Mid-arm and calf circumferences are stronger mortality predictors than body mass index for patients with chronic obstructive pulmonary disease.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) is currently the third most common cause of death in the world. Patients with COPD experience airflow obstruction, weight loss, skeletal muscle dysfunction, and comorbidities. Anthropometric indicators are risk factors for mortality in geriatric assessment.


OBJECTIVE
This study examined and compared the associations of anthropometric indicators, such as low body mass index (BMI), low mid-arm circumference (MAC), and low calf circumference (CC), with the prediction of a 3-year follow-up mortality risk in patients with COPD.


METHODS
We recruited nonhospitalized patients with COPD without acute conditions from a general hospital in Taiwan. The BMI, MAC, and CC of all patients were measured, and they were followed for 3 years through telephone interviews and chart reviews. The Kaplan-Meier survival curves stratified by BMI, MAC, and CC were analyzed. Variables univariately associated with survival were entered into a multivariate Cox regression model. The Bayesian information criterion was used to compare the predictive ability of the three anthropometric indicators to predict mortality rate.


RESULTS
In total, 104 patients were included (mean ± standard deviation age, 74.2±6.9 years; forced expiratory volume in 1 second [%], 58.4±20.4 predicted; males, 94.2%); 22 patients (21.2%) died during the 36-month follow-up. During this long-term follow-up, the three anthropometric indicators could predict mortality risk in patients with COPD (low BMI [<21 kg/m(2)], hazard ratio [HR] =2.78, 95% confidence interval [CI] =1.10-7.10; low MAC [<23.5 cm], HR =3.09, 95% CI =1.30-7.38; low CC [<30 cm], HR =4.40, 95% CI =1.82-10.63). CC showed the strongest potential in predicting the mortality risk, followed by MAC and BMI.


CONCLUSIONS
Among the three anthropometric variables examined, CC can be considered a strong predictor of mortality risk in patients with COPD.
School of Respiratory Therapy, College of Medicine; Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City.
Shu-Chuan
SC
Ho
Department of Healthcare Administration, Asia University, Wufeng; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung.
Jiun-Yi
JY
Wang
Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine.
Han-Pin
HP
Kuo
Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine.
Chien-Da
CD
Huang
Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University.
Kang-Yun
KY
Lee
School of Respiratory Therapy, College of Medicine; Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City.
Hsiao-Chi
HC
Chuang
Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City; Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University.
Po-Hao
PH
Feng
Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City.
Tzu-Tao
TT
Chen
Department of Nursing, Yuanpei University of Medical Technology, Hsinchu City, Taiwan.
Min-Fang
MF
Hsu
D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry / Q000379:methods*; D001132:Arm / Q000473:pathology*; D015992:Body Mass Index; D015897:Comorbidity; D005260:Female; D005541:Forced Expiratory Volume; D006304:Health Status; D006769:Hospitals, General; D006801:Humans; D053208:Kaplan-Meier Estimate; D007866:Leg / Q000473:pathology*; D008168:Lung / Q000503:physiopathology*; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D015431:Weight Loss
BMI; COPD; anthropometric indicator; calf circumference; mid-arm circumference; mortality