Table 1 Studies investigating a link between hyperhomocysteinemia and cardiovascular diseases in rheumatoid arthritis patients

Berglund et al., 2009, Sweden [10]

235 RA patients; 68 males (52 ± 16 years)^a and 166 females (46 ± 16 years)^a

Prospective cohort study

Atherothrombotic events

HHcy levels adjusted for age and sex were a significant predictor of atherothrombotic events (OR = 1.96, 95 % CI 0.99–3.50, p = 0.05).

When adjusted for hypertension alongside age and sex, The predictive value of HHcy was reduced (OR = 1.84, 95 % CI 0.92–3.69, p = 0.084] for hypertension and OR = 1.80, 95 % CI 0.90–3.59, p = 0.096 for diabetes mellitus).

Anan et al., 2009, Japan [40]

25 RA women with WML (61 ± 6 years)^a and and 40 RA women without WML (60 ± 7 years)^a

Case–control study

WML

HHcy independently predicted WML (OR 1.35, 95 % CI: 1.12-1.63, p < 0.0001).

Adjusted for the duration of RA, triglyceride, HDL, FPG

Dala et al., 2012, Egypt [41]

180 RA patients with no history of IHD

Cross-sectional study

SIHD

Serum Hcy was significantly higher in patients with SIHD as compared to those without (p < 0.001)

Chung et al., 2005, USA [42]

141 patients with RA (median age 54, IQR 46–64), 68 % of females; and 86 controls without RA (median age 52, IQR 44–59), 65.1 % of females

Case–control study

Coronary-artery atherosclerosis (calcification)

In unadjusted comparisons, HHcy was more common in RA patients with coronary-artery calcification than in those without.

After adjusting for age and sex, the association was no more significant

Cisternas et al., 2002, Chili [43]

54 RA patients (51 ± 13 years)^a; and 32 age and sex matched healthy controls

Case–control study

History of CVD

There were higher Hcy plasma levels in RA patients with a history of CVD than in those without.

Seriolo et al., 2001, Italy [21]

168 female RA women with WML (cases), 50 ± 10 years^a; and 72 age and sex matched healthy controls (52 ± 9 years)^a.

Case–control study.

History of thrombotic events

Plasma levels of hcy in aPL antibody-positive patients with thrombosis were found to be significantly higher than in aPL antibody-negative RA patients without thrombosis (p < 0.001)

Adjusted for the duration of RA, triglyceride, HDL-Cholesterol, fasting plasma glucose