Serum fetuin-A levels in obese and non-obese subjects with and without type 2 diabetes mellitus

Background: Higher fetuin-A expression is linked to both obesity and type 2 diabetes mellitus (T2DM), However, studies in non-obese patients with T2DM are scarce. Methods: 345 newly diagnosed T2DM patients and 300 subjects with normal glucose tolerance (NGT) were divided into obese and non-obese subgroups, respectively. Serum fetuin-A and adiponectin levels and related parameters were measured. Results: T2DM patients with obesity had higher fetuin-A levels compared with non-obese patients and obese NGT subjects (p < 0.001). Significant correlations were observed between fetuin-A and most metabolic parameters in obese NGT and T2DM subjects, but which was not in non-obese patients with T2DM. The independent associations were found between fetuin-A and free fatty acids, HOMA-IR, C-reactive protein and adiponectin only in obese NGT and T2DM subjects (all p < 0.05). The adjusted, odds ratios for obesity were increased with increasing quartile of fetuin-A in both T2DM and NGT subjects in logistic regression models (p for trend < 0.001), but which was more significant in T2DM patients. Conclusion: Higher serum fetuin-A levels in obese T2DM patients compared with non-obese patients and obese NGT subjects supports the hypothesis that fetuin-A may be as a bridge connecting obesity and obesity-related T2DM.