Study rationale and findings
Hospitalized older adults with diabetes commonly have transiently elevated blood glucose levels that might lead clinicians to discharge them from hospital with a prescription for more intensive diabetes medications than they were on before they were hospitalized, but it is not clear if these diabetes medication changes would improve outcomes.
To investigate this, the researchers analyzed data from patients with diabetes who were 65 and older and hospitalized for common medical conditions in VHA hospitals during January 2011–September 2016, and then discharged to the community.
They excluded patients who were hospitalized for things that require immediate change in diabetes treatment and patients who were using insulin before their hospitalization (because instructions to modify insulin dosing frequently don’t have a new prescription).
The researchers identified 28,198 adults with diabetes who were not on insulin and were hospitalized in the VHA health system for heart failure (18%), coronary artery disease (13%), chronic obstructive pulmonary disease (10%), pneumonia (9.6%), and urinary tract infection (7.5%), and less often and not in decreasing order, for acute coronary syndrome, arrhythmia, asthma, chest pain, conduction disorders, heart valve disorders, sepsis, skin infection, stroke, and transient ischemic attack.
Of these patients, 2,768 patients (9.8%) received diabetes medication intensification, and the researchers matched 2,648 of these patients with an equal number of patients who did not receive this treatment intensification.
The patients in each group had a mean age of 73 and 98.5% were male; 78% were White.
They had a mean A1c of 7.9%. Most were receiving sulfonylurea (43%) or metformin (39%), and few were receiving thiazolidinediones (4.1%), alpha-glucosidase inhibitors (2.7%), dipeptidyl peptidase 4 inhibitors (2.0%), or other types of diabetes drugs (0.1%).
Of the 2,768 patients who received intensified diabetes medication, most received a prescription for insulin (51%) or sulfonylurea (23%).
In the propensity-matched cohort, patients with intensified diabetes medication had a higher rate of severe hypoglycemia at 30 days (1% vs. 0.5%), which translated into a significant twofold higher risk (hazard ratio, 2.17).
The rates of severe hypoglycemia at 1 year were similar in both groups (3.1% and 2.9%).
The incidence of severe hyperglycemia was the same in both groups at 30 days (0.3%) and 1 year (1.3%).
In secondary outcomes, at 1 year, 48% of new oral diabetes medications and 39% of new insulin prescriptions were no longer being filled.
Overall, patients who were discharged with intensified diabetes medication were significantly less likely to die within 30 days than the other patients (1.3% vs. 2.4%; HR, 0.55).
However, this mortality benefit was found only in the subgroup of 2,524 patients who had uncontrolled diabetes when they were admitted to hospital (A1c >7.5%; mean A1c, 9.1%), and not in the propensity-matched subgroup of 2,672 patients who had controlled diabetes then (A1c up to 7.5%; mean A1c, 6.8%).
There was no significant difference in 1-year mortality in patients with versus without intensified treatment (15.8% vs. 17.8%).
There were also no significant between-group difference in rates of hospital readmission at 30 days (roughly 17%) or 1 year (roughly 51%).
The decreases in mean A1c from hospital discharge to 1 year later were also the same in both groups (going from 7.9% to 7.7%).
The study was funded by grants from the National Institute on Aging and the American College of Cardiology. Dr. Anderson has no relevant financial disclosures. Dr. McCoy reported receiving grants from the National Institute of Diabetes and Digestive and Kidney Diseases, AARP, and the Patient-Centered Outcomes Research Institute outside the submitted work. The disclosures of the other authors and the editorial coauthor are available with the article and commentary.