The effectiveness of BMI, calf circumference and mid-arm circumference in predicting subsequent mortality risk in elderly Taiwanese.

BMI, mid-arm circumference (MAC) and calf circumference (CC) are anthropometric indicators often included in geriatric health measurement scales. However, their relative effectiveness in predicting long-term mortality risk has not been extensively examined. The present study aimed to evaluate the relative effectiveness of these anthropometrics in predicting long-term mortality risk in older adults. The study prospectively analysed the ability of these indicators in predicting 4-year follow-up mortality risk of a population-representative sample of 4191 men and women, 53 years of age or older in the 'Survey of Health and Living Status of the Elderly in Taiwan'. Cox regression analyses were performed to evaluate the association of follow-up mortality risk with low ( < 21 kg/m2) or high ( ≥ 27 kg/m2) BMI, low MAC ( < 23·5/22 cm for men/women) and low CC ( < 30/27 cm) respectively, according to Taiwanese-specific cut-off points. Results showed that low CC and low MAC were more effective than low BMI in predicting follow-up mortality risk in 65-74-year-old elderly. But low CC and low BMI were more effective than low MAC in ≥ 75-year-old elderly, and low BMI was more effective than low MAC or low CC in 53-64-year-old persons. High BMI was not effective in predicting mortality risk in any of these age ranges. These results suggest that in elderly adults, CC is more effective than BMI in predicting long-term mortality risk. Thus, more consideration to CC and MAC in designing geriatric health or nutritional measurement scales is recommended.