Is abnormal glucose tolerance in antipsychotic-naive patients with nonaffective psychosis confounded by poor health habits?
BACKGROUND
Some but not all previous studies have found abnormal glucose tolerance or fasting glucose concentrations in antipsychotic-naïve patients with nonaffective psychosis. Our finding of abnormal glucose tolerance in patients with nonaffective psychosis could not be attributed to confounding by age, ethnicity, gender, smoking, socioeconomic status (SES), hypercortisolemia, or body mass index (BMI). However, other factors merit consideration as potential confounders of this association.


METHODS
An extended sample of newly diagnosed, antipsychotic-naive patients with schizophrenia and related disorders and matched controls were administered an oral glucose tolerance test. Confounding factors related to diet, self-care/access to care, and drug abuse were evaluated.


RESULTS
After accounting for the variance due to age, ethnicity, gender, smoking, SES, morning cortisol concentrations, BMI (or waist-hip ratio), our previous finding of abnormal glucose tolerance in these patients was confirmed. This difference could not be attributed to confounding by substance abuse; blood concentrations of vitamin B12, folate, or homocysteine; aerobic conditioning as measured by resting heart rate; or duration of untreated psychosis.


CONCLUSIONS
These results provide further evidence that people with schizophrenia and related disorders have abnormal glucose tolerance and an increased risk of diabetes prior to antipsychotic treatment and independent of health habits and access to care. Other measures should also be examined.
Kirkpatrick
Brian
B
Department of Psychiatry, Texas A&M College of Medicine, Temple, TX, USA. bkirkpatrick@swmail.sw.org
Miller
Brian J
BJ
Garcia-Rizo
Clemente
C
Fernandez-Egea
Emilio
E
Bernardo
Miguel
M
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D018149:Glucose Intolerance / Q000378:metabolism*; D005951:Glucose Tolerance Test; D015438:Health Behavior; D006297:Health Services Accessibility; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000378:metabolism*; D012306:Risk; D012559:Schizophrenia / Q000378:metabolism*
D001786:Blood Glucose