SAN DIEGO – Extra pounds are a perennial problem for schizophrenia patients who take antipsychotic medications with weight-boosting side effects. Now, a new randomized study finds that veterans who took part in a 12-month behavioral intervention program performed better on weight-loss measurements than those in a control group.
The difference between the two groups was far from large, with those undergoing the intervention losing an average of 1.04 centimeters in waist circumference over a year, compared with an average gain of 0.25 centimeters in the control group (P less than .001).
Dr. Donna Ames
A recent meta-analysis found that weight gain is a potential side effect from prolonged use of “virtually all” antipsychotic medications, especially in those who have not taken the drugs previously (PLoS One. 2014 Apr 24;9[4]:e94112).
“Some of the most effective medications are associated with the highest weight-gain liability,” Dr. Ames said in an interview, “and patients with medication-resistant psychosis who don’t want to gain weight will resist taking these medications.”
As the meta-analysis notes, research suggests that the weight gain prompted by antipsychotics may boost mortality risk in patients with severe mental illness. The metabolic havoc linked to schizophrenia may be another factor: A 2010 summary of research notes that newer second-generation antipsychotics “generally tend to cause more problems relating to metabolic syndrome, such as obesity and type 2 diabetes mellitus,” compared with first-generation antipsychotics (FGA).
Weight gain “can be rapid and difficult to control,” the summary authors write,” adding that “the effect is worse with clozapine and olanzapine; minimal with aripiprazole and ziprasidone; and intermediate with other antipsychotics, including low-potency FGAs” (Am Fam Physician. 2010 Mar 1;81[5]:617-22).
For the new study, researchers randomly assigned 121 overweight or obese subjects with serious mental illness to either a “lifestyle balance” (LB) program (n = 62) or a usual care (UC) program (n = 59). All had become obese while taking an antipsychotic.
Subjects in the LB program met with registered dietitians for individual health coaching, weekly for 8 weeks and then monthly for up to 10 months. They also took part in 16 group nutrition and exercise classes over 2 months.
The UC group, meanwhile, met with case managers weekly for 8 weeks and then monthly for up to 10 months. They answered health questionnaires, underwent weight checks, and received self-help materials, Dr. Ames reported at the International Congress on Schizophrenia Research.
All of the participants lost weight, although waist circumference only declined in the intervention group. Body fat percentage declined in both groups, but by more (0.4% vs. 0.2%) in the intervention group, compared with UC (P = .038).
Judging by food diaries kept by 92% of the intervention group participants, their average daily caloric intake declined from 2,055 to 1,650 (P less than 0.001). The UC participants did not keep food diaries, so their caloric intake isn’t available.
Shouldn’t the intervention participants have lost more weight in light of such a large caloric decline? “Not necessarily,” Dr. Ames said. “Participants who were successful at making dietary changes began making these changes at different times throughout the study, some early and some well into the yearlong study. Decreases made in the latter part of the study would result in less weight lost. Also, exercise activity was variable, so decreased caloric intake could be offset by decreased physical activity.”
Other findings: Women did better than men at losing weight, and reducing waist circumference and body fat. There wasn’t a significant difference in the level of exercise between the groups. And researchers linked psychiatric illness insight in the LB group to greater weight loss but not in the UC group.
The study is supported by a $1.9 million VA grant for research from 2010 to 2017, Dr. Ames said.
In regard to cost-effectiveness, she said “a psychiatrist, nurse, or other mental health professional could easily weave these interventions into the care of patients in mental health settings. And the cost savings to patients by even losing just a few pounds could be enormous.”
The researchers hope to examine whether the intervention reduces the cost of medications, emergency department visits, and hospitalizations, she said.
Dr. Ames reports no relevant disclosures.