The diagnostic cut-off points for components of sarcopenia in Finnish Caucasian women: A retrospective cross-sectional study.

Objectives: To determine the diagnostic cut-off values of components for sarcopenia in Caucasian women.

Methods: The present retrospective cross-sectional study based on the REFERENCE sample included 400 healthy women aged 20 to 40 years, and the OSTPRE sample included 344 women aged 63 to 75. The subjects of the OSTPRE population were re-measured five and ten years later after the baseline. Both samples underwent grip strength (GS), quadriceps strength (QS), and total-body DXA (TB-DXA) measurements, from which Relative Skeletal Muscle Mass Index (RSMI) was calculated.

Results: In the REFERENCE population, the -1 SD / -2 SD cut-off points were for RSMI 5.8 kg/m² / 5.1 kg/m², for GS 32.0 kg / 26.4 kg, and for QS 39.8 kg / 29.8 kg. The prevalence of under -2 SD distributions in REFERENCE were: RSMI 1.8%, GS 1.3%, and QS 2.0%, and in OSTPRE (15/20/25 years measurements): RSMI 1.2 %/1.9 %/0.5 %, GS 52.2%/42.3%/48.8%, and QS 47.4%/55.2%/not available. The distributions of GS and QS were statistically significantly different between REFERENCE and all OSTPRE measurement points (p<0.001 in Chi-squared).

Conclusions: The diagnostic cut-offs for components of sarcopenia are RSMI 5.1 kg/m², grip strength 26.4 kg, and quadriceps strength 29.8 kg in Finnish Caucasian women.