
JM
Leonard
S B
SB
Kuske
T T
TT
Feldman
D S
DS
Feldman
E B
EB
D000924:Anticholesteremic Agents / Q000627:therapeutic use; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood* / Q000178:diet therapy / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012177:Retinol-Binding Proteins / Q000032:analysis; D054839:Retinol-Binding Proteins, Plasma; D014280:Triglycerides / Q000097:blood; D014801:Vitamin A / Q000097:blood*
D000924:Anticholesteremic Agents; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014280:Triglycerides; D014801:Vitamin A; D002784:Cholesterol