How Does Health Status Affect Insulin Use in Older Individuals With Type 2 Diabetes?

Among older individuals with type 2 diabetes, insulin use is least prevalent in those in good health, and discontinuation of insulin treatment is most likely in healthier patients, according to study results published in JAMA Internal Medicine.

Current treatment guidelines for type 2 diabetes recommend that healthier individuals with longer life expectancies be treated to lower glycemic targets. Unhealthy individuals with multiple comorbidities may be at increased risk for hypoglycemia with similarly aggressive treatment, and concerns have been raised for potential insulin overtreatment in this population. Researchers aimed to investigate the prevalence of insulin use in patients 75 years of age and assess the factors governing insulin discontinuation over a 4-year follow-up.

A total of 21,531 individuals (48.3% women) with type 2 diabetes were included in the study cohort from the Kaiser Permanente North California Diabetes Registry. Patients were 75 years of age at the start of the study and were assessed for their baseline insulin use and health status. Insulin use was assessed at the start of the study and for each 6-month period during follow-up. Discontinuation of insulin use was defined as having no insulin dispensed over the prior 6 months.

Health status categories were based on the prevalence of comorbidities, functional status, and indicators of end-stage disease (eg, home oxygen use). Individuals in good health were defined as having fewer than 2 comorbidities or 2 comorbidities with evidence of physical activity; those in intermediate health were defined as experiencing more than 2 comorbidities or 2 comorbidities with no self-reported physical activity or use of a walker; and poor health was defined as having any end-stage disease.

The overall rate of insulin use at the start of the study was 18.9%, and was most reported among patients in poor health (29.4%) compared with those in intermediate health (27.5%) or good health (10.5%; P <.01). Compared with healthy individuals, patients in poor health had the greatest likelihood of insulin use (adjusted risk ratio, 2.03; 95% CI, 1.87-2.20; P <.01), followed by those in intermediate health (adjusted risk ratio, 1.85; 95% CI, 1.74-1.97; P <.01).

Of the patients who used insulin at the start of the study, the rate of discontinuation was 32.7% over the course of follow-up and was greatest among patients in good health (38.9%), followed by those in intermediate health (32.7%) and those in poor health (27.6%; P <.01). Compared with healthy individuals, the likelihood of continued insulin use was highest among patients in poor health (adjusted risk ratio, 1.47; 95% CI, 1.27-1.67; P <.01), followed by those in intermediate health (adjusted risk ratio, 1.16; 95% CI, 1.05-1.30; P <.01).

The researchers noted that the generalizability of the study may be limited, as individuals were included only from an insured population within an integrated health system. In addition, as insulin use was assessed as the rate of insulin dispensed rather than ordered, reason for insulin discontinuation (ie, clinician vs patient driven) cannot be determined.

“The results of this study suggest that neither prevalent insulin use nor subsequent insulin discontinuation among older patients is closely aligned with current recommendations to incorporate health status (in conjunction with life expectancy and patient preferences) when making treatment decisions,” the researchers concluded. “The substantial and persistent insulin use among older adults with a high risk of hypoglycemia and limited future benefit suggests that more work is needed to develop systems-based approaches that support guideline-concordant insulin use in people older than 75 years.”

Disclosures: Funding for the study was provided by the Kaiser Permanente of Northern California.

Reference

Weiner JZ, Gopalan A, Mishra P, et al. Use and discontinuation of insulin treatment among adults aged 75 to 79 years with type 2 diabetes [published online September 23, 2019]. JAMA Intern Med. doi:10.1001/jamainternmed.2019.3759