Can obese patients on antipsychotic medications achieve weight loss in an unmodified general population lifestyle-intervention weight management programme?

Abstract

Many antipsychotics s are obesogenic and contribute to significant weight gain. However, patients on antipsychotics are often excluded from the general population lifestyle-intervention weight management trials. We aim to determine if weight loss is possible for antipsychotic-medicated patients when enrolled in an unmodified lifestyle-intervention weight management programme. We examined the data from 37 antipsychotic-medicated participants (AP) and 74 matched control participants (CP) attending the Weight Management Service, St Columcilles Hospital, Loughlinstown to determine weight change outcomes. Dietary and activity behaviours at baseline for a sub-cohort of AP participants were also reported. Results were expressed as mean ± standard deviation (SD) and a Mann-Whitney U test was used to assess differences between cohorts. The mean weight of the AP group at enrolment was 140.5 ± 31.3 kg with a mean BMI of 49.7 ± 10.8 kg/m2. Nineteen participants in the AP group lost weight (mean weight loss -8.7 ± SD kg). There was no difference in weight outcomes in the AP group compared to the CP (-1.2 ± 12.1 kg vs. -2.1 ± 8.9 kg; p = 0.339). At baseline, the AP group ate fast food 1.7 ± 1.2 times/week, fresh fruit 1.0 ± 1.4 times/ day and reported 2.5 ± 3.0 missed breakfasts/week. Baseline gait speed was lower in AP group (0.99 ± 0.2 m/s vs 1.09 ± 0.34 m/s in programme cohort) and improved slightly to 1.01 ± 0.3 m/s. We conclude that modest weight loss can be achieved in patients on longterm antipsychotics enrolled into an unmodified weight management programme designed for the general population. Typical dietary strategies such as encouraging breakfast consumption and reducing fast food and increased physical activities are relevant to this cohort of patients.