Extended-release niacin alters the metabolism of plasma apolipoprotein (Apo) A-I and ApoB-containing lipoproteins.
OBJECTIVE
Extended-release niacin effectively lowers plasma TG levels and raises plasma high-density lipoprotein (HDL) cholesterol levels, but the mechanisms responsible for these effects are unclear.


RESULTS
We examined the effects of extended-release niacin (2 g/d) and extended-release niacin (2 g/d) plus lovastatin (40 mg/d), relative to placebo, on the kinetics of apolipoprotein (apo) A-I and apoA-II in HDL, apoB-100 in TG-rich lipoproteins (TRL), intermediate-density lipoproteins (IDL) and low-density lipoproteins (LDL), and apoB-48 in TRL in 5 men with combined hyperlipidemia. Niacin significantly increased HDL cholesterol and apoA-I concentrations, associated with a significant increase in apoA-I production rate (PR) and no change in fractional catabolic rate (FCR). Plasma TRL apoB-100 levels were significantly lowered by niacin, accompanied by a trend toward an increase in FCR and no change in PR. Niacin treatment significantly increased TRL apoB-48 FCR but had no effect on apoB-48 PR. No effects of niacin on concentrations or kinetic parameters of IDL and LDL apoB-100 and HDL apoA-II were noted. The addition of lovastatin to niacin promoted a lowering in LDL apoB-100 attributable to increased LDL apoB-100 FCR.


CONCLUSIONS
Niacin treatment was associated with significant increases in HDL apoA-I concentrations and production, as well as enhanced clearance of TRL apoB-100 and apoB-48.
Lipid Metabolism Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA. stefania.lamon-fava@tufts.edu
Stefania
S
Lamon-Fava
Margaret R
MR
Diffenderfer
P Hugh R
PH
Barrett
Aaron
A
Buchsbaum
Mawuli
M
Nyaku
Katalin V
KV
Horvath
Bela F
BF
Asztalos
Seiko
S
Otokozawa
Masumi
M
Ai
Nirupa R
NR
Matthan
Alice H
AH
Lichtenstein
Gregory G
GG
Dolnikowski
Ernst J
EJ
Schaefer
D000328:Adult; D000368:Aged; D016632:Apolipoprotein A-I / Q000097:blood*; D016633:Apolipoprotein A-II / Q000097:blood; D053299:Apolipoprotein B-100 / Q000097:blood*; D053283:Apolipoprotein B-48 / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D006949:Hyperlipidemias / Q000097:blood / Q000188:drug therapy*; D000960:Hypolipidemic Agents / Q000627:therapeutic use*; D007700:Kinetics; D050356:Lipid Metabolism / Q000187:drug effects*; D008148:Lovastatin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009525:Niacin / Q000627:therapeutic use*; D016896:Treatment Outcome; D014280:Triglycerides / Q000097:blood
C505693:APOA1 protein, human; C115794:APOA2 protein, human; D016632:Apolipoprotein A-I; D016633:Apolipoprotein A-II; D053299:Apolipoprotein B-100; D053283:Apolipoprotein B-48; D008076:Cholesterol, HDL; D003692:Delayed-Action Preparations; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000960:Hypolipidemic Agents; D014280:Triglycerides; D009525:Niacin; D008148:Lovastatin