The weight of traumatic stress: a prospective study of posttraumatic stress disorder symptoms and weight status in women

Abstract

Importance: Posttraumatic stress disorder (PTSD) indicates a chronic stress reaction in response to trauma. This prevalent condition has been identified as a possible risk factor for obesity. Whether PTSD symptoms alter the trajectory of weight gain or constitute a comorbid condition has not been established.

Objective: To determine whether women who develop PTSD symptoms are subsequently more likely to gain weight and become obese relative to trauma-exposed women who do not develop PTSD symptoms or women with no trauma exposure or PTSD symptoms and whether the effects are independent of depression.

Design, setting, and participants: The Nurses' Health Study II, a prospective observational study initiated in 1989 with follow-up to 2005, using a PTSD screener to measure PTSD symptoms and time of onset. We included the subsample of the Nurses' Health Study II (54 224 participants; ages 24-44 years in 1989) in whom trauma and PTSD symptoms were measured.

Exposures: Trauma and PTSD symptoms.

Main outcomes and measures: Development of overweight and obesity using body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) cut points 25.0 and 30.0, respectively; change in BMI during follow-up among women reporting PTSD symptom onset before 1989; and BMI trajectory before and after PTSD symptom onset among women who developed PTSD symptoms in 1989 or during follow-up.

Results: Among women with at least 4 PTSD symptoms before 1989 (cohort initiation), BMI increased more steeply (b = 0.09 [SE = 0.01]; P < .001) during the follow-up. Among women who developed PTSD symptoms in 1989 or later, BMI trajectory did not differ by PTSD status before PTSD onset. After PTSD symptom onset, women with at least 4 symptoms had a faster rise in BMI (b = 0.08 [SE = 0.02]; P < .001). The onset of at least 4 PTSD symptoms in 1989 or later was also associated with an increased risk of becoming overweight or obese (odds ratio, 1.36 [95% CI, 1.19-1.56]) among women with a normal BMI in 1989. Effects were maintained after adjusting for depression.

Conclusions and relevance: Experience of PTSD symptoms is associated with an increased risk of becoming overweight or obese, and PTSD symptom onset alters BMI trajectories over time. The presence of PTSD symptoms should raise clinician concerns about physical health problems that may develop and prompt closer attention to weight status.

Figure 1

Overall Design for NHSII Study of PTSD and BMI. Modified from Roberts AL, Galea S, Austin SB, Cerda M, Wright RJ, Rich-Edwards JW, Koenen KC. Posttraumatic stress disorder across two generations: concordance and mechanisms in a population-based sample Biol Psychiatry. 2012 Sep 15;72(6):505–11.

Figure 2

Unadjusted mean BMI over time according to trauma/PTSD group (including women with trauma/PTSD prior to or in 1989 or who have no trauma/PTSD through 2005, n = 41,976)