Lead author Yeyi Zhu, PhD, a research scientist with the Kaiser Permanente Division of Research, along with colleagues from Kaiser Permanente Division of Research in Oakland, California, examined the prevalence of prediabetes and diabetes by body mass index (BMI) using a multisite cohort of three integrated healthcare systems from 2012 to 2013. The sample population evaluated 4,906,238 people aged 20 years or older through laboratory results and recorded diagnoses, as well as antihyperglycemic medications, to ascertain diabetes.

The team determined that the prevalence of prediabetes did not increase, but the prevalence of diabetes increased across BMI categories among all racial/ethnic groups (P <.001). Racial/ethnic minorities were more likely to be diagnosed with diabetes at lower BMIs than in whites. Specifically, Hawaiians/Pacific Islanders and those identifying as having Asian ancestry had a diabetes prevalence in both the overweight and obese class 1 categories of 24.6% (95% CI, 24.1-25.2%) and 26.5% (26.3%-26.8%), respectively. 

Comparatively, whites had a prevalence of 23.7% (23.5%-23.8%) in obese class 2. Using age-standardized prediabetes prevalence estimates, the team found that the prevalence in overweight Hispanics (35.6% [35.4%-35.7%]), Asians (38.1% [38.0%-38.3%]), and Hawaiians/Pacific Islanders (37.5% [36.9%-38.2%]) were similar to those in obese class 4 white (35.3% [34.5%-36.0%]), black (36.8% [35.5%-38.2%]), and American Indians/Alaskan Native subjects (34.2% [29.6%-38.8%]). 

Although the research team determined that the association between BMI and prediabetes was less pronounced, senior author Assiamira Ferrara, MD, PhD, who is also senior research scientist with Kaiser Permanente, commented, “For primary care clinicians, the findings could signal a change in how they screen racial and ethnic minority patients for diabetes and prediabetes. This study suggests that along with screening patients who are overweight and obese, minorities should probably be screened even if they have a normal BMI, particularly as they get older.”

Because all patients enrolled in the study had access to insurance, lack of care access was ruled out as a contributing factor. According to Kaiser, the authors speculated that there could be physiological differences among people of varying races and ethnicities relating to diabetes, such as higher percentages of body fat and visceral fat at the same BMI as other groups, which could lead to insulin resistance, prediabetes, and diabetes. Stating the need for better understanding of how the physiological mechanisms of diabetes may vary, Dr. Zhu said, “Future research could focus on body composition, genetics, and other lifestyle factors that may contribute to disparities in chronic disease burden.” Dr. Zhu has suggested tailoring screening and prevention strategies in these minority groups.

 « Click here to return to Diabetes Update.