Cytokines, diabetes mellitus and psychopathology: a challenging combination.

Objectives: The aim of this study was to investigate the association of IL-6, IL-12, and TNF-α with trait and state psychological factors in type 2 diabetic patients.

Design: Patients were divided in two groups. Group A consisted of 86 controlled diabetic patients (HbA1c<7) and the Group B consisted of 45 uncontrolled diabetic patients (HbA1c ≥ 7).

Settings: During the initial phase of the study (T0), blood samples were taken for measuring IL-6, IL-12 and TNF-α serum levels as well as a battery of psychometric instruments. One year later (T1), the uncontrolled diabetic patients were re-evaluated with the use of the same psychometric instruments and with the identical blood analysis.

Results: The average values of tnf-α were significantly different among controlled (7.73 ± 5.51) and uncontrolled patients (9.29 ± 4.52) at a significance level of 5% (p=0.009). Controlled diabetic patients show a statistically significant relationship between IL-6 and neuroticism (rp=0.303, p=0.010), and between IL-12 and psychotism, (rsp=0.382, p=0.001). Controlled diabetic patients show a statistically significant relationship between IL-12 and the act out hostility (rsp=-0.307, p=0.009). The scores of the psychometric tests differ significantly between the first and second evaluation. Acting out hostility and the direction of hostility increased when HbA1c values fell below the threshold of 7, while the total hostility index, as well as all other scales, dropped when patients controlled their metabolic profile.

Conclusions: The present results provide evidence that IL-6, IL-12 and TNF-α are closely related to the course and treatment of type 2 diabetes.