Critical analysis of ageing biomarkers
The major challenge associated with their use is that the changes associated with frailty are also largely associated with the normal aging process. As DHEA is the precursor to both testosterone and estrogen, its circulating level is more similar in men and women than testosterone, though its role in pathology between sexes has still been shown to differ.
Most literature focuses on morbidity and mortality as ageing phenotypes or endpoints and there is no independent, criterion reference measure of healthy ageing against which existing or novel biomarkers may be assessed. In this review, we summarize the present evidence on current and upcoming biomarkers for frailty Figure 1 and their advantages, disadvantages, validity, and predictive value.
One hypothesis on the pathogenesis of frailty suggests a systemic dysregulation of protein synthesis and metabolism as part of the underlying process resulting in its presentation.
Biomarkers of aging examples
A decrease in testosterone levels has been associated with frailty in both men 34 , 35 and women. We undertook comprehensive reviews of the literature searching for biomarkers of ageing on five ageing-related domains including physical capability and cognitive, physiological and musculoskeletal, endocrine and immune functions. Where available, we used existing systematic reviews, meta-analyses and other authoritative reports such as the recently launched NIH Toolbox for assessment of neurological and behavioural function, which includes test batteries for cognitive and motor function the latter described here as physical capability. One hypothesis on the pathogenesis of frailty suggests a systemic dysregulation of protein synthesis and metabolism as part of the underlying process resulting in its presentation. To identify this reference range, we completed the COP Study. Wide variation is seen in circulating VitD levels among seasons, geographical areas, and racial groups, limiting its clinical usability. While a wide range of serum markers have been investigated, hemoglobin, glomerular filtration rate, and albumin levels are particularly noteworthy as potential indicators of frailty. In addition, most of these proposed biomarkers are able to capture only single aspects of the conditions, are weak predictors of disease progression eg, from prefrail to frail , or are poorly associated with clinically meaningful outcomes ie, disability. The human gonadal hormones are vital anabolic factors in musculoskeletal physiology, and their age-linked decline is well understood. This blurs the line between a normal and abnormal result for a patient of a given age, making clear cutoff points to indicate the onset or progression of disease challenging to determine. Strength, locomotion, balance and dexterity are key physical capability subdomains. As life expectancy increases worldwide, the prevalence and clinical consequences of frailty will increase rapidly.
We undertook comprehensive reviews of the literature searching for biomarkers of ageing on five ageing-related domains including physical capability and cognitive, physiological and musculoskeletal, endocrine and immune functions.
Further, the inclusion of the same common panel of measures of healthy ageing in diverse study designs and populations may enhance the value of those studies by allowing the harmonisation of surrogate endpoints or outcome measures, thus facilitating less equivocal comparisons between studies and the pooling of data across studies.
In this report we also highlight areas needing further research. Additionally, there is widespread dissent over what are considered healthy and unhealthy circulating levels of the hormone. Summary We present recommendations for a panel of biomarkers that address these major areas of function which decline during ageing.
However, we recognise that there are important subjective features of the healthy ageing phenotype, including psychological and social wellbeing, which are not covered here [ 14 — 16 ].
based on 85 review