Impact of a sports project centered on scuba diving for adolescents with type 1 diabetes mellitus: New guidelines for adolescent recreational diving, a modification of the French regulations.

BACKGROUND: Recreational scuba diving has been authorized for type 1 diabetics over 18 years old - the age of majority in France - since 2004, but it remained forbidden for younger diabetics by the French underwater federation (FFESSM). Here, we present a study to evaluate: - the conditions under which diving could be authorized for 14- to 18 year olds with type 1 diabetes; - the value of continuous glucose monitoring (CGM) while diving. A secondary objective was to monitor the impact of diving on the teenagers' quality of life. SUBJECT AND METHODS: Sixteen adolescents (14-17.5 years old) were included. Diabetes was known for 6 years (range, 1-14) and Hb1Ac was 9.0% (range, 7.7-11.9). The study was conducted in Mayotte with both capillary glycemia (CG) and CGM measurements taken during five dives. RESULTS: The average CG prior to diving was 283mg/dL and decreased by 75±76mg/dL during the dive. No hypoglycemia occurred during the dives and four episodes occurred after. Glycemia variations during dives and for the overall duration of the study were greater than for adults, most likely due to the general adolescent behavior, notably regarding diet and diabetes management. CGM was greatly appreciated by the adolescents. They had an overall satisfactory quality of life. No significant variations were observed during the entire course of the study. CONCLUSIONS: Although in need of further studies, these preliminary results show that CGM can be used while diving. CGM records show a continuous decrease of glycemia during dives. Based on these results, the French underwater federation has now authorized diving for adolescent type 1 diabetics following a specific diving protocol that includes HbA1c<8.5%, autonomous management of diabetes by the adolescent, reduction of insulin doses, and target glycemia prior to the dive>250mg/dL.

Blood glucose changes and adjustments of diet and insulin doses in type 1 diabetic patients during scuba diving (for a change in French regulations).

OBJECTIVE: In France, diabetic subjects were not allowed to dive. The principal risk is hypoglycemia during immersion. However scuba diving is allowed in many countries. To follow blood glucose changes, food intake and insulin adjustments in type 1 diabetic patients when diving, and to propose specific guidelines for such patients willing to practice recreational scuba diving. METHODS: Fifteen well-controlled (mean HbA1c: 7.2%) type 1 diabetic patients without complications were volunteer to dive under strict medical monitoring. They dove 8 times in 4 days in autumn at a depth of 20 meters, in 12 degrees C to 16 degrees C water. A strict protocol based on blood glucose was implemented to prevent hypoglycaemia. RESULTS: No case of hypoglycemia was observed and no faintness was reported underwater. Mean blood glucose before diving was 200 mg/dl (11 mmol/l). There was a mean fall in blood glucose of 40 mg/dl (2.2 mmol/l) during dives, a mean decrease in daily insulin doses by 19.3% on the last day. Daily energy intake was 3,225 Kcal in average. A continuous glucose monitoring (CGMS) was performed in one patient and showed a rather stable glycemia during immersion but a decrease within the 8 hours after. CONCLUSION: When respecting a strict protocol to prevent hypoglycaemia, the risk of hypoglycaemia appears quite low. We recommend an ideal glycemic goal of 200-250 mg/dl (11-13.75 mmol/l) before immersion, a higher reduction of insulin doses (-30%) and taking carbohydrates on board in any case. The present data have recently led the French diving federation (FESSM) to allow type 1 diabetic patients to dive with some restrictive qualification requirements: dives within the "safety curve" (no decompression curve), in above 14 degrees C water, depth limited to the median space range (6 to 20 meters), plus mandatory guidance by a diving instructor.

[Is scuba diving allowed in diabetic patients treated with insulin?]. / La plongée sous-marine avec scaphandre autonome peut-elle être autorisée aux personnes diabétiques insulinotraitées ?

Scuba diving is usually prohibited in diabetic patients at risk of hypoglycemic attacks (i.e. IDDM and NIDDM treated with sulfonylureas) due to the particular severity of these episodes in a hostile environment. In fact, diabetic subjects can perform this popular leisure activity without extra-risk, provided strict requisites in aptitude, practice and environment are enforced. These limitations lead to the establishment of practical guidelines, as proposed in this paper.