IGF‐I concentrations are positively associated with carotid artery atherosclerosis in women

Figures & data

Table I. Basic characteristics in the hypertensive and control cohorts.

	Hypertensive cohort (n = 519)	Control cohort (n = 526)	P
Age (years)	51.2 (50.7–51.7)	51.4 (50.8–51.9)	0.597
BMI (kg/m^2)	29.0 (28.6–29.5)	26.4 (26.0–26.7)	<0.001
WHR	0.88 (0.88–0.89)	0.85 (0.84–0.86)	<0.001
SBP (mmHg)	155. 3 (153.5–157.1)	141.4 (139.6–143.2)	<0.001
DBP (mmHg)	93.5 (92.5–94.5)	84.8 (83.8–85.8)	<0.001
Fasting insulin (mU/l)	12.9 (12.2–13.6)	9.5 (9.1–10.0)	<0.001
T2D patients, n (%)	71 (13.8 %)	22 (4.2 %)	<0.001
AMI/CHD, n (%)	80 (15.4 %)	38 (7.2 %)	<0.001
IGF‐I (ng/ml)	60.4 (56.8–64.1)	74.8 (71.3–78.4)	<0.001
IGFBP‐1 (ng/ml)	2.6 (2.4–2.8)	3.4 (3.1–3.7)	0.002
LDL‐C (mmol/l)	3.5 (3.5–3.6)	3.5 (3.4–3.6)	0.811
HDL‐C (mmol/l)	1.3 (1.2–1.3)	1.4 (1.3–1.4)	<0.001
Triglycerides (mmol/l)	1.6 (1.5–1.6)	1.2 (1.2–1.3)	<0.001
CRP (μg/ml)	2.2 (1.9–2.4)	1.3 (1.2–1.4)	<0.001

The values presented are means (95% confidence interval (CI), unless otherwise indicated).

WHR: waist‐to‐hip ratio; SBP: systolic blood pressure; DBP:diastolic blood pressure; T2D: type 2 diabetes; AMI: acute myocardial infarction; CHD: coronary heart disease.

Table II. Associations between IGF‐I tertile and CVD risk factors.

Risk factor	1. tertile (n = 338)	2. tertile (n = 334)	3. tertile (n = 336)	P*	P**
Age (years)	53.1 (52.5–53.7)	51.4 (50.8–52.0)	49.8 (49.2–50.5)	<0.001	<0.001^a
BMI (kg/m2)	28.9 (28.3–29.4)	27.4 (26.9–27.9)	27.0 (26.5–27.4)	<0.001	<0.001^b
WHR	0.88 (0.87–0.89)	0.86 (0.85–0.87)	0.85 (0.84–0.86)	<0.001	0.942
SBP (mmHg)	142.7 (139.6–145.9)	141.5 (138.0–145.0)	140.3 (137.3–143.2)	0.559	0.722
DBP (mmHg)	85.0 (83.4–86.6)	84.4 (82.5–86.3)	84.9 (83.0–86.8)	0.876	0.932
Fasting insulin (mU/l)	12.2 (11.4–13.1)	10.1 (9.4–10.9)	11.1 (10.4–11.8)	0.001	0.003
T2D patients, n (%)	45 (13.4)	24 (7.2)	23 (6.8)	0.004	0.283
IGF‐I (ng/ml)	32.0 (30.7–33.4)	74.4 (73.2–75.6)	127.1 (124.1–130.0)	<0.001	<0.001
IGFBP‐1 (ng/ml)	3.1 (2.8–3.4)	3.3 (3.0–3.6)	2.5 (2.3–2.8)	<0.001	<0.001
LDL‐C (mmol/l)	3.6 (3.5–3.7)	3.5 (3.4–3.6)	3.5 (3.3–3.6)	0.071	0.882
HDL‐C (mmol/l)	1.3 (1.3–1.4)	1.4 (1.3–1.4)	1.3 (1.3–1.4)	0.092	0.003
Triglycerides (mmol/l)	1.5 (1.5–1.6)	1.3 (1.2–1.4)	1.3 (1.3–1.4)	<0.001	0.019
CRP (μg/ml)	2.3 (2.0–2.6)	1.8 (1.5–2.0)	1.2 (1.1–1.4)	<0.001	<0.001
Pack‐years	12.1 (10.6–13.7)	12.9 (11.4–14.5)	10.9 (9.4–12.4)	0.175	0.249
Mean IMT (mm)	0.88 (0.86–0.90)	0.85 (0.84–0.87)	0.84 (0.82–0.86)	0.009	0.722

The values presented are means (95% CI, unless otherwise stated ). P* obtained by ANOVA, P** obtained by ANCOVA with age, sex and BMI as covariates (^a adjusted for sex and BMI, ^b adjusted for age and sex). The association with blood pressure was analysed only in the control group in study group‐specific tertiles (1. n = 162, 2. n = 162, 3. n = 168). WHR = waist‐to‐hip ratio; SBP = systolic blood pressure; DBP = diastolic blood pressure; IMT = carotid intima media thickness.

Figure 1 Correlations between IGF‐I concentrations and cardiovascular risk factors in men and women. The values were obtained by partial correlation analysis controlled for study group.

Figure 2 The relationships between IGF‐I concentrations and mean IMT in men and women. a) Age‐adjusted IMT values in sex‐specific IGF‐I tertiles. P‐value for IGF‐I obtained by ANCOVA adjusted for age, b) IMT values after further adjustments. P‐value for IGF‐I obtained by ANCOVA adjusted for age, BMI, systolic blood pressure, LDL cholesterol and pack‐years.

Table III. Linear regression models explaining the variation in mean carotid IMT.

	All (n = 1008)		Men (n = 487)		Women (n = 521)
	ß	P	ß	P	ß	P
Sex	−0.199	<0.001	–	–	–	–
Age	0.261	<0.001	0.309	<0.001	0.362	<0.001
BMI	−0.069	0.020	–	–	−0.093	0.030
LDL‐C	0.154	<0.001	0.242	<0.001	–	–
SBP	0.158	<0.001	0.120	0.004	0.214	<0.001
Pack‐years	0.128	<0.001	0.139	0.001	0.085	0.037
IGF‐I	–	–	−0.089	0.031	0.130	0.008
Adjusted R^2	22.6%		22.1%		16.7%

Linear regression model with stepwise selection method. The following variables were included in the analyses: age, sex, BMI, smoking, systolic blood pressure, LDL cholesterol, IGF‐I, IGFBP‐1, triglycerides, CRP, fasting insulin and type 2 diabetes.

Table IV. Basic characteristics and risk factors of CVD with statistical significance by the GH1 T1169A genotypes.

		A/A (n = 159)	A/T (n = 446)	T/T (n = 398)	P
Age (years)		50.9 (50.0–51.8)	51.5 (51.0–52.0)	51.1 (50.5–51.7)	0.429
BMI (kg/m^2)		28.0 (27.3–28.7)	27.7 (27.2–28.1)	27.6 (27.2–28.1)	0.680
SBP (mmHg)	Men	144.0 (137.7–150.3)	147.1 (143.5–150.7)	144.6 (140.8–148.4)	0.546
	Women	131.8 (125.4–138.1)	134.8 (131.1–138.5)	142.2 (138.5–145.8)	0.003
	All	137.7 (133.2–142.2)	140.8 (138.2–143.4)	143.7 (141.0–146.3)	0.061
DBP (mmHg)		83.2 (80.6–85.8)	84.6 (83.1–86.1)	85.7 (84.2–87.2)	0.221
IGF‐I (ng/ml)		70.6 (64.3–77.8)	67.5 (63.7–71.3)	66.2 (62.2–70.3)	0.518
IGFBP‐1 (ng/ml)		2.9 (2.6–3.3)	2.8 (2.6–3.0)	3.1 (2.9–3.3)	0.283
LDL‐C (mmol/l)		3.3 (3.2–3.4)	3.6 (3.5–3.7)	3.6 (3.5–3.7)	0.005
Mean IMT (mm)		0.84 (0.82–0.86)	0.86 (0.85–0.87)	0.87 (0.86–0.89)	0.067

The values are adjusted means with age, sex and BMI as covariates (95% CI). The associations with blood pressure were analysed only in the control group: A/A n = 72, A/T n = 218, T/T n = 209. SBP = systolic blood pressure; DBP = diastolic blood pressure; IMT = carotid intima media thickness.