Hyperhomocysteinemia is associated with decreased apolipoprotein AI levels in normal healthy people

Differential effects of hyperhomocysteinemia on the lipid profiles and lipid ratios between patients with and without coronary artery disease: A retrospective observational study

This study aimed to investigate the differential effects of hyperhomocysteinemia (HHcy) on lipid profiles and lipid ratios between patients with coronary artery disease (CAD) and without CAD. The data of 872 CAD patients and 774 non-CAD controls were extracted from the information system of hospitalized patients. Serum homocysteine (Hcy), total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI, and ApoB concentrations were detected. HHcy was defined as a serum level of Hcy ≥ 15 μmol/L. The CAD patients had lower levels of HDL-C and ApoAI and higher levels of Hcy than the controls (P < .05). Serum TGs and HDL-C were negatively correlated with Hcy in controls. Serum HDL-C and ApoAI were negatively correlated with Hcy, and the ratios of TC/HDL-C, TG/HDL-C, LDL/HDL-C, and ApoB/ApoAI were positively correlated with Hcy in the CAD patients (P < .05). Although the trends for HHcy to decrease the lipid profiles were not different between the CAD and controls (Pinteraction > 0.05), CAD with HHcy had lower HDL-C and ApoAI levels than those of subjects with normal Hcy; controls with HHcy had lower TC, LDL-C, and ApoB levels than those of subjects with normal Hcy (P < .05). There were different HHcy trends affecting the ratios of TC/HDL-C and LDL/HDL-C between the CAD patients and controls (Pinteraction for TC/HDL-C = 0.025; Pinteraction for LDL/HDL-C = 0.033). CAD patients with HHcy had a higher ratio of TC/HDL-C (P = .022) and LDL/HDL-C (P = .045) than those of patients with normal Hcy, but in the controls, the subjects with HHcy exhibited a trend toward a decreased ratio of TC/HDL-C (P = .481) and LDL/HDL-C (P = .303). There were differential effects of HHcy on the lipid ratios between CAD and non-CAD patients. HHcy was related to higher ratios of TC/HDL-C and LDL/HDL-C in patients with CAD.

Negative Correlation Between Serum Levels of Homocysteine and Apolipoprotein M

BACKGROUND

Homocysteine (Hcy) has been suggested as an independent risk factor for atherosclerosis. Apolipoprotein M (apoM) is a constituent of the HDL particles. The goal of this study was to examine the serum levels of homocysteine and apoM and to determine whether homocysteine influences apoM synthesis.

METHODS

Serum levels of apoM and Hcy in 17 hyperhomocysteinemia (HHcy) patients and 19 controls were measured and their correlations were analyzed. Different concentrations of homocysteine (Hcy) and LY294002, a specific phosphoinositide 3- kinase (PI3K) inhibitor, were used to treat HepG2 cells. The mRNA levels were determined by RT-PCR and the apoM protein mass was measured by western blot.

RESULTS

We found that decreased serum apoM levels corresponded with serum HDL levels in HHcy patients, while the serum apoM levels showed a statistically significant negative correlation with the serum Hcy levels. Moreover, apoM mRNA and protein levels were significantly decreased after the administration of Hcy in HepG2 cells, and this effect could be abolished by addition of LY294002.

CONCLUSIONS

Present study demonstrates that Hcy downregulates the expression of apoM by mechanisms involving the PI3K signal pathway.

Changes in Homocysteine Levels Affect Serum Lipid Response to Atorvastatin in Patients With Acute Coronary Syndrome: A Retrospective Observational Study

OBJECTIVE

The present study investigated whether changes in serum homocysteine (Hcy) levels modify the effects of atorvastatin treatment on blood lipid parameters in patients with acute coronary syndrome (ACS).

METHODS

A total of 159 patients with ACS who received regular, long-term treatment with 20 mg/d atorvastatin were included. Depending on the changes in Hcy parameters, they were divided into Hcy reduction (HR) and Hcy elevation (HE) groups.

RESULTS

After long-term atorvastatin treatment, total cholesterol (TC), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) B, and Hcy levels were decreased (P < .05), and the ApoAI level was increased (P < .01). Correlation and stratified analysis showed that Hcy or hyperhomocysteinemia was correlated with blood lipids. In both the HE and HR groups, the TC, LDL-C, and ApoB levels after treatment were lower than those before treatment (P < .01), and the ApoAI level was increased compared with that before treatment (P < .05). There was no difference in the reduction of TC, LDL-C, and ApoB levels or in the increase of ApoAI level (P _interaction > .05) between the 2 groups. However, there was a clear opposite trend of the effect of atorvastatin on TG and high-density lipoprotein cholesterol (HDL-C) levels between the HR and HE groups (P _interaction < .05). In the HR group, the HDL-C level was increased (P < .05), and TGs were decreased compared with those before treatment (P < .01). Nevertheless, in the HE group, the HDL-C level was decreased (P < .05), and TGs (P < .05) were increased compared with those before treatment.

CONCLUSION

The effects of atorvastatin on TGs and HDL-C depend on changes in Hcy levels. Patients with a reduced Hcy level after atorvastatin treatment had more favorable lipid parameters.