- Research article
- Open Access
The association of carotid intima media thickness with retinol binding protein-4 and total and high molecular weight adiponectin in type 2 diabetic patients
© Mansouri et al.; licensee BioMed Central Ltd. 2012
Received: 16 May 2012
Accepted: 18 July 2012
Published: 2 August 2012
The aim of this study was to investigate whether carotid intima media thickness (CIMT) is associated with serum level of retinol- binding protein-4 (RBP4) and total and high molecular weight (HMW) adiponectin in type 2 diabetes (T2DM) without clinical symptom of atherosclerotic disease.
101 type 2 diabetic patients (mean age, 53.63 ± 8.42 years) and 42 body mass index (BMI) matched control (mean age 50.1 ± 8.4) were recruited. The CIMT was assessed by using B-mode ultrasonography, while serum levels of RBP4 and total and HMW adiponectin were measured by using enzyme linked immunosorbant assay (ELISA). Linear regression analysis was performed with CIMT as dependent variable and adipokines and cardio metabolic risk factors as independent variables.
The CIMT was higher in diabetic group compared to control group (p <0.05). The mean concentration of RBP4 and total and HMW adiponectin did not differ between two groups.
Age (B = 0.44 P <0.05), blood pressure (B = 0.37 P = <0.05), waist circumference (B = −0.21 P <0.05) and TG (B = 0.1 P <0.05) were identified as independent predictors for CIMT in diabetic group, while RBP4 and adiponectin were not associated with CIMT neither in diabetic group nor in control group.
In conclusion, the present study showed that serum levels of RBP4 or total and HMW adiponectin were not potential predictors of CIMT in type 2 diabetic patients who exposed to this risk factor at least for nine years.
The type 2 diabetes (T2DM) is one of the major risk factors of cardiovascular disease (CVD) which is in turn the leading cause of death in these patients .
Therefore, one of the most important issues in the management of diabetes is to predict and prevent the development of CVD . The carotid intima- media thickness (CIMT) is an independent predictor of future cardiovascular events and increased CIMT was recently suggested to be significantly related to the presence and extent of abnormal myocardial perfusion. Therefore the CIMT can be used as a screening test in the diabetic patients who are at risk of coronary artery disease (CAD) [3, 4].
Recent studies have shown that adipose tissues secret a number of various bioactive substances known as adipokines which might affect insulin sensitivity or vascular function [5–8]. Of these adipokines, retinol binding protein-4 (RBP4) acts as a potential determinant of insulin resistance and plays a role to induce sub clinical inflammation leading to cardiovascular diseases in T2DM [7, 9]. It was reported that serum RBP4 levels were increased in individual with obesity, impaired glucose tolerance, T2DM and even gestational diabetes [10–13].
Inversely previous data showing that adiponectin has anti-inflammatory properties and suppresses various mechanisms contributing to atherogenesis . According to the literature plasma adiponectin may be deregulated in disorders susceptible to atherosclerotic vascular diseases, such as diabetes mellitus .
Increasing adiponectin by life style change and exercise has been reported in diabetic patients but not in healthy subject . Regarding the relationship between CIMT and these two adipokines a few information with conflicting results have been published. Moreover the place of these adipokines measurements as plasma markers to predict cardiovascular disease in diabetic patients is not yet clear. Therefore this study was designed to investigate the associations between CIMT and RBP4 and total and HMW adiponectin altogether in diabetic patients who did not have clinical symptom of atherosclerotic vascular disease.
The study samples included a total of 101 type 2 diabetic patients (48 male and 53 female) with a mean age of (53.6 ± 8.4 year) who were diagnosed according to the world health organization criteria as two times fasting blood glucose equal or greater than 126 mg/dl or use of oral hypoglycemic agent. They were visited in a diabetes outpatient clinic in Shariati Hospital of Tehran University of Medical Sciences. The mean duration of diabetes was (8.85 ± 6.24) years. All diabetic patients were on oral anti diabetic agents and none of them were current or previous smoker except nine. The control groups were selected among healthy friends of diabetic patients who volunteered to participate in a medical and laboratory screening examination, including 25 males and 20 females, with a mean age of (50.1 ± 8.4 years). The inclusion criteria for control group included healthy subject without diabetes and known metabolic disease and did not take any medication. We collected information on lifestyle, medical history, smoking and the use of medication by using questioners (which were requested to fill out by all the participants) and subsequent interview. Both groups were within the same age interval and matched for BMI.
The diabetic cases who had clinical symptoms of large vessel diseases including chest pain, abnormal 12-lead electrocardiography, history of myocardial infarction, cerebral infarction and claudication were excluded. In addition for evaluating peripheral vascular disease (PVD) ankle brachial pressure index (ABI) was measured with a Doppler Ultrasound (France). The patients with ABI less than 0.9 and more than 1.3 were excluded . Screening for microvascular complication was performed as follows. Assessment of diabetic retinopathy as no diabetic retinopathy, non proliferative retinopathy and proliferative diabetic retinopathy were performed by two trained ophthalmologist. The subjects with proliferative retinopathy were excluded. Renal dysfunction was assessed by estimated glomerular filtration rate using the modification of diet in renal disease equation (GFR-MDRD) . For evaluating neuropathy, vibratory sensation was examined by placing a 128 hz diapason on the malleolar and the radius of lower extremity and upper extremity respectively. Vibratory sensation seems to be adversely affected early in the pathogenesis of diabetic peripheral poly-neuropathy . The patients with vibration sensation loss were excluded.
Protocol of the study was approved by ethics committee of the Teheran University of Medical Sciences and a written consent form with the required information was signed by the participants prior to the study.
After at least 12 hours fasting, blood samples were collected. Height, weight and resting blood pressure in a sitting position were measured by the study attending nurse.
The BMI was measured by dividing the weight (kg) to height (m2). Waist circumference defined as the minimal abdominal circumference between the xiphoid process and iliac crest.
Hypertension was defined as systolic blood pressure (SBP) ≥ 140 mm/Hg or diastolic blood pressure (DBP) ≥ 90 mm Hg and or using anti-hypertensive medication in the same session. The blood was transformed immediately and kept at -80c C. Fasting plasma glucose (FPG), total cholesterol and triglyceride were measured by commercially available enzymatic reagents (Pars Azmoon, Tehran, Iran) adapted to an Auto analyzer (Hitachi 902, Japan). High density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were assayed by using turbidometric method (Pars Azmoon, Tehran, Iran).
Insulin was measured via ELISA using Monobind kit (Denmark), with inter-assay and intra- assay coefficient variation (CV) being 6.32% and 1.9% respectively. HbA1C levels are measured by High-performance liquid chromatography (HPLC). Homeostasis model assessment (HOMA) index was applied for the determination of the insulin resistant according to the following equation: HOMA index = fasting glucose (mg/dl) x fasting insulin (μU/ml) / 405.
Serum RBP4 was measured using ELISA kit (AdipoGen, Seoul, Korea). The total and HMW adiponectin were also assessed using ELISA kit (Millipore, USA). Three samples of known concentration (low, moderate and high) were tested for both RBP4, the total and HMW adiponectin in eight independent analytical runs to assess precision within and between assays. The measured intra-assay (CV) for low, moderate and high range of RBP4 were 3.5%, 2.0% and 3.7%, respectively, and the inter-assay were 7.1%, 8.2% and 7.4%, respectively. The measured intra-assay CV for total adiponectin was 7.5% and the inter-assay was 6.25%. The measured intra-assay CV for low, moderate and high range of HMW adiponectin were 1.02%, 2.68% and 2.62%, respectively, and the inter-assay were 4.1%, 7.2% and 4.03%, respectively.
CIMT was measured by B- mode ultrasonography which was equipped with a 13 MHZ linear transducer and performed by 2 expert radiologists for all participants. Patients were in the supine position with a little hyper extension and rotation of the neck to the opposite side. The measurements were acquired from three segments including common carotid artery (CCA), carotid bifurcation and internal carotid artery on both left and right sides posteriorly and anteriorly at the end of diastolic phase. The CIMT was measured at the far wall on each carotid segment on both sides as the distance between the interface of the lumen and intima, and the interface between the media and adventitia. The average value of CIMT measurements of twelve locations was expressed as mean CIMT.
Normality assumption of variables was defined by Kolmogorov-Smirnov test and then the comparison between groups mean differences was performed by student’s t test. Normal distributed data are expressed as the mean ± SD. Because of skewed distribution, adiponectin and CIMT concentration were logarithmically transformed. The relationship between CIMT and adipokines was tested by using the spearman correlation and regression models. Univariate analysis of baseline clinical, metabolic markers, and serum adipokines including age, sex, smoking, BMI, waist circumference, blood pressure, fasting glucose, triglyceride, total cholesterol, HDL and LDL cholesterol, serum creatinin. RBP4 and total and HMW adiponectin and ABI was performed separately in diabetic and control groups. Subsequently, risk factors with a significant P-value (<0.05) were included in a linear multiple regression model to determine independent predictors of CIMT. The SPSS 11.5 statistical software package (SPSS Inc. Chicago) was applied for all calculations. A 5% or lower p-value is considered statistically significant
Clinical characteristics of patients
Clinical characteristics of diabetic group and control group
53.6 ± 8.4
50.1 ± 8.4
27.7 ± 4.1
28.7 ± 4.6
Waist circumference (cm)
94.0 ± 10.8
93.5 ± 10.3
Duration of Diabetes (years)
8.8 ± 6.2
SBP (mm Hg)
132.9 ± 17.3
129.1 ± 13.6
DBP (mm Hg)
77.0 ± 9.7
78.7 ± 11.2
165.1 ± 62.2
97.8 ± 10.5
7.9 ± 1.7
5.3 ± 0.6
8.6 ± 6.6
8.5 ± 4.9
3.5 ± 2.7
2.1 ± 1.2
195.3 ± 108.1
171.8 ± 84
174.6 ± 39.4
201.4 ± 39.5
40.7 ± 8.9
45.9 ± 11.7
94.9 ± 23.8
113.9 ± 24.8
Serum creatinine (mg/dl)
1.0 ± 0.2
0.9 ± 0.2
eGFR (ml/min/1.73 m2)
77.3 ± 11.2
Current smoking, (n) (%)
71.9 ± 35.6
80.7 ± 31.6
Totala adiponectin (µg/ml)
6.6 ± 3.4
6.62 ± 2.8
HMWa adiponectin (µg/ml)
3.7 ± 1.9
3.50 ± 1.7
0.8 ± 0.2
0.66 ± 0.2
1.1 ± 0.1
1.2 ± 0.1
Metformin (n) (%)
Glybenclamide (n) (%)
Statin (n) (%)
Aspirin (n) (%)
According to the t test the diabetic patients were older and had significantly higher levels of serum FBS, HbA1C and HOMA index as expected, whereas serum total cholesterol, HDL and LDL cholesterol were significantly higher in control group.
The mean concentration of RBP4 and total and HMW adiponectin did not differ between two groups. CIMT was significantly higher in diabetic group [0.76 ± 0.16 vs. 0.66 ± 0.16 p = 0.001] while ABI was significantly higher in control group (1.11 ± 0.10 vs. 1. 16 ± 0.11 p = 0.015). To reduce the effect of age which were significantly higher in diabetic group, age adjusted analysis were performed but it did not modify our significant findings except for ABI which did not remain significant anymore between the two groups (Table 1).
The association of CIMT with RBP4 and total and HMW adiponectin
The relationship between CIMT and RBP4, total and HMW adiponectin and other cardio metabolic risk factors as independent variable
Standard B coefficient
Standard B coefficient
Standard B coefficient
In this study we evaluated the association of CIMT, an established marker of subclinical atherosclerosis, with RBP4 and total and HMW adiponectin in type 2 diabetic patients without clinical evidence of atherosclerotic vascular disease. We found that the CIMT in diabetic group was significantly higher compared to non-diabetic group. This finding is in agreement with previous study that reported the chronic hyperglycemia in diabetic patients could induce athrogenesis by increasing oxidative stress and decreased nitric oxide bioavailability . It is well known that the risk of atherosclerosis is much higher in diabetic patients and suggested that, in response to diabetes the endogenous defense of the vascular endothelium begins to break down . The main finding of our study is that, the CIMT did not show a significant relationship with total or HMW adiponectin in a univariate regression analysis. Our result is inconsistent with some previous studies reported an inverse correlation between adiponectin levels and CIMT in non-diabetic subjects including middle aged healthy women , obese children  and healthy middle age males . A negative correlation has also been shown between HMW adiponectin level and CIMT in obese and normal weight adolescents . However the lack of correlation between CIMT and adiponectin has also been shown in healthy males  and middle–aged non diabetic women .
Taking together, it seems that the reported association of CIMT with total and HMW adiponectin is stronger in normal adults and obese children than in diabetic patients.
Regarding to RBP4, in multivariable analysis, adjusted for known risk factors which affect on CIMT, no independent association between CIMT and this adipokine was found. In the literature, there are several controversial reports regarding association between CIMT and RBP4. For example, Ingelsson et al.  assessed the relation between RBP4 and CIMT in healthy elderly subjects and found an inverse correlation of RBP4 with intima- media and plaque echogenicity. However, more recent data do not confirm those findings in T2DM. In a study performed in type 2 diabetic patients by Takebayashi and his colleagues , the CIMT showed no association with RBP4. Lack of correlation between CIMT and RBP4 has also been reported in a recent published article performed on newly diagnosed un-treated type 2 diabetes . The possible reasons for not finding significant association between CIMT and adipokines in our study are explained below. Measurements of CIMT could reflect the vascular structural changes including intimal lesion and medial hypertrophy  due to past long term exposure to risk factors . While it could have been the biological effect of these adipokines precedes the structural changes determined by CIMT. As some evidences showed that these adipokines may act as determinant of the early functional change of the vascular system . Endothelial dysfunction occurs during the early stages of atherosclerosis and is responsible for the pathophysiological changes leading to subclinical atherosclerosis determined by CIMT . Endothelial dysfunction resulted from decreased production or availability of NO which is the key factor playing an essential role in the regulation of vascular function [33, 34].
The result of the study performed by Beauloye et al.  showed that adiponectin level were independently associated with increased IMT and they suggest that adiponectin may play an early role in the pathophysiology of atherosclerosis. Established by in vitro studies, adiponectin serves to protect against the onset of endothelial dysfunction by promoting NO generation . Conversely RBP4 may affect endothelial function directly through inhibition of insulin mediated pathway for nitric oxide production in endothelial cells [29, 36].
Moreover some studies showed, adiponectin inhibits expression of adhesion molecules which induces the progression of atherosclerosis [37, 38]. In contrast a positive correlation between RBP4 and several soluble adhesion molecules are reported . In addition some studies suggested that RBP4 might be responsible for up regulation of endothelial adhesion molecules and development of vascular complication [30, 39, 40].
Based on these evidences it seems these adipokines are more related to the markers which induce early stages of vascular changes than established structural changes reflected by CIMT. While the mean duration of diabetes in this study population was nearly nine years (Table 1) and it is not known for how long the patients have been exposed to this major risk factor prior to the confirmed diabetes diagnosis. Therefore, further studies on young adult who are prone or newly exposed to diabetes, are needed to determine whether the serum levels of these adipokines could act as plasma markers to predict vascular thickness.
Another reason for not finding this association is that, many diabetic patients in this study were taking a range of medication that might affect the CIMT measurements, serum level of adipokines and on the relationship between them.
In our study, CIMT showed a significant and positive correlation with age and systolic blood pressure and triglyceride but it did not show a significant relation with any of metabolic markers including fasting glucose, insulin and lipid markers.
The lack of association between CIMT and fasting glucose, insulin and lipid markers has been reported by previous investigators [15, 41] and could be explained at least partially by taking into account the role of anti-hyperglycemic and anti-hyperlipidemic medications consumed by diabetic patients.
In conclusion, the present study showed that serum levels of RBP4 or total and HMW adiponectin were not potential predictors of CIMT, which reflects vascular structural changes, in type 2 diabetic patients who exposed to this risk factor at least for nine years.
This research has been supported by the Endocrinology Metabolism Research Center of Tehran University of Medical Sciences, Tehran, and I.R. Iran.
Conflict of interest statement: authors announce that they do not have anything to disclose
- Wacker FJ, Yaung LH, Inzucchi SH, et al.: Detection of silent myocardial Ischemia in asymptomatic diabetic subjects. Diabetes Care 2004, 27: 1954–1961. 10.2337/diacare.27.8.1954View ArticleGoogle Scholar
- Stehouwer CD, Henry RM, Ferreria I: Arterial stiffness in diabetes and the metabolic syndrome a pathway to cardiovascular disease. Diabetologia 2008, 51: 527–539. 10.1007/s00125-007-0918-3View ArticlePubMedGoogle Scholar
- Thanh HT, Benzaquen BS: Screening for subclinical coronary artery disease measuring carotid intima media thickness. Am J Cardio 2009, 104: 1383–1388. 10.1016/j.amjcard.2009.07.005View ArticleGoogle Scholar
- Djaberi R, Schuijf JD, Jukema JW, et al.: Increased carotid intima-media thickness as a predictor of the presence and extent of abnormal myocardial perfusion in type 2 diabetes. Diabetes Care 2010, 33(2):372–374. 10.2337/dc09-1301View ArticlePubMedGoogle Scholar
- Esteve E, Ricart W, Fernandez-Real JM, Adipocytokines and insulin resistance. The possible role of lipocalin-2, retinol binding protein-4, and insulin resistance: Adipocytokines and insulin resistance. The possible role of lipocalin-2, retinol binding protein-4, and insulin resistance. Diabetes Care 2009, 32(Supplement 2):S362-S367.View ArticlePubMedGoogle Scholar
- Rabe K, Lehrke M, Parhofer KG, et al.: Adipocytokines and insulin resistance. Mol Med 2008, 14(11–12):741–751.PubMedGoogle Scholar
- Rasouli N, Kern PA: Adipocytokines and the metabolic complications of obesity. J Clin Endocrinol Metab 2008, 93(11):564–573.Google Scholar
- Beauloye V, Zech F, Mong HTT, et al.: Determinants of early Atherosclerosis in obese children and adolescents. J Clin Endocrinol Metab 2007, 92(8):3025–3032. 10.1210/jc.2007-0619View ArticlePubMedGoogle Scholar
- Hutley L, Prins B: Fat as endocrine organ: relationship to the metabolic Syndrome. Am J Med Sci 2005, 330: 280–289. 10.1097/00000441-200512000-00005View ArticlePubMedGoogle Scholar
- Hassink S, Balagopal PB: RBP4: from retinol transporter to biomarker. J Pediatr 2009, 154: 5–7. 10.1016/j.jpeds.2008.08.024View ArticlePubMedGoogle Scholar
- Graham TE, Yang Q, Blüher M, et al.: Retinol-binding protein 4 and insulin resistance in lean, obese, and diabetic subjects. N Engl J Med 2006, 354: 2552–2563. 10.1056/NEJMoa054862View ArticlePubMedGoogle Scholar
- Balagopal P, Graham TE, Kahn BB, et al.: Reduction of elevated serum retinol binding protein in obese children by lifestyle intervention: association with subclinical inflammation. J Clin Endocrinol Metab 2007, 92(5):1971–1974. 10.1210/jc.2006-2712View ArticlePubMedGoogle Scholar
- Maghbooli Z, Hossein-Nezhad A, Mirzaei K, et al.: Association between retinol-binding protein 4 concentrations and gestational diabetes mellitus and risk of developing metabolic syndrome after pregnancy. Reprod Sci 2010, 17(2):196–201. 10.1177/1933719109351097View ArticlePubMedGoogle Scholar
- Shimada K, Miyazaki T, Daida H: Adiponectin and atherosclerotic disease. Clin Chim Acta 2004, 344: 1–12. 10.1016/j.cccn.2004.02.020View ArticlePubMedGoogle Scholar
- Hotta K, Funahashi T, Arita Y, et al.: Plasma concentrations of a novel, adipose-specific protein, adiponectin, in type 2 diabetic patients. Arterioscler ThrombVasc Bio 2000, l20: 1595–1599. 159View ArticleGoogle Scholar
- Mansouri M, Keshtkar A, Hasani-Ranjbar S, et al.: The impact of one session resistance exercise on Plasm adiponectin and RBP4 concentration in trained and untrained healthy young men. Endocrin J 2011, 58(10):861–868. 10.1507/endocrj.EJ11-0046View ArticleGoogle Scholar
- Greenland p, Abrams J, Aurigemma GP: Prevention conference: beyond secondary prevention: Identifying the high-risk patient for primary prevention: non invasive tests of atherosclerotic burden. Circulation 2000, 101: E16-E22. 10.1161/01.CIR.101.1.e16View ArticlePubMedGoogle Scholar
- Levey AS, Bosch JP, Lewis JB, et al.: A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med 1999, 130: 461–470.View ArticlePubMedGoogle Scholar
- Shin JB, Seong YJ, Lee HJ, et al.: Foot Screening Technique in a Diabetic Population. J Korean Med Sci 2000, 15: 78–82.View ArticlePubMedGoogle Scholar
- Szmitko PE, Teoh H, Stewart DJ, et al.: Adiponectin and cardiovascular disease: state of the art? Am J Physiol Heart Circ Physiol 2007, 292: 1655–1663.View ArticleGoogle Scholar
- Lo J, Dolan SE, Kanter JR, et al.: Effects of obesity, body composition, and adiponectin on carotid intima-media thickness in healthy women. J Clin Endocrinol Metab 2006, 91: 1677–1682. 10.1210/jc.2005-2775View ArticlePubMedGoogle Scholar
- Pilz S, Horejsi R, Moller R, et al.: Early atherosclerosis in obese juveniles is associated with low serum levels of adiponectin. J Clin Endocrinol Metab 2005, 90: 4792–4796. 10.1210/jc.2005-0167View ArticlePubMedGoogle Scholar
- Iglseder B, Mackevics V, Stadlmayer A, Tasch G, Ladurner G, Paulweber B: Plasma adiponectin levels and sonographic phenotypes of subclinical carotid artery Atherosclerosis. Stroke 2005, 36: 2577–2582. 10.1161/01.STR.0000190834.00284.fdView ArticlePubMedGoogle Scholar
- Mangge H, Almer1 G, Haj-Yahya1 S, et al.: Pre atherosclerosis and adiponectin subfractions in obese adolescents. Obesity 2008, 16(12):2578–2584. 10.1038/oby.2008.439View ArticlePubMedGoogle Scholar
- Norata GD, Raseli S, Grigore L, et al.: Leptin: adiponectin ratio is an independent predictor of intima media thickness of the common carotid artery. Stroke 2007, 38: 2844. 10.1161/STROKEAHA.107.485540View ArticlePubMedGoogle Scholar
- Nilsson PM, Engström G, Hedblad B, et al.: Plasma adiponectin levels in relation to carotid intima media thickness and markers of insulin resistance. Arterioscler Thromb Vasc Biol 2006, 26: 2758–2762. 10.1161/01.ATV.0000249638.01416.4bView ArticlePubMedGoogle Scholar
- Ingelsson E, Lind L: Circulating retinol-binding protein 4 and subclinical cardiovascular disease in the. elderly. Diabetes Care 2009, 32: 733–735. 10.2337/dc08-1656View ArticlePubMedGoogle Scholar
- Takebayashi K, Suetsugu M, Wakabayashi S, et al.: Retinol binding protein-4 levels and clinical features of type 2 diabetes patients. J Clin Endocrinol Metab 2007, 92: 2712–2719. 10.1210/jc.2006-1249View ArticlePubMedGoogle Scholar
- Park SE, Kim DH, Lee JH, et al.: Retinol-binding protein-4 is associated with endothelial dysfunction in adults with newly diagnosed type 2 diabetes mellitus. Atherosclerosis 2009, 204: 23–25. 10.1016/j.atherosclerosis.2008.08.012View ArticlePubMedGoogle Scholar
- Behrendt D, Gans p: Endothelial function. from vascular biology to clinical applications. Am J Cardiol 2002, 90: 40L-48L. 10.1016/S0002-9149(02)02963-6View ArticlePubMedGoogle Scholar
- Crous J: Predictive value of carotid 2-dimensionalultrasound. Am J Cardiol 2001, 88: 27–30. 10.1016/S0002-9149(01)01754-4View ArticleGoogle Scholar
- Wang Z, Nakayama T: Inflammation, a Link between Obesity and Cardiovascular Disease. Mediat Inflamm 2010, 2010: 535918.Google Scholar
- Szmitko PE, Wang CH, Weisel RD, et al.: New markers of inflammation and endothelial cell activation. Circulation 2003, 108: 1917–1923. 10.1161/01.CIR.0000089190.95415.9FView ArticlePubMedGoogle Scholar
- Verma S, Anderson TJ: Fundamentals of endothelial function for the clinical cardiologist. Circulation 2002, 105: 546–549. 10.1161/hc0502.104540View ArticlePubMedGoogle Scholar
- Chen H, Montagnani M, Funahashi T, et al.: Adiponectin stimulates production of nitric oxide in vascular endothelial cells. J Biol Chem 2003, 278: 45021–45026. 10.1074/jbc.M307878200View ArticlePubMedGoogle Scholar
- Iglseder B, Mackevics V, Stadlmayer A, et al.: Plasma adiponectin levels and sonographic phenotypes of subclinical carotid artery atherosclerosis. Stroke 2005, 36: 2577–2582. 10.1161/01.STR.0000190834.00284.fdView ArticlePubMedGoogle Scholar
- Steinberg HO, Chaker H, Leaming R, et al.: Obesity/insulin resistance is associated with endothelial dysfunction implication for the syndrome of insulin resistance. J Clin Invest 1996, 97: 2601–2610. 10.1172/JCI118709View ArticlePubMedGoogle Scholar
- Kobashi C, Urakaze M, Kishida M, et al.: Adiponectin inhibits endothelial synthesis of interleukin-8. Circ Res 2005, 97: 1245–1252. 10.1161/01.RES.0000194328.57164.36View ArticlePubMedGoogle Scholar
- Ouchi N, Kihara S, Arita Y, et al.: Novel modulator for endothelial adhesion molecules: adipocyte-derived plasma protein adiponectin. Circulation 1999, 100: 2473–2476. 10.1161/01.CIR.100.25.2473View ArticlePubMedGoogle Scholar
- Kuboki K, Jiang ZY, Takahara N, et al.: Regulation of endothelial constitutive nitric oxide synthase gene expression in endothelial cells and in vivo: a specific vascular action of insulin. Circulation 2000, 101: 676–681. 10.1161/01.CIR.101.6.676View ArticlePubMedGoogle Scholar
- Peppa-P M, Scordili M, Antoniou A, et al.: Carotid atherosclerosis in adolescents and young adults with IDDM. Relation to urinary endothelin, albumin, free cortisol, and other factors. Diabetes Care 1998, 21(6):1004–1007. 10.2337/diacare.21.6.1004View ArticleGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.