The metabolic syndrome and its constituting variables in atypical antipsychotic-treated subjects: comparison with other drug treatments, drug-free psychiatric patients, first-degree relatives and the general population in Venezuela

Abstract

Background: Few studies on the association between atypical antipsychotic drug (AAP) administration and metabolic dysfunction have concurrently evaluated the general population (GP), other psychotropic drug treatments and drug-free psychiatric patients.

Methods: We assessed the frequency of the metabolic syndrome (MS) according to the National Cholesterol Education Program criteria (NCEP) and its constituting variables in a GP sample (n=271) and in patients receiving, for at least three consecutive months, antiepileptic drugs (n=93), olanzapine (n=162), clozapine (n=105), typical antipsychotics (n=117), other AAP (n=58), other psychotropic drugs (n=185), and drug-free individuals (n=636). Subjects were clinically classified as schizophrenia, bipolar or other axis I disorders (DSM-IV-RT), and as first-degree relatives of each diagnostic group.

Results: The MS was detected in 26.6% of the GP (95% confidence interval: 21.5-31.8). No diagnostic or treatment group had a significantly higher age-adjusted frequency than the GP (p>0.05). Treatment duration did not significantly affect the results. However, significant differences were observed in the frequency of abnormal MS constituting variables in comparison to the GP. For example, schizophrenia patients and their relatives, bipolar subjects and olanzapine- and clozapine-treated patients had higher abnormal waist circumference values. In addition, bipolar patients and their relatives and subjects treated with olanzapine and other AAPs had higher frequencies of abnormal glucose levels. Neither schizophrenia nor bipolar patients in the diagnostic categories nor the olanzapine or the clozapine groups displayed higher proportions of abnormal triglycerides, high density cholesterol or blood pressure levels than the GP.

Conclusions: While we did not demonstrate an increased frequency of the MS in AAP-treated subjects, our results confirm that specific metabolic variables must be monitored in psychiatric patients. Besides they stress the importance, in epidemiological studies, of concurrently comparing the figures recorded in AAP-treated patients with those obtained in the local GP, other drug treatment groups and drug-free subjects when referring to the magnitude of the metabolic effects of specific antipsychotic agents.