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Weight Gain Is Modest Across Classes of Biologic Therapy for IBD

Key findings

  • This prospective study of 269 patients with inflammatory bowel disease (IBD) examined weight gain with antitumor-necrosis factor therapy, vedolizumab and ustekinumab
  • All three classes of biologics were associated with statistically significant weight gain by week 14 or 30, but the magnitude was very modest (overall gain of 2.8 pounds at week 54)
  • The weight gain was independent of disease activity and clinical response to biologic therapy, and it did not significantly affect patients' quality of life
  • Women, patients with Crohn's disease and those on steroid therapy at baseline were at increased risk of weight gain

Weight gain is a common side effect of tumor necrosis factor (TNF) alpha inhibitors. Among patients with inflammatory bowel disease (IBD), weight loss is common due to reduced appetite, malabsorption and increased intestinal losses, but observational studies suggest anti-TNF medications are associated with weight gain beyond what might be expected with control of inflammation.

However, a prospective study at Massachusetts General Hospital found that among patients with IBD who receive biologic therapy, weight gain is very modest and is similar across the different drug classes. Nienke Z. Borren, MSc, research fellow in the Division of Gastroenterology at Massachusetts General Hospital, Ashwin N. Ananthakrishnan, MBBS, MPH, director of the Mass General Crohn's and Colitis Center, and colleagues report the results in Digestive Diseases and Sciences.

Study Details

This study involved 269 adult outpatients with Crohn's disease (CD) or ulcerative colitis who started infliximab or adalimumab (n=99), vedolizumab (n=122) or ustekinumab (n=48) between May 2014 and January 2019. Weight was measured at weeks 0, 14, 30 and 54. The average weight at baseline was similar among the three therapy groups.

Changes in Weight

Overall average weight gain was 0.36 kg at week 14 (P = NS), 0.96 kg at week 30 (P < 0.001) and 1.29 kg at week 54 (P < .001).

The increases by therapy group were:

  • Anti-TNF: 1.06 kg at week 30 (P = 0.04); 1.33 kg at week 54 (P = .056)
  • Vedolizumab: 0.83 kg at week 30 (P = 0.045); 1.10 kg at week 54 (P = .03)
  • Ustekinumab: 0.63 kg at week 14 (P = 0.02); thereafter the increases were not significant, perhaps because of the limited numbers of patients for analysis

Predictors of Weight Gain

Weight gain at week 14 was significantly higher in those with CD and those on steroid therapy at baseline. Female gender was associated with weight gain at weeks 30 and 54.

There were no significant differences between the drug classes with respect to change in weight.

Weight Gain and Other Measures

There was no correlation between disease activity at baseline and weight gain at any of the three time points. Moreover, weight gain was similar at all time points for patients who achieved clinical remission and those who did not.

Health-related quality of life was measured at each time point on the Short Inflammatory Bowel Disease Questionnaire. There was no association between scores and weight gain at different time points.

Counseling Patients

Women, patients with CD and those on steroid therapy should be advised that biologic therapy can be associated with modest weight gain. It is important to emphasize that the benefit of effective biologic treatment is greater than the impact of this potential side effect.

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