Obesity is an important determinant of baseline serum C-reactive protein concentration in monozygotic twins, independent of genetic influences.
BACKGROUND
C-reactive protein (CRP) values predict atherothrombotic cardiovascular disease and type 2 diabetes mellitus. Associations between CRP and obesity, predominantly assessed anthropometrically, may partly explain these observations. Previous studies have been unable to control for genetic influences on CRP and obesity. The aim of this study was to examine the relationship between CRP and accurately measured body fat, lipids, apolipoproteins, blood pressure, and environmental and behavioral factors, independent of genetic influences.


RESULTS
One hundred ninety-four healthy female twins (age 57.2+/-7 years) were studied after excluding pairs with CRP values >10 mg/L. Total body fat and central abdominal fat (CAF) were measured by dual-energy x-ray absorptiometry. CRP concentration was strongly related to surrogate and direct measures of body fat (r=0.31 to 0.54, P<0.001), diastolic blood pressure (r=0.20, P=0.003), and lipid and apolipoprotein levels (r=0.21 to 0.51, P<0.008). Light-to-moderate alcohol consumers and nonusers of hormone replacement therapy (HRT) had lower CRP levels than abstainers and HRT users, respectively. In stepwise multiple regression analysis, CAF, triglycerides, apolipoprotein B, and HRT use explained 46% of the variance in circulating CRP. In analyses controlling for genetic influences in monozygotic twins, within-pair differences in CRP were associated with within-pair differences in total body fat (r=0.39, P<0.001), CAF (r=0.34, P=0.002), diastolic blood pressure (r=0.24, P=0.03), apolipoprotein AI (r=-0.33, P=0.01), HDL cholesterol (r=-0.42, P=0.001), and triglycerides (r=0.35, P=0.007).


CONCLUSIONS
CRP was strongly related to total and central abdominal obesity, blood pressure, and lipid levels, independent of genetic influences. These relationships are likely to contribute significantly to prospective associations between CRP and type 2 diabetes and coronary events.
Greenfield
Jerry R
JR
Department of Endocrinology, St Vincent's Hospital, Sydney, Australia.
Samaras
Katherine
K
Jenkins
Arthur B
AB
Kelly
Paul J
PJ
Spector
Tim D
TD
Gallimore
J Ruth
JR
Pepys
Mark B
MB
Campbell
Lesley V
LV
D000005:Abdomen; D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000097:blood; D001053:Apolipoproteins / Q000032:analysis; D001161:Arteriosclerosis / Q000235:genetics; D001315:Australia / Q000453:epidemiology; D001794:Blood Pressure; D002097:C-Reactive Protein / Q000032:analysis*; D015331:Cohort Studies; D003327:Coronary Disease / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics; D004200:Diseases in Twins / Q000097:blood* / Q000235:genetics; D004739:England / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease; D020249:Hormone Replacement Therapy; D006801:Humans; D008055:Lipids / Q000097:blood; D024821:Metabolic Syndrome / Q000235:genetics; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000000981:diagnostic imaging; D017698:Postmenopause / Q000097:blood; D012907:Smoking / Q000097:blood; D013008:Somatotypes; D014430:Twins, Monozygotic
D001053:Apolipoproteins; D008055:Lipids; D002097:C-Reactive Protein