The inflammatory biomarker YKL-40 decreases stepwise after exercise stress test

Serum YKL-40 in coronary heart disease: linkage with inflammatory cytokines, artery stenosis, and optimal cut-off value for estimating major adverse cardiovascular events

Objective

YKL-40, previously known as chitinase-3-like protein 1 (CHI3L1), is an inflammation-related glycoprotein that promotes atherosclerosis, but its application and optimal cut-off value as a prognostic biomarker in coronary heart disease (CHD) require more clinical evidence. Thus, this prospective study aimed to evaluate the linkage of serum YKL-40 with disease features, inflammatory cytokines, and major adverse cardiovascular events (MACEs) in CHD patients.

Methods

A total of 410 CHD patients were enrolled for serum YKL-40 determination via enzyme-linked immunosorbent assay. Meanwhile, serum YKL-40 levels in 100 healthy controls (HCs) were also quantified.

Results

YKL-40 level was higher in CHD patients compared with that in HCs (P < 0.001). YKL-40 was positively linked with hyperlipidemia (P = 0.014), diabetes mellitus (P = 0.001), fasting blood glucose (P = 0.045), C-reactive protein (P < 0.001), the Gensini score (P < 0.001), and stenosis degree (graded by the Gensini score) (P < 0.001) in CHD patients. In addition, an elevated YKL-40 level was associated with increased levels of tumor necrosis factor alpha (P = 0.001), interleukin (IL)-1β (P = 0.001), IL-6 (P < 0.001), and IL-17A (P = 0.002) in CHD patients. The 1-/2-/3-year cumulative MACE rates of CHD patients were 5.5%, 14.4%, and 25.0%, respectively. Regarding the prognostic capability, YKL-40 ≥100 ng/ml (the median cut-off value) (P = 0.003) and YKL-40 ≥150 ng/ml (the third interquartile cut-off value) (P = 0.021) reflected an elevated accumulating MACE rate, whereas accumulating MACE was not different between CHD patients with YKL-40 ≥80 and <80 ng/ml (the first interquartile cut-off value) (P = 0.083).

Conclusion

Serum YKL-40 is positively linked with inflammatory cytokines and the Gensini score, whose high expression cut-off by 100 and 150 ng/ml estimates a higher MACE risk in CHD patients.

The benefit of exercise rehabilitation guided by 6-minute walk test on lipoprotein-associated phospholipase A2 in patients with coronary heart disease undergoing percutaneous coronary intervention: a prospective randomized controlled study

Background

Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been taken as a biomarker of inflammation in patients with acute coronary diseases. Regular exercise rehabilitation could attenuate inflammation and promote the rehabilitation of coronary heart disease (CHD). The level of Lp-PLA2 is negatively correlated with 6-min walk test (6-MWT). The exercise prescription of appropriate intensity is the basis of exercise rehabilitation. 6-MWT is associated with maximal oxygen consumption, and can be used to determine the intensity of exercise prescription guiding patients how to do exercise rehabilitation. The aim of this study was to observe the benefit of 6-MWT guided exercise rehabilitation on the level of Lp-PLA2 in patients with CHD undergoing percutaneous coronary intervention (PCI).

Methods

We prospectively, consecutively enrolled 100 patients between Dec 2018 and Dec 2020 in the fourth ward of the Department of Cardiology, Yuebei People's Hospital Affiliated to Shantou University. Eligible patients were 1:1 divided into Group A, with no exercise rehabilitation, and Group B, with regular exercise rehabilitation, using random number table method of simple randomization allocation. Clinical data such as general information, the profile of lipids and the level of Lp-PLA2 were collected at baseline and at 12-week follow-up.

Results

There were no statistically significant differences of the percentages of gender, hypertension, type-2 diabetes mellitus (T2DM), the profile of lipids and level of Lp-PLA2 between the groups at baseline (P > 0.05). The level of Lp-PLA2 decreased at 12-week follow-up, moreover, the decline of the Lp-PLA2 level in Group B was more significant than that in Group A (t = 2.875, P = 0.005). Multivariate linear regression analysis indicated that exercise rehabilitation was independently correlated with the level of Lp-PLA2 (β′ = − 0.258, t = − 2.542, P = 0.013).

Conclusion

Exercise rehabilitation for 12 weeks guided by 6-MWT can further reduce the level of LP-PLA2 in patients with CHD undergoing PCI.

Trial registration This trial was registered on the Chinese Clinical Trial Registry: ChiCTR2100048124, registered 3 July 2021- Retrospectively registered. The study protocol adheres to the CONSORT guidelines.

An association between YKL-40 and type 2 diabetes in psychotic disorders

OBJECTIVE

This study examines if YKL-40 is increased in individuals with psychotic disorders and if elevated YKL-40 levels at baseline is associated with subsequent development of type 2 diabetes.

METHOD

A total of 1383 patients with a diagnosis of schizophrenia or affective psychosis and 799 healthy controls were recruited in the period 2002-2015. Plasma YKL-40 and metabolic risk factors were measured and medication was recorded. Using national registry data, association between baseline risk factors and later development of type 2 diabetes was assessed using Cox proportional hazards models.

RESULTS

Plasma YKL-40 was higher in patients vs. healthy controls also after adjusting for metabolic risk factors, with no difference between the schizophrenia and affective psychosis groups. Patients were diagnosed with type 2 diabetes at a significantly younger age. Multivariate Cox regression analyses showed that elevated YKL-40 (hazard ratio (HR) = 5.6, P = 0.001), elevated glucose (HR = 3.6, P = 0.001), and schizophrenia diagnosis (HR = 3.0, P = 0.014) at baseline were associated with subsequent development of type 2 diabetes.

CONCLUSIONS

Patients with psychotic disorders have at baseline increased levels of YKL-40 beyond the effect of comorbid type 2 diabetes and metabolic risk factors. Elevated YKL-40 level at baseline is associated with later development of type 2 diabetes.

Amelioration of atherosclerosis in apolipoprotein E-deficient mice by combined RNA interference of lipoprotein-associated phospholipase A2 and YKL-40

To test the hypothesis that combined RNA interference (RNAi) of lipoprotein-associated phospholipase A₂ (Lp-PLA₂) and YKL-40 is superior to RNAi of Lp-PLA₂ or YKL-40 alone in ameliorating atherosclerosis. A total of 120 apolipoprotein E-deficient mice (apoE^-/- mice) were randomly divided into five groups, including the vehicle alone, scrambled RNAi, Lp-PLA₂ RNAi, YKL-40 RNAi, and combined Lp-PLA₂ and YKL-40 RNAi groups. Constrictive collars were used to induce plaque formation. Lp-PLA₂ RNAi and YKL-40 RNAi viral suspensions were transduced into carotid plaques of the mice. Carotid plaques were harvested for histological analysis four weeks after viral vector transduction. Inflammatory gene expression in the plasma and atherosclerotic plaques was determined by ELISA and real-time PCR. Four weeks after RNAi, the serum concentration and plaque mRNA expression of Lp-PLA₂ and YKL-40 were remarkably attenuated, leading to reduced inflammatory gene expression. Plaques from the Lp-PLA₂ or YKL-40 RNAi group showed lower lipid content, higher collagen content, increased fibrous cap thickness, and lower mRNA expressions of MCP-1 and MMP-8 than than those in the vehicle and scramble groups. When compared with the isolated Lp-PLA₂ or YKL-40 RNAi group, the combined Lp-PLA₂ and YKL-40 RNAi group exhibited higher collagen content and fibrous cap thickness, and lower lipid content and local inflammation. The beneficial effects of RNAi were independent of the plasma lipoprotein profile. Combined RNAi of Lp-PLA₂ and YKL-40 is superior to RNAi of Lp-PLA₂ or YKL-40 alone in ameliorating atherosclerosis.