I am a survivor of celiac disease who has been off gluten for about nine years, but still appear to have protein-losing enteropathy. The primary condition associated with celiac has been Hashimoto's/hypothyroidism, which has been corrected.
My PCP discovered that I have a blood protein level that is just below the bottom of the normal range. The primary symptom of protein deficiency has been middle insomnia. I figured out on my own that use of a free-form essential amino acid supplement (9 aminos, about 12 grams total when I wake up) is a very effective treatment that allows me to get back to sleep. There are a number of essential amino acid blends, with relative amounts of aminos based on a commonly-known formula, available on the market.