VitaDAO have published this. It is perhaps another useful summary of the situation with some biomarkers.
One major barrier to longevity research is evaluating the impact of interventions that improve human health and longevity because they are complex processes that occur over long time scales. Instead, measurable phenotypic traits or proxies of longevity, termed longevity biomarkers, may be used to assess the effectiveness of longevity interventions, or prognosticate clinical outcomes. Longevity biomarkers are critical tools for predicting lifespan and susceptibility to age-related diseases, but there exist a dizzying array of options, with at times contradictory readouts, and other key weaknesses. Strengths of longevity biomarkers include providing insight into an individual’s biological age, as opposed to chronological age, which is pivotal in evaluating targeted interventions that address aging and age-related conditions. However, most longevity biomarkers also exhibit notable weaknesses, such as a lack of specificity and lack of standardization across different studies and applications. These weaknesses underscore the need for more research to enhance their accuracy and reliability in long-term longitudinal studies. In the present review, we discuss key strengths and weaknesses of popular clinical biomarkers used to predict morbidity and mortality associated with advanced age, identify existing bottlenecks, and integrate the field consensus on further directions for robust life- and healthspan estimation.
Further, total testosterone and free testosterone levels are inversely correlated with cognitive impairment in aged males, highlighting the neuroprotective importance of this particular sex hormone—as well as an intact hypothalamus-pituitary axis in general—for healthy aging (Holland et al., 2011).
. Further, 2-hour post-challenge blood glucose (2h-BG) is a better predictor for all-cause and cardiovascular mortality than FBG (Borch-Johnsen et al., 2001). Although all aforementioned parameters correlate with markers of cardiovascular health (such as markers of risk for atherosclerosis), the magnitude of postprandial blood glucose swings, rather than the mean values of glucose concentration over time, has the strongest association (Temelkova-Kurktschiev et al., 2000). This finding suggests the primary importance of acute postprandial fluctuation measurements over FBG or HbA1c for longevity biomarker purposes (Monnier et al., 2006).
Both IL-6 and CRP correlate with lifespan. In men, each standard deviation increase in either biomarker was associated with a 12-15% decrease in survival time and ~1-year shorter lifespan (Wassel et al., 2010). In women, the 7% reduction in survival time and 1.35-year shorter lifespan was linked only to IL-6 and depended on their estrogen therapy status (Wassel et al., 2010).
Moreover, in humans over 75 years old, the decline in GFR does not lead to increases in serum creatinine because the diminished filtration rate is compensated by lower lean muscle and creatinine production. This precludes the use of GFR across all ages (Fastbom et al., 1996).
John, thanks, very interesting! Just did a careful read thru and picked up some good info. The 2-hour post-challenge blood glucose (2h-BG) was new to me as a better marker than HbA1c. The test for IL-6 is something I had heard of but I’m considering it more seriously. Certainly, as noted, Cystatin C is valuable. Surprising was no mention of ApoB but just talk of total cholesterol, HDL and LDL.