Chest, Vol 105, 1392-1398, Copyright © 1994 by American College of Chest Physicians

ARTICLES

Hypophosphatemia and phosphorus depletion in respiratory and peripheral muscles of patients with respiratory failure due to COPD

E Fiaccadori, E Coffrini, C Fracchia, C Rampulla, T Montagna and A Borghetti
Istituto di Clinica Medica e Nefrologia, Universita di Parma, Italy.

In 22 patients (19 men, 3 women; mean [+/- SD] age, 63 +/- 6 years) with chronic obstructive pulmonary disease (COPD), phosphorus content was measured by spectrophotometric methods on muscle fragments of both peripheral (quadriceps femoris needle biopsy in 22 patients) and respiratory muscles (external intercostal muscle surgical biopsy in 14 patients). Thirty age- and sex-matched subjects were used as controls (19 for quadriceps femoris muscle biopsy and 11 for intercostal muscle biopsy). Serum phosphorus levels, as well as the main determinants of overall phosphorus metabolism (dietary intake of phosphorus and renal phosphate handling), were also obtained in all patients and control subjects. Muscle phosphorus content of both respiratory and peripheral muscles was significantly reduced in the COPD patient group, no matter what reference index was used (fat-free dry muscle weight or muscle fragment DNA content); muscle phosphorus depletion was present in about 50 percent of patients with COPD. In the same patient group, a significant relationship between muscle and serum phosphorus levels was demonstrable in the case of peripheral muscles only. No relationship was found between phosphorus content of both types of skeletal muscles and dietary phosphorus intake levels or with nutritional status, even though patients with COPD had significantly reduced anthropometric, biochemical, and immunologic indices as compared with controls. Renal phosphorus handling indices of the COPD patient group were compatible with a condition of inadequacy of the renal compensatory mechanism to hypophosphatemia and phosphorus depletion (low percent tubular reabsorption of phosphorus, low renal threshold concentration values). Our study suggests that phosphorus depletion occurs frequently in COPD, but in this clinical condition serum phosphorus levels are not representative of cellular phosphorus levels. Phosphorus depletion, which is equally severe in respiratory and peripheral muscles, could depend, at least in part, on malnutrition and a condition of renal phosphorus wasting possibly linked to some drugs commonly used in patients with COPD (xanthine derivatives, diuretics, etc).

This article has been cited by other articles:

				F. S. de Menezes, H. P. Leite, J. Fernandez, S. G. Benzecry, and W. B. de Carvalho Hypophosphatemia in children hospitalized within an intensive care unit. J Intensive Care Med, July 1, 2006; 21(4): 235 - 239. [Abstract] [PDF]

				A.G.N. Agusti, A. Noguera, J. Sauleda, E. Sala, J. Pons, and X. Busquets Systemic effects of chronic obstructive pulmonary disease Eur. Respir. J., February 1, 2003; 21(2): 347 - 360. [Abstract] [Full Text] [PDF]

				C. Haccoun, A. A. Smountas, W. J. Gibbons, J. Bourbeau, and L. C. Lands Isokinetic Muscle Function in COPD* Chest, April 1, 2002; 121(4): 1079 - 1084. [Abstract] [Full Text] [PDF]

				I. M. Ferreira, D. Brooks, Y. Lacasse, and R. S. Goldstein Nutritional Intervention in COPD : A Systematic Overview Chest, February 1, 2001; 119(2): 353 - 363. [Abstract] [Full Text] [PDF]

				R. Casaburi Skeletal Muscle Function in COPD Chest, May 1, 2000; 117(5_suppl_1): 267S - 271S. [Abstract] [Full Text] [PDF]

				I. M. Ferreira, D. Brooks, Y. Lacasse, and R. S. Goldstein Nutritional Support for Individuals With COPD: A Meta-analysis Chest, March 1, 2000; 117(3): 672 - 678. [Abstract] [Full Text] [PDF]

				Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease . A Statement of the American Thoracic Society and European Respiratory Society Am. J. Respir. Crit. Care Med., April 1, 1999; 159(4): S2 - 40. [Full Text] [PDF]