I always am amazed and find it quite humorous when we are worried about shit like insulin sensitivity and thyroid suppression. For the overwhelming majority of the people posting on this board, these are not long-term concerns because they are not running high doses for long periods of time.
GH causes your body to "switch off" the mechanism that causes you to use glucose and glycogen as fuel and "switches on" the mechanism that causes you to burn fat and use it for fuel. The issue with insulin sensitivity and the need to supplement with exogenous insulin arises only when people take their GH with a full stomach or while consuming a bunch of carbs within a couple of hours of taking GH. Your blood sugar levels will rise due to the GH causing your body to not use glucose as fuel. It just goes up. And, if your pancreas is normal, it will churn out more insulin because it notices your blood sugar is up, but it won't matter. Your cells become saturated with insulin...receptors become overwhelmed...when blood sugar levels return to normal, the normal amount of insulin your body produces isn't sufficient. Now, your receptors will bounce back and everything will return to normal if you are not doing this shit like this every day for months and months.
As for the thyroid suppression. We are injecting unknown chemicals into our bodies made by some asshole in a storage shed, and suddenly, we are worried about our thyroid gland? Ha! Hell, if you had to pick one gland in your body to go belly-up, it would most likely be the thyroid. Taking a 4 cent thyroid pill every day for the rest of your life...oh, the horror. My mom takes a thyroid pill. LOTS of people take thyroid meds. Thyroid suppression is possible short-term, but only while on GH and, long-term, only with long-term high doses.
If you are above 35, GH will work wonders stacked with some T3 and 500+ mg of test. Just take your GH on an empty stomach in the morning (even if you have to set your alarm clock to get up before breakfast, then go back to bed), and do about 60 to 75 mcg of T3. GH and T3 are very synergistic. I'm sure insulin makes it work better, but if you do your GH on an empty stomach, the fat will melt off of your body and you will never have to worry about your insulin sensitivity.