Associaton between serum IGF-1 levels in healthy individuals and endothelial dysfunction,and IGF-1 as a marker of atherosclerosis

$662&ø$721%(7:((16(580ø168/ø1-/ø.(*52:7+FACTOR-I (IGF-I)/(9(/6ø1+($/7+<ø1'ø9ø'8$/6$1'(1'27+(/ø$/'<6)81&7ø21 AND IGF-I AS A MARKER OFATHEROSCLEROSø6'5)1(6/ø+$1d8+$&,Atherosclerosis, which may cause coronary artery disease, peripheral artery diseaseand acute myocardial infarction is a complex and chronic process. Endothelial dysfunction isan early and major factor in the development of atherosclerosis. It is considered that, in theHDUO\ VWDWH RI DWKHURVFOHURVLV QLWULF R[LGH 12 SURGXFWLRQ LV UHGXFHG DQG VLQFH øQVXOLQ-likegrowth factor-I (IGF-I) stimulates NO production there is relation between IGF-I andendothelial dysfunction and consequently relation between IGF-I and atherosclerosisdevelopment. It has been shown that there is a relation between IGF-I and coronary arterydisease. Also there is increasing evidence that, insulin resistance and endothelial dysfunctionplay a central role in the pathogenesis of atherosclerosis.Our study include 67 participant, who are divided into three groups according to theirIGF-I levels.There was 17 subject in IGF-I lower group, 17 in the higher and 33 in the normalgroup.Their age was between 40-65 years old, and body mass index < 27 kg/m2 . History ofdiabetes mellitus, chronic liver and kidney disease didn?t accept to the study, because thesediseases can affect IGF-I levels. Also people who have hypertension didn?t take place in thestudy though it is a cardiovascular risk factor. Relationship between IGF-I and NO,Endothelin-I (ET-I), markers of endothelial dysfunction, and also between IGF-I and C-reactive protein (CRP), lipid and fibrinogen levels, risk factors that may contribute to theendothelial dysfunction and atherosclerosis, are investigated.No relationship was found between IGF-I and NO, ET-I,high sensitive CRP (hs-CRP)and lipid levels. But in the IGF-I higher group there was positive correlation between NO andTriglyceride (TG) and Very-Low-Density Lipoprotein Cholesterol (VLDL-C). Also contraryto litheratur findings, in the IGF-I lower group there was significantly positive correlationbetween NO and insulin resistance and also in this group significantly relationship betweenNO and Low-Density Lipoprotein Cholesterol (LDL-C), VLDL-C, TG and total cholesterol.These findings considered us, especially in the early state NO can increase as a defense mechanism secondary to increase of cardiovascular risk factors. No correlation was foundbetween IGF-I and hs-CRP, fibrinogen and lipid levels, but in the IGF-I lower group hs-CRPand fibrinogen were higher than the other two groups. Additionally in the IGF-I lower groupwe determined positive correlation between ET-I and hs-CRP. These findings considered us,reduction of IGF-I levels contribute to atherosclerosis by these marksers. Original finding ofour study was, significant correlation between insulin resistance and body mass index.Consequently, it is considered that reduction of IGF-I may contribute to early state ofatherosclerosis, but to bring out the real risk these people must be followed for a long period.