Antipsychotic polypharmacy ‘partially linked to MetS in schizophrenia patients’
The team found thatantipsychotic polypharmacy is associated with an increased risk for pre-MetS but not full MetS in schizophrenia patients.
"Although the validity and safety of antipsychotic polypharmacy remains unclear, it is commonplace in the treatment of schizophrenia," explain Fuminari Misawa (Yamanashi Prefectural KITA Hospital) and colleagues.
They add that patients with schizophrenia are more likely to have MetS than the general population, but few studies have investigated whether antipsychotic polypharmacy - the concomitant use of two or more antipsychotics - is associated with an increased risk for MetS in such patients.
To address this, the researchers studied 334 outpatients with schizophrenia, aged at least 18 years, who regularly attended Yamanashi Prefectural KITA Hospital.
All of the participants were interviewed about the use of prescribed antipsychotics, duration of psychiatric treatment, and lifestyle factors, such as dietary habits, physical activity, and smoking.Demographic data and information from the patients' medical charts were also examined.
MetS was defined by the presence of visceral fat obesity (abdominal circumference≥85 cm in men and ≥90 cm in women) and at least two of the following three criteria: elevated blood glucose (fasting glucose ≥110 mg/dl), lipid abnormalities (triglycerides ≥150 mg/dl and/or high-density lipoprotein cholesterol <40 mg/dl), and elevated blood pressure (systolic blood pressure ≥130 mmHg and/or diastolic blood pressure ≥85 mmHg).
In total, 74 (22.2%) patients had MetS, 61 (18.3%) had visceral fat obesity and one of the three additional MetS criteria (pre-MetS), 41 (12.3%) had visceral fat obesity only, and 158 (47.3%) did not fulfil any of these criteria.
Overall, 167 (50.0%) patients met criteria for antipsychotic polypharmacy.
Multinomiallogistic regression analyses revealed that antipsychotic polypharmacy was significantly associated with pre-MetS, at an adjusted odds ratio(AOR) of 2.348, compared with monotherapy. However, polypharmacy was not significantly associated with MetS (AOR=1.269) or visceral fat obesity only (AOR=1.580).
Misawaand team concludein the journal BMC Psychiatry: "These results suggest that antipsychotic polypharmacy is partially associated with MetS even after adjustment for the effect of patients' lifestyle."
They add: "As metabolic syndrome is associated with anincreased risk of cardiovascular mortality, further studies are needed to clarify the validity and safety ofantipsychotic polypharmacy in this patient population."
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By Mark Cowen