The results indicate that appetite, body weight, and waist circumference should be monitored early and regularly during treatment, the researchers stated.
Researchers from the National Institute of Mental Health (NIMH) and several other institutions monitored weight, waist circumference, body mass index, and metabolic changes in 124 children with ASD and serious behavioral problems, assigned to take risperidone for 24 weeks.
Ninety-seven patients remained in the trial at 24 weeks (75 participants had a reported increase in appetite in the first eight weeks of treatment compared with 22 participants without such reports), with an average weight gain of 5.4 kg. Increased appetite early in treatment predicted weight gain and higher BMI scores over time.
Weight gain precipitated a “cascade” of metabolic effects: from pretreatment to week 16, there were significant increases in glucose, hemoglobin A1c, insulin, and other variables associated with metabolic syndrome. At baseline, seven patients had met conventional criteria for metabolic syndrome, but by week 16, 12 additional patients were so classified.
“The main practical finding of the study is that the metabolic adverse effects of this commonly used antipsychotic seem to begin with a drug-induced increase in appetite that occurs very early after starting treatment and leads to increased caloric intake and then rapid increase in weight, which is followed by elevation in blood sugar and lipids,” Bendetto Vitiello, M.D., chief of the Child and Adolescent Treatment and Preventative Intervention Research Branch at NIMH, told Psychiatric News. “So, the cascade of adverse metabolic events is precipitated by the increase in appetite and food intake. Proactive interventions aimed at controlling caloric intake at the very beginning of treatment may be able to prevent or attenuate the negative metabolic effects of the medication.”
For related information, see the Psychiatric News article “Exposure to Antipsychotics May Increase Risk of Type 2 Diabetes in Youth.”