Retrospective cohort study of diabetes mellitus and antipsychotic treatment in a geriatric population in the United States.
OBJECTIVE
The objective of this study was to investigate risk of diabetes among elderly patients during treatment with antipsychotic medications.


METHODS
We conducted a longitudinal, retrospective study assessing the incidence of new prescription claims for antihyperglycemic agents during antipsychotic therapy.


METHODS
Prescription claims from the AdvancePCS claim database were followed for 6 to 9 months.


METHODS
Study participants consisted of patients in the United States aged 60+ and receiving antipsychotic monotherapy. The following cohorts were studied: an elderly reference population (no antipsychotics: n = 1,836,799), those receiving haloperidol (n = 6481) or thioridazine (n = 1658); all patients receiving any conventional antipsychotic monotherapy (n = 11,546), clozapine (n = 117), olanzapine (n = 5382), quetiapine (n = 1664), and risperidone (n = 12,244), and all patients receiving any atypical antipsychotic monotherapy (n = 19,407).


METHODS
We used Cox proportional hazards regression to determine the risk ratio of diabetes for antipsychotic cohorts relative to the reference population. Covariates included sex and exposure duration.


RESULTS
New antihyperglycemic prescription rates were higher in each antipsychotic cohort than in the reference population. Overall rates were no different between atypical and conventional antipsychotic cohorts. Among individual antipsychotic cohorts, rates were highest among patients treated with thioridazine (95% confidence interval [CI], 3.1- 5.7), lowest with quetiapine (95% CI, 1.3-2.9), and intermediate with haloperidol, olanzapine, and risperidone. Among atypical cohorts, only risperidone users had a significantly higher risk (95% CI, 1.05-1.60; P = 0.016) than for haloperidol. Conclusions about clozapine were hampered by the low number of patients.


CONCLUSIONS
These data suggest that diabetes risk is elevated among elderly patients receiving antipsychotic treatment. However, causality remains to be demonstrated. As a group, the risk for atypical antipsychotic users was not significantly different than for users of conventional antipsychotics.
Feldman
Peter D
PD
Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA. pdfeldman@lilly.com
Hay
Linda K
LK
Deberdt
Walter
W
Kennedy
John S
JS
Hutchins
David S
DS
Hay
Donald P
DP
Hardy
Thomas A
TA
Hoffmann
Vicki P
VP
Hornbuckle
Kenneth
K
Breier
Alan
A
D000368:Aged; D000704:Analysis of Variance; D018687:Antidepressive Agents, Second-Generation / Q000009:adverse effects; D014150:Antipsychotic Agents / Q000009:adverse effects*; D001569:Benzodiazepines; D003024:Clozapine / Q000009:adverse effects; D003920:Diabetes Mellitus / Q000139:chemically induced* / Q000188:drug therapy / Q000453:epidemiology*; D003987:Dibenzothiazepines / Q000009:adverse effects; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D005260:Female; D006220:Haloperidol / Q000009:adverse effects; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D015994:Incidence; D007344:Insurance Claim Reporting / Q000706:statistics & numerical data; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D010890:Pirenzepine / Q000009:adverse effects / Q000031:analogs & derivatives*; D016016:Proportional Hazards Models; D000069348:Quetiapine Fumarate; D012189:Retrospective Studies; D012307:Risk Factors; D018967:Risperidone / Q000009:adverse effects; D017678:Sex Distribution; D013881:Thioridazine / Q000009:adverse effects; D013997:Time Factors; D014481:United States / Q000453:epidemiology
D018687:Antidepressive Agents, Second-Generation; D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D007004:Hypoglycemic Agents; D001569:Benzodiazepines; D000069348:Quetiapine Fumarate; D010890:Pirenzepine; D003024:Clozapine; D006220:Haloperidol; D018967:Risperidone; D013881:Thioridazine; D000077152:Olanzapine