Investigating three ways of measuring the intrinsic capacity domain of vitality: nutritional status, handgrip strength and ageing biomarkers
Authors: Lu Wan-Hsuan , González-Bautista Emmanuel , Guyonnet Sophie , Martinez Laurent O , Lucas Alexandre , Parini Angelo , Rolland Yves , Vellas Bruno , de Souto Barreto Philipe ,   MAPT/DSA Group, Vellas Bruno , Guyonnet Sophie , Carrié Isabelle , Brigitte Lauréane , Faisant Catherine , Lala Françoise , Delrieu Julien , Villars Hélène , Combrouze Emeline , Badufle Carole , Zueras Audrey , Andrieu Sandrine , Cantet Christelle , Morin Christophe , Van Kan Gabor Abellan , Dupuy Charlotte , Rolland Yves , Caillaud Céline , Ousset Pierre-Jean , Lala Françoise , Dartigues Jean-François , Marcet Isabelle , Delva Fleur , Foubert Alexandra , Cerda Sandrine , Rouaud Olivier , Manckoundia Patrick , Quipourt Valérie , Marilier Sophie , Franon Evelyne , Bories Lawrence , Pader Marie-Laure , Basset Marie-France , Lapoujade Bruno , Faure Valérie , Li Yung Tong Michael , Malick-Loiseau Christine , Cazaban-Campistron Evelyne , Desclaux Françoise , Blatge Colette , Dantoine Thierry , Laubarie-Mouret Cécile , Saulnier Isabelle , Clément Jean-Pierre , Picat Marie-Agnès , Bernard-Bourzeix Laurence , Willebois Stéphanie , Désormais Iléana , Cardinaud Noëlle , Bonnefoy Marc , Livet Pierre , Rebaudet Pascale , Gédéon Claire , Burdet Catherine , Pesce Alain , Roth Stéphanie , Chaillou Sylvie , Sudres Kristel , Lebrun Nicolas , Touchon Jacques , Bennys Karim , Gabelle Audrey , Romano Aurélia , Touati Lynda , Marelli Cécilia , Le Duff Franck , Gervais Claire , Gonfrier Sébastien , Gasnier Yannick , Bordes Serge , Begorre Danièle , Carpuat Christian , Khales Khaled , Lefebvre Jean-François , El Idrissi Samira Misbah , Skolil Pierre , Salles Jean-Pierre , Dufouil Carole , Lehéricy Stéphane , Chupin Marie , Mangin Jean-François , Bouhayia Ali , Allard Michèle , Ricolfi Frédéric , Dubois Dominique , Bonceour Martel Marie Paule , Cotton François , Bonafé Alain , Chanalet Stéphane , Hugon Françoise , Bonneville Fabrice , Cognard Christophe , Chollet François , Payoux Pierre , Voisin Thierry , Delrieu Julien , Peiffer Sophie , Hitzel Anne , Allard Michèle , Zanca Michel , Monteil Jacques , Darcourt Jacques , Perret Bertrand , Vinel Claire , Caspar-Bauguil Sylvie , Olivier-Abbal Pascale , Andrieu Sandrine , Cantet Christelle , Coley Nicola 
Published: July 2023

Abstract

Background
Vitality is conceptually considered as the underlying capacity influencing other intrinsic capacity (IC) domains and being related to nutrition, physiological reserve and biological ageing. However, there is no consensus on its operationalisation.

Objective
To investigate the structure and magnitude of the association of vitality with other IC domains and functional difficulties using three operational definitions of vitality.

Methods
We included 1,389 older adults from the Multidomain Alzheimer Preventive Trial with data on Mini Nutritional Assessment (MNA), handgrip strength and plasma biomarkers (comprising inflammatory and mitochondrial markers). Using path analysis, we examined the effects of vitality on difficulties in basic and instrumental activities of daily living (ADL and IADL) exerted directly and indirectly through the mediation of other IC domains: cognition, locomotion, psychological, vision and hearing. We further explored the longitudinal association of vitality with IC domains, ADL and IADL over 4 years using linear mixed-effect regression.

Results
We observed significant indirect effects of vitality on IADL, mainly through cognitive, locomotor and psychological domains, regardless of the vitality measurement. Participants with higher vitality had fewer IADL difficulties at follow-up (MNA score: β [95% CI] = −0.020 [−0.037, −0.003]; handgrip strength: −0.011 [−0.023, 0.000]; plasma biomarker-based index: −0.015 [−0.028, −0.002]). Vitality assessed with the plasma biomarker-based index predicted improved locomotion over time.

Conclusion
Vitality was associated with disability primarily through the mediation of other IC domains. The three indicators examined are acceptable measurements of vitality; biomarkers might be more suitable for the early detection of locomotion decline.