Evaluation of Skinfolds Based Predictive Equations for Estimating Body Fat Percentage in Older Adults: A Comparison Using Digital Adipometer (Lipowise) and Dual-Energy X-Ray Absorptiometry (DXA).

All skinfold-based equations differed significantly from DXA-derived body fat percentage in older adults.

• Cross-sectional pilot study included 149 participants (28 men and 121 women) aged 60 to 86 years.
• Four skinfold equations were evaluated: Lean, Durnin-Womersley, and Visser (using 2 and 4 skinfolds).
• Statistical analyses included Student's t-test, Mann-Whitney, Cohen's Kappa, and Bland-Altman methods.
• A digital calliper (Lipowise) was used to measure skinfolds, with DXA as the reference standard.

Agreement between skinfold equations and DXA was only moderate across all equations tested.

• Cohen's Kappa values ranged from 0.54 to 0.59 for all equations compared to DXA.
• Bland-Altman analysis was used to assess limits of agreement between methods.
• Moderate agreement was observed for both male and female subgroups.

The Durnin-Womersley equation substantially underestimated body fat percentage, particularly in men.

• Durnin-Womersley underestimated %BF by 11.5% in men.
• In women, DXA values were higher than Durnin-Womersley estimates.
• This underestimation was among the largest biases observed across all equations tested.

The Lean equation slightly overestimated body fat percentage relative to DXA.

• Lean equation overestimated %BF by 1.3% overall.
• In women, DXA values were lower than Lean equation estimates.
• In men, DXA also showed lower %BF than the Lean equation.

The Visser equations showed the smallest bias compared to DXA but still demonstrated sex-specific directional errors.

• Visser equations showed slight overestimation in women of 0.3% (2-skinfold version) and 0.4% (4-skinfold version).
• Visser equations showed underestimation in men of 3.7% (2-skinfold version) and 4.3% (4-skinfold version).
• Despite minimal overall bias, sex-specific discrepancies remained evident for the Visser equations.

Sex differences in the direction and magnitude of bias were observed across all skinfold equations.

• In women, DXA values were lower than Lean but higher than Durnin-Womersley estimates.
• In men, DXA showed lower %BF than Lean and higher %BF than other equations.
• The sample was predominantly female (121 women vs. 28 men), which may limit generalizability of male-specific findings.

Age-related physiological changes are proposed as a factor contributing to inaccuracies in skinfold-based prediction equations for older adults.

• Participants ranged in age from 60 to 86 years.
• The authors noted that age-related physiological factors may impact equation accuracy.
• Discrepancies between DXA and skinfold equations were attributed in part to age-specific changes in fat distribution and tissue compressibility.