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

Although physical activity (PA) is a key element in the prevention and management of type 2 diabetes, many with this chronic disease do not become or remain regularly active. High-quality studies establishing the importance of exercise and fitness in diabetes were lacking until recently, but it is now well established that participation in regular PA improves blood glucose control and can prevent or delay type 2 diabetes, along with positively affecting lipids, blood pressure, cardiovascular events, mortality, and quality of life. Structured interventions combining PA and modest weight loss have been shown to lower type 2 diabetes risk by up to 58% in high-risk populations. Most benefits of PA on diabetes management are realized through acute and chronic improvements in insulin action, accomplished with both aerobic and resistance training. The benefits of physical training are discussed, along with recommendations for varying activities, PA-associated blood glucose management, diabetes prevention, gestational diabetes mellitus, and safe and effective practices for PA with diabetes-related complications.

OBJECTIVE DAFNE (Dose Adjustment For Normal Eating), a structured education program in flexible insulin therapy, has been widely adopted in the U.K. after validation in a randomized trial. To determine benefits in routine practice, we collected biomedical and psychological data from all participants attending during a 12-month period. RESEARCH DESIGN AND METHODS HbA1c, weight, self-reported hypoglycemia awareness, severe hypoglycemia frequency, PAID (Problem Areas In Diabetes), HADS (Hospital Anxiety and Depression Scale), and EuroQol Group 5-Dimension Self-Report Questionnaire scores were recorded prior to DAFNE and after 1 year. RESULTS Complete baseline and follow-up HbA1c data were available for 639 (54.9%) of 1,163 attendees. HbA1c fell from 8.51 ± 1.41 (mean ± SD) to 8.24 ± 1.29% (difference 0.27 [95% CI 0.16–0.38]; P 8.5%. Severe hypoglycemia rate fell from 1.7 ± 8.5 to 0.6 ± 3.7 episodes per person per year (1.1 [0.7–1.4]) and hypoglycemia recognition improved in 43% of those reporting unawareness. Baseline psychological distress was evident, with a PAID score of 25.2 and HADS scores of 5.3 (anxiety) and 4.8 (depression), falling to 16.7 (8.5 [6.6–10.4]), 4.6 (0.7 [0.4–1.0]), and 4.2 (0.6 [0.3–0.8]), respectively (all P < 0.001 at 1 year). Clinically relevant anxiety and depression (HADS ≥8) fell from 24.4 to 18.0% and 20.9 to 15.5%, respectively. CONCLUSIONS A structured education program delivered in routine clinical practice not only improves HbA1c while reducing severe hypoglycemia rate and restoring hypoglycemia awareness but also reduces psychological distress and improves perceived well-being.

The reason for weight loss at high altitudes is largely unknown. To date, studies have been unable to differentiate between weight loss due to hypobaric hypoxia and that related to increased physical exercise. The aim of our study was to examine the effect of hypobaric hypoxia on body weight at high altitude in obese subjects. We investigated 20 male obese subjects (age 55.7 +/- 4.1 years, BMI 33.7 +/- 1.0 kg/m(2)). Body weight, waist circumference, basal metabolic rate (BMR), nutrition protocols, and objective activity parameters as well as metabolic and cardiovascular parameters, blood gas analysis, leptin, and ghrelin were determined at low altitude (LA) (Munich 530 m, D1), at the beginning and at the end of a 1-week stay at high altitude (2,650 m, D7 and D14) and 4 weeks after returning to LA (D42). Although daily pace counting remained stable at high altitude, at D14 and D42, participants weighed significantly less and had higher BMRs than at D1. Food intake was decreased at D7. Basal leptin levels increased significantly at high altitude despite the reduction in body weight. Diastolic blood pressure was significantly lower at D7, D14, and D42 compared to D1. This study shows that obese subjects lose weight at high altitudes. This may be due to a higher metabolic rate and reduced food intake. Interestingly, leptin levels rise in high altitude despite reduced body weight. Hypobaric hypoxia seems to play a major role, although the physiological mechanisms remain unclear. Weight loss at high altitudes was associated with clinically relevant improvements in diastolic blood pressure.