Menstrual cycle factors related to increased gastric contractile response to tube feeding

Evidence exists that the ovarian hormones have a modulating effect on gastrointestinal (GI) motility, yet details are sketchy and little attention has been paid to the effect that fluctuating hormone levels might have on women who are receiving enteral feedings. This study compared gastric motility indices in response to tube feedings at two points in the menstrual cycle, concurrently measured ovarian hormone levels, and described three potentially related factors (ie, GI symptoms, uterine cramping pain, reports of daily stressors). Intragastric motility responses to enteral feedings were obtained on 28 women (aged 19-37) during menses and midfollicular phases of two menstrual cycles. Intragastric pressure changes were monitored by an open-tipped cannula method at rest, during and after tube feeding (Ensure, 240 ml at 8 ml/min). Serum estradiol and progesterone levels were measured by radioimmunoassay. Women completed a daily diary of symptoms and stressors throughout the two menstrual cycles. Results showed that intragastric pressure amplitudes and frequencies were higher at menses compared with midfollicular recordings. At menses, prefeeding and feeding gastric pressure amplitudes were positively correlated with uterine cramping pain and GI symptoms (ie, nausea). At menses, postfeeding contraction frequencies were also correlated with uterine cramping pain. At midfollicular phase, progesterone levels correlated with gastric motility indices; number of stressors indirectly correlated with gastric motility indices. These data suggest that gastric responses to enteral feeding are influenced by menstrual cycle phase.