Equitable access to glucose monitoring improves HbA1c levels

Equitable access to glucose monitoring improves HbA1c levels | Image Credit: © Andrey Popov - © Andrey Popov - stock.adobe.com.

This is part 2 in our 3-part series on type 1 diabetes. Click here for part 1. Click here for part 3.

Inclusive initiation of continuous glucose monitoring (CGM) for youths with new-onset type 1 diabetes (T1D) demonstrated improvements in hemoglobin A_1C (HbA_1c) irrespective of ethnicity or insurance status, according to a study published in Jama Network Open. Results suggest expanded access to CGM can improve glycemic outcomes and reduce disparities among youth, but gaps remain.

CGM has been previously associated with improved HbA_1C in youth with T1D, but disparities exist for minoritized racial and ethnic groups and for those with public insurance, as this group faces greater barriers to CGM access, according to authors. Despite higher rates of complications among T1D youths from lower-income backgrounds, diabetes technology is 50% lower among this group. Youths with public insurance have frequent interruptions to CGM access, which are associated with worsening HbA_1C trends. Implicit biases and willingness to recommend diabetes technology to youths from underrepresented backgrounds are likely additional contributors to these disparities, according to authors.

To determine whether HbA_1C decreases differed by ethnicity and insurance status of youths newly diagnosed with T1C that are provided CGM, the cohort study used data from the Teamwork, Targets, Technology, and Tight Control (Pilot-4T) (NCT04336969) study. The Pilot-4T study is a clinal research program aimed to initiate CGM within 1 month of T1D diagnoses. All eligible participants were offered CGM within this 1-month T1D diagnosis timeframe. The Pilot 4T cohort was comprised of 135 youths with a median age of 9.7 years (interquartile [IQR] 6.8 to 12.7 years). All were diagnosed with new-onset T1D between July 25, 2018, and June 15, 2020, at Stanford Children’s Hospital in California. Participants were followed for 12 months, and data analysis was performed and completed on June 3, 2022, according to authors.

The Pilot-4T cohort was compared to a historical cohort of 272 youths diagnosed with T1D between June 1, 2014, and December 28, 2016, and stratified by ethnicity (Hispanic vs non-Hispanic) or insurance status (public vs private) to assess HbA_1C change over 12 months. The historical cohort population received new-onset diabetes education, quarterly clinic visits, and a nonstandardized introduction to CGM (at family and clinician discretion), the clinical standard care at the time.

The primary outcome was a change in HbA_1C from 4 months (established nadir of HbA_1C for the historical cohort) to 12 months postdiagnosis. The proportion of participants achieving the target HbA_1C levels of less than 7.5% and less than 7.0% were secondary outcomes. CGM metrics, including sensor glucose time in range ([TIR] 70-180 mg/dL), hypoglycemia (54-69 mg/dL), and clinically significant hypoglycemia (less than 54 mg/dL) were exploratory outcomes.

Due to the limitation potential difference in available data points when using Dexcom receivers vs smart devices (cloud and internet connectivity of download devices), a secondary analysis evaluating use-time by download device stratified by ethnicity and insurance was used. Locally estimated scatterplot smoothing (LOESS) was used to visualize differences in HbA_1C trajectories in the Pilot-4T cohort, with similarly stratified historical trajectories as the benchmark. Differences in LOESS means between the Pilot-4T cohort and the historical cohort were calculated at 6, 9, and 12 months. Differences in LOESS means at each time point are presented with bootstrapped 95% CIs from 1000 resamples on the participant level, according to the study.

Seventy-one boys (52.6%) and 64 girls (47.4%) made up the Pilot-4T cohort study. Of the 135 enrolled youths, 104 (77.0%) had private insurance and 31 (23.0%) had public insurance. Nineteen (14.1%) self-reported their respective race as Asian or Pacific Islander, 62 (45.9%) as White, and 39 (28.9%) as other race. Race was missing or not reported for 15 participants (11.1%). Twenty-nine (21.5%) participants self-reported their ethnicity as Hispanic and 92 (68.1%) as non-Hispanic. Pilot-4T participants had a mean (SD) HbA_1C of 12.2% (2.1%) at diagnosis, with a median CGM initiation of 7 days (range, 5-11 days). Of the 272 youths in the historical cohort, the median age was 9.7 years (range, 6.7-12.7 years) at diagnosis. There were 137 boys (50.4%) and 135 girls (49.6%). Among them, 197 (72.4%) had private insurance. These participants self-reported their respective race and ethnicity as, “American Indian or Alaska Native (1 [0.4%]), non-Hispanic Black (5 [1.8%]), or non-Hispanic White (116 [42.6%]),” according to authors. The SD HbA_1C was 10.7% (2.5%) at diagnosis with 56.2% CGM use (less than 1.8% started CGM use before 30 days of diagnosis.

According to the authors, “Compared with the historical cohort, similar reductions in HbA_1C at 6, 9, and 12 months postdiagnosis were observed for Hispanic individuals (estimated difference, −0.26% [95% CI, −1.05% to 0.43%], −0.60% [−1.46% to 0.21%], and −0.15% [−1.48% to 0.80%]) and non-Hispanic individuals (estimated difference, −0.27% [95% CI, −0.62% to 0.10%], −0.50% [−0.81% to −0.11%], and −0.47% [−0.91% to 0.06%]) in the Pilot-4T cohort.”

For individuals with public insurance, reductions in HbA_1C at 6, 9, and 12 months (estimated difference, −0.52% [95% CI, −1.22% to 0.15%], −0.38% [−1.26% to 0.33%], and −0.57% [−2.08% to 0.74%]) were similar to reductions observed in privately insured individuals (estimated difference, −0.34% [95% CI, −0.67% to 0.03%], −0.57% [−0.85% to −0.26%], and −0.43% [−0.85% to 0.01%]) in the Pilot-4T cohort. Higher HbA_1C at the 6 (estimated difference, 0.28% [95% CI, −0.46% to 0.86%]), 9 (0.63% [0.02% to 1.20%), and 12-month postdiagnosis marks (1.39% [0.37% to 1.96%]) were observed in Hispanic youths compared to non-Hispanic youths, and in publicly insured youths compared to privately insured youths (estimated difference, 0.39% [95% CI, −0.23% to 0.99%], 0.95% [0.28% to 1.45%], and 1.16% [−0.09% to 2.13%]), according to results of the study.

These results suggest similar improvements in HbA_1C for Hispanic and non-Hispanic youths and for publicly and privately insured youths when CGM is initiated soon after T1D diagnosis. Authors concluded the results demonstrated in the study suggest equitable access to CGM soon after T1D diagnosis could be a first step to improve HbA_1C for all youths, but acknowledge this access alone is, “unlikely to eliminate disparities entirely.” The authors add broader societal strategies to address structural drivers of disparities in diabetes care are required.

Reference:

Addala A, Ding V, Zaharieva DP, et al. Disparities in hemoglobin A_1C levels in the first year after diagnosis among youths withtype 1 diabetes offered continuous glucose monitoring. JAMA Netw Open. 2023;6(4):e238881.doi:10.1001/jamanetworkopen.2023.8881