Accurate positioning of the 24-hour pH monitoring catheter: Agreement between manometry and pH step-up method in two patient positions

Table 1 Comparative results of GERD and non-GERD groups

Variables (mean ± SD)	GERD group	Non-GERD group
n (male/female)	11 (6/5)	7 (4/3)
Age (yr)	48 (26-68)	43 (22-61)
LES length (cm)	3.27 ± 0.9	2.86 ± 0.7
LES resting pressure, mmHg	10.82 ± 2.6	18.43 ± 4.0a
Distance: nose to the PB-LES, cm (by manometry)	42 ± 3.8	41.7 ± 3.5
Distance: nose to the PB-LES, cm (by pH step-up in upright position)	44.7 ± 2.6	43.8 ± 3.5
Distance: nose to the PB-LES, cm (by pH step-up in supine position)	43.4 ± 3.0	42.1 ± 3.3
Clear detection of receptive relaxation of the LES (n)	9/11	7/7

^aP < 0.05 vs GERD group (Mann-Whitney-U test). LES: Lower esophageal sphincter; PB-LES: Proximal border of the LES.