Diabetes and Diving

Historically, DAN has advised divers with insulin-dependent diabetes against diving because of the threat of a hypoglycemic episode underwater. However, in a 1996 survey, DAN discovered that approximately 177 of its members were diabetic and scuba diving. Of these, approximately 74 percent were insulin-dependent.

As a result of these findings, DAN Medical Research launched an observational study in 1997 to analyze current guidelines for divers with diabetes.

The objectives of the study were:

To measure blood glucose levels during scuba diving while following study guidelines

To develop a workable protocol for blood glucose analysis

To access compliance and study guidelines.

For this study, all participants:

visited a personal doctor and had medical verification form signed

had a Hemoglobin A1c (glycosylated hemoglobin) test before dive trip (within two weeks of the study date)

kept a daily log of diet, exercise, insulin doses, and blood glucose levels as described

administered a minimum of three blood glucose tests within one hour of each dive activity and one post-dive test (DAN supplied diabetic equipment and supplies.)

had a Hemoglobin A1c test after study within two weeks of completion of study (DAN covered both test costs.)

To participate, the diver must have:

insulin-dependent diabetes

a scuba diver certification

been between the ages of 18 and 65

not been pregnant

been a DAN Member with DAN Master or Preferred Plan dive insurance

been willing to follow the protocols for DAN's study

had a medical release form signed by a diabetologist or personal primary care physician

To participate, the diver must have had:

a pretrip HbA1c test in range of < 9 percent

no history of any episode of severe insulin reactions (loss of consciousness or seizure) in past 12 months

no advanced secondary complications, coronary artery disease, cardiovascular disease

no advanced peripheral vascular disease, proliferative retinopathy, neuropathy or renal disease

no hospitalization within the previous 12 months for insulin shock or diabetic ketoacidosis

hypoglycemic awareness as well as a good understanding of the relationship between exercise and blood glucose levels

good control of his or her diabetes

the ability to accurately check blood glucose without supervision

the ability to detect and treat hypoglycemia without assistance

no hospitalization or surgery in past 12 months for other conditions

Blood Glucose Monitoring
Blood glucose monitoring occurred one hour, 30 minutes and 10 minutes prior to the dive and again immediately after the dive.

What Are Hypoglycemic or Hyperglycemic Episodes?
Researchers assumed a hypoglycemic episode if the diver's blood glucose level was 70 mg/dl or less, or the diver experienced symptomatic hypoglycemia before, during or after diving.

Signs and Symptoms of Hypoglycemia

sweating

nervousness

faintness

palpitations

confusion

visual disturbances

stupor

seizures

loss of consciousness

Prior to the Dive
Blood glucose levels below 100 mg/dl on predive measurements or falling levels during subsequent tests were treated with an oral glucose gel and a fourth measurement obtained one hour later. The subject was not allowed to dive and was kept under medical supervision until blood glucose level was rising or stable and above 100 mg/dl.

During the Dive
Volunteers who experienced hypoglycemic events (symptoms of hypoglycemia) during the dive signaled their buddies with a pre-established hand signal — an L-shape with their thumb and index finger — and the buddies ascended to the surface. On the surface, the buddy helped the diabetic diver become positively buoyant and ingest a tube of glucose gel (each diabetic diver carried a tube). The buddy team then terminated the dive, returned to the boat and rechecked the diabetic's blood glucose level. An event occurring after the dive required a diabetic diver to eat a carbohydrate snack and recheck his or her blood glucose level until it rose above 80 mg/dl. The diabetic remained under medical supervision during this time.

Results

From 1997 through 1999, DAN collected data on nine trips, 561 dives by 41 insulin-requiring divers and 504 control dives by 43 divers without diabetes. Diving created no adverse effects on the diver with diabetes. There were 18 hypoglycemic episodes outside of the diving.

Resources

List of publications related to this study

"DAN and UHMS Publish Guidelines for Recreational Diving with Diabetes"

Table of Contents for Diabetes and Recreational Diving with Diabetes

Project Supporters

This project was supported by DAN Members, DAN donors and the following businesses and organizations:

Aggressor Fleet Inc.

Nekton Cruises Inc.

Peter Hughes Diving Inc.

Underwater Explorers Society (UNEXSO), Bahamas

Bayer Corporation

Can Am Care

Buceo Medico Mexicano Hyperbaric Chamber, Cozumel

Casa del Mar, Cozumel

Del-Mar Aquatics, Cozumel

AquaWorld, Cozumel

Albatros Charters, Cozumel

Blue Bubble Divers, Cozumel

Caribbean Divers, Cozumel

Cozumel Equalizer SA, Cozumel

Dive Paradise, Cozumel

Mako Tours, Cozumel

Scuba Club Cozumel, Cozumel

Sand Dollar, Cozumel

Cha Cha Cha Divers, Cozumel

Scuba Du, Cozumel

Dive Palancar, Cozumel

Aldora Divers, Cozumel