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Are Older Adults Being Overtreated for Diabetes?

Jul 3, 2021
 
Editor: David L. Joffe, BSPharm, CDE, FACA

Author: Brenda Oppong, PharmD Candidate, LECOM School of Pharmacy

Older adults with diabetes may be at risk of adverse events such as hypoglycemia when overtreated with certain medications. 

The risk of diabetes increases with age. Over 25% of adults age ≥75 years have diabetes and are at risk of experiencing adverse events related to their treatment. Older adults with diabetes are especially at risk of hypoglycemia when receiving intense treatment for glycemic control. Intensive glycemic control when treating patients with diabetes is generally beneficial and recommended due to the reduced risk of developing long-term complications. However, guidelines recommend relaxing glycemic targets in older adults due to the risk of hypoglycemia. Unfortunately, there is continual evidence of overtreatment in older adults. Particular blood glucose-lowering agents such as insulin and sulfonylureas increase the risk of hypoglycemia. Very few studies have focused on the risk of high-risk agents when treating a patient with diabetes with intensive glycemic targets. A retrospective population-based cohort study was conducted on older adults living in the community, using databases in Ontario, Canada. 

 

The databases have been used intensively for the study of older adults with diabetes in Ontario. The participants were Ontario residents aged ≥75 years diagnosed with diabetes who had been prescribed at least one antihyperglycemic agent between September 1, 2014, and August 31, 2015. The participants had to have been diagnosed with diabetes at least one year before the index date. Participants with poorly controlled diabetes HbA1c >69 mmol/mol were excluded from the study due to a higher risk of mortality, hospitalization, and complications caused by factors beyond their diabetes treatment and glycemic control. The individuals were categorized into four groups based on HbA1c at index date and current prescription for diabetes. Glycemic control was categorized as intensive (HbA1c <53 mmol/mol [<7.0%]) or conservative (HbA1c 54–69 mmol/mol [7.1–8.5%]). Each group was divided into subgroups: one group for patients taking at least one high-risk agent (insulin/ sulfonylurea); the other group included individuals taking only one or more low-risk agents (metformin, dipeptidyl peptidase 4 inhibitor, acarbose, thiazolidinediones). 108,620 people were included in the study, 23,484 (21.6%) had intensive glycemic control with high-risk agents; 42,857 (39.5%) had intensive glycemic control with low-risk agents; 25,791 (23.7%) had conservative glycemic control on high-risk agents; and 16,488 (15.2%) with conservative glycemic control on low-risk agents. The primary interest of the study was to observe whether potential overtreatment was represented by intensive glycemic control with high-risk antihyperglycemic agents. 

The primary outcome was a composite measure described as diabetes-related (including hypoglycemia) emergency department (ED) visits or hospitalization or all-cause mortality within 30 days of the index date. The number of individuals with intensive control taking high-risk agents (n = 23,484) was considerably higher than those taking low risk agents (n = 23,484) but smaller than the other two comparator groups (n = 42,857 and n = 25,791). The primary outcome assessment was repeated with an extended 90 days follow-up period to assess longer-term risks associated with intensive glycemic control with high-risk agents. Among the individuals with intensive control taking high-risk agents, 0.92% experienced the primary outcome at 30 days, compared to 0.41% among the individuals with conservative glycemic controls taking low-risk agents, 0.67% among those with conservative glycemic control with high-risk agents, and 0.42% among those with intensive control taking low-risk agents. Weighted analysis results showed a significantly increased risk associated with intensive control with high-risk agents versus conservative glycemic control with high-risk agents. The 90 days extended follow-up showed a 27% increased risk in those with intensive glycemic control with high-risk agents compared to an individual with conservative glycemic control with low-risk agents. However, there was no difference in the follow-up outcome of individuals taking high-risk agents with either conservative or intensive glycemic control. The participants with intensive glycemic control with high-risk agents had a substantially increased risk of hypoglycemia-related ED visits/hospitalization. They increased diabetes-related (excluding hypoglycemia) ED visits/hospitalization and no increased risk of all-cause mortality. 

The database showed that a high proportion of older adults with diabetes in Ontario, Canada, are treated with intensive glycemic targets. One in five are exposed to potentially harmful drugs. There was reportedly close to a 50% increase in short-term risk of diabetes-related deaths or hospitalization associated with intensive glycemic control with insulin or sulfonylureas. 

Practice Pearls:  

  • Ongoing efforts are needed to reduce the burden of overtreatment in treating older adults with diabetes.  
  • The harm outweighs the benefits when treating older adults with intensive glycemic control with high-risk agents. 
  • The guidelines recommend that relaxed glycemic control for older adults is necessary for the safety and efficacy of their diabetes treatment. 

 

Reference for “Are Older Adults Being Overtreated for Diabetes?”:
Lega, Iliana C et al. Potential diabetes overtreatment and risk of adverse events among older adults in Ontario: a population-based study
. Diabetologia; May 2021. 

 

Brenda Oppong, PharmD Candidate, LECOM School of Pharmacy 

 

See more about diabetes in older adults.