we enrolled 1,047 consecutive caucasian patients referred to coronary angiography for the evaluation of stable cad solely on a clinical indication . coronary angiography was performed as described previously ( 4 ) ; coronary stenoses 50% were considered significant ( 5,6 ) . the mets was diagnosed according to american heart association  revised national cholesterol education program adult treatment panel iii criteria ( 7 ) . the ethics committee of the university of innsbruck approved the study ; all participants gave written informed consent . analytical procedures were performed on a cobas integra 800 ( roche , basel , switzerland ) , as described previously ( 4,8 ) . sample - size calculations showed that assuming an sd of 1.5 times the population mean , 393 patients would be needed per study group to detect a between - group difference of crp of 20% with a power of 80% at an  fault of 0.05 . analytical procedures were performed on a cobas integra 800 ( roche , basel , switzerland ) , as described previously ( 4,8 ) . sample - size calculations showed that assuming an sd of 1.5 times the population mean , 393 patients would be needed per study group to detect a between - group difference of crp of 20% with a power of 80% at an  fault of 0.05 . significant cad at angiography was present in 564 patients ( 55.8% ) ; its prevalence was higher in patients with mets than in subjects without mets ( 59.5 vs. 52.8% ; p = 0.034 ) ; adjustment for age , sex , ldl cholesterol , smoking , cardiovascular medications ( statins , aspirin , ace inhibitors / angiotensin receptor blocking agents and -blocking agents ) , and crp confirmed this result , with an odds ratio ( or ) of 1.49 ( 95% ci 1.121.98 ; p = 0.007 ) for mets patients . the low hdl cholesterol ( or 1.57 [ 95% ci 1.112.22 ] ; p = 0.011 ) and the high - glucose traits ( 1.33 [ 1.021.73 ] ; p = 0.038 ) proved significantly and independently of the above covariates associated with significant cad , whereas high triglycerides ( p = 0.082 ) , large waist ( p = 0.826 ) , and high blood pressure criteria ( p = 0.145 ) were not independently associated with significant cad . crp was significantly higher in patients with mets than in subjects without mets ( 0.46  0.62 vs. 0.35  0.49 mg / dl ; p < 0.001 ) . in contrast , crp did not differ significantly between patients with significant cad and subjects without significant cad ( 0.40  0.59 vs. 0.39  0.52 mg / dl ; p = 0.706 ) . crp also was similar in subjects with any atherosclerotic lesion at angiography compared with subjects with completely normal coronary arteries ( 0.41  0.57 vs. 0.36  0.50 mg / dl ; p = 0.325 ) . furthermore , crp was not associated with significant cad in a multivariate model adjusting for age , sex , ldl cholesterol , smoking , cardiovascular medications , and presence of mets ( standardized adjusted or 0.97 [ 95% ci 0.761.25 ] ; p = 0.822 ) . considering both mets and significant cad , crp was significantly higher in patients with mets , both among those without significant cad ( 0.45  0.50 vs. 0.36  0.53 mg / dl ; p < 0.001 ) and among those with significant cad ( 0.47  0.69 vs. 0.34  0.45 ; p = 0.001 ) . in contrast , crp did not differ between patients with significant cad and those without significant cad among subjects without mets ( p = 0.869 ) or among subjects with mets ( p = 0.411 ) . ancova , adjusting for age , sex , ldl cholesterol , smoking , and cardiovascular medications , confirmed that mets ( f = 11.74 ; p = 0.001 ) but not significant cad ( f = 0.01 ; p = 0.983 ) was significantly associated with crp . univariately , serum crp was significantly higher in patients who fulfilled the large waist ( p < 0.001 ) , the low hdl cholesterol ( p < 0.001 ) , the high blood pressure ( p = 0.016 ) , and the high glucose ( p < 0.001 ) criteria but not in patients who fulfilled the high triglyceride criterion ( p = 0.352 ) compared with patients who did not fulfill the respective mets criteria . when all mets traits were entered simultaneously into one ancova model , only low hdl cholesterol proved associated with crp ( f = 44.19 ; p < 0.001 ) independently of age , sex , ldl cholesterol , smoking , major cardiovascular medications , and of all other mets criteria . crp increased significantly ( ptrend < 0.001 ) with an increasing number of mets traits ( fig . 1a ) after adjustment for age , sex , smoking , ldl cholesterol , and major cardiovascular medications . further adjustment for the high waist ( f = 11.66 ; p = 0.001 ) , the high glucose ( f = 14.18 ; p < 0.001 ) , the high blood pressure ( f = 17.94 ; p < 0.001 ) , and the high triglyceride ( f = 32.81 ; p < 0.001 ) traits rendered this relationship virtually unchanged . in contrast , the positive association between the number of metabolic traits and crp was no longer significant ( fig . 1b ) after adjustment for the low hdl cholesterol criterion ( f = 0.87 ; p = 0.352 ) . a : relationship of the number of mets components and crp adjusted for age , sex , ldl cholesterol , smoking , and major cardiovascular medications . p value is given for the association of crp with the number of mets components . significant cad at angiography was present in 564 patients ( 55.8% ) ; its prevalence was higher in patients with mets than in subjects without mets ( 59.5 vs. 52.8% ; p = 0.034 ) ; adjustment for age , sex , ldl cholesterol , smoking , cardiovascular medications ( statins , aspirin , ace inhibitors / angiotensin receptor blocking agents and -blocking agents ) , and crp confirmed this result , with an odds ratio ( or ) of 1.49 ( 95% ci 1.121.98 ; p = 0.007 ) for mets patients . the low hdl cholesterol ( or 1.57 [ 95% ci 1.112.22 ] ; p = 0.011 ) and the high - glucose traits ( 1.33 [ 1.021.73 ] ; p = 0.038 ) proved significantly and independently of the above covariates associated with significant cad , whereas high triglycerides ( p = 0.082 ) , large waist ( p = 0.826 ) , and high blood pressure criteria ( p = 0.145 ) were not independently associated with significant cad . crp was significantly higher in patients with mets than in subjects without mets ( 0.46  0.62 vs. 0.35  0.49 mg / dl ; p < 0.001 ) . in contrast , crp did not differ significantly between patients with significant cad and subjects without significant cad ( 0.40  0.59 vs. 0.39  0.52 mg / dl ; p = 0.706 ) . crp also was similar in subjects with any atherosclerotic lesion at angiography compared with subjects with completely normal coronary arteries ( 0.41  0.57 vs. 0.36  0.50 mg / dl ; p = 0.325 ) . furthermore , crp was not associated with significant cad in a multivariate model adjusting for age , sex , ldl cholesterol , smoking , cardiovascular medications , and presence of mets ( standardized adjusted or 0.97 [ 95% ci 0.761.25 ] ; p = 0.822 ) . considering both mets and significant cad , crp was significantly higher in patients with mets , both among those without significant cad ( 0.45  0.50 vs. 0.36  0.53 mg / dl ; p < 0.001 ) and among those with significant cad ( 0.47  0.69 vs. 0.34  0.45 ; p = 0.001 ) . in contrast , crp did not differ between patients with significant cad and those without significant cad among subjects without mets ( p = 0.869 ) or among subjects with mets ( p = 0.411 ) . ancova , adjusting for age , sex , ldl cholesterol , smoking , and cardiovascular medications , confirmed that mets ( f = 11.74 ; p = 0.001 ) but not significant cad ( f = 0.01 ; p = 0.983 ) was significantly associated with crp . univariately , serum crp was significantly higher in patients who fulfilled the large waist ( p < 0.001 ) , the low hdl cholesterol ( p < 0.001 ) , the high blood pressure ( p = 0.016 ) , and the high glucose ( p < 0.001 ) criteria but not in patients who fulfilled the high triglyceride criterion ( p = 0.352 ) compared with patients who did not fulfill the respective mets criteria . when all mets traits were entered simultaneously into one ancova model , only low hdl cholesterol proved associated with crp ( f = 44.19 ; p < 0.001 ) independently of age , sex , ldl cholesterol , smoking , major cardiovascular medications , and of all other mets criteria . crp increased significantly ( ptrend < 0.001 ) with an increasing number of mets traits ( fig . 1a ) after adjustment for age , sex , smoking , ldl cholesterol , and major cardiovascular medications . further adjustment for the high waist ( f = 11.66 ; p = 0.001 ) , the high glucose ( f = 14.18 ; p < 0.001 ) , the high blood pressure ( f = 17.94 ; p < 0.001 ) , and the high triglyceride ( f = 32.81 ; p < 0.001 ) traits rendered this relationship virtually unchanged . in contrast , the positive association between the number of metabolic traits and crp was no longer significant ( fig . 1b ) after adjustment for the low hdl cholesterol criterion ( f = 0.87 ; p = 0.352 ) . a : relationship of the number of mets components and crp adjusted for age , sex , ldl cholesterol , smoking , and major cardiovascular medications . p value is given for the association of crp with the number of mets components . from our data , we conclude that among angiographied coronary patients crp is strongly associated with the mets but not with angiographically characterized coronary atherosclerosis . specifically , the overall association of the mets with crp is driven by the low hdl cholesterol feature . data from the literature on the association of crp with cross - sectionally determined cad are controversial . this observation likely reflects the fact that inflammation is not associated with plaque burden itself but rather with plaque vulnerability and rupture . thus , our data do not contradict the numerous reports on an association between crp and clinical atherothrombotic events . further , our data show that the low hdl cholesterol mets feature drives the overall association between the mets and crp ; crp was no longer associated with the number of mets traits when adjusted for hdl cholesterol . these data fit into the notion that hdl particles , besides their crucial role in reverse cholesterol transport , also protect the artery wall through anti - inflammatory mechanisms ( 13 ) . thus , crp is strongly associated with the mets but not with angiographically diagnosed coronary atherosclerosis . the overall association of the mets with crp is predominantly driven by the low hdl cholesterol feature , a paramount predictor of vascular events .
objectivethe metabolic syndrome ( mets ) and coronary artery disease ( cad ) frequently coincide ; their individual contribution to inflammation is unknown.research design and methodswe enrolled 1,010 patients undergoing coronary angiography . 
 coronary stenoses 50% were considered significant . 
 the mets was defined according to american heart association  revised national cholesterol education program adult treatment panel iii criteria.resultsc-reactive protein ( crp ) did not differ between patients with significant cad and subjects without significant cad ( p = 0.706 ) but was significantly higher in mets patients than in those without mets ( p < 0.001 ) . the mets criteria low hdl cholesterol ( p < 0.001 ) , large waist ( p < 0.001 ) , high glucose ( p < 0.001 ) , and high blood pressure ( p = 0.016 ) , but not high triglycerides ( p = 0.352 ) , proved associated with crp . 
 when all mets traits were considered simultaneously , only low hdl cholesterol proved independently associated with crp ( f = 44.19 ; p < 0.001).conclusionscrp is strongly associated with the mets but not with coronary atherosclerosis . 
 the association of the mets with subclinical inflammation is driven by the low hdl cholesterol feature .