en Gastroentrology Gastroentrology Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="color:#0000ff;"><strong><em>Background</em></strong><em>:</em> </span>The aim of this study was to evaluate the relationship between the long-term use of PPI and hypomagnesemia in patients with gastroesophageal reflux disease.<br> <span style="color:#0000ff;"><strong><em>Methods</em></strong><em>:</em></span> This case control study was conducted on GERD patients with long-term use of proton pump inhibitor and patients with no history of gastroesophageal reflux and proton pump inhibitor referring to gastrointestinal clinic in 2019. Then concentration of serum magnesium (Mg) and potassium (K) were measured using atomic absorption spectrophotometer according to protocol. Other data were extracted from medical records. Statistical tests such as t-test, chi-square test and ONE WAY ANOVA were used for analysis of data.<br> <span style="color:#0000ff;"><strong><em>Results</em></strong><em>:</em></span> In the current study, 263 patients were classified into two groups (case: 132, control: 131). The mean level of potassium in case and control groups was 3.92&plusmn;0.64 and 4.20&plusmn;0.43, respectively (P=0.001). Moreover, the mean level of Mg in two groups was 2.03&plusmn;0.36 and 2.09&plusmn;0.52, respectively (P=0.24). In addition, significant difference was seen between serum level of K, regarding the type of proton&nbsp;pump&nbsp;inhibitor&nbsp;and duration of medication use (p<0.01). However, no significant difference was seen between serum levels of Mg, regarding the type of proton&nbsp;pump&nbsp;inhibitor&nbsp;such as <em>omeprazole, </em>pantoprazole and other drugs (p>0.05).<br> <span style="color:#0000ff;"><strong><em>Conclusion</em></strong><em>:</em></span> Based on these results, long-term use of proton pump inhibitors is not associated with hypomagnesemia in GERD patients. However, long-term use of PPIs may reduce serum potassium levels in these patients. Therefore, periodic evaluation of serum Mg level in PPI-treated patients seems to be unnecessary.</span></span> Gastroesophageal reflux disease, Hypomagnesemia, Proton pump inhibitor 107 112 http://caspjim.com/browse.php?a_code=A-10-1712-1&slc_lang=en&sid=1 Abbas Arj Abbasarj2019@gmail.com 100319475328460033343 100319475328460033343 No Department of Internal medicine, School of Medicine, Shahid Beheshti Hospital, Kashan University of Medical Sciences, Kashan, Iran Zeinab Ghaletakizadeh zeinabGhaletakizadeh@gmail.com 100319475328460033344 100319475328460033344 No Department of Internal medicine, School of Medicine, Shahid Beheshti Hospital, Kashan University of Medical Sciences, Kashan, Iran Hamidreza Gilassi gilasi@kaums.ac.ir 100319475328460033345 100319475328460033345 No Department of Epidemiology and Biostatics, Health Faculty, Kashan University of Medical Sciences, Kashan, Iran Mohsen Razavizadeh mohsenrazavizadeh2019@gmail.com 100319475328460033346 100319475328460033346 Yes Department of Internal medicine, School of Medicine, Shahid Beheshti Hospital, Kashan University of Medical Sciences, Kashan, Iran