Weight loss - at what point would a cure kick in?

[Mogy]

Another data point.
60 year old, Feb diagnosis with AHI of 19, RDI of 20. Weight 215, height 6ft. I was 225 the month before the diagnosis.
Had problems with treatment emergent apnea, decided weight loss to get off CPAP was my best option. Lost more weight and retested with the same home sleep test-Apnea Link.
I weighed 185 beginning of April when retested. I had 3 nights with machine over the weekend.
Friday 4.75 hours AHI 16
Sat 3.5 hours AHI 6
Sun 4.25 hours AHI of 16
I continued losing weight, got down to 175lbs, where I felt my best. Stayed there for 3 months then started to slip. Currently at 185lbs.
Losing weight is relatively easy for me, keeping it off is harder, even when fully motivated.
I know that I lost the weight too fast but I find losing it slowly harder than keeping it off.

[Shin Ryoku]

This is a good review of weight loss effects on OSA management: https://www.ncbi.nlm.nih.gov/pubmed/28185772

Full text available without subscription .

[overlap]

I lost 20 lbs (I'm now 180lbs, 5'10" and about 18% body-fat). I have "mild OSA" according to the Registered Portable Monitoring" mail-in sleep study I did last week. I didn't do a test at the higher weight - but self diagnosed based on symptoms and Oximeter readings.

Would it follow that if I lost another 10 or even 20 lbs, I might come in as cured? I wouldn't mind being thinner (although the 20lbs was very hard to lose).

I guess I'm really wondering what the limits are with the relationship between weight and apnea.

When first diagnosed (moderate) I mentioned to my doctor that I thought this was related primarily to bigger people. He cleared that up explaining other causes for apnea as others have mentioned. He was also the first doctor to refer to me as “thin” which was amusing. I never thought of myself as thin, I’m about your size and could lose a few pounds but I’ve been assured it won’t have much, if any, effect on my sleep.