Research may reveal why people can suddenly become frail in their 70s

if you plug stem cell exhaustion and "telomere" into google, they have relationships in the literature:

  As a result, the qualitative and quantitative decrease in stem cell function
  during the process of aging, known as stem cell exhaustion, has been specified
  as one of the promoters of aging (3,6). The role of telomere loss in the 
  replicative senescence of stem cells has recently been the focus of 
  considerable interest.

if you plug epigenetic disregulation and "telomere" into google, they have relationships in the literature.

> genomic instability

if you plug genomic instability and "telomere" into google, not surprisingly they have relationship.

> altered cell signaling

I think you can guess what I'm going to say here.

I'm not a cell biologist. I certainly don't think telomeres are the smoking gnu of all of this, but there are indications the commonality of how telomeres alter DNA expression, and the centrality of DNA processing to renew cell function come to the fore: if you don't have a valid end-cap on the instruction set, it may not reproduce accurately which affects all the cellular processes which stem from it's reproduction and application. (a massively overplayed analogy to the digital domain, which is a bit bogus)

> stem cell