Back extensor strength and incident GERD in women receiving osteoporosis treatment: a retrospective cohort study

Introduction We investigated factors associated with incident gastroesophageal reflux disease (GERD) in women receiving osteoporosis treatment. Materials and methods This retrospective cohort study included 82 women with osteoporosis, baseline Frequency Scale for the Symptoms of GERD (FSSG) scores < 8, and an available follow-up assessment at least 4 years later. Incident questionnaire-defined GERD was defined as a final follow-up FSSG score ≥ 8 among participants with baseline scores < 8. Clinical characteristics, radiographic parameters, bone mineral density (BMD), body composition, and muscle strength were compared between groups. Separate age-adjusted logistic regression models assessed follow-up back extensor strength and percentage changes in back extensor strength and lumbar spine BMD expressed as a percentage of the young adult mean (%YAM). Results At the final follow-up assessment, 19 participants (23.2%) were classified as GERD-positive. Follow-up back extensor strength was lower in the GERD group (10.6 ± 4.5 vs 14.3 ± 5.7 kg; p = 0.011). Higher follow-up back extensor strength was associated with lower odds of incident GERD (age-adjusted odds ratio, 0.86 per 1-kg increase; 95% confidence interval, 0.76–0.98; p = 0.019). Neither percentage change was significantly associated with incident GERD. BMD increased during follow-up, and radiographic parameters did not differ significantly between groups. Conclusion Lower back extensor strength at follow-up was associated with questionnaire-defined GERD in women receiving osteoporosis treatment. Although temporal and causal relationships remain uncertain, prospective studies with strength assessments before symptom onset could clarify this association and inform future trials of back extensor strengthening.