Predictive equation for assessing appendicular lean soft tissue mass using bioelectric impedance analysis in older adults: Effect of body fat distribution.

BACKGROUND: Low muscle mass is associated with sarcopenia and increased mortality. Muscle mass, especially that of the limbs, is commonly estimated by dual-energy X-ray absorptiometry (DXA) or bioimpedance analysis (BIA). However, BIA-based predictive equations for estimating lean appendicular soft tissue mass (ALST) do not take into account body fat distribution, an important factor influencing DXA and BIA measurements. OBJECTIVES: To develop and cross-validate a BIA-based equation for estimating ALST with DXA as criterion, and to compare our new formula to three previously published models. METHODS: One-hundred eighty-four older adults (140 women and 44 men) (age 71.5 ±â€¯7.3 years, body mass index 27.9 ±â€¯5.3 kg/m2) were recruited. Participants were randomly split into validation (n = 118) and cross-validation groups (n = 66). Bioelectrical resistance was obtained with a phase-sensitive 50 kHz BIA device. RESULTS: A BIA-based model was developed for appendicular lean soft tissue mass [ALST (kg) = 5.982 + (0.188 × S2 / resistance) + (0.014 × waist circumference) + (0.046 × Wt) + (3.881 × sex) - (0.053 × age), where sex is 0 if female or 1 if male, Wt is weight (kg), and S is stature (cm) (R2 = 0.86, SEE = 1.35 kg)]. Cross validation revealed r2 of 0.91 and no mean bias. Two of three previously published models showed a trend to significantly overestimate ALST in our sample (p < 0.01). CONCLUSIONS: The new equation can be considered valid, with no observed bias and trend, thus affording practical means to quantify ALST mass in older adults.

Consensus paper on postural dysfunction: recommendations for prevention, diagnosis and therapy.

Good fundamentals of posture and balance are essential for the efficient performance of both simple daily tasks and more complex movement patterns. In particular, postural balance is the ability to keep the body in equilibrium and to regain balance after the shift of body segments: postural control mechanisms of integration of the visual, vestibular and foot afferential channels contribute to this. This document provides recommendations based on scientific evidence, clinical practice, and consensus between experts concerning the prevention, diagnosis, and treatment of postural dysfunction at the three stages of life as the developmental age, adult age, and old age > 65 years and follows the "National Guidelines on Classification and Measuring of Posture and its Dysfunctions" per the Italian Ministry of Health (December 2017). The paper answers four main questions: i) "Which measures can be adopted to prevent postural dysfunctions?" ii) "What can we do in order to make a correct diagnosis of postural dysfunction?" iii) "What are the correct treatment programs for postural dysfunctions?" iv) Which professional competencies and experiences are useful for preventing, diagnosing and treating postural dysfunctions? By the Consensus of the Experts and the scientific evidence, emerge that the approach to postural dysfunctions requires a multidisciplinary and interdisciplinary team. Furthermore, rehabilitation treatment interventions must be specific to the age groups that have been indicated, to consider the integration of the main systems and subsystems of postural control that change with age.