The impacts of thiazolidinediones on circulating C-reactive protein levels in different diseases: a meta-analysis.

OBJECTIVES: Thiazolidinediones (TZDs), including rosiglitazone and pioglitazone, are widely used as antidiabetic agents. Here we present an updated meta-analysis of the respective effects of rosiglitazone and pioglitazone on the levels of C-reactive protein (CRP), a biomarker and predictor of CAD risks. METHODS AND RESULTS: PubMed and EMBASE were systematically searched using the terms "C-reactive protein" and "rosiglitazone" or "pioglitazone" or "thiazolidinedione". A total of 59 rosiglitazone studies and 36 pioglitazone studies were included for evaluation. These were classified as 2-group studies and 1-group studies according to their study design. Standard mean difference (SMD) of CRP and 95% CI were calculated to evaluate the effect of TZDs on CRP. The overall SMD for rosiglitazone treatment is -0.392 (95% CI, [-0.446, -0.338]) in 2-group studies and -0.424 (95% CI, [-0.501, -0.346]) in 1-group studies. The overall SMD for pioglitazone treatment is -0.577 (95% CI, [-0.732, -0.421]) in 2-group studies and -0.327 (95% CI, [-0.439, -0.216]) in 1-group studies. Moreover, TZDs were found to significantly reduce CRP levels in both diabetes mellitus (DM) and non-DM patients. CONCLUSIONS: Our meta-analysis suggested that both rosiglitazone and pioglitazone significantly decrease serum CRP levels. TZDs presented their CRP-lowering effect in both DM and non-DM patients.

Association between serum amyloid A and obesity: a meta-analysis and systematic review.

BACKGROUND: Emerging evidence indicates an association of the acute-phase protein serum amyloid A (SAA) with obesity. Here we review and summarize quantitatively the available data related to this association. METHODS: PubMed was systematically searched using the terms "serum amyloid A" and "obesity." Eighty-one relevant studies between January 1966 and July 2009 were identified. Of these, only 11 cross-sectional studies and 10 prospective studies with successful interventions met our inclusion criteria for the meta-analysis. All analyses were conducted using the Comprehensive Meta-Analysis software. Literature pertaining to the relationship between SAA and other inflammatory markers, and the association between SAA and obesity-related disorders, such as cardiovascular diseases, atherosclerosis, diabetes, and insulin resistance was also reviewed. RESULTS: A strong association between body mass index and SAA levels was found in the 11 cross-sectional studies. The overall correlation coefficient is 0.230 (95% CI 0.160-0.297, P < 0.0005). The ten prospective studies were subsequently analyzed, and the difference in SAA levels before and after weight loss, expressed as standardized mean difference was -0.480 (95% CI -0.678 to -0.283, P < 0.0005). We discuss some potential underlying mechanisms and clinical applications for reducing SAA levels in obesity.