Table 1 Studies investigating the association of leptin and rheumatoid arthritis in humans
Authors | Study design | Subjects | Results/outcomes |
|---|---|---|---|
Rho et al. (2010) [19] | Cross-sectional study evaluating correlation between HOMA-IR and serum adipokine levels. | 169 RA patients | Positive correlation between serum leptin and insulin resistance. |
Targońska-Stepniak et al. (2010) [20] | Cross-sectional study evaluating correlation between disease activity and serum adipokine levels. | 80 RA patients | Positive correlation between serum leptin and DAS28. |
Yoshino et al. (2011) [21] | Case-control study evaluating correlation between inflammation markers and serum adipokine levels. | 141 RA patients 146 controls without RA | Positive correlation between serum leptin and CRP. |
Kontunen et al. (2011) [22] | Cross-sectional study evaluating correlation between serum adipokines levels and markers of inflammation and MetS. | 54 RA patients, 20 with MetS | Increased levels of serum leptin observed only in patients with MetS. |
Olama et al. (2012) [15] | Case-control study evaluating differences between serum leptin and synovial/serum leptin ratio. | 40 RA patients 30 controls without RA | Inverse correlation between leptin concentration and protection of joints in severe RA. |
Allam e Radwan (2012) [28] | Case-control study evaluating correlation between serum leptin levels and disease activity. | 37 RA patients 34 controls without RA | No correlation between leptin levels and disease activity. |
Kang et al. (2013) [23] | Cross-sectional study evaluating correlation between adipokine levels, inflammation markers, insulin resistance and atherosclerosis. | 192 RA patients | Positive correlation between serum leptin and TNF-α and metabolic risk, including insulin resistance |
Mirfeizi et al. (2014) [30] | Cross-sectional study evaluating correlation between adipokine levels and radiographic joint damage. | 54 RA patients (29 with erosion and 25 without erosion) | No differences in serum leptin between the two groups. |
Abdalla et al. (2014) [29] | Case-control study evaluating correlation between serum leptin levels and clinical manifestations of disease activity. | 60 RA patients 30 healthy controls | No correlation between leptin levels and clinical and laboratorial markers of disease activity. |
Bustos Rivera-Bahena et al. (2015) [24] | Cross-sectional study evaluating correlation between adipokine levels and disease activity. | 121 RA patients | Positive correlation between serum leptin and disease activity. |
Xibille-Friedmann et al. (2015) [25] | Cohort study evaluating if baseline levels of adipokines may predict disease activity or response to treatment. | 127 RA patients after 6 months of follow up; 91 after 1 year of follow up; 52 after 2 years of follow up | Positive correlation between serum leptin and prevention of disease activity progression. |
Oner et al. (2015) [31] | Case-control study evaluating correlation between serum leptin levels and disease activity. | 106 RA patients 52 healthy controls 37 osteoarthritis patients | No correlation between serum leptin and disease activity. |
Lee e Bae (2016) [27] | Meta-analysis evaluating correlation between serum leptin levels and disease activity. | 13 studies: 648 RA patients 426 controls without RA | Leptin levels significantly higher in RA patients and weak positive correlation between leptin levels and disease activity. |