Blood Glucose Response in Insulin-Requiring Diabetics
BLOOD GLUCOSE RESPONSE TO RECREATIONAL DIVING IN INSULIN-DEPENDENT DIABETICS
D.M. Uguccioni, N.W. Pollock*, J.A. Dovenbarger, G.DeL. Dear, R.E. Moon. Divers Alert Network and Duke University Medical Center, Durham and *East Carolina University, Greenville, NC. (Sponsor: J.A. Houmard, FACSM)
Insulin-dependent diabetes mellitus (IDDM) has traditionally excluded people from participation in scuba diving. However, a growing record of safe diving in defiance of this ban is prompting reassessment. The purpose of this study was to measure blood glucose in divers with IDDM during the course of a multi-day diving vacation. Sixteen certified divers (nine male: 43±8 y [mean±SD], 85.1±14.1 kg, 1.77±0.12 m, 27.4±5.3 kg/m-2; and seven female: 44±5 y, 66.6±14.2 kg, 1.62±0.07 m, 25.3±5.3 kg/m-2) with a history of well-controlled IDDM (confirmed by HbA1c test no higher than 9% and physician documentation) participated in one of two, week-long subtropical diving trips.
Participants could dive up to four times per day, with blood glucose measured using a calibrated glucometer at 60, 30 and 5-10 min pre-dive, and immediately post-dive. Divers were restricted from diving if blood glucose level was below 80 mg/dL-1 immediately preceding a dive. A total of 131 dives were monitored. Divers conducted 8.2±3.3 dives per trip, 2.0±0.5 dives per day, with mean underwater time and depth of 38±7 min and 60±16 feet seawater, respectively.
Blood Glucose -60 min -30 min -10 to -5 min Post-Dive
Male (mg/dL-1) 188±71 203±75 210±68 159±59
Female (mg/dL-1) 196±56 237±58 248±49 193±60
Post-dive blood glucose was <100 mg/dL-1 following 13 dives, <80 following four and <65 following one (47 mg/dL-1). Divers refrained from making a dive in five instances because of inability to eat due to seasickness. There were no complications related to low blood glucose levels arising from any dives. These findings are consistent with recent observations that individuals with well-controlled IDDM may safely participate in recreational scuba diving under moderate conditions.
Supported by DAN Medical Research Program, Bayer Corp. and CAN-AM Care
Diving Medicine Articles
Summary Form - Guidelines for Recreational Diving with Diabetes
Table 1: Guidelines for Recreational Diving with Diabetes - Summary Form1
Selection and Surveillance
Age ≥18 years (≥16 years if in special training program)
Delay diving after start/change in medication
Three (3) months with oral hypoglycemic agents (OHA)
One (1) year after initiation of insulin therapy
No episodes of hypoglycemia or hyperglycemia requiring intervention from a third party for at least one year
No history of hypoglycemia unawareness
HbA1c ≤9% no more than one month prior to initial assessment and at each annual review
values >9% indicate the need for further evaluation and possible modification of therapy
No significant secondary complications from diabetes
Physician/Diabetologist should carry out annual review and determine that diver has good understanding of disease and effect of exercise
in consultation with an expert in diving medicine, as required
Evaluation for silent ischemia for candidates >40 years of age
after initial evaluation, periodic surveillance for silent ischemia can be in accordance with accepted local/national guidelines for the evaluation of diabetics
Candidate documents intent to follow protocol for divers with diabetes and to cease diving and seek medical review for any adverse events during diving possibly related to diabetes
Scope of Diving
Diving should be planned to avoid:
depths >100 fsw (30 msw)
durations >60 minutes
compulsory decompression stops
overhead environments (e.g., cave, wreck penetration)
situations that may exacerbate hypoglycemia (e.g., prolonged cold and arduous dives)
dive buddy/leader informed of divers condition and steps to follow in case of problem
dive buddy should not have diabetes
Glucose Management on the Day of Diving
general self-assessment of fitness to dive
blood glucose (BG) ≥150 mgdL-1 (8.3 mmolL-1), stable or rising, before entering the water, complete a minimum of three pre-dive BG tests to evaluate trends: 60 minutes, 30 minutes and immediately prior to diving
alterations in dosage of OHA or insulin on evening prior or day of diving may help
Delay dive if BG is:
<150 mgdL-1 (8.3 mmolL-1)
>300 mgdL-1 (16.7 mmolL-1)
Rescue medications
carry readily accessible oral glucose during all dives
have parenteral glucagon available at the surface
if hypoglycemia noticed underwater, the diver should surface (with buddy), establish positive buoyancy, ingest glucose and leave the water
check blood sugar frequently for 12-15 hours after diving
ensure adequate hydration on days of diving
log all dives (include BG test results and all information pertinent to diabetes management)
1 For full text see: Pollock NW, Uguccioni DM, Dear GdeL, eds. Diabetes and recreational diving: guidelines for the future. Proceedings of the UHMS/DAN 2005 June 19 Workshop. Durham, NC: Divers Alert Network; 2005.
Additional Resources:
Table 1: Guidelines for Recreational Diving with Diabetes - Summary Form1
Selection and Surveillance
¥ Age >18 years (>16 years if in special training program)
¥ Delay diving after start/change in medication
- 3 months with oral hypoglycemic agents (OHA)
- 1 year after initiation of insulin therapy
No episodes of hypoglycemia or hyperglycemia requiring intervention from a third party for at least one year
No history of hypoglycemia unawareness
¥ HbA1c <9% no more than one month prior to initial assessment and at each annual review
- values >9% indicate the need for further evaluation and possible modification of therapy ¥ No significant secondary complications from diabetes
¥ Physician/Diabetologist should carry out annual review and determine that diver has good understanding of disease and effect of exercise
- in consultation with an expert in diving medicine, as required
Evaluation for silent ischemia for candidates >40 years of age
- after initial evaluation, periodic surveillance for silent ischemia can be in accordance with accepted local/national guidelines for the evaluation of diabetics
Candidate documents intent to follow protocol for divers with diabetes and to cease diving and seek medical review for any adverse events during diving possi bly related to diabetes
Scope of Diving
Diving should be planned to avoid
- depths >100 fsw (30 msw)
- durations >60 minutes
- compulsory decompression stops
- overhead environments (e.g., cave, wreck penetration)
- situations that may exacerbate hypoglycemia (e.g., prolonged cold and arduous dives) ¥ Dive buddy/leader informed of divers condition and steps to follow in case of problem
Dive buddy should not have diabetes
Glucose Management on the Day of Diving
¥ General self-assessment of fitness to dive
Blood glucose (BG) >150 mgádL-1 (8.3 mmoláL-1), stable or rising, before entering the water - complete a minimum of three pre-dive BG tests to evaluate trends
 60 minutes, 30 minutes and immediately prior to diving
- alterations in dosage of OHA or insulin on evening prior or day of diving may help
Delay dive if BG
- <150 mgádL-1 (8.3 mmoláL-1)
- >300 mgádL-1 (16.7 mmoláL-1)
¥ Rescue medications
- carry readily accessible oral glucose during all dives
- have parenteral glucagon available at the surface
If hypoglycemia noticed underwater, the diver should surface (with buddy), establish positive buoyancy, ingest glucose and leave the water
Check blood sugar frequently for 12-15 hours after diving
¥ Ensure adequate hydration on days of diving
¥ Log all dives (include BG test results and all information pertinent to diabetes management)
For full text see: Pollock NW, Uguccioni DM, Dear GdeL, eds. Diabetes and recreational diving: guidelines for the future. Proceedings of the UHMS/DAN 2005 June 19 Workshop. Durham, NC: Divers Alert Network; 2005.
