Negative and independent influence of apolipoprotein E on C-reactive protein (CRP) concentration in obese adults. Potential anti-inflammatory role of apoE in vivo.
BACKGROUND
Obesity is frequently associated with an increase in the early inflammation marker C-reactive protein (CRP), insulin resistance and changes in lipoprotein metabolism. Increased CRP is known as an independent cardiovascular risk factor. Since the apolipoproteins (apo) E and CIII components of HDL are associated with reduced cardiovascular risk and since apoE has in vitro anti-inflammatory effect, we have investigated the relationships between apoE, apoCIII (in apoB and non apoB containing lipoproteins) and CRP in obese adults.


METHODS
The following parameters from 34 healthy obese fasting women (age 22-64 y, body mass index (BMI) 28-68 kg/m2) were measured: (1) ApoE and apoCIII, in total plasma, in apoB- (E LpB, CIII LpB) and non-apoB-containing lipoproteins (E LpnonB, CIII LpnonB); (2) CRP and cytokine secreted by adipose tissue (TNF-alpha and its soluble receptor TNFR2); (3) triglyceride, HDL-cholesterol, systolic blood pressure, diastolic blood pressure, waist and hip circumferences, insulin, glucose. HOMA, a marker of insulin sensitivity, and the ratio E/CIII in LpB and LpnonB were calculated.


RESULTS
CRP was positively correlated with BMI (P<0.05), waist circumference (WC, P<0.05), triglyceride (P<0.05) and negatively correlated with apoE (P<0.01) and E LpnonB (P<0.05). Two multiple regression models including parameters related to CRP with a P<0.25 were run stepwise to assess their independent contribution to CRP concentration. In the first model (including BMI, WC, HOMA, insulin, triglyceride, apoE, E LpnonB), apoE was the best predictor of CRP (P=0.01) together with triglyceride (P=0.02) and BMI (P=0.08). The second model took into account E/CIII LpnonB ratio with the parameters included in the first model. In this second model, E/CIII LpnonB was the best predictor of CRP (P=0.007), explaining 39% of CRP variance.


CONCLUSIONS
ApoE is strongly correlated with CRP and could have an anti-inflammatory effect in vivo in obese subjects. This correlation could be limited to LpnonB lipoproteins, depending on their apoE and CIII relative content.
Bach-Ngohou
K
K
Laboratoire de Biochimie fondamentale et appliquée, UFR de Pharmacie, Nantes, France.
Nazih
H
H
Nazih-Sanderson
F
F
Zaïr
Y
Y
Le Carrer
D
D
Krempf
M
M
Bard
J M
JM
D000273:Adipose Tissue / Q000378:metabolism; D000328:Adult; D053305:Apolipoprotein C-III; D001056:Apolipoproteins C / Q000097:blood*; D001057:Apolipoproteins E / Q000097:blood* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D001824:Body Constitution; D002097:C-Reactive Protein / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000276:immunology; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000276:immunology; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood
D053305:Apolipoprotein C-III; D001056:Apolipoproteins C; D001057:Apolipoproteins E; D015415:Biomarkers; D016207:Cytokines; D007328:Insulin; D008074:Lipoproteins; D014280:Triglycerides; D002097:C-Reactive Protein