Serum levels of leptin as marker for patients at high risk of gastric cancer
Background: Serological screening for gastric cancer (GC) may reduce mortality. However, optimal serum markers for advanced gastric precursor lesions are lacking. Aim: To evaluate in a case-control study whether serum leptin levels correlate with intestinal metaplasia (IM) and can serve as a tool to identify patients at high risk for GC. Materials and Methods: Cases were patients with a previous diagnosis of IM or dysplasia, controls were patients without such a diagnosis. All patients underwent endoscopy. Fasting serum was collected for the measurement of leptin, pepsinogens I/II, gastrin, and Helicobacter pylori. Receiver operating characteristic (ROC) curves and their area under the curve (AUC) were provided to compare serum leptin levels with other serological markers. Results: One hundred nineteen cases and 98 controls were included. In cases, the median leptin levels were 116.6 pg/mL versus 81.9 pg/mL in controls (p =.01). After adjustment for age, sex and BMI, leptin levels remained higher in cases than in controls (p <.005). In multivariate analysis, male sex (p =.002), age (<0.001), low pepsinogen levels (p =.004) and high leptin levels (p =.04) were independent markers for the presence of IM. In addition, a ROC curve including age, sex and pepsinogen I levels had an AUC of 0.79 (95% CI (0.73-0.85)). Adding serum leptin levels increased the AUC to 0.81 (95% CI (0.75-0.86)). Conclusions: High leptin levels are associated with an increased risk of IM. Moreover, serum leptin levels are a significant independent marker for the presence of IM. However, in combination with the serological test for pepsinogen I the additional value of serum leptin levels is rather limited.