LDL-cholesterol and HDL-cholesterol concentrations decrease during the day.
BACKGROUND
Homogenous assays for LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) are highly accurate, with little interference from triglyceride. Using these methods, we measured postprandial LDL-C and HDL-C. Earlier studies suggested a postprandial decrease in LDL-C.


METHODS
To elucidate whether LDL-C and HDL-C decrease significantly during the day, we determined daily profiles of LDL-C and HDL-C using homogeneous assays in subjects with normal coronary arteries (N; n=10), and subjects with coronary artery disease (CAD; n=23).


RESULTS
In both groups, LDL-C and HDL-C were significantly lower from after breakfast until midnight than they were before breakfast. The next morning, they returned to baseline levels. The mean reduction in LDL-C was 0.09-0.13 mmol/L in N and 0.05-0.20 mmol/L in CAD, while that in HDL-C was 0.02-0.06 mmol/L in N and 0.00-0.05 mmol/L in CAD.


CONCLUSIONS
LDL-C and HDL-C decrease significantly over the course of the day.
Miida
Takashi
T
Department of Community Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences, Japan. miida@med.niigata-u.ac.jp
Nakamura
Yuichi
Y
Mezaki
Toru
T
Hanyu
Osamu
O
Maruyama
Seitaro
S
Horikawa
Yoshinori
Y
Izawa
Sachiko
S
Yamada
Yukio
Y
Matsui
Hiroshi
H
Okada
Masahiko
M
D000328:Adult; D000418:Albumins / Q000032:analysis; D008076:Cholesterol, HDL / Q000097:blood* / Q000378:metabolism*; D008078:Cholesterol, LDL / Q000097:blood* / Q000378:metabolism*; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D000418:Albumins; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides