title: Diurnal variation of LDL and HDL cholesterol.
abstract: Determination of a 24-hour lipoprotein lipid profile on a mixed diet showed a typical increase in VLDL (includes chylomicrons) lipids following food intake in normal subjects. The change was less marked or absent in patients with jejuno-ileal by-pass and after cholestyramine treatment of a case with post-ileal-resection diarrhoea. Triglycerides of other lipoproteins did not fluctuate very much but free and esterified cholesterol of LDL and HDL showed a significant diurnal variation: lowest values were seen early in the morning followed by an increase before breakfast, with the highest levels during the afternoon in most cases. No clearcut precursor-product relationship could be seen between VLDL and LDL or HDL, yet the rhythmic changes in the VLDL levels and/or in cholesterol synthesis may be causally associated with the diurnal variation of cholesterol in LDL and HDL.
mesh_terms: D000293:Adolescent; D000328:Adult; D002784:Cholesterol / Q000097:blood*; D002792:Cholestyramine Resin / Q000627:therapeutic use; D002940:Circadian Rhythm; D003967:Diarrhea / Q000097:blood / Q000188:drug therapy; D004032:Diet; D005260:Female; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood*; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood / Q000188:drug therapy
chemical_list: D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D002792:Cholestyramine Resin; D002784:Cholesterol