Prevalence of sarcopenia among community-dwelling elderly of a medium-sized South American city: results of the COMO VAI? study

Abstract

Background: There is insufficient data concerning sarcopenia prevalence in South America. The aim of this study was to estimate sarcopenia prevalence and its clinical subgroups in a Southern Brazilian city.

Methods: A cross-sectional population-based study was performed among community-dwelling elderly aged 60 years or over. Subjects were evaluated according to the European Working Group on Sarcopenia in Older People established criteria. Muscle mass was estimated by calf circumference (CC). Cut-off CC points were defined by a subsample's dual X-ray absorptiometry estimation of the appendicular skeletal muscle mass index (ASMI), which was subsequently compared with the values of a young adult population from the same city. Muscle strength was measured by manual dynamometry. Muscle performance was assessed through the 4 m gait speed test.

Results: The three diagnostic tests were performed in 1291 subjects. CC of ≤34 cm (males) and ≤33 cm (females) were defined as indicatives of low ASMI. The overall sarcopenia prevalence was 13.9% (CI95% 12.0; 15.8%). Its frequency was significantly higher among elderly with low schooling, without a partner, with low socioeconomic status, smokers, inactive, and with low body mass index. A higher prevalence of pre-sarcopenia was found in the youngest elderly; a higher prevalence of the clinical stages of the syndrome was found in older age groups.

Conclusions: Approximately one in ten elderly aged 60-69 years was in the preclinical stage of the disease. This is the age group in which public policies should focus to establish early diagnosis and prevent clinical progression of the syndrome.

Keywords: Calf circumference; Elderly; Muscle mass; Prevalence; Sarcopenia.

Figure 1

Study flowchart. Step 1: body composition substudy sample chosen through deterministic sampling of the Masters Consortium for Valuation of Elderly Care (COMO VAI?) study sample. Step 2: calf circumference cut‐off points applied to the COMO VAI? study sample. Step 3: sarcopenia prevalence in the COMO VAI? study determined by previously established EWGSOP criteria. (A) Elderly born in the months of March or September, (B) one death, three hospitalizations, and (C) two subjects with missing data concerning calf circumference, one subject with an anatomical abnormality in the calf. ASMI, appendicular skeletal muscle mass index; SD, standard deviation; MM, muscle mass; Adeq., adequate; ROC, receiving operator characteristic; CC, calf circumference; HGS, handgrip strength; 4mGS, 4 m gait speed; EWGSOP, European Working Group on Sarcopenia in Older People.

Figure 2

Sex‐stratified receiving operator characteristic curves for appendicular skeletal muscle mass index/calf circumference. Area under the curves: 0.91 (females), 0.76 (males) (N = 189; Pelotas, Brazil; 2014).

Figure 3

Sarcopenia prevalence in the elderly (60 years or more) of Pelotas, stratified by sex and clinical stages (Pelotas, Brazil; 2014).