Childhood sexual abuse and IL6 mediated by change in BMI over an 18-year period: A growth curve model.

ABSTRACT

BACKGROUND: Childhood sexual abuse can increase both body weight and inflammation later in life. Higher weight or faster changes in weight, as measured by changes in body mass index (BMI), may mediate the relationship between childhood sexual abuse and inflammation, however, most studies to date have used a cross-sectional design limiting causal inferences. OBJECTIVE: The current study aimed to investigate the interrelationships between childhood sexual abuse, BMI, and C-reactive protein (CRP) and interleukin-6 (IL6). PARTICIPANTS AND SETTING: Data from 461 adults who participated in the Midlife in the United States (MIDUS) study were utilized. METHODS: Growth curve modeling was used to test initial levels of BMI and changes of BMI over an 18-year period as mediators linking childhood sexual abuse to CRP and IL6. RESULTS: Sexual abuse was not significantly associated with the initial level of BMI; however, sexual abuse was associated with the slope of BMI (b = 0.072, p = .006). BMI intercept (b = 0.080, p = .001) and slope (b = 0.240, p = .002) predicted IL6 values whereas the slope of BMI (b = 0.398, p = .033) but not intercept predicted CRP values. The indirect effect from sexual abuse to IL6 through BMI slope was significant (b = 0.017, 95 % [CI.001, 0.033]) while the indirect effect from sexual abuse to CRP through BMI slope was not significant (b = 0.028, 95 % [CI -0.004, 0.061]). CONCLUSION: Childhood sexual abuse was indirectly associated with IL6 through rates of change in BMI over time.