Declining neck circumference is an anthropometric marker related to frailty in middle-aged and elderly women.

Neck circumference (NC) has been associated with cardiovascular disease and metabolic syndrome. However, the association between NC and frailty remains unknown. We aimed to determine the relationship between frailty and NC in middle-aged and elderly women. Frailty was diagnosed based on the Japanese version of the Cardiovascular Health Study criteria. Of women who underwent health checkup, 295 women with the following measurements were targeted: four trunk circumferences and appendicular skeletal muscle index (aSMI) measured using bioelectrical impedance analysis; albumin, total cholesterol, triglycerides, and C-reactive protein levels measured using a blood test; and physical function measured using back muscle strength and timed up-and-go test (TUG). Normal and frailty group comparisons were conducted using a statistical method. Significant differences were observed between the two groups in terms of age, body mass index, all trunk circumferences, aSMI, back muscle strength, and TUG. Logistic regression analysis showed that NC was more related with frailty among the four trunk circumferences. In multiple regression analysis, declining NC was significantly associated with frailty. In middle-aged and elderly women, NC has a significant association with frailty. Declining NC was shown to be an anthropometric marker of frailty, and may be a frailty risk factor.