Insulin Pump Lowers Risk of Diabetic Retinopathy in Pediatric T1D

Among children, adolescents, and young adults with type 1 diabetes, insulin pump use was associated with a lower risk of developing diabetic retinopathy (DR), according to a cross-sectional study in JAMA Network Open.

“We know that insulin pump use is associated with better glycemic control and lower HbA_1c level so we would expect that it would be associated with lower risk of complications,” Roomasa Channa, MD, from the Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, and Risa Wolf, MD, from the Division of Endocrinology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, told BreakingMED in an email correspondence. “However, it was a little unexpected that the insulin pump use was protective of DR independent of A1c levels.” Channa and Wolf were the two senior co-authors of the study.

They hypothesized that this could be due to “a decrease in glycemic variability or an increase in time in range (ie, the percentage of time blood glucose levels remain within the 70-180 mg/dL range) among those receiving insulin pump therapy.”

Channa and Wolf noted that the take-home message for clinicians taking care of patients with type 1 diabetes is to “utilize diabetes technology such as insulin pumps. Not only was there a protective effect on DR,” but they added, quoting from their study, “patients who used insulin pumps in our study also had significantly fewer admissions for diabetic ketoacidosis than those who did not use pumps, the benefits of increased access to insulin pumps would likely be multifactorial.”

Not surprisingly, Channa and Wolf also highlighted their findings about disparities in care as related to the development of DR and access to insulin pumps.

“The likelihood of having DR was twice as high among African American youth compared with White youth but this difference was no longer significant after controlling for duration of diabetes, insurance status, insulin pump use and glycated hemoglobin levels,” they told BreakingMED. “Insulin pump use was found to be associated with a lower likelihood of DR in our study, but there were disparities in access to insulin pumps. Insulin pump users were more likely to be white and have private or commercial insurance. Fifty-nine percent of all white youth were pump users compared to 27% of African American youth. This highlights the importance of making sure that diabetes technology use is accessible to all children with diabetes, with a focus on identifying barriers and increase uptake in minority populations.”

Writing in a commentary accompanying the study, Martin de Bock, MBChB, PhD, from the Department of Paediatrics, University of Otago, Christchurch, New Zealand, and colleagues noted that the study: “adds to the body of data supporting the use of technologies to improve glycemia, both in terms of the traditional hemoglobin A_1c measure and its established association with DR and in terms of newer measures, such as glycemic variability and time in range… However, as [the study authors] highlight, socioeconomically deprived young patients who have limited means to access diabetes technologies continue to have the worst glycemic indices and remain at the highest risk for developing complications. Improving technologies simply will not improve outcomes when those who need them most cannot access them. Thus, a focus on health equity to enable universal access to diabetes technologies is important if we are to make meaningful changes in the long-term prognosis of young patients with diabetes.”

Channa concurred and also told BreakingMED: “We have more work to do in improving outcomes for minority youth with diabetes. For children with type 1 diabetes, diabetes providers should encourage use of insulin pump therapy which can improve glycemic control and reduce the risk of DR.”

Channa, Wolf, and fellow researchers “pooled data from 2 large academic pediatric centers in the U.S. (Baylor College of Medicine/Texas Children’s Hospital [BCM/ TCH] Diabetes and Endocrine Care Center and Johns Hopkins University [JHU] Pediatric Diabetes Center) to form a diverse population for analysis,” they wrote in their study. They looked at prospective data—point-of-care screening using fundus photography at JHU—from Dec. 3, 2018 to Nov. 1, 2019, as well as retrospective data from BCM/TCH culled from electronic health records of patients receiving “point-of-care screening using retinal cameras between June 1, 2016, and May 31, 2019).”

The patient population evaluated included 1,640 individuals with a mean (SD) age of 15.7 (3.6) years. Most were female (n=867; 52.9%), and had type 1 diabetes 1,216 (74.1%) versus 416 (25.4%) with type 2 diabetes. Looking at demographics, 506 participants were Hispanic, 384 were non-Hispanic Black or African American, 647 were non-Hispanic White, with 103 listed as other races or ethnicities. There were 51 who did not list a race or ethnicity.

“Overall, DR was present in 57 of 1,640 participants (3.5%), and the prevalence did not vary between those with type 1 vs type 2 diabetes (43 of 1,216 patients [3.5%] versus 13 of 416 patients [3.1%], respectively; P=0.35) or between institutions (13 of 308 patients [4.2%] at JHU versus 44 of 1,332 patients [3.3%] at BCM/TCH; P=0.19),” the study authors wrote.

Of the 57 who developed DR:

• 11 (19.3%) had mild nonproliferative DR (non-PDR).
• 45 (78.9%) had moderate non-PDR.
• 1 (1.8%) had PDR.

Notably, those with DR were older than those who did not develop DR (mean [SD] age, 18.2 [2.6] years vs 15.7 [3.5] years, respectively; P<0.001). They also had diabetes for a longer time—(mean [SD], 9.4 [4.4] years versus 6.6 [4.4] years; P<0.001). And looking at insulin pump use, those who developed DR “were less likely to use an insulin pump (10 of 57 patients [17.5%] versus 554 of 1,583 patients [35.0%]; P=0.006), and had higher mean HbA_1c levels (mean [SD], 10.3% [2.4%] versus 9.2% [2.1%]; P<0.001).”

For type 1 diabetes, the study authors noted that “insulin pump use was associated with a lower likelihood of DR after adjusting for race and ethnicity, insurance status, diabetes duration, and HbA_1c level (odds ratio [OR], 0.43; 95%CI, 0.20-0.93; P=0.03),” they wrote. “The likelihood of having DR was 2.1 times higher among Black or African American participants compared with White participants (OR, 2.12; 95%CI, 1.12-4.01; P=0.02); this difference was no longer significant after adjusting for duration of diabetes, insurance status, insulin pump use (among patients with type 1 diabetes only), and mean HbA1c level (type 1 diabetes: OR, 1.79; 95%CI, 0.83-3.89; P=0.14; type 2 diabetes: OR, 1.08; 95%CI, 0.30-3.85; P=0.91).”

In this analysis, the effect of insulin pump use for those with type 2 diabetes was “too small to allow a multivariable analysis that included pump use,” researchers wrote.

Also of note, in their email correspondence, Channa and Wolf pointed out another key finding: “Those who used a pump versus those who did not were also more likely to have private/commercial insurance (404 of 550 patients [73.5%] versus 351 of 628 [55.9%]; P<0.001), use a continuous glucose monitor (308 of 558 patients [55.2%] versus 116 of 658 [17.6%]; P<0.001), have a lower mean HbA1c level (mean [SD], 8.7% [1.5%] versus 10.0% [2.1%]; P<0.001), have fewer hospital admissions for diabetic ketoacidosis (mean [SD], 0.04 [0.22] vs 0.09 [0.37] admission [1 admission per 25 pump users per year versus 1 admission per 11 nonpump users per year]; P=0.01), and attend more endocrine appointments within the past 12 months (mean [SD],2.5 [1.4] visits versus 1.9 [1.5] visits; P<0.001).”

Limitations of the study include the different patient enrollment criteria at the two centers and the variation in method for grading fundus images between the two centers.

1. Insulin pump use in this study was associated with a decreased risk of children and young adults developing diabetic retinopathy.

2. The researchers found that the insulin pump use was protective against diabetic retinopathy independent of A1c levels.

Candace Hoffmann, Managing Editor, BreakingMED™

Cat ID: 12

Topic ID: 76,12,730,446,12,138,669,918