A post-hoc analysis compared metabolic outcomes between the six-month and three-month long-acting injectable formulations of paliperidone palmitate over a twelve-month double-blind phase and a 24-month extension.
The six-month formulation showed numerically less weight gain, lower BMI and waist circumference, and more weight loss. The differences were most visible in 18 to 25-year-olds and in those already overweight, and were consistent through the extension. Fasting lipids favoured the six-month formulation numerically across HDL, LDL, triglycerides and total cholesterol.
The honest qualifier is substantial, and the authors state it: the study was not powered for weight or metabolic endpoints, most were summarised descriptively, and formal testing was limited to the proportion with an abnormal change of 7% or more — which did not differ significantly between formulations.
So this is a signal, not a finding. It matters because antipsychotic-associated metabolic harm is the main driver of the mortality gap in schizophrenia, and it accrues fastest in exactly the young, early-illness patients where the difference here appeared largest. If a dosing interval choice carries a metabolic consequence, that is worth a properly powered trial rather than a post-hoc analysis.
- Post-hoc, not powered for metabolic endpoints — descriptive for most measures
- The one formally tested endpoint, abnormal weight change, did not differ
- Differences were largest in 18 to 25-year-olds and overweight patients
- Consistent direction across 24 months, which strengthens a weak design
- Metabolic harm drives much of the mortality gap in schizophrenia
The statistics, in plain English
"Numerically less" is the phrase to notice — it means a difference was observed without a statistical test supporting it. Post-hoc analyses of endpoints a trial was not designed to measure carry a high false-positive rate, because many comparisons are examined and only some reported. Consistency across a 24-month extension makes this more credible than most, and still not conclusive.
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