Insulin-Like Growth Factor-I And Brachial-Ankle Pulse Wave Velocity In Patients With Essential Hypertension

Objective: To investigate the relationship between serum insulin-like growth factor-1(IGF-1)and brachial-ankle pulse wave velocity(baPWV)in patients with essential hypertension(EH) and the influence of combined antihypertensive therapy on the serum levels of IGF-1 and baPWV, in orde to illustrate the role of serum IGF-1 in the pathophysiological process of hypertensive arteriosclerosis.Methods: Thirty-four normal individuals(male 18, female 16) aged for 25~ 60 years old (45.94±8.71 years in average) were selected to be a control group, the experimental group included Sixty-eight patients with EH(male 35, female 33) aged for 24~70 years old (46.79±9.84 years in average). According to the clinical grading of EH, patients in the experimental group were divided into three Subgroups, stage 1 hypertension (n=24, male 10, female 14), stage 2 hypertension(n=28, male 15, female 13) and stage 3 hypertension (n=16, male 10, female 6). All participants need to undertake the tests of sitting blood pressure,liver function,renal function,blood-fasting sugar,blood-lipoids and serum IGF-1, while the EH patients also need to take the tests of ambulatory blood pressure monitoring(ABPM)and baPWV. According to the values of baPWV before antihypertensive therapy, the experimental group was also divided into the arteriosclerosis (baPWV≥1400cm/s, n=50, male 27, female 23) and nonarteriosclerosis (baPWV<1400cm/s, n=18, male 8, female 10) group. After combined antihypertensive therapy (amlodipine +Telmisartan)for 12 weeks,all EH patients needed to undertake again the tests of blood pressure,liver function,renal function,blood-fasting sugar,blood-lipoids,serum IGF-1,ABPM and baPWV, the resuts should be taken to compare with that of pre-therapy.Results:①Serum IGF-I levels in patients with EH were significantly higher than that in normal controls(115.39±69.46μg/L vs 66.23±30.14μg/L, P<0.05); Serum IGF-I levels in patients with EH increased with the clinical grading of EH(stage 1 hypertension: 82.37±15.16μg/L, stage 2 hypertension: 114.85±68.84μg/L, stage 3 hypertension: 165.87±90.58μg/L,P<0.05); Before the antihypertensive therapy, Serum IGF-I levels in EH patients of arteriosclerosis group were significantly higher than that of nonarteriosclerosis group(124.28±78.43μg/L vs 90.68±20.13μg/L, P<0.05).②After the antihypertens -ive therapy, the blood pressure level of EH patients decreased significantly.(sitting SBP 155.85±13.13mmHg vs 130.71±9.35 mmHg, P<0.05; sitting DBP 100.69±6.54mmHg vs 84.24±6.22mmHg, P<0.05; ABPM: 24 hour mean SBP 147.86±12.18mmHg vs 130.48±14.19mmHg, P<0.05; 24 hour mean DBP 96.79±8.97mmHg vs 83.74±9.96 mmHg, P < 0.05; Daytime mean SBP 152.53±12.80mmHg vs 135.28±14.37mmHg, P<0.05; Daytime mean DBP 99.88±9.48mmHg vs 86.79±10.28mmHg, P < 0.05; Nighttime mean SBP 136.53±12.45 mmHg vs119.88±13.99 mmHg, P<0.05; Nighttime mean DBP 89.50±8.71 mmHg vs 77.07±9.70 mmHg, P<0.05).③Before and after the antihypertensive therapy, there were not significant differences about the levels of blood-lipoids and blood-fasting sugar(TC 4.55±0.78 mmol/L vs 4.41±0.77 mmol/L,P>0.05; TG 1.70±0.81mmol/L vs 1.79±0.99mmol/L, P>0.05; HDL-C 1.35±0.36mmol/L vs 1.35±0.35mmol/L, P > 0.05; LDL-C 3.07±0.97mmol/L vs 3.16±0.91mmol/L, P>0.05; BFS 5.04±0.65mmol/L vs 5.00±0.44 mmol/L, P>0.05); while the levels of serum C(r84.79±17.11mmol/L vs 79.19±19.61 mmol/L,P<0.05)and BUN(5.62±1.03mmol/L vs 4.79±1.18 mmol/L, P<0.05)showed significant differences.④After antihypertensive therapy, the levels of serum IGF-1 and the values of baPWV showed significantly decreased(IGF-1 115.39±69.46μg/L vs 82.07±30.62μg/L,P<0.05;baPWV 1678.37±280.03 cm/s vs 1570.82±223.21cm/s, P<0.05).⑤After 12 weeks's treatment, compared with EH patients with abnormal blood pressure(sitting SBP≥140mmHg or/and sitting DBP≥90mmHg; n=22, male 13, female 9), the patients with normal blood pressure (sitting SBP<140mmHg and sitting DBP<90mmHg; n =46, male 21, female 25 ) had lower serum levels of IGF-I(IGF-1 92.78±27.62μg/L vs 76.95±30.93μg/L,P<0.05) and smaller values of baPWV(baPWV 1652.98±253.10cm/s vs 1531.52±198.51 -cm/s, P<0.05).⑥Whether before or after antihypertensive therapy, serum IGF-I correlated positively with baPWV (before antihypertensive therapy rs=0.506, P<0.05; after antihypertensive therapy rs=0.492, P<0.05).Conclusions: The serum levels of IGF-1 in patients with essential hypertension are higher than that in normal individuals, and increased with the clinical grading of blood pressure. There was a positive correlation between serum levels of IGF-1 and baPWV. IGF-I is probably as a promter involved in the pathophysiological process of artery atherosclerosis in patients with essential hypertension. The combined antihypertensive therapy(amlodipine+Telmisartan)can reduced the serum levels of IGF-1 and the values of baPWV, and improved the degree of artery atherosclerosis. It was more significant that lowering the serum levels of IGF-1 and improving the degree of artery atherosclerosis in the EH patients achieved successful blood pressure control.