Elderly Man Survives Severe Hypoglycemia Caused by Insulin Overdose at Age 73

Understanding a Life-Threatening Case of Insulin-Induced Hypoglycemia

In elderly patients with type 2 diabetes, insulin therapy is often essential for maintaining glycemic control. However, improper dosing—especially in older adults—can lead to dangerous complications such as severe hypoglycemia. This case report explores the medical journey of a 73-year-old male who experienced sudden loss of consciousness due to accidental insulin overdose. Prompt diagnosis and timely glucose intervention prevented long-term neurological damage, highlighting the importance of safe insulin management in aging populations.

Patient Overview and Clinical Presentation

Demographics: Male, 73 years oldDiagnosis: Acute hypoglycemic encephalopathy secondary to insulin overdoseHospital: Beijing Hospital (patient data anonymized)Date of Admission: October 2020Treatment Approach: Intravenous dextrose infusion + adjunctive hyperbaric oxygen therapyDuration of Hospitalization: 6 daysOutcome: Full recovery with stabilized blood glucose levels; discharged in stable condition

Symptoms Leading to Emergency Care

The patient was brought to the emergency department after being found unconscious at home around 4:20 AM. Family members reported that he was unresponsive when called, had deep breathing, excessive salivation, and had vomited twice without signs of projectile vomiting or blood. There were no indications of seizures, facial drooping, or incontinence. Initial assessment revealed a critically low blood glucose level of 1.8 mmol/L on arterial blood gas testing. A non-contrast head CT scan showed no evidence of hemorrhage or stroke, ruling out acute cerebrovascular events.

Upon admission, vital signs were relatively stable: temperature 36.5°C, heart rate 72 bpm, respiratory rate 18 breaths per minute, and blood pressure 128/70 mmHg. Physical examination indicated mild lethargy but intact pupillary response, clear lung sounds, regular cardiac rhythm, and soft abdomen without tenderness. Neurological evaluation did not reveal focal deficits. The patient had a 15-year history of type 2 diabetes managed with acarbose, gliclazide, and bedtime subcutaneous injections of recombinant human insulin (NPH formulation), with previously well-controlled glucose readings.

Diagnostic Evaluation and Treatment Strategy

Laboratory investigations post-admission—including complete blood count, coagulation profile, liver and kidney function tests, thyroid function panels, urinalysis, stool analysis, HbA1c, BNP, and cardiac enzymes—were all within normal limits. Echocardiography revealed mildly impaired left ventricular diastolic function, while carotid ultrasound detected bilateral intima-media thickening, suggesting early atherosclerotic changes.

Confirming the Cause: Accidental Insulin Misuse

After reviewing medication logs with family members, it became evident that the patient may have mistakenly administered a higher-than-prescribed dose of insulin the night before symptom onset. Given his age, cognitive factors such as forgetfulness or misreading dosage instructions could have contributed. With confirmed hypoglycemia (glucose: 1.8 mmol/L) and rapid improvement following intravenous glucose infusion, the diagnosis of insulin-induced hypoglycemic coma was established.

Immediate Intervention: Continuous intravenous administration of 50% dextrose solution followed by maintenance with 10% dextrose to stabilize blood glucose near 10 mmol/L. Intermittent boluses of concentrated glucose were used based on real-time capillary glucose monitoring.

Recovery Process and Supportive Therapies

On day two of hospitalization, the patient regained full consciousness, responded appropriately to questions, and resumed independent mobility. Hyperbaric oxygen therapy was initiated to support cerebral metabolic recovery and reduce potential oxidative stress from transient brain ischemia during hypoglycemia.

By day three, intravenous glucose was discontinued, and the patient transitioned back to a standard diabetic diet. Capillary glucose measurements remained between 7–10 mmol/L throughout the day. On day five, a C-peptide release test indicated delayed insulin secretion peak, consistent with long-standing beta-cell dysfunction in chronic diabetes.

Discharge Readiness and Follow-Up Plan

On day six, fasting glucose levels ranged from 5–7 mmol/L, and postprandial values stayed below 10 mmol/L. Repeat biochemical panels showed normalization of all parameters. With clinical stability confirmed, the patient was discharged with a revised treatment plan focused on safety and sustainability.

Key Recommendations for Long-Term Management

To prevent future episodes, several critical strategies were emphasized:

Individualized Glycemic Targets: For older adults, strict glucose control increases hypoglycemia risk. Aim for pre-meal glucose under 8 mmol/L and post-meal levels under 10 mmol/L.
Insulin Safety Measures: Due to risks of calculation errors or double-dosing, caregivers should supervise insulin administration whenever possible.
Mental Health Monitoring: Depression, anxiety, and diabetes-related distress are common in elderly patients. Regular psychological screening using validated tools like the Diabetes Distress Scale (DDS) or PHQ-9 can help detect emotional struggles early.
Dietary Consistency: Eating regular meals with balanced carbohydrates helps maintain steady glucose levels and reduces hypoglycemia risk.
Self-Monitoring Education: Teach patients and families how to recognize early signs of low blood sugar—such as sweating, tremors, confusion—and initiate immediate treatment with fast-acting sugars.

Clinical Insights and Broader Implications

Why This Case Matters

While insulin remains a cornerstone in diabetes care, this case underscores its potential dangers in vulnerable populations. Studies show that the average age of individuals experiencing acute insulin toxicity is approximately 44.7 years, with up to 89.4% of cases linked to intentional overdose. In contrast, our patient's overdose appeared unintentional—likely due to age-related memory lapses or misunderstanding of injection protocols.

Research also links intensive insulin regimens with increased psychological burden. Stricter glycemic goals often require higher insulin doses, which elevate both physical and mental strain. Adopting more flexible targets not only improves safety but also enhances quality of life.

A Holistic Approach to Diabetes Care

Beyond pharmacological management, comprehensive diabetes care must include psychosocial support. Tools such as the Family Support Scale and Generalized Anxiety Disorder (GAD-7) scale can identify gaps in coping mechanisms. Integrating mental health services, caregiver involvement, and structured education programs into routine follow-ups significantly reduces adverse outcomes.

Moreover, continuous glucose monitoring (CGM) systems and smart insulin pens may offer technological safeguards against accidental overdoses, particularly in high-risk seniors living alone.

Final Thoughts

This case serves as a powerful reminder that effective diabetes management goes beyond numbers on a lab report. It requires empathy, individualized planning, and multidisciplinary collaboration. By prioritizing patient safety, simplifying treatment regimens, and addressing emotional well-being, healthcare providers can protect elderly patients from life-threatening complications—even those caused by life-saving medications like insulin.