Circulating angiopoietin-2 levels in children and adolescents with type 1 diabetes mellitus: relation to carotid and aortic intima-media thickness

Serum angiopoietin-2: a promising biomarker for early diabetic kidney disease in children and adolescents with type 1 diabetes

Albuminuria has been considered the golden standard biomarker for diabetic kidney disease (DKD), but appears once significant kidney damage has already occurred. Angiopoietin-2 (Angpt-2) has been implicated in the development and progression of DKD in adults. We aimed to explore the association of serum Angpt-2 levels with DKD in children and adolescents with type 1 diabetes mellitus (T1DM) of short duration (3-5 years) and to evaluate the predictive power of serum Angpt-2 in the early detection of DKD prior to the microalbuminuric phase. The current cross-sectional study included 90 children divided into three age and sex-matched groups based on urinary albumin-to-creatinine ratio (UACR): microalbuminuric diabetic group (n = 30), non-albuminuric diabetic group (n = 30), and control group (n = 30). All participants were subjected to anthropometric measurements, serum Angpt-2 and fasting lipid profile (total cholesterol, triglycerides, LDL-C, HDL-C, and Non-HDL-C) assessment. Glomerular filtration rate was estimated based on serum creatinine (eGFR-Cr). Higher serum Angpt-2 levels were detected in both diabetic groups compared to controls and in microalbuminuric compared to non-albuminuric diabetic group. There was no detected significant difference in eGFR-Cr values across the study groups. Serum Angpt-2 was positively correlated with triglycerides, LDL, Non-HDL-C, HbA1c, and UACR, while UACR, HbA1c, and Non-HDL-C were independent predictors for serum Angpt-2. Serum Angpt-2 at level of 137.4 ng/L could discriminate between microalbuminuric and non-albuminuric diabetic groups with AUC = 0.960 and at level of 115.95 ng/L could discriminate between the non-albuminuric diabetic group and controls with AUC = 0.976.Conclusion: Serum Angpt-2 is a promising potent biomarker for the detection of early stage of DKD in childhood T1DM before albuminuria emerges. What is Known? • Urine albumin-to-creatinine ratio (UACR) and glomerular filtration rate (GFR) are the golden standard but late biomarkers for DKD. • Angiopoietin-2 has been implicated in the development and progression of DKD in adults with diabetes, but has not been explored in T1DM children with DKD. What is New? • Higher serum angiopoietin-2 was detected in diabetic groups compared to controls and in microalbuminuric compared to non-albuminuric group. • Angiopoietin-2 correlated positively with triglycerides, LDL, Non-HDL-C, HbA1c, and UACR. • Serum angiopoietin-2 is a promising early diagnostic biomarker for DKD in children with T1DM.

Minireview: Understanding and targeting inflammatory, hemodynamic and injury markers for cardiorenal protection in type 1 diabetes

The coexistence of cardiovascular disease (CVD) and diabetic kidney disease (DKD) is common in people with type 1 diabetes (T1D) and is strongly associated with an increased risk of morbidity and mortality. Hence, it is imperative to explore robust tools that can accurately reflect the development and progression of cardiorenal complications. Several cardiovascular and kidney biomarkers have been identified to detect at-risk individuals with T1D. The primary aim of this review is to highlight biomarkers of injury, inflammation, or renal hemodynamic changes that may influence T1D susceptibility to CVD and DKD. We will also examine the impact of approved pharmacotherapies for type 2 diabetes, including renin-angiotensin-aldosterone system (RAAS) inhibitors, sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists (GLP-1RAs) on candidate biomarkers for cardiorenal complications in people with T1D and discuss how these changes may potentially mediate kidney and cardiovascular protection. Identifying predictive and prognostic biomarkers for DKD and CVD may highlight potential drug targets to attenuate cardiorenal disease progression, implement novel risk stratification measures in clinical trials, and improve the assessment, diagnosis, and treatment of at-risk individuals with T1D.

Impact of Angiopoietin-2 on Kidney Diseases

Background

Angiopoietins (Ang) are essential angiogenic factors involved in angiogenesis, vascular maturation, and inflammation. The most studied angiopoietins, angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2), behave antagonistically to each other in vivo to sustain vascular endothelium homeostasis. While Ang-1 typically acts as the endothelium-protective mediator, its context-dependent antagonist Ang-2 can promote endothelium permeability and vascular destabilization, hence contributing to a poor outcome in vascular diseases via endothelial injury, vascular dysfunction, and microinflammation. The pathogenesis of kidney diseases is associated with endothelial dysfunction and chronic inflammation in renal diseases.

Summary

Several preclinical studies report overexpression of Ang-2 in renal tissues of certain kidney disease models; additionally, clinical studies show increased levels of circulating Ang-2 in the course of chronic kidney disease, implying that Ang-2 may serve as a useful biomarker in these patients. However, the exact mechanisms of Ang-2 action in renal diseases remain unclear.

Key Messages

We summarized the recent findings on Ang-2 in kidney diseases, including preclinical studies and clinical studies, aiming to provide a systematic understanding of the role of Ang-2 in these diseases.

The rs2442598 polymorphism in the ANGPT-2 gene is associated with risk for diabetic retinopathy in patients with type 1 diabetes mellitus in a Brazilian population

OBJECTIVE

As studies have reported the involvement of angiopoietin-2 (ANGPT-2) in the pathogenesis of diabetic retinopathy (DR), the aim of this study was to investigate the association between the ANGPT-2 rs2442598 polymorphism and DR.

METHODS

This case-control study comprised 107 patients with type 1 diabetes mellitus (T1DM) and DR (cases) and 129 patients with T1DM without DR (controls) and with ≥ 10 years of DM. The ANGPT-2 rs2442598 (G/A) polymorphism was genotyped by real-time PCR using TaqMan MGB probes.

RESULTS

Genotype distributions of this polymorphism were consistent with the Hardy-Weinberg equilibrium. The frequency of the rs2442598 A allele was higher in cases compared to controls (p = 0.011). Moreover, the A/A genotype was more frequent in cases than in controls (p = 0.017) and was associated with risk for DR after adjustments for duration of DM, HbA1c, triglycerides, estimated glomerular filtration rate, and hypertension (odds ratio [OR] = 5.19, 95% confidence interval [CI] 1.21-22.27). This association was maintained under recessive (OR = 4.78, 95% CI 1.14-19.99) and additive (OR = 6.861, 95% CI 1.45-32.38) inheritance models.

CONCLUSION

Our data demonstrated, for the first time, an association between the ANGPT-2 rs2442598 A allele and risk for DR in T1DM patients from southern Brazil. Additional studies are necessary to replicate this association in other populations.

Blocking angiotensin 2 receptor attenuates diabetic nephropathy via mitigating ANGPTL2/TL4/NF-κB expression

BACKGROUND

Diabetic nephropathy (DN) is a consequence of diabetes mellitus (DM) and is associated with early changes in renal angiotensin II (ANG II). These changes were evaluated using ANG II blocker valsartan early from week two of diabetes (experiment I, renoprotective) and late from week nine of diabetes (experiment II, renotherapeutic) to the end of both experiments at week twelve.

METHODS AND RESULTS

In both experiments, adult male Wister rats were divided into (i) vehicle group; (ii) valsartan received oral 30 mg/Kg/day; (iii) diabetic received single 50 mg/Kg intraperitoneal streptozotocin injection; (iv) renoprotection, diabetic rats received valsartan treated in experiments I and II. DM effects on urine albumin excretion, blood pressure, and renal ANG II were measured. Urinary nephrin, kidney injury molecule-1 (KIM-1), renal angiopoietin-like protein 2 (ANGPTL2), and toll-like receptor 4 (TLR 4) mRNA expression were tested. DM-initiated fibrotic markers integrin, α-smooth muscle actin expression, and collagen IV and apoptotic protein caspase 3 were tested. DM induced early changes starting from week four in the tested variables. At week twelve, in both experiments, valsartan intervention showed a significant reduction in ANG II, ANGPTL2, TLR 4 and integrin expression and improvement in albuminuria, blood pressure, urinary biomarkers, fibrotic and apoptotic markers.

CONCLUSIONS

Changes leading to DN starts early in the disease course and ANG II reduction decreased the expression of ANGPTL2 and integrin which preserve the glomerular barrier. Blocking ANG II was able to decrease TLR 4 and inflammatory cytokines leading to decreasing DN.

Imbalance in the Levels of Angiogenic Factors in Patients with Acute and Chronic Central Serous Chorioretinopathy

BACKGROUND

The pathogenesis of central serous chorioretinopathy (CSC) remains a subject of intensive research. We aimed to determine correlations between plasma levels of selected angiogenic factors and different forms of CSC.

METHODS

Eighty patients were enrolled in the study including 30 with a chronic form of CSC, 30 with acute CSC, and 20 controls. Presence of active CSC was determined by fluorescein angiography (FA), indocyanine green angiography (ICGA), and swept-source optical coherence tomography (SS-OCT). Plasma concentrations of angiopoietin-1, endostatin, fibroblast growth factor, placental growth factor (PlGF), platelet-derived growth factor (PDGF-AA), thrombospondin-2, vascular endothelial growth factor (VEGF), VEGF-D, and pigment epithelium-derived factor were measured, and the results were compared between groups. Additionally, mean choroidal thickness (CT) was measured in all patients.

RESULTS

Levels of angiopoietin-1 (p = 0.008), PlGF (p = 0.045), and PDGF-AA (p = 0.033) differed significantly between the three groups. Compared with the controls, VEGF (p = 0.024), PlGF (p = 0.013), and PDGF-AA (p = 0.012) were downregulated in the whole CSC group, specifically PDGF-AA (p = 0.002) in acute CSC and angiopoietin-1 (p = 0.007) in chronic CSC. An inverse correlation between mean CT and VEGF levels was noted in CSC patients (rho = -0.27, p = 0.044).

CONCLUSIONS

Downregulated angiopoietin-1, VEGF, PDGF-AA, and PlGF levels may highlight the previously unknown role of the imbalanced levels of proangiogenic and antiangiogenic factors in the pathogenesis of CSC. Moreover, downregulated VEGF levels may suggest that choroidal neovascularization in CSC is associated with arteriogenesis rather than angiogenesis.

The Impact of Diabetes Mellitus on Cardiovascular Risk Onset in Children and Adolescents

The prevalence of diabetes mellitus is rising among children and adolescents worldwide. Cardiovascular diseases are the main cause of morbidity and mortality in diabetic patients. We review the impact of diabetes on establishing, during childhood and adolescence, the premises for cardiovascular diseases later in life. Interestingly, it seems that hyperglycemia is not the only factor that establishes an increased cardiovascular risk in adolescence. Other factors have been recognized to play a role in triggering the onset of latent cardiovascular diseases in the pediatric population. Among these cardiovascular risk factors, some are modifiable: glucose variability, hypoglycemia, obesity, insulin resistance, waist circumference, hypertension, dyslipidemia, smoking alcohol, microalbuminuria and smoking. Others are unmodifiable, such as diabetes duration and family history. Among the etiological factors, subclinical endothelial dysfunction represents one of the earliest key players of atherosclerosis and it can be detected during early ages in patients with diabetes. A better assessment of cardiovascular risk in pediatric population still represents a challenge for clinicians, and thus further efforts are required to properly identify and treat pediatric patients who may suffer from cardiovascular disease later in early adulthood.

Angiopoietin 2 and Neuropeptide Y are Associated with Diabetic Kidney Disease in Type 1 Diabetes Mellitus

BACKGROUND

Serum angiopoietin 2 levels have been associated with endothelial dysfunction and diabetic kidney disease. Derangements in autonomous nervous system lead to increased production of vasoconstrictory and angiogenic mediators such as norepinephrine and neuropeptide Y and are associated with increased risk of microvascular complications.

AIM

To investigate associations between angiopoietin 2, neuropeptide Y and diabetic kidney disease in patients with type 1 diabetes mellitus.

METHODS

289 patients with type 1 diabetes mellitus duration > 1 year were included. Patients were stratified according to presence of diabetic nephropathy (macroalbuminuria, estimated glomerular filtration rate<60 ml/min/1.73 m² or end-stage renal disease). Angiopoietin 2 was measured by Luminex technology. Neuropeptide Y was measured by ELISA.

RESULTS

Patients with diabetic nephropathy had significantly increased levels of angiopoietin 2 (4020.5 (2172.4-5778.1) pg/ml vs. 2001.0 (1326.7-2862.7) pg/ml) and neuropeptide Y (18.22 (14.85-21.85) ng/ml vs. 12.91 (9.96-17.07) ng/ml). Higher levels of angiopoietin 2 and neuropeptide Y were observed also in patients with arterial hypertension. Angiopoietin 2 and neuropeptide Y correlated significantly (ρ=0.245, p<0.001). Both biomarkers were significant predictors of estimated glomerular filtration rate and diabetic nephropathy in univariate regression models. In the fully adjusted regression models and after application of a stepwise selection regression method, angiopoietin 2 demonstrated a stronger predictive power for diabetic nephropathy compared to neuropeptide Y.

CONCLUSION

Diabetic nephropathy is associated with increased serum concentrations of angiopoietin 2 (marker of endothelial dysfunction) and neuropeptide Y (marker of sympathetic activity) in type 1 diabetes. Angiopoietin 2 is a more potent predictor of diabetic nephropathy compared to neuropeptide Y.

Osteopontin for Early Detection of Microvascular and Macrovascular Type 1 Diabetic Complication

AIM

To evaluate the relationship between osteopontin and diabetes complication in type 1 diabetic patient.

PATIENTS AND METHODS

Seventy types 1 diabetic and 60 healthy volunteers were studied. Full history, examination, laboratory tests of glycosylated haemoglobin (HbA1c), serum lipids {cholesterol, triglyceride (Tg), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein - cholesterol (LDL-c)}, oxidised low-density lipoprotein (OxLDL), Osteopontin and urinary microalbuminuria (albumin/creatinine ratio) were done. Image study in the form of a carotid intimal medial thickness (cIMT) and aortic intimal medial thickness (aIMT), renal doppler for resistivity index was also done for all participant included in the study.

RESULTS

Urinary albumin/creatinine ratio, lipid profile, osteopontin, cIMT and aIMT were higher in people with diabetes. Osteopontin was higher in people with diabetes with positive microalbuminuria and cIMT. Systolic blood pressure, microalbuminuria and cIMT had a positive correlation with osteopontin in people with diabetes. Stepwise multiple regression analysis showed that osteopontin had a significant correlation with cIMT. Receiver operating characteristic (ROC) curve showed that the cut off value of Osteopontin for detection of cIMT was > 60 with a specificity of 100% and sensitivity 80.5%, while that of albumin/creatinine ratio was > 64 with a specificity of 66.7 and sensitivity of 92.3.

CONCLUSION

Osteopontin is higher in type 1 diabetics and is useful for early detection of diabetic microvascular and macrovascular complication.

Angiopoietin-2 as a Marker of Retinopathy in Children and Adolescents With Sickle Cell Disease: Relation to Subclinical Atherosclerosis

OBJECTIVES

Angiopoietin-2 (Ang-2) is a multifaceted cytokine that functions in both angiogenesis and inflammation. A proangiogenic state has been found in adults with sickle cell disease (SCD), mainly because of elevated Ang-2 levels. We determined Ang-2 level in 40 children and adolescents with SCD compared with 40 healthy controls and assessed its relation to retinopathy as well as carotid intimamedia thickness (CIMT).

METHODS

Hematologic profile, serum ferritin, and serum Ang-2 were measured. CIMT was assessed using high-resolution ultrasound. Fundus examination was performed followed by fundus fluorescein angiography. Optical coherence tomography angiography (OCTA) was used to find small vascular changes not clinically manifested.

RESULTS

Ang-2 levels and CIMT were significantly higher in SCD patients compared with controls. The incidence of nonproliferative retinopathy was 45%. SCD patients with retinopathy were older in age with a history of sickling crisis of >3 attacks per year and had a higher incidence of sickle cell anemia than sickle β-thalassemia. Ang-2 cutoff value 9000 pg/mL could significantly detect the presence of retinopathy among SCD patients with 100% sensitivity and specificity. Serum Ang-2 levels were positively correlated with HbS and CIMT. Logistic regression analysis revealed that Ang-2 and HbS significantly contribute to retinopathy among patients with SCD.

CONCLUSIONS

Elevated Ang-2 highlights the role of angiogenesis in the pathophysiology of SCD and may be considered a promising marker for screening of patients at risk of sickle retinopathy and vascular dysfunction.

Changes in aortic pulse wave components, pulse pressure amplification, and hemodynamic parameters of children and adolescents with type 1 diabetes

BACKGROUND/OBJECTIVE

Type 1 diabetes mellitus (DM1) presents important risk factors for cardiovascular events.

OBJECTIVE

To compare the components of the aortic pulse wave (APW) and the hemodynamic parameters among children and adolescents with DM1 and healthy individuals.

METHODS

This is a cross-sectional study, with 36 children and adolescents diagnosed with DM1 (11.9 ± 3.2 years) matched by sex and age with the control group (n = 36, 12.4 ± 2.9 years). The components of the APW and the hemodynamic parameters were evaluated non-invasively, using Mobil-O-Graph.

RESULTS

On the week of the evaluation, DM1 patients presented glycated hemoglobin (hemoglobin A1C [HbA1c]) of 9.48 ± 2.22% and fasting glycemia of 222.58 ± 93.22 mg/dL. Augmentation index (AIx@75), reflection coefficient, and augmentation pressure (AP) were significantly higher in the DM1 group (29.0 ± 9.7%, 63.0 ± 7.9, and 7.8 ± 2.7 mm Hg, respectively) compared with the control group (20.6 ± 7.9%, 53.4 ± 9.1 and 4.9 ± 2.1 mm Hg, respectively). The systolic volume (52.6 ± 11.9 and 60 ± 12.4 mL) and the cardiac output (4.3 ± 0.5 and 4.6 ± 0.5 L/min) decreased in the DM1 group in relation to the control group. The pulse pressure amplification (PPA) was significantly lower in the DM1 group (1.4 ± 0.15) compared with the control group (1.6 ± 0.17). PPA correlated negatively with total vascular resistance (TVR), AP and reflection coefficient, and positively with cardiac index in both groups. In the DMI group, the AIx@75 correlated negatively with age, height, systolic volume, and PPA, and correlated positively with the TVR and reflection coefficient.

CONCLUSIONS

These results confirm the presence of arterial stiffness in this population and extend the knowledge, showing, for the first time, the reduction of PPA in the DM1 group.

Association of serum angiopoietin-2 with malnutrition, inflammation, atherosclerosis and valvular calcification syndrome and outcome in peritoneal dialysis patients: a prospective cohort study

Background

To examine serum angiopoietin-2 (Angpt-2) in relation to malnutrition, inflammation, atherosclerosis and cardiac valvular calcification, so-called MIAC syndrome and its predictive role in outcomes of peritoneal dialysis (PD) patients.

Methods

A prospective observational study was conducted in 324 chronic PD patients. Biochemical analysis was performed at baseline for serum angiopoietins, albumin and high sensitive C-reactive protein (hs-CRP) and echocardiography was done to detect cardiac valvular calcification. Primary study end points were fatal or nonfatal cardiovascular events and mortality.

Results

The median of serum Angpt-2 levels was 5.44 ng/mL (interquartile range, 3.41–7.85). Across the three tertiles of serum Angpt-2, a significant trend effect was observed for body mass index, normalized protein catabolic rate, calcium × phosphorus product, hs-CRP, brain natriuretic peptide, lower-density lipoprotein cholesterol, left ventricular ejection fraction, total weekly urea clearance and residual renal function (all p < 0.05). Serum Angpt-2 showed a significant increase across the four groups of patients with increasing components of MIAC syndrome (p < 0.001). There were 77 deaths and 57 cardiovascular events. High serum Angpt-2 was an independent predictor of fatal and nonfatal cardiovascular events in PD patients (p = 0.02), however serum Angpt-2 was not an independent predictor of all-cause mortality (p = 0.3).

Conclusions

Serum Angpt-2 showed close association with valvular calcification, atherosclerosis, inflammation and malnutrition, having significant independent prognostic value and is useful for cardiovascular event stratification in chronic PD patients. Angpt-2 might be a potential mediator of increased cardiovascular risk in patients undergoing PD treatment.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1687-0) contains supplementary material, which is available to authorized users.

Osteopontin as a marker of vasculopathy in pediatric patients with type 1 diabetes mellitus: Relation to vascular structure

BACKGROUND

Type 1 diabetes mellitus (T1DM) is associated with serious micro-vascular and macro-vascular complications. Osteopontin (OPN) has emerged as a strong predictor of incipient diabetic nephropathy and a first-ever cardiovascular event in adults with T1DM. OPN is linked to coronary atherosclerosis in type 2 diabetes. The aim of the study was to test the hypothesis that OPN could be a potential marker for micro-vascular complications in children and adolescents with T1DM and we assessed its relation to carotid and aortic intima media thickness (CIMT and AIMT) as non-invasive index for subclinical atherosclerosis.

METHODS

Eighty patients with T1DM ≤18 years were divided into 2 groups according to the presence of micro-vascular complications and compared with 40 age- and sex-matched healthy controls. Fasting blood glucose, high sensitivity C-reactive protein (hs-CRP), HbA1c, urinary albumin creatinine ratio (UACR), OPN, CIMT, and AIMT were assessed.

RESULTS

Both CIMT and AIMT were significantly higher in patients with and without micro-vascular complications compared with healthy controls (P < .001). OPN concentrations were significantly elevated in all diabetic patients compared with controls (P = .002). OPN was also significantly higher in patients with micro-vascular complications than patients without (P < .001) but levels were comparable among those without complications and controls (P = .322). Receiver operating characteristic curve analysis revealed that OPN cut-off value 90 ng/mL could differentiate patients with and without micro-vascular complications with 81.7% sensitivity and 95.8% specificity. Significant positive correlations were found between OPN and HbA1c, UACR, CIMT, and AIMT.

CONCLUSIONS

OPN could be considered a marker of vasculopathy and subclinical atherosclerosis in pediatric T1DM.

Urinary miRNA-377 and miRNA-216a as biomarkers of nephropathy and subclinical atherosclerotic risk in pediatric patients with type 1 diabetes

BACKGROUND

Urinary microRNAs (miRNAs) play a role in the pathogenesis of chronic kidney disease (CKD).

AIM

To identify the expression of urinary miR-377 and miR-216a in 50 children and adolescents with type 1 diabetes (T1DM) compared with 50 healthy controls and assess their relation to the degree of albuminuria, glycemic control and carotid intimal thickness (CIMT) as an index of atherosclerosis.

METHODS

Diabetic subjects were divided into normoalbuminuric and microalbuminuric groups according to urinary albumin creatinine ration (UACR). Urinary miRNAs were assessed using real time polymerase chain reaction. CIMT was measured using high resolution carotid ultrasound.

RESULTS

The expression of urinary miR-377 was significantly higher in patients with microalbumiuria (median, 3.8) compared with 2.65 and 0.98 in normoalbuminic patients and healthy controls, respectively (p<0.05). Urinary miR-216a was significantly lower in all patients with type 1 diabetes and the lowest levels were among the microalbumiuric group. Significant positive correlations were found between urinary miR-377 and HbA1C, UACR and CIMT while urinary miR-216a was negatively correlated to these variables.

CONCLUSIONS

Urinary miR-377 and miR-216a can be considered early biomarkers of nephropathy in pediatric type 1 diabetes. Their correlation with CIMT provides insights on the subclinical atherosclerotic process that occurs in diabetic nephropathy.

Modifiable Risk Factors for Cardiovascular Disease in Children with Type 1 Diabetes: Can Early Intervention Prevent Future Cardiovascular Events?

PURPOSE OF REVIEW

Patients with type 1 diabetes have increased risk for cardiovascular disease. The purpose of this review is to examine the following: i) current evidence for subclinical cardiovascular disease (CVD) in children with type 1 diabetes (T1DM) ii) known modifiable risk factors for CVD and their relationship to subclinical CVD in this population iii) studies that have addressed these risk factors in order to improve CVD outcomes in children with T1DM RECENT FINDINGS: Subclinical CVD presents in children as increased carotid intima-media thickness, increased arterial stiffness, and endothelial and myocardial dysfunction. Modifiable risk factors for CVD include hyperglycemia, hyperlipidemia, obesity, hypertension, depression, and autonomic dysfunction. Very few randomized controlled studies have been done in children with T1DM to examine how modification of these risk factors can affect their CVD. Children with T1DM have subclinical CVD and multiple modifiable risk factors for CVD. More research is needed to define how modification of these factors affects the progression of CVD.