High cortisol levels are associated with low quality food choice in type 2 diabetes

Hypothalamic-pituitary-adrenal (HPA) axis control may be impaired in type 2 diabetes (T2DM). Glucocorticoids increase consumption of low quality foods high in calories, sugar, and fat. We explored the relationship between cortisol levels, poor blood glucose control, and food quality choice in T2DM. Twenty-seven healthy controls were age-, gender- and education-matched to 27 T2DM participants. Standard clinical blood tests and cortisol values were measured from fasting blood samples. Participants recorded all consumed food and drink items in a consecutive 3-day food diary. Diaries were analyzed for "high quality" and "low quality" foods using a standardized method with high reliability (0.97 and 0.86, respectively). Controlling for education, body mass index (BMI) and hemoglobin A1C (HbA1C), log-transformed cortisol (LogC) predicted the percent of low quality foods (R (2) = 0.092, β = 0.360, P < 0.05), but not the percent of high quality foods chosen. Controlling for education, BMI, and LogC, HbA1C significantly predicted both the percent of low quality foods (ΔR (2) = 0.079, β = 0.348, P = 0.024) and high quality foods chosen (ΔR (2) = 0.085, β = -0.362, P = 0.022). The relationship between HbA1C and low quality food choice may be mediated by cortisol, controlling for BMI and education (P < 0.01). HbA1C displayed both an indirect (cortisol-mediated) effect (P < 0.05) and direct effect on low quality food choice (P < 0.05). The relationship between HbA1C and low quality food choice may be partially mediated by cortisol. Poor blood glucose control may cause HPA axis disruption, increased consumption of low quality foods.