Prevalence of low-body cell mass evaluated by bioelectrical impedance vector analysis related to aging

The objective of this study was to determine the prevalence of low-body cell mass by sex and age in a community-dwelling population.

In this retrospective study, 981 community-dwelling adults aged ≥35 years (648 women and 333 men) from Mexico City were recruited in a subway station between February and April 2012. Demographic data, anthropometry, and body composition were assessed, and self-reported comorbidities were recorded in the consulting room. Impedance values were obtained using mono-frequency equipment at 50 kHz. For the diagnosis of low-body cell mass by bioelectrical impedance vectorial analysis: resistance (R, Ohm) and reactance (Xc, Ohm) values were adjusted for height to obtain impedance vector (R/H and Xc/H) and then plotted in the R/Xc to perform the bioelectrical impedance vectorial analysis RXc Z-score analysis.

The total prevalence of low body cell mass by bioelectrical impedance vectorial analysis was 29.4% (n=288) with a 95%CI 26.5-32.3%; was higher in men (39%) compared with women (24.4%) (p<0.0001). The group aged>75 years had the highest prevalence (men: 85.3%, p<0.001; women: 63.3%, p<0.001). The bioelectrical impedance vectorial analysis RXc Z-score analysis showed lower cell mass in men aged>75 years (R Z-score -0.30, Xc Z-score -2.13), and women aged 65-74 years also presented with overhydration (Z-score -2.6, Z-score -1.27).

The prevalence of low body cell mass, evaluated by bioelectrical impedance vectorial analysis, increased with age. RXc Z-score analysis could be a useful tool to evaluate nutritional status and changes in hydration in community-dwelling populations.