Being bullied during childhood and the risk of obesity in adulthood: A co-twin control study

Background: The etiology of adult obesity is still poorly understood. It has been shown that over-weight children suffer from adverse psychological events, but less is known about the association of adverse psychological factors among normal weight children and adult obesity. Aim: The aim of this study was to examine if the exposure of perception of being bullied during childhood could be associated with development of adult obesity. Methods: Adult, same-sexed twin pairs discordant for BMI were identified from the Danish Twin Registry. The twins underwent an interview and a physical examination. Data were analyzed by means of a growth-curve model and an intra-pair comparison. This design controls for other influences of early lifestyle and socio economic status and is therefore a powerful tool to study independent effects of specific exposures. Results: In total 236 (81.7%) of the twin individuals identified participated in the study. Participants who reported having been bullied in school, had attained a BMI which was on average 1.4 kg/m2 (95% CI = 0.2;2.5, p = 0.02) higher than those not bullied. Two other questions on specific types of bullying resulted in BMI that were 1.1 kg/m2 (CI = 0.1;2.2, p = 0.03) and 1.9 kg/m2 (CI = 0.7;3.1, p = 0.002) larger than subjects who had not been exposed to bullying. There was a direct association between intra pair differences in BMI and exposure to bullying. Conclusion: The results of the study could indicate that being bullied during childhood seems be associated with adult obesity.

The relation between birth weight and hypertension. A study among Danish nurses

The fetal origin hypothesis suggests that birth weight is related to several adult diseases. One hypothesis is that low birth weight is associated with increased risk of hypertension. ADDIN RW.CITE{{119 Barker,D.J. 2009}}In the present study we analyzed the association between self-reported birth weight and risk of hypertension with detailed confounder control, and the modification on this association by familial obesity and own weight history during childhood and youth. Methods: In 1999 the Danish Nurse Cohort study included 31,642 females aged 44 years or more of whom 76% replied to questions on birth weight, weight history, familial obesity disposition, parents socioeconomic status and presence of hypertension. Results: In total 14% reported birth weights below 3000 g. The univariate hazard ratio of hypertension for those born with birth weight < 3000 g was 1.24 (95% CI (1.13 - 1.36)) compared to those with birth weight > 3000 g. The association remained stable after adjustment for important confounders, as lifestyle, weight history and socioeconomic status during upbringing. Conclusion: Our results support the hypothesis that low birth weight is associated with hypertension in adult life, also after considering several confounding factors and weight history later in life. Furthermore, the previous weight history might have an influence on the association between birth weight and the risk for adult hypertension.