Associations of childhood trauma with food addiction and insulin resistance in African-American women with diabetes mellitus

Abstract

Food addiction (FA) describes a group of disordered eating behaviors. Childhood trauma has been associated with adult FA and trauma has known effects on the endocrine system, but it is unclear whether FA is associated with insulin resistance. We hypothesized that severity of childhood trauma will be associated with FA and higher insulin resistance (HOMA-IR) in a sample of obese women with type 2 diabetes mellitus (T2DM), and that FA will mediate the association between childhood trauma and HOMA-IR. Women with a diagnosis of T2DM (N = 73; M_BMI = 35.86, SD_BMI = 7.72; M_age = 50.59, SD_age = 9.72) were recruited from a diabetes clinic at a county hospital. Participants completed the Childhood Trauma Questionnaire and the Yale Food Addiction Scale. Fasting blood samples were obtained from 64 participants to assess plasma hemoglobin A1c (HbA1c), insulin and glucose (used to calculate HOMA-IR); Oral Glucose Tolerance Test (OGTT) was performed to measure change in glucose and insulin secretion. 48% of the sample met diagnostic criteria for FA. Women with FA reported significantly higher HOMA-IR (F = 25.692, p < 0.001, df = 1,62), HbA1c (F = 4.358, p = 0.041, df = 1,62), and OGGT glucose (F = 5.539, p = 0.022, df = 1,62) as well as severity of childhood trauma (F = 10.453, p = 0.002, df = 1,71). In a hierarchical linear regression controlling for BMI, income level, and T2DM treatment, the severity of childhood trauma did not contribute to the prediction of HOMA-IR (β = -0.011, p = 0.942) whereas FA did (β = 0.422, p = 0.007). In a bootstrapped mediation analysis, the association between childhood trauma and HOMA-IR was mediated by FA severity (b = 0.596, p = 0.020). Understanding the psychological factors that contribute to HOMA-IR in an underserved population of African American women may lead to more effective diabetes management and prevention strategies.

Keywords: Childhood abuse; Childhood trauma; Diabetes; Disordered eating; Food addiction; Insulin resistance.

Figure 1.

The severity of metabolic dysregulation as measured by HOMA-IR (Panel A), hemoglobin A1c (Panel B) and change in glucose (AUCg) during the oral Glucose Tolerance Test (OGTT; Panel C) in a sample of African-American women with type 2 diabetes mellitus (N=64; n=32 women with FA; n=32 women without FA; for the OGTT test [panel C], N=61; n=30 women with FA; n=31 women without FA). Women with FA, compared to those without FA, demonstrated higher severity of insulin resistance (p<0.001), higher levels of hemoglobin A1c (p=0.041) and greater change in glucose during the OGTT (p=0.022).

Figure 2.

The level of childhood trauma in a sample of African-American women with type 2 diabetes mellitus. Women with food addiction, compared to those without food addiction, have higher severity of overall childhood trauma (p=0.002).

Figure 3.

Mediation Model: Association between Childhood Trauma and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) by Way of Food Addiction Severity, controlling for BMI, income, and T2DM treatment (metformin, insulin, bromocriptine, nateglinide, glimepride, glipizide, glyburide, pioglitazone, or a combination of these medications) as covariates. Unstandardized regression coefficients for each path. Note: a = Effect of childhood trauma severity on food addiction severity; b = Effect of food addiction severity on HOMA-IR; c = Total effect of childhood trauma severity on HOMA-IR; c’ = Direct effect of childhood trauma severity on HOMA-IR adjusting for the mediator; ab = Indirect effect of childhood trauma severity on HOMA-IR via food addiction severity. BMI, household income, and current treatment with metformin were entered as covariates. The model is based on 57 participants (n=27 women with FA, and n=30 women without FA).