What community measurements can be used to predict bone disease in patients with COPD?
BACKGROUND
Osteoporosis is common in patients with COPD. Previously we have reported that loss of fat-free mass (FFM), measured by dual X-ray absorptiometry (DXA) is associated with loss of bone mineral density (BMD). In addition, in patients with a low body mass index (BMI) and a low FFM, all had evidence of bone thinning, 50% having osteopenia and 50% osteoporosis. We explored the utility of different anthropometric measures in detecting osteoporosis in a community-based COPD population.


METHODS
Patients with confirmed COPD and not on long-term oral corticosteroids (n=58) performed spirometry. They underwent nutritional assessment by skinfold anthropometry, midarm circumference, calculation of both % ideal body weight (IBW) and BMI. All had DXA assessment of BMD.


RESULTS
A total of 58 COPD patients had anthropometric measurements taken, with a mean age of 66.8 (SD 8.7) years, 31 (58%) were male, with a forced expiratory volume in 1s (FEV(1)) of 54.17 (20.18)% predicted. Osteoporosis was present at either the hip or lumbar region in 14 patients (24%). The useful anthropometric measurements identifying those with osteoporosis were both % IBW and BMI. The adjusted odds ratio for %IBW was 0.93 (95% confidence interval (CI) 0.87, 0.99), p=0.016 and for BMI: 0.79 (0.64-0.98), p=0.03. The receiver operating characteristics (ROC) score for both was 0.88, indicating a good fit.


CONCLUSIONS
Osteoporosis is common, even in patients with mild airways obstruction. Nutritional assessment, incorporating a calculation of their BMI or %IBW may confer an additional benefit in detecting those at risk of osteoporosis and guide referral for BMD measurement.
Bolton
C E
CE
Department of Respiratory Medicine, School of Medicine, Cardiff University, Academic Centre, Llandough Hospital, Penarth, Penlan Road, Vale of Glamorgan, CF64 2XX, UK.
Cannings-John
R
R
Edwards
P H
PH
Ionescu
A A
AA
Evans
W D
WD
Pettit
R J
RJ
Faulkner
T A
TA
Stone
M D
MD
Shale
D J
DJ
D015502:Absorptiometry, Photon; D000368:Aged; D015992:Body Mass Index; D001835:Body Weight; D015519:Bone Density; D005260:Female; D005542:Forearm / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000150:complications / Q000175:diagnosis*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000503:physiopathology; D012372:ROC Curve; D012885:Skinfold Thickness; D013147:Spirometry