Hypoglycemia in Athletes with Diabetes

General Medical Emergencies in Athletes

This article focuses on the management of the most common on-field medical emergencies. As with any discipline in medicine, a well-defined plan and systematic approach is the cornerstone of quality health care delivery. In addition, the team-based collaboration is necessary for the safety of the athlete and the success of the treatment plan.

American Medical Society for Sports Medicine Position Statement on the Care of the Athlete and Athletic Person With Diabetes

ABSTRACT

The American Medical Society for Sports Medicine (AMSSM) developed this position statement to assist physicians and other health professionals in managing athletes and active people with diabetes. The AMSSM selected the author panel through an application process to identify members with clinical and academic expertise in the care of active patients with diabetes. This article reviews the current knowledge and gaps regarding the benefits and risks of various types of exercise and management issues for athletes and physically active people with diabetes, including nutrition and rehabilitation issues. Resistance exercises seem to be beneficial for patients with type 1 diabetes, and the new medications for patients with type 2 diabetes generally do not need adjustment with exercise. In preparing this statement, the authors conducted an evidence review and received open comment from the AMSSM Board of Directors before finalizing the recommendations.

Exercise Testing in Individuals With Diabetes, Practical Considerations for Exercise Physiologists

Exercise and sports activities are crucial for individuals with diabetes. Diabetic patients are often referred to sports clinics for cardiopulmonary exercise testing to evaluate physical capacity, exercise-related symptoms, or to obtain medical clearance. While there is an abundance of literature on cardiopulmonary testing, practical recommendations for exercise physiologists and sports clinic specialists performing exercise testing for this specific population are lacking. The goal of this report is to provide a practical framework to understand, prepare, and perform exercise testing in patients with diabetes, maximizing exercise physiology outcomes, diagnostic value, and ensuring safety.

Care of the Athlete With Type 1 Diabetes Mellitus: A Clinical Review

CONTEXT

Type 1 diabetes mellitus (T1DM) results from a highly specific immune-mediated destruction of pancreatic β cells, resulting in chronic hyperglycemia. For many years, one of the mainstays of therapy for patients with T1DM has been exercise balanced with appropriate medications and medical nutrition. Compared to healthy peers, athletes with T1DM experience nearly all the same health-related benefits from exercise. Despite these benefits, effective management of the T1DM athlete is a constant challenge due to various concerns such as the increased risk of hypoglycemia. This review seeks to summarize the available literature and aid clinicians in clinical decision-making for this patient population.

EVIDENCE ACQUISITION

PubMed searches were conducted for "type 1 diabetes mellitus AND athlete" along with "type 1 diabetes mellitus AND exercise" from database inception through November 2015. All articles identified by this search were reviewed if the article text was available in English and related to management of athletes with type 1 diabetes mellitus. Subsequent reference searches of retrieved articles yielded additional literature included in this review.

RESULTS

The majority of current literature available exists as recommendations, review articles, or proposed societal guidelines, with less prospective or higher-order treatment studies available. The available literature is presented objectively with an attempt to describe clinically relevant trends and findings in the management of athletes living with T1DM.

CONCLUSIONS

Managing T1DM in the context of exercise or athletic competition is a challenging but important skill for athletes living with this disease. A proper understanding of the hormonal milieu during exercise, special nutritional needs, glycemic control, necessary insulin dosing adjustments, and prevention/management strategies for exercise-related complications can lead to successful care plans for these patients. Individualized management strategies should be created with close cooperation between the T1DM athlete and their healthcare team (including a physician and dietitian).

Accuracy assessment of online glucose monitoring by a subcutaneous enzymatic glucose sensor during exercise in patients with type 1 diabetes treated by continuous subcutaneous insulin infusion

AIM

Online continuous glucose monitoring (CGM) during physical exercise would be highly useful in patients with insulin-treated diabetes. For this reason, this study assessed whether such a goal could be reached with a subcutaneous 'needle-type' enzymatic sensor.

METHODS

Ten patients (five women/five men), aged 51 ± 12 years, with type 1 diabetes for 24 ± 11 years treated by continuous subcutaneous insulin infusion (CSII) for more than 1 year (HbA1c: 7.5 ± 0.8%) performed a 30-min bout of exercise at a constant high-intensity load (15% above their individual ventilatory threshold) on a cycle ergometer. All patients wore a subcutaneous 'needle-type' enzymatic glucose sensor linked to a portable monitor (Guardian(®) RT, Medtronic-MiniMed, Northridge, CA, USA) that had been inserted the previous evening. Sensor calibration was performed against capillary blood glucose immediately before the exercise. CGM values were recorded every 5 min from T(-10) to T(+30), then every 10 min during the recovery period from T(+30) to T(+90). These recorded values were compared with blood glucose assays performed on simultaneously collected venous samples.

RESULTS

Sensor functioning and tolerability raised no problems except for one sensor that could not be adequately calibrated. Data from this patient were excluded from the data analysis. An average blood glucose decrease of 63 ± 63 mg/dL (3.5 ± 3.5 mmol/L) (median decrease: 58 mg/dL [3.22 mmol/L]; range: -3 mg/dL [0.16 mmol/L] to 178 mg/dL [9.8 mmol/L]) occurred during exercise bouts, while CGM values decreased by 38 ± 49 mg/dL (2.11 ± 2.72 mmol/L) (median: 32 mg/dL [1.7 mmmol/L]; range: -15 mg/dL [0.83 mmol/L] to 58 mg/dL [3.22 mmol/L]). Cumulative paired glucose values (n = 135) could be analyzed. The correlation factor between CGM and blood glucose values was 0.957 with an intercept of 0.275. The mean difference between paired values according to Bland-Altman analysis was 10 ± 31 mg/dL (0.56 ± 1.72 mmol/L). Clarke error grid analysis showed 91% of paired points in A and B zones, while 0%, 9% and 0% of paired points were in the C, D and E zones, respectively.

CONCLUSION

Blood glucose changes during intensive physical-exercise bouts performed by CSII-treated type 1 diabetes patients can be estimated with acceptable clinical accuracy by online CGM.

Exercise-related hypoglycemia in diabetes mellitus

Current recommendations are that people with Type 1 and Type 2 diabetes mellitus exercise regularly. However, in cases in which insulin or insulin secretagogues are used to manage diabetes, patients have an increased risk of developing hypoglycemia, which is amplified during and after exercise. Repeated episodes of hypoglycemia blunt autonomic nervous system, neuroendocrine and metabolic defenses (counter-regulatory responses) against subsequent episodes of falling blood glucose levels during exercise. Likewise, antecedent exercise blunts counter-regulatory responses to subsequent hypoglycemia. This can lead to a vicious cycle, by which each episode of either exercise or hypoglycemia further blunts counter-regulatory responses. Although contemporary insulin therapies cannot fully mimic physiologic changes in insulin secretion, people with diabetes have several management options to avoid hypoglycemia during and after exercise, including regularly monitoring blood glucose, reducing basal and/or bolus insulin, and consuming supplemental carbohydrates.