Symlin Observations

I've been taking Symlin again for several weeks and have noticed some significant changes in how my blood glucose responds to food, insulin and exercise. After the suggested ramp-up period, I am now taking 10 units, or 60 micrograms, or Symlin at breakfast, lunch and dinner, and have been very consistent about taking it (e.g., I am not skipping doses if I just exercised or plan to exercise after work). These are some of my observations, which may be confounded because I also cut down my weekly long ride from 90+ to about 45 miles, and similarly reduced my long runs from 16-20 miles to 8-12. I am still exercising nearly every day, although the daily volume is somewhat reduced as well. Another possible confound is that I am trying to eat a lot less, in general, but during exercise in particular.

• I have had to change my carb ratio from about 9g:1U to 15-20g:1U and must take an extended bolus anywhere from 90-120 minutes with only 15-25% of insulin upfront (typically). If I am on the low side, I will take less upfront and if my BG is high, I'll increase the upfront amount accordingly. (Thanks, Scott, for the tip on extending the bolus from an hour to 90 minutes.)
  
• I tend to go high in the evenings so take a longer extended bolus after dinner than after breakfast. Maybe this is a basal rate problem; I'm not sure.
• I must reduce my basal rates by 30-50% an hour before exercise; previously I could pretty much keep my basal right where it was. I have a sense that this is not just due to the fact that I am eating less, because I am not spiking as much during intense workouts, either. Previously, this was a pretty reliable response for me, regardless of whether I ate anything. I had feared that I would have have a lot of bad lows during exercise but have been okay as long as I reduce the basals in advance. For example, this morning, I reduced my basal rate from 0.7 to 0.575 one hour before going for a very early 45-mile bike ride. I didn't eat anything the entire 3 hours and was 142 at the start and 82 at the finish. It was an interesting test.
  
• My BG's are much more stable, and the Dexcom has been really important in my being able to fine-tune the symlin/insulin strategy. I initially would have a low after bolusing, then rebound with a bad high about an hour later. The extended bolus has pretty much resolved this.
• Sometimes my blood sugar seems to randomly take off more than a few hours after eating. The Dexcom shows a straight line with a steady positive slope. I'm not sure what is going on here but this seems to happen every now and then. Perhaps it is related to what I ate but I don't have a good explanation.
• I still have some nausea and occasionally wake up sickeningly hungry. You know that feeling when you are so hungry you could almost throw up? I try to ignore it and go back to sleep. Don't worry; I am definitely eating enough.
• Symlin really stings! And I don't like shots after all. I think the rubber is so thick on the vial top that it slightly dulls the needle going in. I remember this from before. I am injecting mostly in my arm and thigh since my abdomen is already crowded with my pump infusion site and the Dexcom sensor. I know there is a Symlin pen now, but I will have to wait until I use up my current supply.
• It takes longer to recover from lows. I try to avoid getting low in the first place by watching the Dexcom.

My experience has been much more positive this time around, but I still have some reservations about using Symlin for safety reasons. Although amylin is naturally produced in the body, Symlin is an analogue and I feel like I am basically a guinea pig here. (I know they do safety studies on it but how many other drugs have been pulled even after the safety studies were satisfied?) I don't like having to pull out a needle before eating, though, and am not sure if I have really committed myself for the long haul with Symlin. We'll see!