One more thing to add to this....I assume you are using a Human Blood meter. I have always read that Human blood meters read low blood glucose readings lower than the actual, in an attempt to prompt or "scare" the person into eating or seeking help. So, the 36 that you are getting, is probably lower than the actual reading.
We cannot make this same assumption, due to precautionary reasons, when we think a cat receiving insulin is in hypo numbers. It would be a dangerous assumption. But, in a cat that has received no insulin, it is fair to assume that the BG reading is probably reading lower than the actual.