Increased insulin requirements during exercise at very high altitude in type 1 diabetes
Pieter de Mol, Suzanna T de Vries, Eelco J P de Koning, Rijk O B Gans, Cees J Tack, Henk J G Bilo, Pieter de Mol, Suzanna T de Vries, Eelco J P de Koning, Rijk O B Gans, Cees J Tack, Henk J G Bilo
Abstract
Objective: Safe, very high altitude trekking in subjects with type 1 diabetes requires understanding of glucose regulation at high altitude. We investigated insulin requirements, energy expenditure, and glucose levels at very high altitude in relation to acute mountain sickness (AMS) symptoms in individuals with type 1 diabetes.
Research design and methods: Eight individuals with complication-free type 1 diabetes took part in a 14-day expedition to Mount Meru (4,562 m) and Mount Kilimanjaro (5,895 m) in Tanzania. Daily insulin doses, glucose levels, energy expenditure, and AMS symptoms were determined. Also, energy expenditure and AMS symptoms were compared with a healthy control group.
Results: We found a positive relation between AMS symptoms and insulin requirements (r = 0.78; P = 0.041) and AMS symptoms and glucose levels (r = 0.86; P = 0.014) for Mount Kilimanjaro. Compared with sea level, insulin doses tended to decrease by 14.2% (19.7) (median [interquartile range]) (P = 0.41), whereas glucose levels remained stable up to 5,000 m altitude. However, at altitudes >5,000 m, insulin dose was unchanged (36.8 ± 17 vs. 37.6 ± 19.1 international units [mean ± SD] P = 0.75), but glucose levels (7.5 ± 0.6 vs. 9.5 ± 0.8 mmol/L [mean ± SD] P = 0.067) and AMS scores (1.3 ± 1.6 vs. 4.4 ± 4 points [mean ± SD] P = 0.091) tended to increase. Energy expenditure and AMS symptoms were comparable in both groups (P = 0.84).
Conclusions: Our data indicate that in complication-free individuals with type 1 diabetes, insulin requirements tend to increase during altitudes above 5,000 m despite high energy expenditure. This change may be explained, at least partly, by AMS.
Figures
![Figure 1](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3041186/bin/591fig1.jpg)
![Figure 2](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3041186/bin/591fig2.jpg)
![Figure 3](https://www.ncbi.nlm.nih.gov/pmc/articles/instance/3041186/bin/591fig3.jpg)
References
- Dietz TE. International Society for Mountain Medicine ISMM: an altitude tutorial [article online], 2006. Available from Accessed 30 January 2011
- Brubaker PL. Adventure travel and type 1 diabetes: the complicating effects of high altitude. Diabetes Care 2005;28:2563–2572
- Larsen JJ, Hansen JM, Olsen NV, Galbo H, Dela F. The effect of altitude hypoxia on glucose homeostasis in men. J Physiol 1997;504:241–249
- Sawhney RC, Malhotra AS, Singh T, Rai RM, Sinha KC. Insulin secretion at high altitude in man. Int J Biometeorol 1986;30:231–238
- Yki-Järvinen H, DeFronzo RA, Koivisto VA. Normalization of insulin sensitivity in type I diabetic subjects by physical training during insulin pump therapy. Diabetes Care 1984;7:520–527
- Cryer PE. Mechanisms of hypoglycemia-associated autonomic failure and its component syndromes in diabetes. Diabetes 2005;54:3592–3601
- Loeppky JA, Icenogle MV, Maes D, Riboni K, Scotto P, Roach RC. Body temperature, autonomic responses, and acute mountain sickness. High Alt Med Biol 2003;4:367–373
- Pavan P, Sarto P, Merlo L, et al. Metabolic and cardiovascular parameters in type 1 diabetes at extreme altitude. Med Sci Sports Exerc 2004;36:1283–1289
- Admettla J, Leal C, Ricart A. Diabetes and mountain sports [article online], 2001. Available from Accessed 30 January 2011
- Moore K, Vizzard N, Coleman C, McMahon J, Hayes R, Thompson CJ. Extreme altitude mountaineering and type 1 diabetes; the Diabetes Federation of Ireland Kilimanjaro Expedition. Diabet Med 2001;18:749–755
- Bas van de Goor Foundation Kilimanjaro Challenge 2008 [article online], 2008. Available from Accessed 30 January 2011
- Machame route [article online], 2010. Available from Accessed 30 January 2011
- de Mol P, Krabbe HG, de Vries ST, et al. Accuracy of handheld blood glucose meters at high altitude. PLoS ONE 2010;5:e15485.
- Maggiorini M, Müller A, Hofstetter D, Bärtsch P, Oelz O. Assessment of acute mountain sickness by different score protocols in the Swiss Alps. Aviat Space Environ Med 1998;69:1186–1192
Source: PubMed