Among older adults with type 2 diabetes, insulin use most prevalent in those with poor health
In a longitudinal study of 21,531 patients, those in poor or intermediate health at age 75 years were more likely to use insulin than those in good health (29.4% and 27.5% versus 10.5%, respectively) and less likely to discontinue it during follow-up.
Older adults with type 2 diabetes who are in poor health may be more likely to receive insulin therapy, according to a recent study.
Researchers performed a longitudinal cohort study using data from the Kaiser Permanente Northern California Diabetes Registry to determine whether insulin is used less frequently and discontinued more frequently in adults with poor versus good health. Patients with type 2 diabetes were followed for up to four years beginning at age 75 years. Good, intermediate, and poor health status were defined as fewer than two comorbid conditions or two comorbid conditions but physically active, more than two comorbid conditions or two comorbid conditions and no self-reported weekly exercise, and end-stage pulmonary, cardiac, or renal disease, dementia, or metastatic cancer, respectively. The main outcome measures were prevalence of insulin use at age 75 years and discontinuation over the next four years, or six months before death. The study results were published Sept. 23 by JAMA Internal Medicine.
Overall, 21,531 patients were included in the study. Of these, 10,396 (48.3%) were women and 4,076 (18.9%) used insulin. Mean follow-up was 3.7 years, and mean diabetes duration was 9.4 years. At baseline, 51.3% of the cohort were in good health, 40.1% were in intermediate health, and 8.6% were in poor health. At age 75 years, patients in poor health and those in intermediate health were more likely to be using insulin than those in good health (29.4% and 27.5% versus 10.5%, respectively). Adjusted risk ratios for insulin use were also higher in patients with poor health (2.03 [95% CI, 1.87 to 2.20]) and intermediate health (1.85 [95% CI, 1.74 to 1.97]) (P<0.01 for each comparison with those in good health, the reference group). Among patients using insulin at age 75 years, 1,335 (32.7%) discontinued it within four years of entering the cohort and at least six months before death. Patients in poor and intermediate health had a higher likelihood of continuing insulin use (adjusted risk ratios, 1.47 [95% CI, 1.27 to 1.67] and 1.16 [95% CI, 1.05 to 1.30]; P<0.01 for each comparison with the reference group). No difference in these prevalence and discontinuation patterns was seen when researchers looked only at patients with tight glycemic control, defined as an HbA1c below 7.0%. Three variables, diabetes duration less than 10 years, HbA1c level less than 7.0%, and long-acting insulin use, were independently associated with discontinuation of insulin.
Among other limitations, the researchers said their study was observational and included only insured patients in an integrated health system, which may limit the generalizability of their findings. They concluded that in this population, older adults in poor health were most likely to be using insulin and that discontinuation of insulin was more likely among older adults who were healthy. Their findings suggest that patients' health status is not always considered in decision making about insulin use and subsequent discontinuation in older adults with diabetes, they said.
“As the population with type 2 diabetes continues to age, there is a growing need for evidence-based treatment strategies related specifically to the use of insulin for these older patients,” the authors wrote. “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.”