Reduced adipose tissue lipoprotein lipase responses, postprandial lipemia, and low high-density lipoprotein-2 subspecies levels in older athletes with silent myocardial ischemia.
Healthy older (64 +/- 1 years, mean +/- SEM) athletic (maximal oxygen consumption [VO2max] > 40 mL/kg/min) normocholesterolemic men with no prior history of coronary artery disease (CAD) were recruited for cardiovascular and metabolic studies. Thirty-three percent had asymptomatic exercise-induced ST segment depression on their exercise electrocardiogram (ECG), consistent with silent myocardial ischemia (SI). We hypothesized that abnormalities in high-density lipoprotein (HDL) and postprandial triglyceride (TG) metabolism may increase their risk for CAD. Compared with 12 nonischemic controls of comparable age, percent body fat, and VO2max, the 13 men with SI had decreased fasting HDL cholesterol ([HDL-C] 41 +/- 2 v 50 +/- 2 mg/dL, P < .001) and %HDL2b subspecies levels as measured by gradient gel electrophoresis (22 +/- 2 v 34 +/- 3, P < .001). Fasting plasma TG and low-density lipoprotein cholesterol (LDL-C) levels were the same in both groups. Although plasma glucose levels during an oral glucose tolerance test (OGTT) were similar in both groups, the total insulin area was higher in men with SI (P < .05). After consumption of a standard high-fat meal (680 kcal/m2 body surface area of a formula in which 86% of the calories were derived from fat), postprandial plasma TG, chylomicron-TG, and very-low-density lipoprotein (VLDL)-TG levels and postprandial areas were higher in men with SI (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)
Katzel
L I
LI
Department of Medicine, University of Maryland School of Medicine, Baltimore.
Busby-Whitehead
M J
MJ
Rogus
E M
EM
Krauss
R M
RM
Goldberg
A P
AP
D000273:Adipose Tissue / Q000201:enzymology*; D000368:Aged; D000375:Aging / Q000378:metabolism*; D004435:Eating; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008055:Lipids / Q000097:blood*; D008066:Lipolysis / Q000187:drug effects; D008071:Lipoprotein Lipase / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000378:metabolism*
D008055:Lipids; D008077:Lipoproteins, LDL; D006493:Heparin; D008071:Lipoprotein Lipase