Thanks again everyone. I have spent a fair bit of time last night reading up, and first off I am confused by the (a) welter of information and (b) how some of it seems to contradict - as exemplified above in some ways. Persoanlly, I am deeply suspicious of statins and will do whatever i can to stay away from them.
I don't have my results to hand but seem to recall that my ratio was in excess of 7.5. I will ask family but I doubt many have ever had it checked. Not aware anyway of any issues.
I researched the underactive thyroid and am reasonably convinced in a self-diagnosis way that I don't fit the bill - it's just the weight gain.
Danny, I am slightly ashamed to say you may have it. I was recommended the myfitnesspal thing and started it yesterday morning. I am absolutely horrified about how easy it is to cancel out eg my 30 minute walk each morning by some seemingly trivial food. Either that thing is way out or I have no idea about what I have been eating. I stayed around my claorie target yesterday and was silly hungry and felt as if I'd eaten about a third of usual.
I will keep at it for a few weeks, and then I think use it as a record to see a nutritionist about both my weight and my crazy chloresterol levels.
Thanks again everyone - deeply appreciated.