Do differences in female sex hormone levels contribute to gastro-oesophageal reflux disease?

BACKGROUND: Hormone replacement therapy is associated with both reflux symptoms and oesophagitis. During pregnancy, elevated sex hormones are thought to contribute to the high prevalence of reflux symptoms. Increased female sex hormone levels may thus contribute to the aetiology of gastro-oesophageal reflux disease (GORD). AIM: To determine if female sex hormone levels are associated with symptomatic acid reflux. MATERIALS AND METHODS: Women with GORD symptoms undergoing oesophageal pH monitoring were prospectively recruited. 'Cases' and 'controls' were defined by normal and excess total acid exposure on pH monitoring and were age-matched and BMI-matched. Case and control groups were further stratified into premenopausal and postmenopausal groups. Demographic data were collected, body morphological parameters were measured and oestradiol, oestrone, progesterone and sex hormone-binding globulin were measured. RESULTS: One hundred and twenty-one women [mean age 52 (SD 11.6) years] were recruited and 104 [mean age 51 (SD 11.6) years] were matched for age and BMI. Increasing BMI, as expected, correlated with increasing acid exposure [premenopausal (r=0.404, P=0.02), postmenopausal (r=0.401, P=0.01)]. Increasing BMI also correlated with sex hormone levels [premenopausal oestradiol (r=0.52, P=0.004), postmenopausal oestrone (r=0.364, P=0.01)]. In premenopausal women, sex hormone binding globulin (r=-0.27, P=0.05) and testosterone (r=0.29, P=0.05) correlated with increasing acid exposure, but oestradiol fell just short of significance (r=0.26, P=0.06). However, on matching for BMI, no association between sex hormones and increased acid exposure on pH monitoring was found on multivariate logistic regression analysis. CONCLUSIONS: Female sex hormone levels do not appear to contribute to GORD, once adjustment is made for the influence of increasing BMI.