Complement C3 and C-reactive protein are elevated in South Asians independent of a family history of stroke.
OBJECTIVE
Complement components are emerging risk factors for cardiovascular disease. In this study, we examined the relation among C3, C-reactive protein (CRP), factor B, and features of the insulin resistance (IR) syndrome in 143 first-degree relatives of South Asian subjects with ischemic stroke, 141 South Asian controls, and 121 white controls.


METHODS
C3, CRP (high-sensitivity assay), and factor B levels were measured by ELISAs, and their relation to features of the IR syndrome were assessed. Data are presented as geometric mean (95% CI).


RESULTS
There was no significant difference in the levels of C3 between South Asian relatives (1.25 [1.21, 1.29] g/L) and South Asian controls (1.20 [1.15, 1.24] g/L, P=0.2). Levels in both South Asian groups were significantly higher than in white controls (0.95 [0.92, 0.98] g/L; P<0.001 for both comparisons). These differences remained significant after adjustment for covariates. Similarly, levels of CRP were not different between the 2 South Asian groups, but levels in both South Asian groups, after adjustment for covariates, were significantly higher than in white controls. There was no difference in the levels of factor B among the 3 groups. South Asian subjects with elevated C3 levels clustered risk factors associated with IR to a greater extent than those with high CRP.


CONCLUSIONS
These results suggest that South Asians have a greater level of chronic subclinical inflammation than do whites, independent of a family history of stroke. In addition, C3 is more likely to cluster with features of the IR syndrome compared with CRP in South Asians.
Somani
Riyaz
R
Academic Unit of Molecular Vascular Medicine, The LIGHT Laboratories, Clarendon Way, University of Leeds, Leeds, LS2 9JT. UK. r.somani@leeds.ac.uk
Grant
Peter J
PJ
Kain
Kirti
K
Catto
Andrew J
AJ
Carter
Angela M
AM
D000328:Adult; D044466:Asian People / Q000235:genetics*; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D002908:Chronic Disease; D016000:Cluster Analysis; D003176:Complement C3 / Q000378:metabolism*; D011415:Complement Factor B / Q000378:metabolism; D005260:Female; D006801:Humans; D007249:Inflammation / Q000453:epidemiology; D007333:Insulin Resistance; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D020521:Stroke / Q000097:blood* / Q000235:genetics*; D044465:White People / Q000235:genetics
D003176:Complement C3; D002097:C-Reactive Protein; D011415:Complement Factor B