Hypoglycemia and Impaired Renal Function

Case Study: An Elderly Patient With Hypoglycemia and Impaired Renal Function

—This case shows the importance of re-evaluating treatment regimens to address adverse effects without exacerbating other comorbidities.

This case presents an elderly man with type 2 diabetes and impaired renal function. He has recently been experiencing hypoglycemia with his current treatment regimen. The importance of re-evaluating treatment regimens to address adverse effects without exacerbating other comorbidities, such as renal dysfunction, is discussed.

Case presentation and patient assessment

An 84-year-old man with type 2 diabetes is admitted to the hospital with altered mental status and hypoglycemia. He had experienced recurring episodes of mild hypoglycemia over the previous week, which were managed with food. With this episode, however, he could not be aroused, so the family called EMS. His past medical history includes chronic lymphocytic leukemia, gout, hypertension, and atrial fibrillation. Approximately 6 weeks ago, his serum creatinine increased from 1.6 mg/dL to 2.4 mg/dL following a bout of pneumonia. He had been taking glimepiride 4 mg twice daily. He admitted that he sometimes skipped the dose entirely because of hypoglycemia, and when he did so, his glucose was >200 mg/dL. His glycosylated hemoglobin (HbA1c) is 6.9%. Information and laboratory values collected at the hospital are as follows:

• Height, 5’9”
• Weight, 198 lb
• BMI, 28
• BP, 114/73 mm Hg
• Current medications, glimepiride 4 mg BID and atorvastatin 10 mg QD
• HbA1c, 6.9%
• Lipids, LDL-C 45 mg/dL; HDL-C 55 mg/dL; Total-C 109 mg/dL; triglycerides 47 mg/dL
• Serum creatinine 1.94 mg/dL

Diagnosis

The patient is found to have acceptable glycemic control, but unacceptable episodes of severe hypoglycemia. His worsening renal dysfunction and poor overall health status were likely responsible for the hypoglycemia, since he had tolerated glimepiride in the past. Hypoglycemia with his current treatment regimen was a particular concern given his age, concomitant renal disease, and other comorbidities.

Treatment

While in the hospital, the patient required a small dose of insulin glargine to control his blood glucose, 16 units.

This patient is elderly and has other comorbidities, including moderate renal impairment. Developing a treatment plan that helps maintain normal glucose levels with little or no associated hypoglycemia as well as limited complexity is important for this elderly patient.¹Lastly, renal dysfunction and advanced age are two key risk factors for hypoglycemia.^1-3

At discharge, the decision was made to discontinue insulin glargine and initiate oral therapy with a dipeptidyl peptidase-4 inhibitor, given the low rates of hypoglycemia associated with this class and ease of use (ie, oral administration).¹

Linagliptin 5 mg/day was prescribed at hospital discharge, and a follow-up visit was scheduled in 2 weeks. At the follow-up appointment, the patient reported that he was feeling well and eating better. He stated that his glucose ranged from 140 mg/dL to 210 mg/dL. His serum creatinine had increased to 2.4 mg/dL. He has had no hypoglycemic episodes since leaving the hospital. At this time, a small dose of insulin glargine was added to his glucose-lowering regiment (8 units), with adjustments made on an outpatient basis.

At a 6-month follow-up, the patient’s HbA1c was 6.6%. He reported that his glucose ranges from 110 mg/dL to 155 mg/dL, and he had not experienced any hypoglycemia. His serum creatinine was 1.99 mg/dL. Information and laboratory values collected during the 6-month follow-up visit are summarized here:

• Weight, 186 lb
• BP, 112/70 mm Hg
• Current medications, linagliptin 5 mg/d; insulin glargine 10-14 units/day; atorvastatin 10 mg QD
• HbA1c, 6.6%
• Lipids, LDL-C 28 mg/dL; HDL-C 38 mg/dL; Total-C 103 mg/dL; triglycerides 73 mg/dL
• Serum creatinine 1.99 mg/dL

Over the next 2 years, the patient’s serum creatinine fluctuated from 1.7 mg/dL to 2.5 mg/dL. He required additional chemotherapy for chronic lymphocytic leukemia with small cell lymphoma. His diabetes remained stable on the same regimen of linagliptin 5 mg/day and insulin glargine 10 to 14 units/day.