Procedure and participants
Adult participants were recruited between January 2016 to January 2017. Only male included to minimize gender confounder variance, particularly considering that OSA is more common in males. Of all 128 participants, 17 (13%) declined to participate and 20 (16%) were found to be ineligible (female, with CPAP or anti-reflux treatment) leaving 91 (71%) for the present study. The study included cases with newly diagnosed OSA (confirmed by PSG). Controls were selected without OSA (confirmed by PSG). Participants from OSA were eligible for LPR if both RSI score >13 and RFS score >7. The study design has been described in Figure 1 .