Study Details "Troubling" Rates of Chronic Kidney Disease in People with Diabetes

Katherine R. Tuttle, MD

A study examining the trends in the incidence of chronic kidney disease (CKD) among people with diabetes in the US has returned mixed results.

Although results of the study, which estimated incidence trends of CKD in people with diabetes from 2015-2020, indicate rates of CKD among people with diabetes have decreased by about 17 cases per 1000 person-years during the study period, the authors call attention to “troubling” overall rates as well as racial disparities in incidence of CKD amidst rising diabetes incidence in the US.

“Despite a recent decline, the persistently high incidence of CKD in the United States is troubling, given the large increase in the prevalence of diabetes and its accompanying high rates of kidney failure,” wrote investigators.

A collaborative effort between investigators from the US Centers for Disease Control and Prevention, the UCLA David Geffen School of Medicine, and Spokane Health, the current study was led by Katherine R. Tuttle, MD, of Providence Health, with the of providing clinicians insight into the incidence of CKD among people with diabetes, which they purport could help improve public health efforts to reduce incidence among this patient population. With this in mind, Tuttle and a team of 10 colleagues representing the aforementioned institutions designed their study as an analysis of electronic health record data from the Center for Kidney Disease Research, Education, and Hope (CURE-CKD) registry, which contains data from 654,459 adults aged 20 years or older with diabetes from the Spokane, WA and Los Angeles, CA areas.

The study population had a mean age 61±15 years and 55.2% were women. The primary outcome of interest for the investigators’ analyses was incident CKD, which was defined as at least 2 positive test results on laboratory tests performed at least 90 days apart or by an administrative code. Investigators defined a positive result as a GFR of less than 60 mL/min/1.73m2 of body surface, a UACR of 30 or greater, or a UPCR of 150 or greater. For the purpose of analysis, the overall incidence of CKD was standardized according to 2010 US Census Bureau data.

Upon analysis, results indicated the incidence rate ratios for CKD were greater among almost all minority populations compared to their White counterparts, including people identifying as Native Hawaiian or other Pacific Islander (RR, 1.56 [95% CI, 1.38-1.77]), Black people (RR, 1.41 [95% CI, 1.33-1.50), American Indian or Alaska Native people (RR, 1.33 [95% CI, 1.19-1.50]), and Hispanic or Latinx people (RR, 1.25 [95% CI, 1.20-1.30]). The only racial/ethnic group with a decreased rate ratio compared to White people with diabetes was among Asian people with diabetes (RR, 0.87 [95% CI, 0.82-0.92]).

Further analysis into trends by year demonstrated the overall incidence of CKD declined from 81.6 cases per 1000 person-years (95% CI, 78.0-85.2) from 2015-2016 to 64.0 cases per 1000 person-years (95% CI, 62.2-65.9) from 2019-2020, with consistent trends across demographic subgroups defined by age, racial/ethnic group, and sex. Investigators pointed out comparisons of demographic data in the CURE-CKD registry against the US general population revealed multiple differences in proportions of different racial/ethnic backgrounds, which they speculate could reflect a Western regional population and possible differences in access to health care. Of note, the investigators’’ analysis revealed use of SGLT2 inhibitors increased from 0.9% of people with diabetes but without CKD at baseline in2015-2016 to 1.5% among those enrolled from 2019-2020.

“Our study shows that despite a recent decline, a high incidence of CKD persists in the United States. The incidence was lower among White adults with diabetes than among most other adults with diabetes,” investigators added.

This study, “Incidence of Chronic Kidney Disease among Adults with Diabetes, 2015–2020,” was published as a correspondence in The New England Journal of Medicine.