Thanks for your kind appreciation and for sharing your parents' story, Louise.

Indeed, frailty is a major issue for otherwise healthy elderly. The key component for frailty is muscle wasting (sarcopenia), and there are studies showing that statin may play a role in it, though these studies are mostly association studies, that is, they compare groups of elderly who take statins with those who don't. I'm aware of at least one such comparison that, by correcting for possible confounders, found that taking statins was associated with a decrease in muscle strength and increased risk of falls. So, your suspicion might be correct. Coincidentally, muscle problems are the most cited reason for discontinuation of statin use.