+Model DIABET 171 1–7 ARTICLE IN PRESS Diabetes & Metabolism xxx (2009) xxx–xxx 1 Original article 2 Safety of recreational scuba diving in type 1 diabetic patients: 3 The Deep Monitoring programme a,∗ b c d e f 4 M. Bonomo , R. Cairoli , G. Verde , L. Morelli , A. Moreo , M. Delle Grottaglie , a a g h i 5 M.-C. Brambilla , E. Meneghini , P. Aghemo , G. Corigliano , A. Marroni 6 a Departments of Diabetology and Metabolic Diseases, Niguarda Ca’ Granda Hospital, Milan, Italy 7 b Departments of Haematology, Niguarda Ca’ Granda Hospital, Milan, Italy 8 c Departments of Endocrinology, Niguarda Ca’ Granda Hospital, Milan, Italy 9 d Departments of Hyperbaric Medicine, Niguarda Ca’ Granda Hospital, Milan, Italy 10 e Departments of Cardiology, Niguarda Ca’ Granda Hospital, Milan, Italy 11 f Departments of Ophthalmology, Niguarda Ca’ Granda Hospital, Milan, Italy 12 g Sport Physiology Center, Milan, Italy 13 h Diabetes Unit AID ASL Napoli-1, Naples, Italy 14 i DAN Europe, Roseto, Italy Received 2 January 2008; received in revised form 21 August 2008; accepted 24 August 2008 15 16 Abstract 17 Aim. – To verify whether, with thorough practical and theoretical training, well-controlled, non-complicated diabetic patients can safely go 18 diving underwater with no additional medical or metabolic risks. 19 Methods. – Twelve diabetic patients participated in the study after undergoing training focused on their diabetic status. Two dives per day were 20 scheduled during two five-day stays on the island of Ventotene (Italy). Capillary blood glucose (BG) was checked at 60, 30 and ten minutes before 21 diving, and corrective measures adopted if necessary, based on BG absolute levels and dynamics. A device for continuous subcutaneous glucose 22 monitoring (CGM), expressly modified for the purpose, was worn during each dive. 23 Results. – Data were gathered from 90 dives; mean BG at 60, 30 and ten minutes before diving was 205.8 ± 69.6 mg/dL, 200.0 ± 66.4 mg/dL and 24 200.5 ± 61.0 mg/dL, respectively. In 56 of the 90 dives, supplementary carbohydrates or insulin were necessary, but only one dive was interrupted 25 on account of hypoglycaemic symptoms. Mean post-dive BG was 158.9 ± 80.8 mg/dL. CGM recordings showed that glucose levels gradually 26 decreased during the dives (nadir: –19.9%). 27 Conclusion. – Experienced, well-controlled, complication-free young diabetic patients can safely go scuba diving, provided that they apply a 28 rigorous protocol based on serial pre-dive BG measurements. The specific variables of underwater diving do not appear to involve significant 29 additional risks of hypoglycaemia. 30 © 2009 Published by Elsevier Masson SAS. 31 Keywords: Scuba diving; Continuous glucose monitoring; Physical activity; Diabetes and sports 32 Résumé 33 Sécurité de la plongée sous-marine pour les personnes diabétiques de type 1 : le programme Deep Monitoring. 34 Objectif. – Le but de cette étude est de vérifier si, après avoir rec¸u une formation spécifique, des jeunes diabétiques bien équilibrés, sans 35 complications, peuvent plonger en conditions de sécurité, sans sur-risques médicaux et métaboliques. 36 Méthodes. – Douze jeunes diabétiques de type 1 ont participé à l’étude, après un cours de plongée dont le programme était ciblé sur la condition 37 diabétique. Pendant deux stages de cinq jours sur l’île de Ventotene (Italie), deux plongées par jour ont été programmées. La glycémie capillaire 38 (GC) était mesurée 60, 30, et dix minutes avant la mise à l’eau, et des mesures de correction étaient adoptées en cas de nécessité, en fonction des 39 niveaux absolus de GC et de leur dynamique. Un dispositif portable de mesure en continu du glucose subcutané (CGM), expressément modifié à 40 cette fin, a été utilisé aussi en immersion. ∗ Corresponding author. S.C. Diabetologia e Malattie Metaboliche, Ospedale Niguarda Ca’ Granda, Piazza Ospedale Maggiore 3, 20162 Milano, Italy. E-mail address: [email protected](M. Bonomo). PROOF 1262-3636/$ – see front matter © 2009 Published by Elsevier Masson SAS. doi:10.1016/j.diabet.2008.08.007 Please cite this article in press as: Bonomo M, et al. Safety of recreational scuba diving in type 1 diabetic patients: The Deep Monitoring programme. Diabetes Metab (2009), doi:10.1016/j.diabet.2008.08.007 +Model DIABET 171 1–7 ARTICLE IN PRESS 41 2 M. Bonomo et al. / Diabetes & Metabolism xxx (2009) xxx–xxx 42 Résultats. – Nous avons obtenu des données valides de 90 plongées ; la GC moyenne mesurée 60, 30 et dix minutes avant immersion était 43 205,8 ± 69,6 ; 200,0 ± 66,4 et 200,5 ± 61,0 mg/dL. En 56 des 90 plongées des carbohydrates ou des injections d’insuline supplémentaires ont été 44 nécessaires. Une seule plongée a dû être interrompue à cause de symptômes d’hypoglycémie. Après la plongée, nous avons relevé une GC moyenne 45 Q1 à 158,9 ± 80,8 mg/dL. Les résultats du CGM ont montré des niveaux de glucose subcutané modérément diminuant pendant les plongées d’une 46 fac¸on progressive (nadir : −19,9%). 47 Conclusion. – Après une formation spécifique, et appliquant rigoureusement un protocole de prévention basé sur contrôles sériels de la GC 48 avant l’immersion, un jeune diabétique expert, bien équilibré, libre de complications chroniques, peut pratiquer en raisonnable sécurité la plongée 49 avec scaphandre autonome. En particulier, en ces patients les variables directement liées à l’immersion sous-marine ne semblent pas comporter 50 une augmentation signifiante des risques d’hypoglycémie. 51 © 2009 Publie´ par Elsevier Masson SAS. 52 Mots clés : Plongée sous-marine ; Mesure en continu du glucose ; Exercice physique ; Diabète et sport 53 41 1. Introduction Virgin Islands at St Thomas, Virgin Islands, himself a diabetic 84 [11]. 85 42 Type 1 diabetes mellitus (T1DM) is commonly considered The next step was to verify the efficacy and safety of the 86 43 a contraindication for scuba diving, mainly because of the protocol outside of the protected setting of ‘confined waters’ 87 44 risk of hypoglycaemia [1,2]. In recent years, however, sev- during normal recreational diving. For this reason, in 2005 88 45 eral reports have suggested that this total prohibition should and 2006, we organized two five-day stays on the Island of 89 46 be reconsidered [3–5], and the Divers Alert Network (DAN) Ventotene (Italy), during which previously trained diabetic 90 47 has recently proposed a change in current policies [6,7] to divers took part in Deep Monitoring, an intensive programme 91 48 allow a specific group of diabetics to participate in scuba div- of consecutive dives in which technical, physiological and 92 49 ing. However, it is well known that many patients with T1DM metabolic parameters were closely followed using innovative 93 50 dive without declaring their condition [8–10], thereby expos- techniques. 94 51 ing themselves to risks as a consequence of a lack of specific 52 training. 2. Material and methods 95 53 The Diabete Sommerso (‘Submerged Diabetes’) Project was 54 launched in 2004 by our Center in close collaboration with the 2.1. 2004–2006: the OWD courses 96 55 Milan Association of Diabetic Patients; in 2005, it was approved 56 as a special project by DAN Europe. Fourteen young diabetics were certified in three OWD 97 57 The project’s rationale was that, provided that appropriate courses in 2004, 2005 and 2006. To be admitted to the course, 98 58 security conditions are met, success in a sport requiring physi- all patients had to undergo a series of multispecialist clinical and 99 59 cal efficiency, precision, reliability and self-control in an ‘alien’ instrumental investigations to ensure that they had no clinically 100 60 environment can be invaluable for boosting self-esteem and per- important chronic diabetic complications (microalbuminuria: 101 61 sonal image. This can even shift the patient’s general attitude > 20 mg/day, retinal involvement beyond background retinopa- 102 62 toward the illness, with positive consequences for its clinical thy, sensorimotor or autonomic neuropathy, macroangiopathic 103 63 course. lesions) or other clinical conditions commonly considered 104 64 Our aim was, therefore, to verify whether or not—after contraindications for scuba diving (cardiopathy favouring arte- 105 65 a thorough, dedicated training programme—well-controlled, riovenous shunt, epilepsy or disorders of the primary airways, 106 66 complication-free diabetic patients could safely dive without paranasal sinuses and ears). 107 67 incurring additional medical or metabolic risks. As regards metabolic control, candidates were allowed to 108 68 In cooperation with a team of certified scuba instructors, we participate only if they satisfied the following criteria: 109 69 helped a group of young adults with well-controlled T1DM to 70 obtain first-level Professional Association of Diving Instructors • HbA1c less than 8.5% at the last examination (within two 110 71 (PADI) Open Water Diver (OWD) certification. This authorizes months); 111 72 people to dive within the safety curve (with no decompres- • no episodes of acute metabolic complications requiring hos- 112 73 sion stops during ascent). All patients were selected in advance pitalization in the last 12 months; 113 74 to exclude hypoglycaemia unawareness, chronic micro- or • absence of ‘hypoglycaemia unawareness’, defined as asymp- 114 75 macrovascular diabetic complications and any other medical tomatic hypoglycaemic episodes (glucose concentrations less 115 76 situations usually considered contraindications for underwater than 60 mg/dL for at least ten minutes) during 72-hour con- 116 77 diving. In the OWD course, the standard PADIteaching schedule tinuous glucose monitoring (CGM). This turned out to be the 117 78 was combined with additional theoretical and practical modules most selective criterion as, in the experience of our Center, 118 79 dealing with the diabetes status, with special attention paid to the this situation occurs in almost half of T1DM patients with 119 80 prevention and management ofUNCORRECTED acute metabolic complications.