Predictors of low bone mineral density in elderly males with chronic obstructive pulmonary disease: the role of body mass index.
OBJECTIVE
The aim of this study was to investigate the relationships between nutritional indices (Body mass index (BMI), serum albumin), sarcopenia, bone mineral density (BMD) and the severity of their pulmonary obstruction in elderly patients with chronic obstructive pulmonary disease (COPD).


METHODS
The method involved was a prospective transversal study; 82 males >65 years old, 41 stable patients with COPD and 41 healthy elderly individuals (controls). All subjects underwent spirometry, biochemical analyses and dual energy X-ray absorptiometry. The significance of the differences between mean values and prevalence rates was tested. The relationships between BMD and independent predictors were analysed by multiple linear regressions. Logistic regression models were applied on dichotomised variables.


RESULTS
In patients with COPD, the prevalence of osteoporosis was higher in subjects with sarcopenia (46% vs. 0%; p < 0.05) and with BMI < 25.1 kg/m(2) (58% vs. 15%; p < 0.02). Multiple regression analysis indicated that BMI, appendicular skeletal muscle mass (ASMM), albumin, and forced expiration volume after 1 s (FEV1) explained the 70% of BMD variability at the hip and 56% at the spine. Logistic regression showed that a BMI < 25.1 kg/m(2) was independently associated with osteoporosis risk (OR = 10.0; 95%CI 1.3-76); no independent effect emerged for FEV1% (<and 50%).


CONCLUSIONS
In elderly males with COPD, the BMI values < or =25 kg/m(2) are more strongly related to low BMD levels than albumin values. Among those patients, BMI values within the normal range for younger adults might point out a higher risk of osteoporosis.
Coin
Alessandra
A
Department of Medical and Surgical Sciences, University of Padova, Italy. alessandra.coin@unipd.it <alessandra.coin@unipd.it>
Sergi
Giuseppe
G
Marin
Sara
S
Vianello
Andrea
A
Perissinotto
Egle
E
Sarti
Silvia
S
Rinaldi
Giulia
G
Mosele
Marco
M
Inelmen
Emine Meral
EM
Enzi
Giuliano
G
Manzato
Enzo
E
D000368:Aged; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D010024:Osteoporosis / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012307:Risk Factors; D012709:Serum Albumin / Q000032:analysis; D012907:Smoking; D018709:Statistics, Nonparametric
D012709:Serum Albumin