First 90 days after starting antipsychotics are critical for monitoring diabetes risk, study finds

A new study published in The Lancet Psychiatry reveals that the first 90 days following the initiation of antipsychotic treatment are critical for monitoring potential risks of diabetes and weight gain in patients with severe mental illness. Researchers from UCL analyzed data from nearly 97,000 adults in England, ages 18-59, who had schizophrenia or bipolar disorder and began taking antipsychotic medications such as olanzapine, quetiapine, risperidone, or aripiprazole between 2000 and 2023.

The study discovered that the most significant metabolic changes occurred during the initial 90 days after starting treatment. HbA1c, a measure of average blood sugar, increased approximately 14 times faster and weight rose nine times faster compared to before antipsychotic treatment began. However, changes in blood sugar and weight did not always occur simultaneously, highlighting the importance of monitoring both factors during this period.

Dr. Juan Carlos Bazo-Alvarez, the study's lead author, emphasized that while antipsychotic medications are valuable treatments for severe mental illnesses, this crucial period poses a heightened risk for diabetes and weight gain. The findings suggest that health care professionals should check both weight and blood sugar before treatment commences and again within the first few months after starting medication. Olanzapine was identified as the drug with the most substantial early increases in both HbA1c and weight.

The study also highlighted the disproportionate impact on women, with HbA1c increasing 24 times faster and weight increasing 12 times faster during the first 90 days compared to men. Patients with prediabetes at the start of treatment had a significantly higher risk of developing type 2 diabetes within two years, with 19% of those at baseline developing the condition compared to 3% of those with normal blood sugar levels.