From the Guidelines
For a type 1 diabetic experiencing exertional breathlessness with moderately controlled blood glucose on a basal-bolus insulin regimen, a comprehensive cardiopulmonary workup is essential to rule out underlying cardiac and pulmonary causes, with a focus on optimizing diabetes management and evaluating for potential complications such as diabetic cardiomyopathy or autonomic neuropathy. Begin with basic tests including spirometry, chest X-ray, ECG, and echocardiogram to assess for both cardiac and pulmonary causes, as recommended by recent guidelines 1. Laboratory tests should include HbA1c, complete blood count, comprehensive metabolic panel, BNP, and thyroid function tests to identify any underlying conditions that may be contributing to breathlessness. Ensure the patient's diabetes management is optimized by adjusting insulin dosing to achieve target blood glucose levels (typically 80-130 mg/dL before meals and <180 mg/dL post-meals) and an HbA1c <7%, as suggested by recent studies 1. Consider diabetic complications that could contribute to breathlessness, particularly diabetic cardiomyopathy or autonomic neuropathy affecting cardiac function, and evaluate for these conditions using tests such as echocardiogram and exercise stress testing 1. Pulmonary function tests can identify restrictive or obstructive patterns, and coronary artery disease assessment may be warranted in patients with long-standing diabetes due to their higher risk of cardiovascular disease. Addressing any anemia, thyroid dysfunction, or electrolyte imbalances is also important as these conditions can exacerbate breathlessness. Some key points to consider in the evaluation and management of exertional dyspnea in a patient with type 1 diabetes include:
- Optimizing diabetes management to achieve target blood glucose levels and HbA1c
- Evaluating for underlying cardiac and pulmonary causes of breathlessness
- Considering diabetic complications such as cardiomyopathy or autonomic neuropathy
- Assessing for anemia, thyroid dysfunction, or electrolyte imbalances
- Using tests such as spirometry, chest X-ray, ECG, and echocardiogram to evaluate cardiac and pulmonary function. The connection between diabetes and breathlessness often relates to microvascular complications affecting lung tissue, cardiac function, or skeletal muscle metabolism, all of which can impair oxygen delivery and utilization during exertion, highlighting the importance of a comprehensive evaluation and management approach 1.
From the Research
Possible Causes of Exertional Dyspnea
- Exertional dyspnea in a patient with type 1 diabetes mellitus (T1DM) can be caused by various factors, including respiratory, cardiovascular, and muscular issues 2
- Chronic exertional compartment syndrome is a possible cause of exertional dyspnea in patients with diabetes, particularly those with a long duration of the disease 3
- Exercise-induced hypoglycemia is a common barrier to exercise in T1D, and hypoglycemia can cause symptoms such as breathlessness 4
- Abnormally high exertional breathlessness can predict mortality in people referred for incremental cycle exercise testing, suggesting that exertional dyspnea may be a marker of underlying cardiorespiratory disease 5
Assessment and Measurement of Exertional Dyspnea
- Exertional breathlessness can be assessed using multidimensional tools in response to a standardized and individualized exercise stimulus 6
- Constant work rate tests, such as the 3-min constant-rate stair stepping and walking tests, can be used to quantify breathlessness response 6
- The Borg 0-10 scale can be used to measure breathlessness intensity during incremental exercise testing 5
Relationship between Exertional Dyspnea and Diabetes
- Patients with T1D are at risk of developing exertional dyspnea due to various factors, including chronic exertional compartment syndrome and exercise-induced hypoglycemia 4, 3
- Exertional dyspnea can limit exercise tolerance and mobility in patients with T1D, which can have negative impacts on quality of life and disease management 2