Genetic influence on inflammation variables in the elderly.
BACKGROUND
Inflammation variables (C-reactive protein [CRP], fibrinogen, and soluble intercellular adhesion molecule-1 [sICAM-1]) have been identified as risk factors for cardiovascular disease. It is still not known how much the regulation of inflammatory risk factors is determined by genetic factors, and the aim of this study was to determine the heritability of these inflammation variables and of the acute phase regulating cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) at older ages.


RESULTS
The heritability of CRP, fibrinogen, sICAM-1, IL-6, and TNF-alpha was determined in a twin study consisting of 129 monozygotic twin pairs and 153 dizygotic same-sex twins aged 73 to 94 years who participated in the Longitudinal Study of Aging of Danish Twins. Furthermore, we determined the influence of selected genetic polymorphisms on the plasma level variations. Genetic factors accounted for 20% to 55% of the variation in plasma levels of the inflammation variables. The highest heritability was found for sICAM-1. The genetic polymorphisms we studied explained only a small, insignificant part of the heritability.


CONCLUSIONS
This study in elderly twins provides evidence for a substantial genetic component of inflammatory cardiovascular risk factors among the elderly.
de Maat
Moniek P M
MP
Department for Thrombosis Research, University of Southern Denmark, Esbjerg, Denmark. m.demaat@erasmusmc.nl
Bladbjerg
Else Marie
EM
Hjelmborg
Jacob von Bornemann
Jv
Bathum
Lise
L
Jespersen
Jørgen
J
Christensen
Kaare
K
D000209:Acute-Phase Proteins / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics*; D002318:Cardiovascular Diseases / Q000097:blood / Q000235:genetics*; D016207:Cytokines / Q000097:blood; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000235:genetics; D008137:Longitudinal Studies; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics; D011159:Population Surveillance; D018433:Twin Studies as Topic / Q000379:methods; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics
D000209:Acute-Phase Proteins; D016207:Cytokines