Tailored BMI Thresholds for Screening Could Improve Diabetes Diagnoses in Minority Patients

Dhruv Kazi, MD, MSc, MS

A flawed “one-size-fits-all” approach to diabetes screenings may be contributing to increased prevalence among minority patients, according to results of a recent study.

A cross-sectional analysis of data from the National Health and Nutrition Examination Survey (NHANES) from 2011-2018, results of the study suggest tailoring the BMI threshold for diabetes screening according to racial and ethnic background could reduce disparities in diabetes diagnosis, with investigators recommending lowering the threshold for screening to 18.5 kg/m2 or greater in Black and Hispanic Ameri can and to 20 kg/m2 or greater among Asian Americans.

“The simplicity of a single screening threshold for all Americans is alluring, but it is deeply inequitable,” said senior investigator Dhruv Kazi, MD, MSc, MS, associate director of the Smith Center and associate professor of medicine at Harvard Medical School, in a statement. “Our findings suggest that Asian, Hispanic, and Black Americans may need to get screened at lower BMI or younger ages than white Americans. If the current thresholds are universally applied, without accounting for differential risk in racial/ethnic groups, clinicians may underdiagnose diabetes in Asian, Hispanic, and Black Americans.”

Despite an enhanced emphasis in recent guidelines and initiatives, racial disparities in diagnosis and treatment of diabetes continue to be among the most prominent issues in disease management on a population level. Citing previous research indicating racial/ethnic minority patients were less aware their diagnosis and more likely to die of diabetes, Kazi and a team of colleagues from Beth Israel Deaconess Medical Center (BIDMC) sought to assess whether a more tailored approach to screening might improve diagnosis rates using data from NHANES cycles occurring between 2011 and 2018.

The specific intent of the investigators’ efforts was to determine the equivalent BMI thresholds for diabetes screening among racial/ethnic minority Americans that would be expected to produce similar tradeoffs of screening-related benefits and harms to the implementation of the 2021 US Preventive Services Task Force recommendations, which recommends screening for diabetes among adults aged 40-70 years with 25 kg/m2 or greater and the starting age was later amended to begin at 35 years.

For the purpose of analysis, logistic regression was used to estimate diabetes prevalence at various BMIs for White, Asian, Black, and Hispanic Americans. For each group, the equivalent BMI threshold was defined as the BMI which the prevalence of diabetes in 35-year-old persons in that group is equal to that in 35-year-old White adults at a BMI of 25 kg/m2. Investigators pointed out ranges were estimated to account for uncertainty in prevalence estimates for White and minority populations.

Results of the investigators' analyses found the prevalence of diabetes among adults aged 35 years with a BMI of 25 kg/m2 was significantly higher among Asian Americans (3.8% [95% CI, 2.8-5.1]), Black Americans (3.5% [95% CI, 2.7-4.7]), and Hispanic Americans (3.0% [95% CI, 2.1-4.2%]) than among White Americans (1.4% [955 CI, 1.0-2.0]). When compared to a BMI threshold of 25 kg/m2 among White Americans, the equivalent BMI thresholds for diabetes prevalence were 20 kg/m2 (range, <18.5-23 kg/m2) for Asian Americans, less than 18.5 kg/m2 (range, <18.5-23 kg/m2) for Black Americans, and 18.5 kg/m2 (range, <18.5-24 kg/m2) for Hispanic Americans.

“Delayed diagnosis and inadequate treatment of diabetes can produce catastrophic consequences, jeopardizing one’s heart, kidney, eyes, and limbs. But it doesn’t affect all of us equally – there are striking disparities that are largely the legacy of structural racism,” added lead investigator Rahul Aggarwal, MD, internal medicine resident at BIDMC, in the aforementioned statement. “Fixing the health disparities for Americans with diabetes will require a range of strategic investments in health care and efforts to reduce structural inequities. Making screening more equitable is a place to start, as it ensures that individuals with diabetes can receive preventive care and treatment in a timely manner and avert the most catastrophic consequences of diabetes.”

This study, “Diabetes Screening by Race and Ethnicity in the United States: Equivalent Body Mass Index and Age Thresholds,” was published in the Annals of Internal Medicine.