7 Responses

  1. Scott E
    Scott E May 11, 2013 at 5:09 am | | Reply

    This is a very good point, Wil. I also wonder if there’s a residual effect from the dive itself. I believe scuba-diving increases the nitrogen content in the blood because of the change in pressure (I could be very wrong on this!). Could this somehow dilute the glucose measured in the blood, or affect the electrochemical reaction that measures it?

    I’d be curious to know how Marianne “recovered” from this alleged low, and how long it took… whether it was stuffing her face with sugary stuff like we T1s do, or if some time above sea-level did the trick (and if she washed her hands before a re-test). They might offer some clues.

    Of course, it could be an authentic, genuine low sugar level. I don’t want to accuse her of being a liar…

    1. Marianne
      Marianne May 12, 2013 at 5:54 am | | Reply

      Thanks for your thoughts Scott.

      I had a couple of glucose jelly beans as soon as I got back on board and then started eating some low GI snacks that I took with me. There is about 45 minutes between the two dives.

      My levels started to improve and I got up to 6.7mmol/l (120mg/dl) but then they started dropping again so I wasn’t too keen to get back into the water with a level lower than my starting point for the first dive.

      The nitrogen content of my blood shouldn’t have been too bad because I didn’t go deeper than about 12 metres and this is described as a no-decompression dive. But I will ask my doctor about this the next time I visit.

      There might be something about the nature of water sports that deserves a bit of investigation though – you burn more calories with water sports than with any equivalent ‘dry land’ sports because of the added pressure that comes with depth.

  2. pwd doc
    pwd doc May 11, 2013 at 7:53 pm | | Reply

    I agree this may not be a true low glu and your approach to the meter issue sounds very reasonable. I assume Marianne isn’t on insulin or any other diabetes drug other than metformin. If she is only on metformin and decreasing her dose, she must still be making a lot of her own insulin.

    Normally, insulin is released from the pancreas in 2 phases. The first phase occurs very soon after ingesting food, followed by a slower, more prolonged second phase. Some people with type 2 have a delay or absent first phase insulin release. If they eat fast acting carbs, their bg may initially spike high, and then their body may actually release too much insulin in the second phase causing lows.

    If the lows turn out to be real, I suggest that Marianne discuss with her doctor skipping the pre-dive fruit juice, but having some complex carb with protein before the dive. Alternatively (or if necessary in addition), she can buy 2 diver’s water bottles (apparently they make special water bottles to use while diving so divers don’t get dehydrated). She can fill one with a sugar containing liquid like powerade or gatorade which have less carb than fruit juice, or if necessary with fruit juice and fill the other with a sugar free fluid. She can sip the carb containing bottle periodically during the dive – the same amount of carb sipped periodically over 30 minutes to 1 hour during strenous activity is much less likely to spike the blood sugar and cause excessive delayed insulin release and lows than drinking the same amount of carb all at once before the dive. If she sips sugar during the dive, she made need less carb before the dive. It is also a good idea to start with short dives and work her way up to longer dives so she can see if her plan is working. Have fun!

    1. Marianne
      Marianne May 12, 2013 at 6:05 am | | Reply

      Thanks for your comment pwc doc.

      I’m taking 1g Metformin a day and that is my only diabetes medication.

      I think between us, we’ve hit on the strategy to try next. I’ll abandon the glucose hit (just in case I’m reacting the way you describe) and start with a protein/complex carb snack. If that doesn’t work, I’ll try the water bottle strategy.

      I like it when a plan comes together …

  3. Marianne
    Marianne May 12, 2013 at 5:45 am | | Reply

    Wow, Will, you’ve given me a bit to think about there – and it’s going to have to be a speedy thought or two because I’m booked in for a dive next weekend and I really want to do two dives this time (it’s getting a bit chilly down under and the water temperature is dropping fast).

    Giving my last dive trip a bit of thought – I did most of what you said about the meter but I probably didn’t dry my hands thoroughly so I’m going to be a lot more determined about that next time. The boat is pretty small and open to the elements so I’ll put some serious effort into controlling its environment other ways. And I’ll see if I can borrow another meter before then too.

    I’m in two minds about whether the low was a low or whether is was a normal dressed down as a low. I do have a bit of a tendency to drop into the low 4mmol ranges (70-90 mg/dl) and I have dipped into the 3s (<70 mg/dl) on occasion – usually when I've been exercising above sea level involving water sports …)

    I think I've come to a new plan with your help:

    1 more protein and fats (less carbs) but a smaller meal in case I'm overreacting to a larger than normal meal – and, from what I've read, fats slow down the absorption of the carbs/glucose and that could just be what I need.

    2 make sure my hands are totally clean and dry when I test.

    3 check the calibration of my meter before the next trip.

    4 get hold of another meter so that I can double check.

    Keep your fingers crossed for me – I'm keen to take the plunge.

  4. Doug
    Doug May 13, 2013 at 3:57 am | | Reply

    Interesting read.
    Ive been scuba diving a number of times as a Type 1 and hope to do more. Ive found that for treatment of low BG the tubes of cake frosting fit well in the BCD pockets. Ive tested taking out the regulator at depth and eating some. Just dont forget to cut the tube open before the dive. ( like I did the first time in the training pool ) It was reassuring to have the frosting with me on a night dive where we surfaced WAY down the reef from our goal. The long surface swim could have easily caused low BG. But didnt.

    I used a freestyle meter on my dives and didnt see any “false lows ” that I know of, from salt water. I keep the meter in a dry box in my dive bag on the dive boat when we dove from a boat. Im SURE i tested with salt water in my fingers.

    My Endo and I came up with a plan where I took half my daily basal from my pump as a lantus injection from a pen and I left the pump in the safe, in the room. When I was not diving I just set the pump to a 50 % temp basal. For me that worked remarkably well.

    Glad to see other diabetics are out diving …

  5. Marianne
    Marianne June 3, 2013 at 2:54 am | | Reply

    As it turns out, “chocolate is the answer” – or to quote another quote “There are times when chocolate really can fix all your problems”.

    I must confess though, I’m not 100% convinced that it was the chocolate but I’m going to continue with it as my solution. At what other time can a diabetic say “Give me chocolate, it’ll solve my problems”.

    I took my initial cue from the point Wil made that by increasing the amount I ate, my pancreas might be having a panic attack at the sight of so much sugar. I also spent a bit of time thinking about how a low GI approach definitely wasn’t working. I contemplated the meter giving me false readings and then thought that it was a bit strange that it always gave me low readings when diving and rarely at other times (though I do have lows from time to time). I also came across this article about mixing diabetes and fluoxetine ( ) … sorry, Wil, I think I forgot to mention that I also have depression … and arthritis … and … and …

    I also read somewhere that fats slow down the processes that happen when carbs enter your system so I thought I’d try a totally different approach to managing my scuba excursions.

    Throw out the low GI diet.

    Start eating high protein/high fat.

    Scrambled eggs + bacon + tomato + cheese + avocado for breakfast.

    Toss out the metformin on the morning of the dive (as suggested by my doctor).

    Chocolate for snacks after I get on the boat (so I really think it might have been the fat content in the chocolate that really did the deal). I took some dark chocolate, a nut bar and an apple with me.

    I had a wonderful time doing two dives on Sunday.

    Thanks for your advice Wil. I learnt so much more about Diabetes from your response.

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