A prospective study of glycaemic status in anti-psychotic-treated patients.

Anti-psychotic drugs, particularly the second generation, or ;atypical' agents, have been implicated in the development of metabolic dysfunction such as diabetes mellitus. There is a paucity of longitudinal data on the natural history of glucose homeostasis in anti-psychotic-treated patients, and there are no universally accepted strategies for managing worsening glycaemic control in this population. Notwithstanding, several guidelines recommend switching to a ;lower risk' agent if patients develop worsening glycaemic control during anti-psychotic treatment. We prospectively followed a cohort of 106 anti-psychotic-treated patients from across the diagnostic spectrum, and investigated changes in glycaemic status. Between baseline and follow-up assessment (mean follow-up time, 599.3 [SD+/-235.4] days glycaemic status was unchanged in 78 (86.7%) patients; 5 (5.6%) reverted from impaired fasting glucose (IFG) to normoglycaemia in the absence of any pharmacological or lifestyle intervention and all were taking a ;high risk' drug (clozapine or olanzapine). These preliminary data suggest that progression to overt diabetes mellitus is not inevitable in patients who develop IFG during anti-psychotic treatment. Switching to another agent simply on the basis of the development of IFG may not offer any advantage, especially if the mental state is stable.