Physiological clocks and their types
The majority of people would like to find out how many years of “good health” they have left. With this in mind, researchers have suggested a prediction concept of biological age or "biological clock". There are various modeling techniques allowing to develop a certain level of prediction- artificial intelligence, biomarkers, measurements in large cohort studies. Authors from China describe various "aging clocks", including phenotypic, epigenomic, transcriptomic, proteomic and other. For example, a metabolic clock has been found to have strong associations with aging. The first metabolic age predictor was established based on the large-scale urine metabolite profiling. Another predictor described is a circadian clocks, that is responsible for sleep-wake cycles, body temperature, energy metabolism, hormone secretion and locomotor activity. But the main challenge remains in establishing the most accurate biological predictor that could answer the question of longevity.