Projected Impact of Weight-Loss Pharmacotherapy Use on Racial and Ethnic Disparities in Adolescent Obesity

Abstract

Background:

Pediatric obesity disproportionately impacts individuals from minoritized racial and ethnic backgrounds. Recent guidelines support use of anti-obesity pharmacotherapy for adolescents with obesity, but the potential impact on disparities in obesity prevalence has not been evaluated.

Objectives:

To model changes in obesity prevalence with increasing utilization of anti-obesity pharmacotherapy among adolescents.

Methods:

Data representative of American adolescents ages 12 – 17 years was obtained from the National Health and Nutrition Examination Survey, cycles 2011 through pre-pandemic 2020. A body mass index (BMI) reduction of 16.7% was applied to each participant based on clinical trial results of weekly subcutaneous semaglutide 2.4 mg among adolescents. Utilization disparities were based on utilization of the same medication class among adults. Obesity prevalence was calculated assuming utilization of 10–100%, stratified by race and ethnicity.

Results:

Among 4,442 adolescents representing 26,247,384 American adolescents, projected overall obesity prevalence decreased from 22.2% to 8.4% with 100% utilization. However, disparities increased relative to Non-Hispanic White youth, with prevalence among Non-Hispanic Black and Mexican American youth rising from 40–60% higher to 90–120% higher, respectively.

Conclusions:

Increasing utilization of anti-obesity pharmacotherapy may widen relative disparities in obesity, particularly if utilization is unequal. Advocacy for equitable access is needed to minimize worsening of obesity-related disparities.

Introduction

In January 2023, the American Academy of Pediatrics released a clinical practice guideline for treatment of youth with obesity that, for the first time, recommended anti-obesity pharmacotherapy as an adjunct to therapeutic lifestyle changes for adolescents ≥12 years with obesity.¹ This guideline was released soon after the US Food and Drug Administration approved 2.4 mg, weekly subcutaneous semaglutide for adolescents with obesity based on clinical trial data demonstrating a placebo-subtracted 16.7% (95% CI 13.2 – 20.3%) body mass index (BMI) reduction over 68 weeks, ² which translated to resolution of obesity in nearly half of participants.³ This degree of efficacy represents a significant improvement over previously approved pharmaceuticals for weight-loss in youth⁴ and may herald a future in which anti-obesity pharmacotherapy has an efficacy similar to that of bariatric surgery. Unfortunately, clinical trials of semaglutide have included very few youth of color,^2,3 and although glucagon-like peptide-1 receptor agonists like semaglutide have been available for adult use since 2005, there remain racial and ethnic disparities in real-world utilization.^5,6 Because obesity disproportionately impacts individuals from minoritized racial and ethnic backgrounds,⁷ we investigated the potential consequences of similar disparities in the utilization of highly effective anti-obesity pharmacotherapy for adolescents with obesity.

Methods

Using the National Health and Nutrition Examination Survey (NHANES) cycles 2011 to pre-pandemic 2020, we identified a nationally representative sample of 12 – 17-year-olds. NHANES, a repeated cross-sectional study led by the National Center for Health Statistics (NCHS), is designed to provide nationally representative estimates of health-related measures collected through interviews and physical and laboratory examinations. Using NHANES-measured BMI and appropriate survey weights, we calculated the proportion of adolescents with obesity (BMI ≥95^th percentile for age/sex) and stratified by self-reported race and ethnicity.¹ To model the potential impact of highly effective anti-obesity pharmacotherapy, we used semaglutide efficacy as a proxy and assumed the average placebo-subtracted treatment effect and 95% confidence intervals from the clinical trial, which is the only available data on semaglutide efficacy in adolescents. ² Using this treatment effect, we calculated the post-treatment BMI for each NHANES participant eligible for anti-obesity pharmacotherapy (i.e., 83.3% of original BMI) and recalculated obesity prevalence for each race-ethnicity group, varying semaglutide utilization from 0 – 100% of eligible adolescents. We also applied real-world disparities in utilization of glucagon-like peptide-1 receptor agonists based on data from adults with diabetes. Utilization was modeled as 0%, 8%, 11%, and 45% lower for Other/Mixed Race, Hispanic, Black, and Asian individuals, respectively, compared to White individuals.⁵ All survey cycles were approved by the NCHS Research Ethics Review Board, and informed consent was obtained from parents or legal guardians.⁸

Results

We identified 4,442 participants who represented 26,247,384 U.S. adolescents (14.6% Mexican American, 7.9% Other Hispanic, 53.3% Non-Hispanic White, 14.2% Non-Hispanic Black, 5.0% Asian, and 5.0% Other/Mixed Race). The baseline prevalence of obesity was 22.2% overall but varied from 11.7% for Non-Hispanic Asian adolescents to 30.1% for Mexican Americans. Figure 1 depicts the projected overall and stratified prevalence of obesity with increasing utilization of anti-obesity pharmacotherapy. With 100% utilization, the projected overall prevalence of obesity decreased to 8.4%. However, among Non-Hispanic Black and Mexican American youth, the minimum projected prevalence for each group remained high at 14.3% and 12.5%, respectively.

Figure 1.

The projected prevalence of adolescents with obesity decreases with increasing utilization of anti-obesity pharmacotherapy. Vertical lines overlying markers depict the estimated range of obesity prevalence based on 95% CIs for average treatment effect reported in the clinical trial assessing BMI reduction among adolescents with obesity treated with 2.4 mg once-weekly subcutaneous semaglutide².

*Racial-ethnic disparities in utilization rate were modeled as 0%, 8%, 11%, and 45% lower for Other/Mixed Race, Hispanic, Black, and Asian individuals, respectively, compared to White individuals⁵.

n_w signifies the number of US adolescents represented by the sample based on survey weights.

Additionally, relative disparities by race and ethnicity worsened with increasing utilization. For example, at baseline, Non-Hispanic Black adolescents had an obesity prevalence 1.4-fold higher than Non-Hispanic White adolescents, but this rose to 2.2-fold with 100% utilization among Non-Hispanic White youth with real-world disparities applied (Figure 2). Similarly, Mexican American adolescents had an obesity prevalence 1.6-fold higher than Non-Hispanic White youth, but this rose to 1.9-fold with 100% utilization among Non-Hispanic White youth. A sensitivity analysis without utilization disparities applied had similar results (data not shown).

Figure 2.

The projected prevalence of obesity relative to Non-Hispanic White adolescents increases among Non-Hispanic Black and Hispanic adolescents with increasing utilization of anti-obesity pharmacotherapy.

*Racial-ethnic disparities in utilization rate were modeled as 0%, 8%, 11%, and 45% lower for Other/Mixed Race, Hispanic, Black, and Asian individuals, respectively, compared to White individuals⁵.

n_w signifies the number of US adolescents represented by the sample based on survey weights.

Discussion

Pediatric obesity is an often-stigmatized medical condition that results from an interplay of environmental, genetic, and socioeconomic factors.¹ We demonstrate that increasing use of anti-obesity pharmacotherapy for adolescents with obesity will decrease absolute obesity prevalence but will exacerbate existing racial and ethnic disparities in obesity prevalence. This worsening of disparities occurs because significant decreases in BMI will create a downward shift in obesity prevalence overall, leaving behind a larger proportion of youth in groups who have the highest baseline obesity prevalence.

As obesity-related complications in youth become increasingly common, including type 2 diabetes ⁹ and fatty liver disease,¹⁰ efforts to reduce metabolic risk are warranted and must be made available to all youth who would benefit in order to avoid exacerbating existing health disparities. However, one of the most important criticisms of the AAP guideline, on which our study is based, is the use of BMI to define obesity and define treatment thresholds,¹¹ particularly as this indirect measure of adiposity differs in its ability to predict persistence of obesity into adulthood by race.¹² Additionally, if not used in the setting of a supervised weight management program,¹³ a focus on weight loss as a primary objective could worsen weight stigma and disordered eating behaviors, which have been reported in nearly one-quarter of children and adolescents and are more common with increasing BMI.¹⁴

One limitation of our study is the assumption that real-world effectiveness of anti-obesity pharmacotherapy will be the same as the efficacy of semaglutide in the clinical trial.¹ However, emerging therapies, such as tirzepatide, have led to a similar degree of weight loss in adults with obesity.¹⁵ Additionally, we did not account for pre-existing conditions that may preclude use of anti-obesity pharmacotherapy. Finally, we did not account for insurance type, though doing so would likely lead to larger disparities due to lower access to newly introduced pharmacotherapy among publicly insured adolescents, who are more often from minoritized backgrounds.

In conclusion, our findings demonstrate that introduction of anti-obesity pharmacotherapy to treat adolescents may reduce overall obesity prevalence but will worsen existing inequities. Unfortunately, even with equal utilization, a higher proportion of adolescents from minoritized racial and ethnic backgrounds will continue to have BMI ≥95^th percentile and to be at risk for obesity-related complications in adolescence and young adulthood. This underscores the necessity of a multifaceted approach to pediatric obesity, including not only pharmacoequity to ensure appropriate utilization among adolescents who would most benefit,¹⁶ but also primary prevention and policies to address social determinants of health that contribute to existing disparities in pediatric obesity. Thus, although increasing utilization of highly effective anti-obesity pharmacotherapy could reduce obesity prevalence in adolescents, this may widen relative disparities, particularly if utilization follows the pattern of real-world use among adults. Vigilance and advocacy for equitable access are needed to minimize worsening of obesity-related disparities in adolescents.

Abbreviations:

BMI:

Body mass index

NCHS

National Center for Health Statistics