Maternal obesity surgery : effects in women, spouses and offspring

Sammanfattning: Introduction: Bariatric surgery is an important treatment for the worldwide increasing epidemic of obesity. However, the effects of such surgery on offspring epigenetic profile and effects on objectively measured physical activity and sedentary behavior in women undergoing bariatric surgery and family members are essentially unknown. Aim: The aim of this thesis was to investigate possible effects of maternal weight loss after bariatric surgery and effects on differences in maternal gestational weight gain in repeated pregnancies of the same women on sibling body size in childhood, epigenetic profile and physical activity among siblings and spouses. Methods: Longitudinal studies with repeated objective measures in the same women, spouses and offspring before and after maternal bariatric surgery. Results: There were positive associations, in women undergoing bariatric surgery (n = 124), between differences in total and second trimester gestational weight gain and differences in offspring birth weight. Maternal bariatric surgery, with subsequent weight loss between pregnancies, is associated with overrepresentation of differences in methylated sites in genes involved in inflammation and type-2 diabetes signaling when comparing offspring born before (n = 31) and after (n = 31) maternal bariatric surgery. There were no significant differences in objectively measured physical activity or time spent sedentary from three months before to nine months after surgery in women undergoing Roux- en-Y Gastric Bypass (n = 56), despite substantial weight loss. Objectively measured physical activity and time spent sedentary three months before and nine months after the women’s Roux-en-Y Gastric Bypass did not differ significantly in spouses (n = 33). However, during the same period, physical activity decreased significantly in children (n = 75), while time spent sedentary increased significantly. Conclusion: Interpregnancy differences in gestational weight gain, in women undergoing bariatric surgery, are associated with increased differences in offspring birth weights and differences in the epigenetic regulation of obesity-related genes in comparison of siblings born before and after maternal bariatric surgery. Furthermore, large weight loss after maternal Roux-en-Y Gastric Bypass is not associated with significant change in physical activity or time spent sedentary in women or spouses, while children decrease physical activity and increase time spent sedentary from three months before to nine months after maternal Roux-en-Y Gastric Bypass.