Definition of an adapted cut-off for determining low lean tissue mass in older women with obesity: a comparison to current cut-offs.

ABSTRACT

The prevalence of sarcopenia in patients with obesity varies according to the definition used. The purpose of our study was to (i) determine the prevalence of sarcopenia in terms of lean tissue mass in older women with obesity using the current cut-offs, (ii) redefine a specific cut-off for low lean tissue mass (LLTM), and (iii) re-determine the prevalence of LLTM using this new cut-off. Appendicular lean mass (ALM) and the ALM index [ALM/height2 ALMI(h2)] and ALMI/body mass index [ALMI(BMI)] were determined in 791 women with or without obesity. LLMM prevalence was calculated using the current cut-offs EWGSOP2 ALM < 15 kg and ALMI(h2) < 5.5 kg/m2; FNIH ALM < 15.02 kg and ALMI(BMI) < 0.51; and IWGS ALMI(h2) < 5.67 kg/m2 and cut-offs newly determined from data provided from young women with obesity. ALM, ALMI(h2) and ALMI(BMI) were lower in older compared to young obese women. Using the current cut-offs, a wide distribution of LLTM prevalence (0 to 29.2%) was observed. When the newly determined cut-offs were applied - i.e., ALM < 18.51 kg; ALMI(h2) < 7.15 kg/m2, ALMI(BMI) < 0.483, and T-score [(ALMI(h2) measured)-(2.08 + 0.183*BMI)]/0.72] - the LLTM mass prevalence was 17.37%; 8.47, 14.8 and 12.71%. respectively. This study showed that the current cut-offs for LLTM as criteria for sarcopenia diagnosis are not adapted to the obese population. Although the new "static" cut-offs appeared to be more adapted, a "dynamic" cut-off for ALMI(h2) that took into account the BMI and thus the obesity severity appeared even more relevant.