The Relationship Between Bioelectrical Impedance Analysis Parameters and Laboratory Biomarkers in an Elderly Polish Cohort: A Cross-Sectional Study.

MNA-defined malnutrition risk was associated with significantly lower muscle mass and phase angle, and altered fluid distribution, but not with reduced fat mass.

• Cross-sectional study of 126 elderly Polish participants (106 women, 20 men; mean age 72.4 years)
• Malnutrition risk was associated with higher extracellular-to-total body water ratio indicating fluid shifts
• Fat mass was not significantly different between nutritional risk groups
• Nutritional status was assessed using the Mini Nutritional Assessment (MNA)

Adiposity correlated strongly with leptin and CRP in the elderly cohort.

• Both leptin (a hormonal biomarker) and CRP (an inflammatory biomarker) were linked to fat mass measures
• The relationship was identified through analysis of BIA-derived fat mass parameters against the comprehensive biomarker panel
• Venous blood samples were analyzed for hematological, inflammatory (CRP), hormonal (leptin), and metabolic biomarkers

Hematological parameters were linked to lean mass, while zinc and albumin correlated with phase angle.

• Phase angle (PA) was measured using multi-frequency segmental BIA
• Zinc and albumin were specifically identified as correlates of phase angle
• Hematological parameters showed association with fat-free or lean mass components rather than fat mass

Canonical analysis identified two distinct physiological axes describing the relationships between BIA parameters and biomarkers.

• The first axis was a dominant 'adipo-hormonal' axis linking leptin to fat mass
• The second axis was a 'metabolic-cellular integrity' axis linking zinc and iron status to Phase Angle and fluid balance
• These two axes were identified through canonical (multivariate) analysis of the full dataset

The study cohort was predominantly female elderly Polish adults assessed with multi-frequency segmental BIA.

• 126 total participants: 106 women and 20 men
• Mean age was 72.4 years
• BIA measured fat-free mass, skeletal muscle mass, and phase angle
• Design was cross-sectional

BMI was characterized as an inadequate metric for assessing nutritional status in older adults compared to BIA-derived parameters.

• Standard metrics like BMI can be misleading in elderly populations
• Nutritional risk in older adults was driven by sarcopenia and fluid shifts rather than low adiposity, undermining BMI utility
• BIA parameters, especially phase angle, were proposed as promising indicators of cellular health in geriatric assessment