Elevated serum sortilin is related to carotid plaque concomitant with calcification

Serum sortilin as a predictor of stroke in patients with intermediate carotid artery stenosis

BACKGROUND

Sortilin was an important molecular protein involved in the pathogenesis of atherosclerosis. Besides, serum sortilin was associated with adverse cerebrovascular events. Atherosclerotic stenosis in the carotid artery is a major etiology for ischemic stroke. The risk of stroke in patients with intermediate carotid artery stenosis (CAS) was unknown. Hence, the aim of the present study was to evaluate the relationship between serum sortilin levels and stroke in patients with intermediate CAS.

METHODS

A total of 195 intermediate CAS patients were included in this cross-sectional study. The patients were divided into two groups as symptomatic (N = 95) and asymptomatic (N = 100) patients. Patients with a transient ischemic attack (TIA), retinal ischemic event, or ischemic stroke resulting from the narrowed carotid artery were considered to be symptomatic. Serum sortilin concentrations were measured using the enzyme-linked immunosorbent assay.

RESULTS

Serum sortilin level was significantly higher in the symptomatic group than in the severe asymptomatic group (1.53 ± 0.25 ng/mL vs 1.34 ± 0.19 ng/mL, p < 0.001). Besides, high serum sortilin levels (odds ratio = 4.91, 95% confidence intervals 1.24-19.51, p = 0.023) were identified as independent predictors of symptomatic carotid plaque. In the receiver operating characteristic curve analysis, serum sortilin levels higher than 1.34 ng/mL predicted stroke/TIA with a sensitivity of 66.3% and a specificity of 67% (AUC = 0.725, p < 0.001).

CONCLUSIONS

Serum sortilin level is increased in the presence of symptomatic intermediate CAS and may have clinical value in the management of patients with carotid artery disease.

Sortilin and hypertension

PURPOSE OF REVIEW

The current review aims to present the latest scientific updates on the role of Sortilin in the pathophysiology of hypertension.

RECENT FINDINGS

The main focus of this systematic overview is on the functional contribution of Sortilin to the pathogenesis of hypertension. Sortilin is a glycoprotein mostly known for its actions as a trafficking molecule directing proteins to specific secretory or endocytic compartments of the cell. Emerging evidence indicates that Sortilin is associated with pathological conditions, including inflammation, arteriosclerosis, dyslipidemia, insulin resistance, and vascular calcification. Most recently, Sortilin has been shown to finely control endothelial function and to drive hypertension by modulating sphingolipid/ceramide homeostasis and by triggering oxidative stress.

SUMMARY

The latest findings linking Sortilin and hypertension that are herein discussed can inspire novel areas of research which could eventually lead to the discovery of new therapeutic strategies in cardiovascular medicine.

The association of plasma sortilin with essential hypertension and subclinical carotid atherosclerosis: A cross-sectional study

Background

Sortilin, a protein that regulates glucose and lipid metabolism, has recently been linked to cardiovascular diseases (CVDs) such as coronary heart disease and carotid artery stenosis. In this study, we measured circulating sortilin concentrations in essential hypertensive (EH) patients, and evaluated the association between sortilin, hypertension, and subclinical carotid atherosclerosis in hypertensive individuals.

Methods

This cross-sectional study included 336 individuals, including 186 newly diagnosed EH patients and 150 age-and-sex-matched normotensive healthy subjects (NT). Plasma sortilin and adiponectin (ADI) levels were measured using ELISA kits. In the EH group, high-resolution B-mode ultrasound was used to detect the existence of subclinical carotid atherosclerosis (subAS), which was defined as having a carotid intima–media thickness (cIMT) ≥ 1.0 mm and/or plaque on the carotid artery without any clinical manifestations.

Results

Our findings showed that plasma sortilin concentrations ranged from 3.34–11.34 ng/ml for all subjects. Sortilin levels were significantly higher in the EH group than in the NT group (8.10 ± 1.82 ng/ml vs. 6.37 ± 1.52 ng/ml, P < 0.001) and were further upregulated in the EH with subclinical carotid atherosclerosis (EH + subAS) group compared to the EH without subclinical carotid atherosclerosis (EH-subAS) group (8.42 ± 1.75 ng/ml vs. 7.79 ± 1.84 ng/ml, P < 0.05). In correlation analysis, sortilin was positively correlated with systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), white blood cell (WBC), endothelin-1 (ET-1), high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and cIMT (all P < 0.05) and negatively associated with NO and ADI (P < 0.001). Multiple linear regression analysis revealed that SBP, LDL-C, and ET-1 were independently associated with plasma sortilin levels. Increased sortilin levels were independently associated with the risk of EH (OR: 1.86, 95%CI: 1.56–2.20, P < 0.001) and EH + subAS (OR: 1.33, 95%CI: 1.07–1.66, P = 0.011), after adjustment for multiple risk factors. Restricted spline curve showed that elevated sortilin levels increase the odds of having EH.

Conclusion

Elevated sortilin levels are associated with an increased risk of essential hypertension and subclinical carotid atherosclerosis in hypertensive patients.

Correlation between serum sortilin levels and severity of extracranial carotid artery stenosis

OBJECTIVE

Atherosclerosis is a chronic inflammatory vascular condition characterised by intimal thickening with cholesterol accumulation and macrophage foam cell infiltration causing plaque formation at the site of the injured vessel wall. This condition is a major contributor to carotid artery stenosis (CAS). Sortilin, a member of the mammalian vacuolar protein sorting 10 protein family, promotes uptake of low-density lipoprotein particles into macrophages with consequent foam cell formation independent of the low-density lipoprotein receptor, and thereby, accelerates atherosclerotic plaque formation and progression. We investigated the correlation between serum sortilin levels and the severity of extracranial CAS.

MATERIALS AND METHODS

The study included 149 patients who underwent carotid angiography for suspected carotid artery disease. The North American Symptomatic Carotid Endarterectomy Trial 2011 criteria were used to determine the degree of CAS. Serum sortilin concentrations were measured using the enzyme-linked immunosorbent assay.

RESULTS

Serum sortilin levels were significantly higher in the severe CAS than in the non-severe CAS group (2.71 ± 0.71 ng/mL vs 1.63 ± 0.57 ng/mL, P < .001). Receiver operating characteristic curve analysis showed that serum sortilin levels >1.66 ng/mL predicted severe CAS with sensitivity of 83.49% and specificity of 56.76%.

CONCLUSION

Current data suggest that prediction of severe CAS may serve as an atherosclerosis biomarker and significantly contribute to research on disease progression in atherosclerosis, as well as in other arterial diseases. Sortilin may be a potential therapeutic target owing to its role in the pathogenesis of atherosclerotic carotid artery disease.