Measurement of serum remnant-like lipoprotein particle-triglyceride (RLP-TG) and RLP-TG/total TG ratio using highly sensitive triglyceride assay reagent.
BACKGROUND
Serum concentration of remnant-like lipoprotein particles (RLP) have been measured by cholesterol as RLP-C for clinical diagnostic purpose. However, the measurement of TG in RLP and the ratio of RLP-TG/total TG has not been well established.


METHODS
Highly sensitive triglyceride assay reagent (TG-EX) was used for RLP-TG assay and compared with the previously used TG reagent (Determiner LTGII). Sera in health check-up populations, cardiovascular disease, diabetes and oral fat load cases were used for the evaluation of the new RLP-TG assay. Serum TC, TG, HDL-C, LDL-C and RLP-C concentrations were also determined in above cases.


RESULTS
The detection limit of new RLP-TG using TG-EX was 2.0mg/dl. The within-run imprecision (n=10) was CV=3.0% (RLP-TG: 4.1 mg ± 0.7 mg/dl), CV = 1.4% (RLP-TG: 42.0 ± 0.6 mg/dl) and CV=0.5% (RLP-TG: 100.6 ± 0.6 mg/dl). Cut-off value (75 percentile) of RLP-TG determined in the fasting Japanese population was 13.1mg/dl in men and 9.9 mg/dl in women. In patients with metabolic syndrome, cardiovascular disease and diabetes, RLP-TG levels were significantly higher than those in normal control subjects. RLP-TG levels increased significantly after an oral fat load and the ratio of RLP-TG/total TG increased > 3-fold compared to the ratio in the fasting state. Approximately 80% of TG increased after an oral fat load was TG derived from remnant lipoproteins.


CONCLUSIONS
Normal range of plasma RLP-TG in the fasting Japanese population was first determined using a highly sensitive TG assay reagent. RLP-TG was shown to be higher in cases with metabolic syndrome, cardiovascular disease, etc and a better marker than RLP-C for the measurement of postprandial remnant lipoproteins, together with total TG for RLP-TG/total TG ratio.
School of Health Sciences, Gunma University, Maebashi, Gunma, Japan.
Takamitsu
T
Nakano
Yoshiharu
Y
Tokita
Takeaki
T
Nagamine
Akira
A
Tanaka
Mitsuyo
M
Okazaki
Shinichi
S
Yatsuzuka
Noriko
N
Tamei
Younosuke
Y
Shimomura
Yoshitaka
Y
Ando
Suguru
S
Akamatsu
Masaki Q
MQ
Fujita
Katsuyuki
K
Nakajima
D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards; D002318:Cardiovascular Diseases / Q000097:blood; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003920:Diabetes Mellitus / Q000097:blood; D004041:Dietary Fats; D005215:Fasting; D005260:Female; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D057230:Limit of Detection; D016014:Linear Models; D008074:Lipoproteins / Q000097:blood* / Q000378:metabolism; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood; D008875:Middle Aged; D019518:Postprandial Period; D012016:Reference Values; D013997:Time Factors; D014280:Triglycerides / Q000097:blood* / Q000378:metabolism
D004041:Dietary Fats; D007202:Indicators and Reagents; D008074:Lipoproteins; D014280:Triglycerides; C112017:remnant-like particle cholesterol; D002784:Cholesterol