JMIR Publications

ABSTRACT

Background:

The usual diagnosis of sarcopenia requires a Dual-Energy X-Ray Absorptiometry (DXA) exam, whose accessibility in primary care is scarce in Latin American countries.

Objective:

To design and validate a software for mobile devices (Android, IOS) and computer-based on an adapted version of the diagnostic algorithm of sarcopenia proposed by the European Working Group on Sarcopenia in Older People (EWGSOP).

Methods:

The follow-up of 430 community-dwelling Chilean participants 60 years and older was conducted; these individuals were beneficiaries of public health centers (mean±SD: 68.2±4.9years) and were included in the HTSMayor and Alexandros cohorts designed to study sarcopenia. The software was designed according to an adapted version of the algorithm proposed by the EWGSOP and was divided into four phases: longitudinal validation of diagnostic algorithm of sarcopenia, alpha version, beta version and release version. The software estimates appendicular muscle mass (ASM) using an anthropometric equation or DXA measurements with Chilean cut-off points. The predictive validation of the algorithm was estimated, comparing functional limitations (one activity of daily living; and/or two instrumental activities of daily living, and/or three mobility limitations) and falls at follow-up in non-sarcopenic and sarcopenic subjects at baseline, using logistic models.

Results:

After 2078.42 person-years of 4.82 years (median) of follow-up, 37 new cases of sarcopenia (10% approximately) were identified (incidence density rate=1.78 per 100 persons-years). ASM estimated with the anthropometric equation showed a high sensitivity and specificity compared with those estimated by DXA measurements, yielding a concordance of 0.933. The diagnostic algorithm of sarcopenia considered in the software with the equation showed a high sensitivity (81.3%) and specificity (95.1%) when compared with DXA (reference standard). Non-sarcopenic subjects (in baseline) showed better physical performance (after approximately 5 years) than sarcopenic adults. Loss of functionality is greater in sarcopenic adults (adjusted OR=5.6) than in non-sarcopenic adults. Similar results were observed in falls (adjusted OR=2.2) and osteoporosis (adjusted OR=2.8) is higher in persons with sarcopenia than robust adults. In beta and release test the measurements and results were completed in mean time of 10 and 11 minutes, respectively.

Conclusions:

We obtained a validated software for the diagnosis of sarcopenia in Chilean elders that can be used on a mobile device or a computer with a good sensitivity and specificity, thus allowing for the development of programs for the prevention, delay or reversal of this disease.