I am 40 and got diagnosed with it it one of my hips about a year ago , and was told by the specialist that cycling and excercise was ok as it keeps things moving without too much impact, if you dont excercise then you gain weight and put more pressure on your joints. mine is due to my hip angles being too shallow and causing wear and that I will need both hips replaced at some point.
I was devasted me when first told , but now just get on with life and will deal with the inevitable when it gets here.
I have tried eliminating all sorts of things. movement wise , food , drink , biking , not biking , sitting position , standing position ,sleeping position, different shoes and there seems no real pattern to what can be painful one day and gives me no pain the next , so you just have to go with whats ok on the day.
I now have slight pain in my other hip somedays so it is obviously progressing , but as I wrote earlier I just take it day to day and do everything I used to .
Matt