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Switch from analogue to human insulin safe, cost-effective in older adults with type 2 diabetes

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January 29, 2019

Older adults with type 2 diabetes who switched from analogue to human insulin as part of a managed care intervention experienced a small increase in HbA1c over 12 months but no increase in serious hypoglycemia or hyperglycemia when compared with baseline outcomes, according to findings published in JAMA.

Jing Luo

“This was a real-world, pragmatic study of a health plan intervention switching 14,000 older adults with type 2 diabetes from analogue to human insulin,” Jing Luo, MD, MPH, an instructor of medicine in the division of pharmacoepidemiology and pharmacoeconomics at Brigham and Women’s Hospital and Harvard Medical School, told Endocrine Today. “We found that the switch intervention was not associated with substantially worsened glycemic control or increased risk of serious hypoglycemia but was associated with cost-savings and reduced risk of reaching the Medicare Part D coverage gap.”

Goals of insulin switch

In a retrospective study, Luo and colleagues analyzed member data from CareMore, a managed accountable care organization and Medicare Advantage plan based in Cerritos, California, serving members in Arizona, California, Nevada and Virginia. Members filled at least one insulin prescription from 2014 to 2016 (mean age, 73 years; 51% women; 93% with type 2 diabetes). In 2015, the organization piloted an intervention to switch members from analogue to human insulin, with a preference for regimens containing fewer daily injections, according to the study background. Goals of the intervention, according to researchers, were to reduce daily injection burden and delay or avoid the Medicare Part D coverage gap for members with insufficient coverage. Researchers evaluated the association between the intervention and outcomes, including change in mean HbA1c estimated for three 12-month periods: preintervention (baseline) in 2014, intervention in 2015 and postintervention in 2016. Secondary outcomes included rates of serious hypoglycemia and hyperglycemia, as well as the proportion of members who reached the Medicare Part D coverage gap and total spending on insulin products.

Glycemic changes

Over 3 years, 14,635 members filled 221,866 insulin prescriptions (median follow-up time, 729 days). Mean HbA1c was 8.46% at baseline and decreased at a mean rate of –0.02% per month in the year before the intervention (2014).

Researchers observed an association between the start of the intervention and an overall mean HbA1c increase of 0.14% (95% CI, 0.05-0.23) and a slope change of 0.02% (95% CI, 0.01-0.03). However, at the completion of the intervention, researchers did not observe any between-group differences in HbA1c (0.08%; 95% CI, –0.01 to 0.17) or in slope of mean HbA1c (< 0.001%; 95% CI, –0.008 to 0.01) when compared with the intervention period.

The intervention was not associated with changes in rates of serious hypoglycemia or hyperglycemia.

Economic outcomes

Researchers found that total monthly expenditures for analogue insulin increased from $2,226,389 in January 2014 to a high of $3,214,437 by December 2014. By December 2015, monthly expenditures for analogue insulins decreased to $1,372,942, and fell to $515,875 by December 2016. The percentage of members who reached the Medicare Part D coverage gap fell from 20.6% in 2014 to 11.1% in 2016.

“It may be clinically appropriate and cost-saving to switch many older adults with type 2 diabetes from analogue to human insulins,” Luo said. “Follow-up studies should examine patient adherence after switching to human insulin, persistence and satisfaction with the human insulin regimens, as well as provide more detailed economic analyses.” – by Regina Schaffer

Disclosures: Luo reports he consults for the nonprofit groups Alosa Health and Health Action International.

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This is a large study showing the efficacy of human insulin in a population of insulin-requiring type 2 diabetes. The lack of significant clinical difference with a dramatic reduction of costs needs to be appreciated by both clinicians and patients. However, there are several caveats we need to appreciate. These are individuals with relatively poorly controlled type 2 diabetes. Initial HbA1c level was 8.46%, which would correlate to a mean glucose of approximately 215 mg/dL ( How would this study differ if initial starting HbA1c was 7.5% or 7%? Would we expect greater rates of hypoglycemia, especially nocturnal hypoglycemia, similar to what we saw in the original studies comparing NPH insulin with insulin analogues?

I also wonder about frequency of home blood glucose monitoring. While there are increasing data about the lack of efficacy of home blood glucose monitoring in noninsulin-requiring patients (Young LA, et al. JAMA Intern Med. 2017;doi:10.1001/jamainternmed.2017.1233), there is no argument about the need for glucose monitoring with home blood glucose monitoring or continuous glucose monitoring for patients requiring over 50 U of insulin per day, as in this trial.

It therefore appears that before we switch all of our type 2 patients to human insulin, the results of this study need to be interpreted with caution. What we really need is a randomized trial with modern-day glucose monitoring technology, treating patients to agreed-upon glucose and HbA1c targets. My prediction is that human insulin would do well, but the study would need to be completed to make any definitive conclusions. Nevertheless, for all of the poorly controlled patients with very high HbA1c levels (≥ 9%) needing to initiate insulin therapy, clinicians should feel safe starting with human insulin.

Irl B. Hirsch, MD

Professor of Medicine,
University of Washington School of Medicine

Disclosure: Hirsch reports he has received consultant fees from Abbott Diabetes Care, Intarcia and Roche Diagnostics.