The use of bioelectrical impedance analysis (BIA) in clinical settings is common. However, the value of BIA-based parameters in diagnosing metabolic syndrome (MetS) in children is under-investigated. Herein, we aimed to study the usefulness of BIA-indices in the diagnoses of MetS in 6–10-year-old girls. Therefore, a diagnostic accuracy case-control study was conducted, which included 75 girls aged 10–16 years, divided into three age-matched groups (normal, None-MetS, and MetS). Anthropometric indices, BIA parameters (including fat-free mass (FFM), body fat percent (BFP), and total body water (TBW)), blood pressure (BP), and blood samples were collected. Our main findings show that for girls in None-MetS and MetS groups, the waist circumference (WC) correlated positively with waist-hip ratio and mid-arm circumference (r = 0.58, 0.47, respectively), but not with BFP based on skinfold thickness (SFT), or mid-arm muscle area. WC was positively correlated with FFM and TBW, while high-density lipoprotein was inversely correlated with FFM. However, fasting blood glucose, triglycerides and BP showed no association with anthropometric measurements and BIA components. WC was the best indicator of MetS (AUC = 0.88, cut-off = 81.5 cm), followed by BMI (AUC = 0.84, cut-off = 26.9 kg/m²), while BFP based on SFT was the least sensitive (62.5%). In conclusion, apart from the FM index, anthropometric parameters such as WC are more valuable in diagnosing MetS in young adolescent girls.

Ultrasound (US) is a promising tool for skeletal muscle assessment; however, US studies have scarcely focused on Arabic populations. This study examined the association of handheld US indicators and bioelectrical impedance analysis (BIA) parameters in healthy Arabic females. A cross-sectional study was conducted on 60 healthy Arabic females whose muscle thickness (MT) and cross-sectional area (CSA) of the rectus femoris (RF) were measured alongside their MT and pennation angle (PA) of the medial gastrocnemius (MG) muscle (both muscles on the dominant side). Anthropometric and body composition analyses quantified fat-free mass (FFM) and appendicular skeletal muscle mass (ASMM). Muscle strength was assessed using a handgrip dynamometer, and physical activity levels were recorded with the Global Physical Activity Questionnaire (GPAQ). The CSA of the RF and the MT of both the RF and MG correlated significantly with FFM and ASMM. The PA of MG showed no significant correlations with ASMM, FFM, or handgrip strength. The CSA of RF was significantly correlated with handgrip strength (r = 0.313, p = 0.015), while the PA of MG correlated positively with GPAQ score (r = 0.346, p = 0.007). The CSA of RF significantly predicted both ASMM (β = 0.883, p = 0.0002) and FFM (β = 1.935, p = 0.0001). In conclusion, handheld US parameters, especially the RF’s CSA, correlate with and can predict BIA-based FFM and ASMM in healthy females.