Ethnic variation in lower oesophageal sphincter pressure and length

Background Oesophageal manometry (OM) is used to diagnose oesophageal motor disorders. Normal values of OM among United States ethnic groups are only available for Hispanic Americans (HA). Aim To obtain normal values of OM in adult African American (AA) volunteers, compare these with those obtained in HA and non-Hispanic white (nHw) volunteers to determine if ethnic variation in normal oesophageal motor function exists. Methods Healthy AA, HA and nHw were recruited from the Jacksonville metropolitan area. Ethnicity was self-reported. Exclusion criteria were symptoms suggestive of oesophageal disease, medication use or concurrent illness affecting OM. All underwent OM using a solid-state system with wet swallows. Resting lower oesophageal sphincter (LOS) pressure and LOS length were measured at mid-expiration, while per cent peristaltic contractions, distal oesophageal contraction velocity, amplitude and duration were measured after 5 cc water swallows. Results Fifty-six AA, 20 HA and 48 nHw were enrolled. All completed OM. AA had significantly higher resting LOS pressure, LOS length and distal oesophageal contraction duration than nHw (P < 0.05). Conclusions Significant ethnic exist in OM findings between AA and nHw. These underscore the need for ethnic specific reference values for OM to allow for correct diagnosis of oesophageal motor disorders in AA.