Associations between plasma glucose and DSM-III-R cluster B personality traits in psychiatric outpatients

Associations between personality traits, measured with the Karolinska Scales of Personality, the Impulsiveness subscale from the Impulsiveness, Venturesomeness and Empathy (IVE) Inventory, and with self-assessed personality traits and disorders (SCID-II Screen Questionnaire), and plasma insulin, glucagon and glucose, respectively, were explored in a sample of 101 psychiatric outpatients of both sexes. No relationships between the peptide hormones and personality measures were found. However, fasting glucose values, which were all essentially within the normal biological variation, were significantly related to several personality measures. For males, a low blood glucose was associated with low stable general level of functioning, with high IVE Impulsiveness, and with self-assessed histrionic and narcissistic traits. High number of self-assessed personality traits for all cluster B personality disorders was strongly associated with high IVE Impulsiveness. The results of the present study support the generalizability of earlier findings from alcoholic impulsive offenders: in males, low blood glucose is associated with an extrovert and impulsive, acting-out behavior that includes the breaking of societal norms and rules. In contrast, for females a positive relationship between fasting glucose and self-assessed histrionic personality traits was found. Because no association between global level of functioning and glucose was found in women, these personality traits may not necessarily be maladaptive, as was the case for males.