Relationship of Fat Mass Index and Fat Free Mass Index With Body Mass Index and Association With Function, Cognition and Sarcopenia in Pre-Frail Older Adults

Abstract

BackgroundBody mass index (BMI) is an inadequate marker of obesity, and cannot distinguish between fat mass, fat free mass and distribution of adipose tissue. The purpose of this study was twofold. First, to assess cross-sectional relationship of BMI with fat mass index (FMI), fat free mass index (FFMI) and ratio of fat mass to fat free mass (FM/FFM). Second, to study the association of FMI, FFMI and FM/FFM with physical function including sarcopenia, and cognition in pre-frail older adults.MethodsCross-sectional study of 191 pre-frail participants ≥ 65 years, 57.1% females. Data was collected on demographics, cognition [Montreal Cognitive Assessment (MoCA)], function, frailty, calf circumference, handgrip strength (HGS), short physical performance battery (SPPB) and gait speed. Body composition was measured using InBody S10. FMI, FFMI and FM/FFM were classified into tertiles (T1, T2, T3) with T1 classified as lowest and T3 highest tertile respectively and stratified by BMI.ResultsHigher FFMI and lower FM/FFM in the high BMI group were associated with better functional outcomes. Prevalence of low muscle mass was higher in the normal BMI group. FMI and FM/FFM were significantly higher in females and FFMI in males with significant gender differences except for FFMI in ≥ 80 years old. Small calf circumference was significantly less prevalent in the highest tertile of FMI, FM/FMI and FFMI. Prevalence of sarcopenic obesity and low physical function (HGS, gait speed and SPPB scores) were significantly higher in the highest FMI and FM/FFM tertile. Highest FFMI tertile group had higher physical function, higher MoCA scores, lower prevalence of sarcopenic obesity and sarcopenia, After adjustment, highest tertile of FFMI was associated with lower odds of sarcopenia especially in the high BMI group. Highest tertile of FM/FFM was associated with higher odds of sarcopenia. Higher BMI was associated with lower odds of sarcopenia.ConclusionFFMI and FM/FFM may be a better predictor of functional outcomes in pre-frail older adults than BMI. Cut-off values for healthy BMI values and role of calf circumference as a screening tool for sarcopenia need to be validated in larger population. Health promotion intervention should focus on FFMI increment.

Sarcopenia, Obesity, Sarcopenic Obesity and Risk of Poor Nutritional Status in Polish Community-Dwelling Older People Aged 60 Years and Over

“…This parameter does not distinguish between FFM and FM nor assesses the amount and distribution of body fat. For these reasons, BMI may lead to a false classification of subjects with normal body mass and excessive fatness as healthy individuals [ 59 , 60 , 61 ]. Some authors demonstrated that fat tissue percentage increased in older subjects independently of body mass.…”

Correlation between preoperative body composition and postoperative muscle volume and degeneration after total hip arthroplasty

“…BMI also has been used for assessing metabolic disease. However, metabolically health and abnormal obesity can not be distinguished, because the FMI and FFMI can not be distinguished by BMI [34]. Merchant et al reported that FMI was associated with higher rate of sarcopenia, and there was a possibility that the FFMI and FMI were more useful for predicting functional outcome in prefrail patients than BMI [34].…”

“…Lower PhA values indicate an increase in the extra water and a decrease in muscle mass [38,39]. PhA has also been associated with osteoarthritis severity [40], functional ability [23,34,41,42], and Barthel's index [43]. It is reported that PhA was associated with muscle strength [44] and quadriceps strength [40].…”

Association between the Phase Angle and the Severity of Horizontal Gaze Disorder in Patients with Idiopathic Dropped Head Syndrome: A Cross-Sectional Study

“…Propensity score (PS) matching was used for adjusting covariates in both groups [ 21 ]. Previous studies have reported covariate relationships between phase angle and age, height, and FFMI [ 22 , 23 ]. However, some researchers have stated that BMI is a determinant of phase angle [ 13 , 24 ].…”