Plasma glucose response to recreational diving in novice teenage divers with insulin-requiring diabetes mellitus.

A growing number of individuals with insulin-requiring diabetes mellitus (IRDM) dive, but data on plasma glucose (PG) response to diving are limited, particularly for adolescents. We report on seven 16-17 year old novice divers with IRDM participating in a tropical diving camp who had recent at least moderate PG control (HbA1c 7.3 +/- 1.1%) (mean +/- SD). PG was measured at 60, 30 and 10 min pre-dive and immediately following 42 dives. Maximum depth (17 +/- 6 msw) and total underwater times (44 +/- 14 min) were not extreme. Pre-dive PG exceeded 16.7 mmol x L(-1) (300 mg x dL(-1)) in 22% of dives. Males had significantly higher pre-dive levels (15.4 +/- 5.6 mmol x L(-1) [277 +/- 100 mg x dL(-1)] vs. 12.8 +/- 2.9 mmol x L(-1) [230 +/- 52 mg x dL(-1)], respectively) and greater pre-post-dive changes (-4.3 +/- 4.4 mmol x L(-1) [-78 +/- 79 mg x dL(-1)] vs. -0.5 +/- 4.3 mmol x L(-1) [-9 +/- 77 mg x dL(-1)], respectively). Post-dive PG was < 4.4 mmol x L(-1) [< 80 mg x dL(-1)] in two dives by two different males (3.4 and 3.9 mmol x L(-1) [61 and 70 mg x dL(-1)]). No symptoms or complications of hypoglycemia were reported. These data show that in a closely monitored situation, and with benign diving conditions, some diabetic adolescents with good control and no secondary complications may be able to dive safely. The impact of purposeful elevation of PG to protect against hypoglycemia during diving remains to be determined.