Comparison of field- and laboratory-based estimates of muscle quality index between octogenarians and young older adults: an observational study

Abstract

Muscle quality (the ratio of strength to lean muscle mass) might be a better indicator of muscle function than strength alone. Differences in muscle quality index (MQI) between octogenarians and young older adults remain unclear. The aims of the present cross-sectional study were to compare (1) MQI between octogenarians and young older adults, (2) lab versus field-based MQI tools, and (3) determine possible confounding factors affecting MQI in older adults. Compiled data from two cross-sectional studies included 175 younger and older adults (31 men and 144 women) with a mean age of 75.93± 9.49 years. Participants with age ≥ 80 years old were defined as octogenarians (n= 79) and < 80 years was defined as young older adults (n= 96). Laboratory MQI was derived from the ratio of grip strength to arm muscle mass (in kg) measured by dual-energy x-ray absorptiometry. Field-based MQI was quantified from the ratio of grip strength to body mass index (BMI). Octogenarians displayed lower field (P= 0.003) and laboratory MQI (P< 0.001) as compared with young older adults. There was a strong correlation effect between field MQI and laboratory MQI (P= 0.001, R= 0.85). BMI (P= 0.001), and diabetes mellitus (P= 0.001) negatively affected MQI. Women presented lower MQI (P= 0.001) values than men. In light of this information, rehabilitation specialists should consider the use of fieldbased MQI as a tool for evaluation and follow-up of older population.

Relationship between Lower Limbs Performance and Spinal Alignment in Parkinson’s Disease Patients: An Observational Study with Cross Sectional Design

“…As expected by the results derived by other studies [23][24][25], there is a significant negative correlation between age and MQI in PD patients: older age correlates with decreased lower-limb function. The significant correlation only present in the PD group may suggest that the negative effect of the aging process affects Parkinson's disease patients more than the general population.…”

Body composition and functional performance of older adults

“…MQ considered the ratio of handgrip to the entire arm muscle (kgs) measured by DXA [ 19 ]. The validity and reliability of MQ is established and is commonly used in large-scale studies [ [22] , [23] , [24] ].…”

A medida da força muscular relativa de preensão manual representa a força muscular global em idosas?

“…Para calcular a força relativa de preensão manual de campo, o maior valor obtido foi dividido pelo IMC. Além disso, pesquisas anteriores corroboram com o uso da força muscular absoluta corrigida para o IMC (Choquette et al, 2010;Lawman et al, 2016;Lee et al, 2016;Nascimento et al, 2020;Prestes & Tibana, 2013;Silva et al, 2018). Ademais, a força muscular relativa foi calculada para todos os exercícios (leg press horizontal, supino máquina, cadeira extensora, remada fechada e cadeira flexora) utilizados para a estimativa de 1 RM, dividindo-se a carga de 1 RM pelo IMC da participante.…”