Ethnicity may be a reason for lipid changes and high Lp(a) levels in rheumatoid arthritis

Serum apolipoprotein B/apolipoprotein A1 ratio in relation to intervertebral disk herniation: a cross-sectional frequency-matched case-control study

Study design

This was a cross-sectional frequency-matched case–control study.

Background and aim

The serum lipid profile of lipoprotein(a) [Lp(a)] level and apolipoprotein B/apolipoprotein A1 ratio (Apo B/Apo A1) ratio were found to be more representative for serum lipid level and were recognized as the independent risk factors for various diseases. Although the blood levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were found to be associated with symptomatic intervertebral disk herniation (IDH), no studies to date have evaluated the association of Apo AI, Apo B, Lp(a), and Apo B/Apo AI levels with symptomatic IDH. This study aimed to assess the link between blood lipid levels and symptomatic IDH.

Method

The study included 1839 Chinese patients. Of these, 918 patients were diagnosed with IDH and enrolled in the experimental group. A control group of 921 patients underwent a physical examination during the same period. The serum lipid levels of TC, TG, LDL-C, HDL-C, Lp(a), Apo B, and Apo B/Apo AI were examined and analyzed. The control group comprised randomly selected patients who met the baseline levels of the aforementioned lipid molecules.

Results

Patients with IDH exhibited significantly higher TC, TG, LDL, Apo B, and Lp(a) levels than controls. The percentage of high TC, high TG, high LDL, high Apo B, and high Lp(a) were obviously higher in the IDH group than in the control group. However, hyperlipidemia had no relationship with the degenerated segment of the IDH (P = 0.201). The odds ratio (OR) for the incidence of IDH with elevated levels of LDL-C, TC, TG, Lp(a), Apo B, and Apo B/Apo AI was 1.583, 1.74, 1.62, 1.58, 1.49, and 1.39, respectively. The correlation analysis revealed the correlation between elevated LDL-C, TC, TG, Apo B, Lp(a), and incidence of IDH was significant (R²_LDL = 0.017; R²_TC = 0.004; R²_TG = 0.015; R²_{Apo B} = 0.004; R²_Lp(a) = 0.021) (P < 0.05).

Conclusion

This study suggested that elevated levels of serum TC, TG, LDL, Apo B, Lp(a), and Apo B/Apo AI were associated with a higher risk of IDH. This study provided useful information to identify a population that might be at risk of developing IDH based on elevated lipid levels.

Effects of 12 months of treatment with disease-modifying anti-rheumatic drugs on low and high density lipoprotein subclass distribution in patients with early rheumatoid arthritis: a pilot study

OBJECTIVES

Patients with rheumatoid arthritis (RA) have increased cardiovascular risk. The aim of the present study was the assessment of low density lipoprotein (LDL) and high density lipoprotein (HDL) subclass distribution in patients with early RA (ERA, n = 30) compared with age- and sex-matched healthy subjects (n = 30), as well the effect of treatment for 12 months with the disease-modifying anti-rheumatic drugs (DMARDs) methotrexate and prednisone in this distribution.

METHOD

LDL and HDL subclass distribution was determined using a polyacrylamide gel-tube electrophoresis method.

RESULTS

ERA patients exhibited increased levels of inflammatory markers and high disease activity score. ERA patients had higher serum levels of total cholesterol (TC), LDL cholesterol (LDL-C), and triglycerides (TG) whereas their serum HDL cholesterol (HDL-C) levels were significantly lower compared with controls. ERA patients exhibited significantly higher plasma levels of small dense LDL-C (sdLDL-C), leading to a significantly decreased mean LDL diameter. ERA patients had significantly decreased small HDL particles (HDL-3) concentration whereas serum levels of large HDL particles (HDL-2) did not differ compared with controls. Treatment with DMARDs resulted in a significant decrease in inflammatory markers and disease activity, along with a significant increase in HDL-C serum levels. The concentration of sdLDL-C did not change significantly during treatment. We observed a significant increase in the levels of large HDL-2 whereas the concentration of small HDL-3 did not significantly change.

CONCLUSIONS

Patients with ERA have increased sdLDL-C levels and decreased HDL-C levels because of decreased concentration of the small HDL-3 subclass. The administration of DMARDs induced a significant increase in HDL-C levels, which was attributed to the increase in large HDL-2 serum concentration.

A Systematic Literature Review of the Association of Lipoprotein(a) and Autoimmune Diseases and Atherosclerosis

Objective. To investigate the association of lipoprotein(a) and atherosclerosis-related autoimmune diseases, to provide information on possible pathophysiologic mechanisms, and to give recommendations for Lp(a) determination and therapeutic options. Methods. We performed a systematic review of English language citations referring to the keywords "Lp(a)" AND "autoimmune disease" AND "atherosclerosis," "Lp(a)" AND "immune system" OR "antiphospholipid (Hughes) syndrome (APS)" OR "rheumatoid arthritis" OR "Sjögren's syndrome" OR "systemic lupus erythematosus" OR "systemic sclerosis" OR "systemic vasculitis" published between 1991 and 2011 using Medline database. Results. 22 out of 65 found articles were identified as relevant. Lp(a) association was highest in rheumatoid arthritis (RA), followed by systemic lupus erythematosus (SLE), moderate in APS and lowest in systemic sclerosis (SSc). There was no association found between Lp(a) and systemic vasculitis or Sjögren's syndrome. Conclusion. Immune reactions are highly relevant in the pathophysiology of atherosclerosis, and patients with specific autoimmune diseases are at high risk for CVD. Elevated Lp(a) is an important risk factor for premature atherosclerosis and high Lp(a) levels are also associated with autoimmune diseases. Anti-Lp(a)-antibodies might be a possible explanation. Therapeutic approaches thus far include niacin, Lp(a)-apheresis, farnesoid x-receptor-agonists, and CETP-inhibitors being currently under investigation.

Native, oxidized lipoprotein(a) and lipoprotein(a) immune complex in patients with active and inactive rheumatoid arthritis: plasma concentrations and relationship to inflammation

BACKGROUND

Several studies suggest that lipoprotein (a) [Lp(a)] act as acute phase reactant and be associated with early atherosclerosis in rheumatoid arthritis (RA). Oxidized Lp(a) [ox-Lp(a)] and Lp(a) immune complex (IC) concentrations both increased in patients with coronary heart disease. We investigated Lp(a), ox-Lp(a) and Lp(a)-IC concentrations in RA patients and to explore the relationships with inflammatory disease activity markers.

METHODS

Plasma Lp(a), ox-Lp(a) and Lp(a)-IC concentrations, and inflammatory markers were analyzed in 54 patients with RA, including 23 active and 21 inactive RA, and 60 control subjects.

RESULTS

Lp(a) and ox-Lp(a) concentrations in active RA were higher than those in both inactive RA and control; Lp(a)-IC concentrations in active RA were also higher than inactive RA, while no difference was found in Lp(a), ox-Lp(a) and Lp(a)-IC concentrations between inactive RA and control. Lp(a) concentrations were found positively correlated with ox-Lp(a) and Lp(a)-IC concentrations, respectively; ox-Lp(a) concentrations were also related with Lp(a)-IC. Lp(a), ox-Lp(a) and Lp(a)-IC were all found positively related with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), respectively.

CONCLUSIONS

Native, oxidized Lp(a) and Lp(a)-IC concentrations increased in active RA patients. Inflammation may induce the changes of Lp(a), resulting in increased ox-Lp(a) and Lp(a)-IC, and may play an important role in atherosclerosis.