Aging, Body Water
Conditions
Keywords
bioelectrical impedance analysis, extracellular water, intracellular water, ECW/TBW ratio, segmental body composition, cellular hydration
Brief summary
This study examines how body water distribution changes with age. Using a non-invasive body composition device (bioelectrical impedance analysis), researchers measured the amount of water inside and outside the body's cells, both for the whole body and separately for the arms, trunk, and legs, in adults aged 18 to 83. The study explores whether the balance between water inside and outside cells shifts as people get older, independent of their body weight, and whether this pattern differs between men and women or between different parts of the body.
Detailed description
This is a retrospectively registered, cross-sectional observational study based on body composition data collected using a bioelectrical impedance analyzer (InBody S10; BioSpace, Seoul, Republic of Korea). Whole-body and segmental (right arm, left arm, trunk, right leg, left leg) measures of intracellular water (ICW), extracellular water (ECW), total body water (TBW), and the ECW/TBW ratio were obtained. The primary aim is to characterize the relationship between age and the ECW/TBW ratio, a marker of cellular hydration status, both overall and after adjusting for body mass index (BMI). Secondary aims include evaluating whether this relationship differs by body segment, by sex, and whether it is better explained by body fat percentage or muscle mass than by BMI. Left-right asymmetry in segmental water and lean mass was also assessed.
Interventions
None listed
Sponsors
Medical University of Silesia
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 83 Years
Healthy volunteers
Yes
Inclusion criteria
* Adults aged 18 years or older * Completion of the study participation agreement (informed consent) * General good health
Exclusion criteria
* Pregnancy * Presence of a cardiac pacemaker or other implanted electronic medical device * Presence of metal implants contraindicating bioelectrical impedance analysis * Inability to stand or maintain the position required for measurement
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Whole-Body ECW/TBW Ratio in Relation to Age | At enrollment | The extracellular-to-total body water ratio (ECW/TBW), a marker of cellular hydration status, was measured for the whole body using bioelectrical impedance analysis (InBody S10). Values were correlated with participant age, both unadjusted and adjusted for body mass index, to assess whether cellular hydration status changes with age independently of body mass. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Segmental ECW/TBW Ratio in Relation to Age | At enrollment | The extracellular-to-total body water ratio (ECW/TBW) was additionally calculated separately for five body segments (right arm, left arm, trunk, right leg, left leg) using bioelectrical impedance analysis. Correlations with age were assessed for each segment individually, unadjusted and adjusted for body mass index (BMI), to determine whether the age-related increase in extracellular water proportion is uniform across body regions or differs by segment. |
| Right-Left Difference in Segmental Water Content | At enrollment | Right-minus-left differences in segmental water content (kg) were calculated for the arm pair and the leg pair. Paired comparisons were used to assess whether these differences deviate significantly from zero, separately for men and women. |
| Right-Left Difference in Segmental Lean Mass | At enrollment | Right-minus-left differences in segmental lean (fat-free) mass (kg) were calculated for the arm pair and the leg pair. Paired comparisons were used to assess whether these differences deviate significantly from zero, separately for men and women. |
| Whole-Body Intracellular Water (ICW) in Relation to Age and Body Weight | At enrollment | Intracellular water (liters) was correlated with participant age and with body weight/BMI, to characterize the determinants of this water compartment and to contrast them with the determinants of the ECW/TBW ratio. |
| Whole-Body Extracellular Water (ECW) in Relation to Age and Body Weight | At enrollment | Extracellular water (liters) was correlated with participant age and with body weight/BMI, to characterize the determinants of this water compartment and to contrast them with the determinants of the ECW/TBW ratio. |
| Whole-Body Total Body Water (TBW) in Relation to Age and Body Weight | At enrollment | Total body water (liters), the sum of intracellular and extracellular water, was correlated with participant age and with body weight/BMI, to characterize the determinants of absolute water volume as distinct from the determinants of the ECW/TBW ratio. |
| ECW/TBW Ratio in Relation to BMI | At enrollment | The association between the whole-body extracellular-to-total body water ratio (ECW/TBW) and body mass index (BMI) was assessed, to evaluate BMI as a potential correlate of cellular hydration status. |
| ECW/TBW Ratio in Relation to Percent Body Fat | At enrollment | The association between the whole-body extracellular-to-total body water ratio (ECW/TBW) and percent body fat (PBF), derived from bioelectrical impedance analysis, was assessed as an alternative body composition correlate to body mass index (BMI). |
| ECW/TBW Ratio in Relation to Skeletal Muscle Mass | At enrollment | The association between the whole-body extracellular-to-total body water ratio (ECW/TBW) and skeletal muscle mass (SMM), derived from bioelectrical impedance analysis, was assessed as an alternative body composition correlate to body mass index (BMI). |
Countries
Poland
Contacts
PRINCIPAL_INVESTIGATORBarbara Błońska-Fajfrowska, Prof
Medical University of Silesia, Katowice, Poland
Outcome results
None listed