UIAA Medical Commission Recommendations for Mountaineers, Hillwalkers, Trekkers, and Rock and Ice Climbers with Diabetes

Hillebrandt, David, Anil Gurtoo, Thomas Kupper, Paul Richards, Volker Schöffl, Pankaj Shah, Rianne van der Spek, Nikki Wallis, and Jim Milledge. UIAA Medical Commission recommendations for mountaineers, hillwalkers, trekkers, and rock and ice climbers with diabetes. High Alt Med Biol. 24: 110-126.-The object of this advice article is not only to give the diabetic mountaineer general guidance but also to inform his or her medical team of practical aspects of care that may not be standard for nonmountaineers. The guidelines are produced in seven sections. The first is an introduction to the guidelines, and the second is an introduction to this medical problem and is designed to be read and understood by diabetic patients and their companions. The third section is for use in an emergency in mountains. The fourth is for rock, ice, and competition climbers operating in a less remote environment. These initial sections are deliberately written in simple language. The fifth and sixth sections are written for clinicians and those with skills to read more technical information, and the seventh looks at modern technology and its pros and cons in diabetes management in a remote area. Sections One and Two could be laminated and carried when in the mountains, giving practical advice.

Acute glycaemic management before, during and after exercise for cardiac rehabilitation participants with diabetes mellitus: a joint statement of the British and Canadian Associations of Cardiovascular Prevention and Rehabilitation, the International Council for Cardiovascular Prevention and Rehabilitation and the British Association of Sport and Exercise Sciences

Type 1 (T1) and type 2 (T2) diabetes mellitus (DM) are significant precursors and comorbidities to cardiovascular disease and prevalence of both types is still rising globally. Currently,~25% of participants (and rising) attending cardiac rehabilitation in Europe, North America and Australia have been reported to have DM (>90% have T2DM). While there is some debate over whether improving glycaemic control in those with heart disease can independently improve future cardiovascular health-related outcomes, for the individual patient whose blood glucose is well controlled, it can aid the exercise programme in being more efficacious. Good glycaemic management not only helps to mitigate the risk of acute glycaemic events during exercising, it also aids in achieving the requisite physiological and psycho-social aims of the exercise component of cardiac rehabilitation (CR). These benefits are strongly associated with effective behaviour change, including increased enjoyment, adherence and self-efficacy. It is known that CR participants with DM have lower uptake and adherence rates compared with those without DM. This expert statement provides CR practitioners with nine recommendations aimed to aid in the participant's improved blood glucose control before, during and after exercise so as to prevent the risk of glycaemic events that could mitigate their beneficial participation.

Biochemical, Physiological and Psychological Changes During Endurance Exercise in People With Type 1 Diabetes

BACKGROUND

Increasing numbers of people with diabetes are adopting exercise programs. Fear of hypoglycemia, hypoglycemia itself, and injuries are major issues for many people with diabetes undertaking physical activity. The purpose of this study was to investigate the effects of type 1 diabetes mellitus on the risk of hypoglycemia, glycemic variability, exercise performance, changes in body composition, changes in insulin dosage, and psychosocial well-being during a multiday endurance exercise event.

METHODS

Eleven participants (7 with type 1 diabetes, 4 with normal glucose tolerance) undertook a 15-day, 2300 km cycling tour from Barcelona to Vienna. Data were prospectively collected using bike computers, continuous glucose monitors, body composition analyzers, and mood questionnaires.

RESULTS

Mean blood glucose in riders with and without diabetes significantly reduced as the event progressed. Glycemic variability and time spent in hypoglycemia did not change throughout the ride for either set of riders. Riders with diabetes in the lowest quartile of sensor glucose values had significantly reduced power output. Percentage body fat also significantly fell. Hypo- and hyperglycemia provoked feelings of anxiety and worry.

CONCLUSIONS

This is the first study to describe a real-time endurance event in type 1 diabetes, and provides important new data that cannot be studied in laboratory conditions. Hypoglycemia continues to occurs in spite of peer support and large reductions in insulin dose. Glycemic variability is shown as a potential barrier to participation in physical activity through effects on mood and psychological well-being.

Techniques for Exercise Preparation and Management in Adults with Type 1 Diabetes

OBJECTIVES

People with type 1 diabetes are at risk for early- and late-onset hypoglycemia following exercise. Reducing this risk may be possible with strategic modifications in carbohydrate intake and insulin use. We examined the exercise preparations and management techniques used by individuals with type 1 diabetes before and after physical activity and sought to determine whether use of differing diabetes technologies affects these health-related behaviours.

METHODS

We studied 502 adults from the Type 1 Diabetes Exchange's online patient community, Glu, who had completed an online survey focused on diabetes self-management and exercise.

RESULTS

Many respondents reported increasing carbohydrate intake before (79%) and after (66%) exercise as well as decreasing their meal boluses before (53%) and after (46%) exercise. Most reported adhering to a target glucose level before starting exercise (77%). Despite these accommodations, the majority reported low blood glucose (BG) levels after exercise (70%). The majority of users of both insulin pump therapy (CSII) and continuous glucose monitoring (CGM) (Combined) reported reducing basal insulin around exercise (55%), with fewer participants adjusting basal insulin when using other devices (SMBG only = 20%; CGM = 34%; CSII = 42%; p<0.001). However, CSII and Combined users reported that exercise makes their BG levels harder to control (p<0.05) and makes them feel less able to predict their BG levels while exercising (p<0.001); they show agreement that fear of low BG levels keeps them from exercising (p<0.01).

CONCLUSIONS

These findings highlight the need for exercise-management strategies tailored to individuals' overall diabetes management, for despite making exercise-specific adjustments for care, many people with type 1 diabetes still report significant difficulties with BG control when it comes to exercise.

Similar risk of exercise-related hypoglycaemia for insulin degludec to that for insulin glargine in patients with type 1 diabetes: a randomized cross-over trial

We compared changes in blood glucose (BG) and risk of hypoglycaemia during and after exercise in 40 patients with type 1 diabetes (T1D) treated with insulin degludec (IDeg) or insulin glargine (IGlar) in a randomized, open-label, two-period, crossover trial. After individual titration and a steady-state period, patients performed 30 min of moderate-intensity cycle ergometer exercise (65% peak rate of oxygen uptake). BG, counter-regulatory hormones and hypoglycaemic episodes were measured frequently during and for 24 h after exercise. BG changes during exercise were similar with IDeg and IGlar [estimated treatment difference (ETD) for maximum BG decrease: 0.14 mmol/l; 95% confidence interval (CI) -0.15, 0.42; p = 0.34], as was mean BG (ETD -0.16 mmol/l; 95% CI -0.36, 0.05; p = 0.13). No hypoglycaemic episodes occurred during exercise. Post-exercise mean BG, counter-regulatory hormone response and number of hypoglycaemic episodes in 24 h after starting exercise were similar with IDeg (18 events in 13 patients) and IGlar (23 events in 15 patients). This clinical trial showed that, in patients with T1D treated with a basal-bolus regimen, the risk of hypoglycaemia induced by moderate-intensity exercise was low with IDeg and similar to that with IGlar.

Diabetes, trekking and high altitude: recognizing and preparing for the risks

Although regular physical activity is encouraged for individuals with diabetes, exercise at high altitude increases risk for a number of potential complications. This review highlights our current understanding of the key physiological and clinical issues that accompany high-altitude travel and proposes basic clinical strategies to help overcome obstacles faced by trekkers with Type 1 or Type 2 diabetes. Although individuals with diabetes have adaptations to the hypoxia of high altitude (increased ventilation, heart rate, blood pressure and hormonal responses), elevated counter-regulatory hormones can impair glycaemic control, particularly if mountain sickness occurs. Moreover, high-altitude-induced anorexia and increased energy expenditure can predispose individuals to dysglycaemia unless careful adjustments in medication are performed. Frequent blood glucose monitoring is imperative, and results must be interpreted with caution because capillary blood glucose meter results may be less accurate at high elevations and low temperatures. It is also important to undergo pre-travel screening to rule out possible contraindications owing to chronic diabetes complications and make well-informed decisions about risks. Despite the risks, healthy, physically fit and well-prepared individuals with Type 1 or Type 2 diabetes who are capable of advanced self-management can be encouraged to participate in these activities and attain their summit goals. Moreover, trekking at high altitude can serve as an effective means to engage in physical activity and to increase confidence with fundamental diabetes self-management skills.

A low-glycemic index meal and bedtime snack prevents postprandial hyperglycemia and associated rises in inflammatory markers, providing protection from early but not late nocturnal hypoglycemia following evening exercise in type 1 diabetes

OBJECTIVE

To examine the influence of the glycemic index (GI) of foods consumed after evening exercise on postprandial glycemia, metabolic and inflammatory markers, and nocturnal glycemic control in type 1 diabetes.

RESEARCH DESIGN AND METHODS

On two evenings (∼1700 h), 10 male patients (27 ± 5 years of age, HbA1c 6.7 ± 0.7% [49.9 ± 8.1 mmol/mol]) were administered a 25% rapid-acting insulin dose with a carbohydrate bolus 60 min before 45 min of treadmill running. At 60 min postexercise, patients were administered a 50% rapid-acting insulin dose with one of two isoenergetic meals (1.0 g carbohdyrate/kg body mass [BM]) matched for macronutrient content but of either low GI (LGI) or high GI (HGI). At 180 min postmeal, the LGI group ingested an LGI snack and the HGI group an HGI snack (0.4 g carbohdyrate/kg BM) before returning home (∼2300 h). Interval samples were analyzed for blood glucose and lactate; plasma glucagon, epinephrine, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α); and serum insulin, cortisol, nonesterified fatty acid, and β-hydroxybutyrate concentrations. Interstitial glucose was recorded for 20 h postlaboratory attendance through continuous glucose monitoring.

RESULTS

Following the postexercise meal, an HGI snack induced hyperglycemia in all patients (mean ± SD glucose 13.5 ± 3.3 mmol/L) and marked increases in TNF-α and IL-6, whereas relative euglycemia was maintained with an LGI snack (7.7 ± 2.5 mmol/L, P < 0.001) without inflammatory cytokine elevation. Both meal types protected all patients from early hypoglycemia. Overnight glycemia was comparable, with a similar incidence of nocturnal hypoglycemia (n = 5 for both HGI and LGI).

CONCLUSIONS

Consuming LGI food with a reduced rapid-acting insulin dose following evening exercise prevents postprandial hyperglycemia and inflammation and provides hypoglycemia protection for ∼8 h postexercise; however, the risk of late nocturnal hypoglycemia remains.

Simulated games activity vs continuous running exercise: a novel comparison of the glycemic and metabolic responses in T1DM patients

To compare the glycemic and metabolic responses to simulated intermittent games activity and continuous running exercise in type 1 diabetes. Nine patients (seven male, two female; 35 ± 4 years; HbA1c 8.1 ± 0.2%/65 ± 2 mmol/mol) treated on a basal-bolus regimen completed two main trials, a continuous treadmill run (CON) or an intermittent running protocol (INT). Patients arrived to the laboratory fasted at ∼ 08:00 h, replicating their usual pre-exercise meal and administering a 50% reduced dose of rapid-acting insulin before exercising. Blood glucose (BG), K(+) , Na(++) , pH, triglycerides, serum cortisol and NEFA were measured at baseline and for 60 min post-exercise. Interstitial glucose was measured for a further 23 h under free-living conditions. Following exercise, BG declined under both conditions but was less under INT (INT -1.1 ± 1.4 vs CON -5.3 ± 0.4 mmol/L, P = 0.037), meaning more patients experienced hypoglycemia (BG ≤ 3.5 mmol/L; CON n = 3 vs INT n = 2) but less hyperglycemia (BG ≥ 10.9 mmol/L; CON n = 0 vs INT n = 6) under CON. Blood lactate was significantly greater, and pH lower, with a temporal delay in K(+) under INT (P < 0.05). No conditional differences were observed in other measures during this time, or in interstitial glucose concentrations during the remaining 23 h after exercise. Simulated games activity carries a lower risk of early, but not late-onset hypoglycemia than continuous running exercise in type 1 diabetes.

Modification of severe insulin resistant diabetes in response to lifestyle changes in Alström syndrome

BACKGROUND

Alström syndrome is a recessively inherited condition characterised by severe insulin resistance and metabolic syndrome with progression to type 2 diabetes, hepatic dysfunction and coronary artery disease. The metabolic responses to lifestyle changes in the syndrome have not been reported.

CASE REPORTS

We describe the effects on glycaemia of intense cycling in two insulin treated Alström patients with diabetes, and the effects of opposite lifestyle changes over one year in two others.

METHODS

After practise and clinical assessment two patients aged 21 and 39 years undertook a 380 km cycle ride over 4 days by tandem. The effects of planned reductions in insulin therapies and increased regular carbohydrate ingestion were monitored by frequent capillary blood glucose measurements. Two siblings aged 22 and 25 years underwent assessment of glycaemia, C-peptide/glucose ratio serum lipids, hepatic function and ultrasound, Enhanced Liver Fibrosis test and measures of insulin resistance. Measurements were repeated one year later after profound lifestyle changes.

RESULTS

Aerobic exercise strikingly improved blood glucose control despite reduction in insulin dose and increased carbohydrate intake. Increase in exercise and exclusion of fast foods improved all aspects of the metabolic syndrome and induced remission of diabetes in one sibling. Reduction in exercise and consumption of high energy foods in the other resulted in development of type 2 diabetes, severe metabolic syndrome and fatty liver in the other.

CONCLUSIONS

Despite dual sensory loss and genetic basis for insulin resistance, Alström patients can successfully ameliorate the metabolic syndrome with lifestyle changes.

Metabolic regulation during constant moderate physical exertion in extreme conditions in Type 1 diabetes

BACKGROUND

Constant moderate intensity physical exertion in humid environments at altitude poses a considerable challenge to maintaining euglycaemia with Type 1 diabetes. Blood glucose concentrations and energy expenditure were continuously recorded in a person trekking at altitude in a tropical climate to quantify changes in glucose concentrations in relation to energy expenditure.

CASE REPORT

Blood glucose concentrations and energy expenditure were continuously monitored with a Guardian® real-time continuous glucose monitoring system (CGMS) and a SenseWear® Pro3 armband (BodyMedia Inc., USA), in a 27-year-old woman with Type 1 diabetes, during her climb up Mount Kinabalu in Borneo (c. 4095 m). Comparative control data from the same person was collected in the UK (temperate climate at sea level) and Singapore (tropical climate at sea level). Maximum physical effort during the climb was < 60% VO(2MAX) (maximal oxygen consumption). Mean daily calorific intakes were 2300 kcal (UK), 2370 kcal (Singapore) and 2274 kcal (Mount Kinabalu), and mean daily insulin doses were 54 U (UK), 40 U (Singapore) and 47 U (Mount Kinabalu). Despite markedly increased energy expenditure during the climb [4202 kcal (Mount Kinabalu) vs. 2948 kcal (UK) and 2662 kcal (Singapore)], mean blood glucose was considerably higher during the trek up Mount Kinabalu [13.2 ± 5.9 mmol/l, vs. 7.9 ± 3.8 mmol/l (UK) and 8.6 ± 4.0 mmol/l (Singapore)].

CONCLUSION

Marked unexpected hyperglycaemia occurred while trekking on Mount Kinabalu, despite similar calorie consumption and insulin doses to control conditions. Because of the risk of unexpected hyperglycaemia in these conditions, we recommend that patients embarking on similar activity holidays undertake frequent blood glucose monitoring.

Managing blood glucose during and after exercise in Type 1 diabetes: reproducibility of glucose response and a trial of a structured algorithm adjusting insulin and carbohydrate intake

AIMS AND OBJECTIVES

To enable people with Type 1 diabetes to exercise safely by investigating the reproducibility of the glucose response to an algorithm for carbohydrate and insulin adjustment during and after exercise compared to their self-management strategies.

BACKGROUND

Difficulties in managing blood glucose levels in Type 1 diabetes whilst exercising is known to deter people from exercise. Currently there is a limited evidence base to aid health care professionals enable people with diabetes to exercise safely. This study seeks to address this gap.

DESIGN

A quasi-experimental study was undertaken amongst people with Type 1 diabetes.

METHODS

Over 14 days, 14 participants undertook four exercise sessions (40 minutes at 50%VO2max). Two sessions were undertaken in week 1 self-managing their diabetes and two sessions in week 2 using an algorithm for carbohydrate and insulin adjustment.

RESULTS

The mean reduction of glucose levels detected by Continuous Glucose Monitoring during exercise was 3·1 (SD 2·03) mmol/l. Time spent within the range of 4-9 mmol/l during exercise was not significantly different between the self-managed and the algorithm weeks (-3-22·4 min). The mean reduction of blood glucose for each individual over all four exercise sessions ranged between 0·8-5·95 mmol/l. The technical error between days one and two was 2·4 mmol/l (CV=33·2%) and between days 3-4 the technical error was 2·7 mmol/l (CV=33·7%).

CONCLUSIONS

The results provide useful data about the reproducibility of the blood glucose response to moderate intensity exercise, despite the variability of individual responses 40 minutes of moderate intensity exercise decreases Continuous Glucose Monitoring glucose by 3 mmol/l with or without a 30% decrease of insulin before exercise.

RELEVANCE TO CLINICAL PRACTICE

This information provides valuable baseline information for people with diabetes and health care professionals who wish to encourage physical activity and undertake further research in this area.

Risks of marathon running and hypoglycaemia in Type 1 diabetes

BACKGROUND

Exercise-induced hypoglycaemia is common in people with insulin-treated diabetes and if severe can provoke neurological morbidity including coma and seizures. Depending on the duration and demands of the physical activity, various strategies can be used to limit the risk of hypoglycaemia with strenuous exercise. However, metabolic events occurring in the 48 h before the exercise can influence the risk and responses to exercise-induced hypoglycaemia.

CASE REPORT

A 27-year-old man with Type 1 diabetes suffered an episode of nocturnal hypoglycaemia which provoked a tonic-clonic seizure. Despite this he ran in a marathon the following day during which he collapsed with severe hypoglycaemia and a further associated seizure. He subsequently developed severe myalgia accompanied by a pronounced and persistent elevation of plasma creatine kinase, indicating rhabdomyolysis, and deranged liver function, suggestive of hypoxic hepatitis. The biochemical abnormalities and symptoms lasted for several weeks.

CONCLUSIONS

The case highlights the dangers of intense and prolonged physical exercise following severe hypoglycaemia, demonstrating the risks of acute damage to skeletal muscle and to organs such as the liver, in addition to the risk of severe neuroglycopenia and the induction of seizures. The mechanisms underlying these problems are discussed. People with insulin-treated diabetes should be advised not to undertake prolonged intensive exercise after severe hypoglycaemia.

Hypoglycaemia: an overview

Hypoglycaemia is a frequent side-effect of treatment with insulin and sulfonylureas for people with diabetes, threatening potentially serious morbidity and preventing optimal glycaemic control. Fear of hypoglycaemia and development of syndromes such as impaired awareness and counterregulatory deficiency provide additional hazards for intensification of treatment. Rapid lowering of HbA1c may be potentially dangerous in type 2 diabetes because of the adverse cardiovascular effects induced by hypoglycaemia. Hypoglycaemia can disrupt many everyday activities such as driving, work performance and recreational pursuits. Measures to reduce the risk of hypoglycaemia are labour-intensive and require substantial resources.