How many frailties exist? – Authors' reply
Authors: Francesco Panza, Vittorio Dibello, Rodolfo Sardone, Madia Lozupone
Journal: The Lancet Healthy Longevity (2021)

We thank Matteo Cesari and Marco Canevelli for their interest in our systematic review. Of course, behind their observations lies a theoretical debate on frailty that is being held among researchers worldwide. In fact, after more than 20 years of intensive clinical research, although a consensus on the theoretical foundations of frailty has been established, a consensus about a single operational definition is still lacking, and over 70 different operational definitions still exist. Nevertheless, at present, two main frailty models are most commonly used.1Howlett SE Rutenberg AD Rockwood K The degree of frailty as a translational measure of health in aging.Nat Aging. 2021; 1: 651-665Crossref Google Scholar The so-called deficit accumulation model incorporates a large number of candidate factors ranging from disease states, symptoms, and signs to abnormal laboratory values. Conversely, the most widely used operational definition of frailty, the biological or syndromic construct, describes a phenotype. This original phenotype is often referred to as physical frailty, to distinguish it from similarly constructed frailty syndromes for cognitive frailty, social frailty, and organ-specific frailties.1Howlett SE Rutenberg AD Rockwood K The degree of frailty as a translational measure of health in aging.Nat Aging. 2021; 1: 651-665Crossref Google Scholar All of these phenotypes combine specific health deficits that increase with age and, taken individually, are associated with adverse health-related outcomes.1Howlett SE Rutenberg AD Rockwood K The degree of frailty as a translational measure of health in aging.Nat Aging. 2021; 1: 651-665Crossref Google Scholar Therefore, the two principal approaches to frailty might not be in conflict but rather complementary to each other. In fact, in 2013, Cesari and Canevelli proposed an operational definition of the cognitive frailty phenotype,2Kelaiditi E Cesari M Canevelli M et al.Cognitive frailty: rational and definition from an (IANA/IAGG) international consensus group.J Nutr Health Aging. 2013; 17: 726-734Crossref PubMed Scopus (418) Google Scholar and all research groups interested in frailty applied different approaches to evaluating the risk of adverse health-related outcomes for research purposes or in older individuals with specific conditions. In geriatric medicine, an approach that accounts for different frailty phenotypes (cognitive, nutritional, oral, social, and so on) could suit a holistic view of this condition. Frailty is a multidimensional concept, partly captured by general frailty models, and it is considered as primary or preclinical when the state is not directly associated with a specific disease, or when there is no substantial disability. In this context, frailty phenotypes seem to be more appropriate to define primary frailty and could potentially be applied in a preclinical context to tailor specific prevention strategies or treatments. By contrast, frailty is considered secondary or clinical when it is associated with known multimorbidity, such as dementia, cardiovascular disease, or disability,3Strandberg TE Pitkälä KH Frailty in elderly people.Lancet. 2007; 369: 1328-1329Summary Full Text Full Text PDF PubMed Scopus (137) Google Scholar and is better defined using the deficit accumulation frailty model. According to the precision medicine initiative, researchers and clinicians of geriatric sub-specialties (eg, gerodontologists, old age psychiatrists, and old age nutritionists), after a screening with general frailty models, might need to use specific frailty phenotypes to more accurately predict effective treatments and prevention strategies. Of course, different frailty phenotypes must be operationalised and tested in different settings to confirm their true usefulness in relation to adverse health-related outcomes, using novel health indicators (eg, oral frailty),4Morley JE Editorial: oral frailty.J Nutr Health Aging. 2020; 24: 683-684Crossref PubMed Scopus (7) Google Scholar or adding existing constructs to various other linked health conditions, namely cognitive dysfunction plus physical frailty for cognitive frailty,2Kelaiditi E Cesari M Canevelli M et al.Cognitive frailty: rational and definition from an (IANA/IAGG) international consensus group.J Nutr Health Aging. 2013; 17: 726-734Crossref PubMed Scopus (418) Google Scholar or nutritional imbalance plus physical frailty for nutritional frailty.5Zupo R Castellana F Guerra V et al.Associations between nutritional frailty and 8-year all-cause mortality in older adults: the Salus in Apulia Study.J Intern Med. 2021; (published online Aug 26.)https://doi.org/10.1111/joim.13384Crossref PubMed Scopus (5) Google Scholar Our systematic review investigated the role of oral health indicators in different frailty models, briefly introducing the concept of oral frailty defined as a diminished oral function with a co-existing decline in cognitive and physical functions. This could therefore be considered a geriatric syndrome and routinely screened for in older age.4Morley JE Editorial: oral frailty.J Nutr Health Aging. 2020; 24: 683-684Crossref PubMed Scopus (7) Google Scholar The importance of this phenotype is linked to the potential reversibility of all oral health deficits and to its relevant role as a risk factor for Alzheimer's disease and other neurodegenerative conditions. The interplay among oral health indicators, sarcopenia, nutrition, and frailty might further support the novel constructs of oral frailty4Morley JE Editorial: oral frailty.J Nutr Health Aging. 2020; 24: 683-684Crossref PubMed Scopus (7) Google Scholar and nutritional frailty.5Zupo R Castellana F Guerra V et al.Associations between nutritional frailty and 8-year all-cause mortality in older adults: the Salus in Apulia Study.J Intern Med. 2021; (published online Aug 26.)https://doi.org/10.1111/joim.13384Crossref PubMed Scopus (5) Google Scholar Maintaining or increasing oral function could decrease the impact of oral frailty and might be associated with an improvement of dietary and functional status in older people, thus decreasing the risk of mortality and other adverse health-related outcomes, including dementia and Alzheimer's disease. We declare no competing interests. Oral frailty and its determinants in older age: a systematic reviewPoor oral health is common among older adults and can impair essential activities of daily living and contribute to frailty. We did a systematic review of studies on the relationship between oral health factors and frailty among older adults (>60 years), consulting six different electronic databases for studies published from database inception to March 20, 2021. In total, 39 articles met the eligibility requirements, including 12 different indicators of poor oral health related to frailty, which we grouped in four different categories: oral health status deterioration; deterioration of oral motor skills; chewing, swallowing, and saliva disorders; and oral pain. Full-Text PDF Open AccessHow many frailties exist?We have read with interest the systematic review by Vittorio Dibello and colleagues1 in The Lancet Healthy Longevity, discussing the condition of oral frailty. We strongly agree with the authors that oral health is highly relevant, and its assessment should always be part of the clinical routine in older people. However, we are sceptical about the rationale and benefits underlying the introduction of another version of frailty. Full-Text PDF Open Access