Central adiposity is associated with increased risk of esophageal inflammation, metaplasia, and adenocarcinoma: a systematic review and meta-analysis

Abstract

Background & aims: Central adiposity has been implicated as a risk factor for Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC), possibly promoting the progression from inflammation to metaplasia and neoplasia. We performed a systematic review and meta-analysis of studies to evaluate the association between central adiposity and erosive esophagitis (EE), BE, and EAC, specifically exploring body mass index (BMI)-independent and gastroesophageal reflux (GERD)-independent effects of central adiposity on the risk of these outcomes.

Methods: We performed a systematic search of multiple databases through March 2013. Studies were included if they reported effect of central adiposity (visceral adipose tissue area, waist-hip ratio, and/or waist circumference) on the risk of EE, BE, and EAC. Summary adjusted odds ratio (aOR) estimates with 95% confidence intervals (CIs), comparing highest category of adiposity with the lowest category of adiposity, were calculated by using random-effects model.

Results: Forty relevant articles were identified. Compared with patients with normal body habitus, patients with central adiposity had a higher risk of EE (19 studies; aOR, 1.87; 95% CI, 1.51-2.31) and BE (17 studies; aOR, 1.98; 95% CI, 1.52-2.57). The association between central adiposity and BE persisted after adjusting for BMI (5 studies; aOR, 1.88; 95% CI, 1.20-2.95). Reflux-independent association of central adiposity and BE was observed in studies that used GERD patients as controls or adjusted for GERD symptoms (11 studies; aOR, 2.04; 95% CI, 1.44-2.90). In 6 studies, central adiposity was associated with higher risk of EAC (aOR, 2.51; 95% CI, 1.54-4.06), compared with normal body habitus.

Conclusions: On the basis of a meta-analysis, central adiposity, independent of BMI, is associated with esophageal inflammation (EE), metaplasia (BE), and neoplasia (EAC). Its effects are mediated by reflux-dependent and reflux-independent mechanisms.

Keywords: BE; BMI; Barrett's Esophagus; Barrett's esophagus; Body Habitus; CI; CT; EAC; EE; Esophageal Cancer; GERD; OR; RR; Visceral Fat; WC; WHR; aOR; adjusted odds ratio; body mass index; computed tomography; confidence interval; erosive esophagitis; esophageal adenocarcinoma; gastroesophageal reflux disease; odds ratio; relative risk; waist circumference; waist-hip ratio.

Figure 1

Flowchart showing study identification and selection process.

Figure 2

Central adiposity, overall obesity (BMI), and risk of (A) EE, (B) BE, and (C) EAC. This represents the overall pooled OR by combining categorical OR (for highest category, compared with lowest referent category) with estimated OR from continuous variables.