My husband is diabetic, too, and we started using palm sugar (also called coconut sugar--doesn't taste like coconut, though), which has a low glycemic rating of 35. Someone on the forum here posted this recipe for coconut palm sugar syrup and it can be used in place of the agave in all of Elana's almond flour recipes. It works great as a substitute! I usually make it in advance and store it in a pint-sized mason jar in the refrigerator so it's ready to use.
Coconut Palm Sugar Syrup
* 1 ½ cups palm sugar
* ½ cup water.
1. To make the syrup, bring the coconut palm sugar and water to a boil in a medium-size saucepan over medium heat, stirring to dissolve the sugar. Stop stirring and reduce the heat to low. Simmer for 3 minutes. Keep warm if to be used immediately. Or, let it cool and keep refrigerated to use later on.
You can read a good article about palm sugar here: http://www.bigtreefarms.com/coconutsugar/
(Although I've been buying the "Nativas Naturals" brand of palm sugar online.)
You might want to make sure to buy the "Cocos Nuciferas" variety of palm sugar as supposedly this was the one tested for its low glycemic benefits. The Nativas Naturals brand is that variety along with the Sweet Tree brand.
This helps explain what I've read:
http://cocopalmsugar.sch.ph/node/54
Good luck!