Incidence and predictors of sarcopenia onset in community-dwelling elderly Japanese women: 4-year follow-up study.

OBJECTIVES

Several studies have explored the prevalence and risk factors of sarcopenia, but they have been based on cross-sectional data. The objective of this study was to determine the incidence and predictors of the onset of sarcopenia over 4 years in community-dwelling elderly women.

DESIGN

Four-year longitudinal follow-up study.

SETTING

Urban community in Tokyo, Japan.

PARTICIPANTS

A total of 538 nonsarcopenic women older than 75 years.

MEASUREMENTS

Body composition was determined by bioelectrical impedance analysis. Functional fitness measurements, including grip strength, usual walking speed, timed up and go (TUG), and interview surveys were conducted at baseline and 4-year follow-up. Blood samples were obtained to analyze serum albumin and hemoglobin A1c, and kidney function was analyzed using serum creatinine and cystatin C. Sarcopenia was defined based on the criteria suggested by the European Working Group on Sarcopenia in Older People, and the development of all stages, that is, presarcopenia, sarcopenia, and severe sarcopenia as well as the components of sarcopenia skeletal muscle index (SMI), grip strength, and walking speed, were analyzed.

RESULTS

The incidence of total sarcopenia was 39.6% (presarcopenia 23.8%, sarcopenia 11.2%, severe sarcopenia 4.6%). Older age was significantly predictive of the development of presarcopenia and severe sarcopenia. Body mass index (BMI) lower than 21.0 kg/m(2) was significantly predictive of the development of all stages of sarcopenia, as well as declines in SMI, grip strength, and walking speed. Slow TUG was a predictor of the development of presarcopenia and severe sarcopenia. Increased calf circumference showed protective effects from the development of all stages of sarcopenia. Greater albumin levels also showed lower risk of declines in SMI, walking speed, and development of presarcopenia. Cystatin C was positively associated with the development of severe sarcopenia (odds ratio 1.83, 95% confidence interval 1.08-3.12). Heart disease and hyperlipidemia history were associated with presarcopenia and sarcopenia, respectively.

CONCLUSION

Age, BMI, calf circumference, and TUG were consistent predictors of the various stages and components of sarcopenia. The data also suggest that cystatin C was associated with higher odds of incident severe sarcopenia, and further study into kidney function and onset of sarcopenia in large populations is needed.