The relationship between C-reactive protein and subclinical carotid arteriosclerosis in military pilots

Abstract

Background/Aim. Inflammation plays a key role in the physiopathology of arteriosclerosis. C-reactive protein (CRP) and common carotid artery intima-media thickness are independent predictors of cardiovascular events and diabetes mellitus in apparently healthy men, but relationship between them is not fully elucidated. The aim of the study was to assess the cross-sectional relationship between CRP and cardiovascular risk factors with common carotid artery intima-media thickness in military pilots as representatives of healthy men. Methods. We studied 161 military pilots (age 38 ? 6 years) free of cardiovascular disease and diabetes mellitus. Traditional and metabolic risk factors were determined. Plasma CRP was measured by immunonephelometry. The common carotid artery intima-media thickness was measured by ultrasonography in the posterior wall of both common carotid arteries. Results. A total of 66.5% subjects had common carotid artery intima-media thickness > 0.9 mm (p < 0.01). The mean CRP plasma concentration was significantly higher in the subjects with common carotid artery intima- media thickness > 0.9 mm than in those with common carotid artery intima-media thickness ? 0.9 mm. In a simple regression analysis age adjusted CRP was associated with common carotid artery intima-media thickness (? = 0.285, p < 0.01), and only high density lipoprotein cholesterol was not associated with common carotid artery intima-media thickness. The association between CRP and common carotid artery intima-media thickness remained highly significant after controlling for body mass index, blood pressure, total cholesterol, low density lipoprotein cholesterol, triglycerides, glycosylated hemoglobin and smoking (p < 0.01). Controlling for glucose, triglycerides to high density lipoprotein cholesterol ratio, and total cholesterol to high density lipoprotein cholesterol ratio resulted in some reduction in the strength of the association, but including waist circumference in the regression made the relationship no longer significant (p = 0.119). Body mass index (? = 0.352; p < 0.01), total cholesterol to high density lipoprotein cholesterol ratio (? = 0.334; p < 0.01) and age (? = 0.190; p = 0.036) were the independent predictors of common carotid artery intima-media thickness. Conclusions. In the studied group of healthy men CRP per se is not an independent predictor of early arteriosclerosis, and may mediate the effect of certain traditional risk factors, especially visceral obesity, on promoting aterogenesis.Uvod/Cilj. Inflamacija ima kljucnu ulogu u procesu arterioskleroze. C-reaktivni protein (CRP) i debljina intime i medije zajednickih karotidnih arterija nezavisni su prediktori rizika od kardiovaskularnih dogadjaja i secerne bolesti kod zdravih ljudi; medjutim, njihova povezanost nije razjasnjena. Cilj ove studije bio je da se proceni povezanost C-reaktivnog proteina sa faktorima rizika i debljinom intime i medije zajednickih karotidnih arterija kod vojnih pilota, kao predstavnika zdravih osoba. Metode. U studiju preseka bio je ukljucen 161 vojni pilot, starosti 38 ? 6 godina, bez kardiovaskularnih bolesti, secerne bolesti i aktivne inflamacije. Svima su odredjeni tradicionalni i metabolicki faktori rizika. C-reaktivni protein meren je imunonefelometrijskom metodom, a debljina intime i medije zajednickih karotidnih arterija ultrazvucno. Rezultati. Debljina intime i medije zajednickih karotidnih arterija > 0,90 mm zabelezena je kod 66,5% ispitanika (p < 0,01). Univarijantnom linearnom regresionom analizom pokazano je da postoji povezanost CRP, kontrolisanog za godine starosti, sa debljinom intime i medije zajednickih karotidnih arterija (? = 0,285, p < 0,01). Povezanost CRP sa debljinom intime i medije zajednickih karotidnih arterija ne slabi nakon statisticke kontrole za indeks telesne mase, krvni pritisak, ukupni holesterol, lipoproteine male gustine, trigliceridemiju, glikozilirani hemoglobin i pusenje (p < 0,01). Ukljucivanjem glikemije i lipidnih indeksa dolazi do statisticki neznacajnog slabljenja ove povezanosti, dok se statistickom kontrolom za obim struka gubi njena statisticka znacajnost (p > 0,05). Nezavisni prediktori debljine intime i medije zajednickih karotidnih arterija bili su indeks telesne mase (? = 0,352; p < 0,01), odnos ukupnog holesterola i lipoproteina male gustine (? = 0,334; p < 0,01) i starost (? = 0,190; p = 0,036). Zakljucak. U posmatranoj grupi zdravih osoba CRP nije nezavisni prediktor preklinicke arterioskleroze i moze da bude posrednik dejstva nekih faktora rizika, posebno visceralne gojaznosti, na proces aterogeneze.