More telomerase tidbits
When I started following telomere/telomerase-related research 15 years ago, this was an arcane subject. Research publications related to it were extremely far-between and only a few far-out thinkers saw it as having a lot to do with human longevity. Nowadays, hardly a day goes by without new research related to telomeres or telomerase coming to my attention. Here are two tidbits.
– Leukocyte telomere length like HDL cholesterol is a predictor of susceptibility to coronary artery disease.
A study of 662 males and females followed over a a 29.8 year period, the Bogalusa Heart Study, showed that a) longer telomere length is positively correlated with higher levels of HDL cholesterol, b) shorter telomere length and lower levels of HDL: are highly correlated with increase in the risk for atherosclerosis and susceptibility to coronary artery disease, and c) shortening of longer telomeres is significantly reduced when higher levels of HDL is present. The simplest explanation is that low levels of HDL increase the level of oxidative risk and that cell reproduction is accelerated to replace cells damaged by oxidation and therefore average telomere lengths are higher when there is more HDL. I suspect there may be more to it than that. Namely, telomere lengths may also affect cholesterol levels. Another analysis of data from the Heart and Soul Study looked at patients with stable coronary artery disease. “ — patients in the lowest quartile of (leukocyte) telomere length remained at significantly increased risk of death compared to those in the highest quartile. Patients in the lowest quartile of telomere length were also at significantly increased risk of HF (Heart Failure) hospitalization –. This study suggests that leukocyte telomere length may be a predictor of mortality risk that provides information not included in the usual predictors such as cholesterol levels. These studies stop short of stating what to me seems obvious – that active intervention to maintain telomere lengths could possibly reduce the risk of susceptibility to coronary artery disease and the death rate of those that already have it.
– The longest living birds have very long telomeres and manage to keep them long. This was brought to my attention by reader of this blog Res and is covered in the discussion under the Naked Mole Rat item. Because of its importance I repeat the substance here. Res brought to my attention these citations relevant to the telomere lengths of different bird species and storm petrels in particular:
My initial response to Res was: Extremely interesting articles. I get the following messages: 1. Since the storm petrels are tiny birds always on the go and live up to 40 years, this tends to knock out the theory that lifespan is centrally shaped by rate of metabolism. One explanation given for the long lifespan of the naked mole rat is that its existence is very laid back and it mostly sleeps. It is the opposite for the bird. 2. The accumulated oxidative damage theory of aging also does not seem very applicable for these birds since high metbolism generates a lot of free radicals. 3. The evidence connected with these and other birds is that long initial telomere lengths and telomere length maintenance are factors very correlated with longevity, e.g. a boost to the telomere shortening theory of aging. 4. Despite telomere lengths growing with age and low cancer rates these birds still die, suggesting that some other form of aging is operational and life-limiting for them.
About a week ago I updated the telomerase section in the Anti-Aging Firewalls treatise with a new perspective on the Telomere shortening theory of aging.