Biological Processes and Biomarkers Related to Frailty in Older Adults: A State-of-the-Science Literature Review.
Biol Res Nurs. 2018 Sep 9:1099800418798047. doi: 10.1177/1099800418798047. [Epub ahead of print]
Wang J1, Maxwell CA2, Yu F3.
1 School of Nursing, University of Rochester, Rochester, NY, USA.
2 School of Nursing, Vanderbilt University, Nashville, TN, USA.
3 School of Nursing, University of Minnesota, Minneapolis, MN, USA.
Many studies find a stong association of Vitamin D to Fraility
- Frailty 2X less likely in depressed seniors having a good level of vitamin D – Nov 2018
- Vitamin D In Older Women - Fractures, Frailty and Mortality – Buchebner thesis 2017
- Vitamin D improves muscle strength, reduces falling, and reduces frailty – review March 2015
- 80 percent of the characteristics of frailty associated with low vitamin D – May 2013
- Frailty can be avoided – vitamin D is one of the ways – July 2017
- Frailty associated with low levels of vitamin D – 2012, 2016
- Frailty risk increases 12 percent for every 10 ng less vitamin D – meta-analysis Sept 2018
- Sarcopenia (muscle loss) and Vitamin D
- Sarcopenia reduction: Protein, Leucine, Omega-3, Vitamin D, and exercise - hypothesis Aug 2018
- Sarcopenia does not officially exist in Australia, but 1 in 3 of their seniors have it - July 2018
- Added 1 lb of muscle to sarcopenia adults in 13 weeks with just 800 IU vitamin D and protein – RCT Jan 2017
PDF is available free at Sci-Hub 10.1177/1099800418798047
The objectives of this literature review were to (1) synthesize biological processes linked to frailty and their corresponding biomarkers and (2) identify potential associations among these processes and biomarkers. In September 2016, PubMed, Cumulative Index to Nursing and Allied Health, Cochrane Library, and Embase were searched. Studies examining biological processes related to frailty in older adults (≥60 years) were included. Studies were excluded if they did not employ specific measures of frailty, did not report the association between biomarkers and frailty, or focused on nonelderly samples (average age < 60). Review articles, commentaries, editorials, and non-English articles were also excluded. Fifty-two articles were reviewed, reporting six biological processes related to frailty and multiple associated biomarkers.
The processes (biomarkers) include
- brain changes (neurotrophic factor, gray matter volume),
- endocrine dysregulation (growth hormones [insulin-like growth factor-1 and binding proteins],
- hormones related to glucose and insulin,
- the vitamin D axis,
- thyroid function,
- reproductive axis, and
- hypothalamic-pituitary-adrenal axis),
- enhanced inflammation (C-reactive protein, interleukin-6),
- immune dysfunction (neutrophils, monocytes, neopterin, CD8+CD28-T cells, albumin),
- metabolic imbalance (micronutrients, metabolites, enzyme-activity indices, metabolic end products), and
- oxidative stress (antioxidants, telomere length, glutathione/oxidized glutathione ratio).
Bidirectional interrelationships exist within and between these processes. Biomarkers were associated with frailty in varied strengths, and the causality remains unclear. In conclusion, frailty is related to multisystem physiological changes. Future research should examine the dynamic interactions among these processes to inform causality of frailty. Given the multifactorial nature of frailty, a composite index of multisystem biomarkers would likely be more informative than single biomarkers in early detection of frailty.