95 Baseline body-mass-index and risk for obesity in children with rheumatic disease starting high-dose prednisone therapy
Authors: Pang Renee , Rieder Michael , Berard Roberta , Miller Michael , Demirkaya Erkan 
Published: October 2021

Abstract

Primary Subject area
Rheumatology

Background
Prednisone is a glucocorticoid (GC) medication commonly used in moderate (&gt;7.5 mg/day) to high doses (≥ 1 mg/kg/day to maximum 60 mg/day) for children with moderate to severe presentations of rheumatic disease, including systemic lupus erythematosus (SLE), juvenile idiopathic arthritis (JIA), and juvenile dermatomyositis (JDM). Adverse effects (AE) to GCs impose a significant burden on health and quality of life including frequent development of weight gain, mood changes, sleep difficulties, osteoporosis, and Cushingoid features, amongst others.

Objectives
We sought to evaluate a possible relationship between baseline patient body-mass-index (BMI) measure and development of select GC-mediated toxicity within the first 12 months of starting moderate or high-dose prednisone therapy using conventional weight-based dosing of prednisone. Secondary outcomes were to examine rates of GC-mediated hypertension, osteopenia, and osteoporosis.

Design/Methods
We performed a retrospective chart review on children with rheumatic disease aged ≤ 17 years treated with moderate and high-dose prednisone therapy at a single Canadian academic hospital between January 1, 2010 and December 31, 2019. Demographic variables collected included diagnosis, age, sex, ethnicity. Clinical variables collected include weight, height, and body-mass-index (BMI), hepatitis (AST&gt;41 U/L, ALT&gt;40 U/L, or GGT&gt;60 U/L), proteinuria (&gt;0.1 g/L), and presence of hypoalbuminemia (&lt;38g/L) at baseline. We collected weight, height, and body-mass-index (BMI), at 6 and 12 months, the maximum BMI, and transformed them to z-scores according to the World Health Organization's Child Growth standards. Cumulative prednisone dose (mg/kg/12 months), total days on prednisone in the first 12 months of therapy were also obtained, in addition to bone-mineral-density cores after 12 months of prednisone therapy.
Baseline characteristics, which were significant for the subsequent development of obesity during the first 12 months at the bivariate level (p &lt; 0 .05), were included as predictors of obesity in separate logistic regression analyses. In each regression analysis, we also adjusted for baseline BMI, and for confounding variables of hepatitis, hypoalbuminemia (albumin less than 38 grams per litre), proteinuria and prednisone dose. We conducted a complete case analysis, and all analyses were performed using SPSS v.26 (IBM Corp., Armonk, NY, USA), and p-values &lt; 0 .05 were considered statistically significant.

Results
Seventy-four charts were reviewed, and 72 patients met criteria for analysis. The median prednisone dose was 35 mg per day (IQR 20 to 60 mg), and median duration of therapy was 302 days (IQR 126.75 to 581.25). Thirty-five (48.6%) patients developed obesity, 33 (45.8%) hypertension, five (7.0%) osteopenia, and three (4.2%) osteoporosis. Greater BMI at baseline was associated with greater total weight gain (OR 4.04, 95% CI = [1.98-8.33], p &lt; 0 .001).

Conclusion
Greater baseline patient BMI may be a predictor of weight gain on high-dose prednisone therapy in children with rheumatic disease requiring high-dose therapy. Further work is required to determine methods for individualized prednisone dosing and counseling and behavioral interventions to mitigate risk for weight gain.