OBJECTIVE

To investigate the impact of obesity on the course of gastroesophageal reflux disease (GERD) using a comprehensive analysis of pH-impedance monitoring parameters in comorbid patients, and to assess the relationship between additional indicators — mean nocturnal baseline impedance (MNBI) and symptom index (SI) — and key parameters such as acid exposure time (AET) and the total number of gastroesophageal reflux episodes (GER).

MATERIALS AND METHODS

A total of 89 patients underwent esophagogastroduodenoscopy and 24-hour esophageal pH-impedance monitoring. Participants were stratified into four groups according to GERD symptoms and body mass index.

RESULTS

A statistically significant decrease in MNBI values was observed in GERD patients irrespective of body weight, as well as in obese individuals without GERD. A negative correlation was found between the total number of reflux episodes and MNBI in both normal-weight GERD patients (r=–0.29; p=0.000034) and those with obesity (r=–0.44; p=0.000029). A similar inverse relationship was identified between AET and MNBI in both groups (r=–0.31; p=0.0004 and r=–0.48; p=0.0001, respectively). Among normal-weight patients, heartburn and cough were more frequently associated with acid reflux, whereas in obese GERD patients these symptoms were predominantly linked to non-acid reflux (p=0.001).

CONCLUSION

Decreased MNBI values in patients with GERD and obesity reflect a more severe disease course. The demonstrated correlations between MNBI, AET, and the number of reflux episodes highlight the potential utility of these parameters for differentiating non-erosive from erosive forms of GERD.