Bone mineral density improvement after lung volume reduction surgery for severe emphysema.
BACKGROUND
In patients with severe emphysema, bone mineral density (BMD) is reduced and the risk of osteoporosis is increased.


OBJECTIVE
To identify the impact of lung volume reduction surgery on BMD.


METHODS
Prospective cohort study.


METHODS
University hospital.


METHODS
Forty emphysematous patients, all receiving oral steroid therapy, underwent bilateral lung volume reduction surgery. Thirty similar patients, who refused the operation, followed a standard respiratory rehabilitation program.


METHODS
All subjects were evaluated pretreatment and 12 months posttreatment for respiratory function, nutritional status, and bone-related biochemical parameters. BMD was assessed by dual-energy radiograph absorptiometry.


RESULTS
After surgery, we observed significant improvements in respiratory function (FEV1, + 18.8% [p < 0.01]; residual volume [RV], -29.6% [p < 0.001]; diffusing capacity of the lung for carbon monoxide [Dlco], + 21.6% [p < 0.01]) nutritional parameters (fat-free mass, + 6.0% [p < 0.01]), levels of bone-related hormones (free-testosterone, + 20.5% [p < 0.01]; parathormone, -11.2% [p < 0.01]), bone turnover markers (osteocalcin, -12.7% [p < 0.05]; bone-alkaline-phosphatase, -14.0% [p < 0.05]; beta-crosslaps, -33.6% [p < 0.001]), BMD (lumbar, + 8.8% [p < 0.01]; femoral, + 5.5% [p < 0.01]), and T-score (lumbar, + 21.0% [p < 0.01]; femoral, + 12.4% [p < 0.01]) with reduction in osteoporosis rate (50 to 25%). Nineteen patients who had undergone surgery were able to discontinue treatment with oral steroids. These subjects showed a more significant improvement in BMD (lumbar, + 9.6%; femoral, + 6.8%; p < 0.001) and T-score (lumbar, + 27.3%; femoral, + 14.3%; p < 0.001). The remaining 21 patients who had undergone surgery experienced significant improvement compared to respiratory rehabilitation subjects despite continued therapy with oral steroids (BMD: lumbar, + 4.5% vs -0.7%, respectively [p < 0.01]; femoral, + 2.7% vs -1.1%, respectively [p < 0.05]; T-score: lumbar, + 14 vs -2.1, respectively [p < 0.01]; femoral, + 7.4 vs -2.7, respectively [p < 0.01]). The increase in lumbar BMD was correlated with the surgical reduction of RV (p = 0.02) and with the increase in Dlco (p = 0.01) and fat-free mass (p = 0.01).


CONCLUSIONS
Lung volume reduction surgery significantly improves BMD compared to respiratory rehabilitation therapy, even in patients requiring oral steroids. The increase in BMD correlates with RV, Dlco, and fat-free mass, suggesting that the restoration of respiratory dynamics, gas exchange, and nutritional status induces improvement in bone metabolism and mineral content.
Mineo
Tommaso Claudio
TC
Division of Thoracic Surgery, Tor Vergata University Policlinic, Rome, Italy.
Ambrogi
Vincenzo
V
Mineo
Davide
D
Fabbri
Andrea
A
Fabbrini
Elisa
E
Massoud
Renato
R
D015502:Absorptiometry, Photon; D000368:Aged; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000517:prevention & control; D011013:Pneumonectomy / Q000379:methods*; D011336:Probability; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000534:rehabilitation / Q000601:surgery; D011656:Pulmonary Emphysema / Q000175:diagnosis / Q000534:rehabilitation* / Q000601:surgery*; D012129:Respiratory Function Tests; D012138:Respiratory Therapy / Q000379:methods*; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome