Results
A total of 69 patients were enrolled in the study. Demographic
parameters and baseline reflux symptoms are summarized in Table
1 . The male-to-female ratio was 25/43. The mean value of Age, BMI, and
RSI were 55.93 ± 13.02, 24.8 ± 2.71, and 12.28 ± 6.19. The most severe
reflux symptom was globus, with a mean value of 3.77 ± 1.7.
The 24hr MII-pH monitoring revealed the characteristics of pharyngeal
reflux patterns. Table 2 shows the properties of pharyngeal
reflux depending on acidity, event time, and body position. The number
of weakly acidic pharyngeal reflux was high (3.41 ± 3.27), while acidic
and weakly alkaline reflux were 0.93 ± 2.34 and 0.55 ± 1.02,
respectively. The hourly incidence of daytime reflux, 0.229 ± 0.282, was
statistically more frequent than that of nighttime reflux (0.097 ± 0.13;
p < 0.001). The reason for using hourly incidence, and not the
total number of reflux, is for even statistical comparison over the same
observation time. In the analysis according to body position, the hourly
incidence of pharyngeal reflux was statistically higher in the upright
position (0.327 ± 0.339) than during the recumbent position (0.064 ±
0.117; p < 0.001).
We sought to evaluate the relationship between reflux episodes and
mealtimes. The common mealtimes of enrolled patients were concentrated
at 9:00–10:00 and 16:00–18:00 out of 24 hours (Figure 1A ).
The high incidence of pharyngeal reflux was recorded at 10:00–11:00 and
19:00–20:00 out of 24 h (Figure 1B ). We found that the
incidence of pharyngeal reflux increased after mealtime (Figure
1C ). Therefore, we compared the number of pharyngeal reflux episodes
for 2 h before and after mealtime (Table 3 , Figure 2 ).Table 3 shows the comparison between pre- and post-prandial
pharyngeal reflux frequency within 2 h around mealtime. All
post-prandial reflux episodes (1.256 ± 0.878) were statistically more
frequent than all pre-prandial reflux episodes (0.632 ± 0.548, p
< 0.001). In classification according to acidity, the number
of weakly acidic post-prandial reflux (0.853 ± 0.665) was significantly
higher than that of pre-prandial weakly acidic reflux (0.433 ± 0.447, p
< 0.001). The numbers of post-prandial acid reflux and
pre-prandial acid reflux were 0.212 ± 0.420 and 0.134 ± 0.375,
respectively (p = 0.11). The numbers of post-prandial weakly alkaline
reflux and pre-prandial weakly alkaline reflux were 0.191 ± 0.390 and
0.065 ± 0.180 (p = 0.012), respectively. Figure 2 shows the
frequency of pharyngeal reflux for all participants based on the center
zero, which represented the mealtime. The number of post-prandial
pharyngeal reflux was relatively larger than that of pre-prandial
pharyngeal reflux.
Twenty-six patients were recruited as a normal control group, and
pharyngeal reflux episodes were found in 5 patients on 24hr-MII-pH
monitoring. The mean number of pharyngeal reflux episodes in the 5
patients was 1.4 times. Table 4 reveals whether there was a
difference in the timing of post-prandial pharyngeal reflux between
normal controls and LPR patients. Analyzing the time relationship
between mealtime and pharyngeal reflux episodes, the timing of
post-prandial reflux was 58.2 ± 61.8 minutes in the LPR patient group
and 38.4 ± 34.2 minutes in the normal control group, with no statistical
difference (p = 0.322).