The effect of zinc supplements in cystic fibrosis patients.

Aim: To study the effect of Zn supplements in cystic fibrosis (CF) on disease evolution.

Methods: A retrospective study of all CF patients treated with Zn supplements (January 2002 to December 2004). Data from patient files for the year before and the first year of supplementation were compared. The controls were CF patients with normal serum Zn and without Zn supplementation.

Results: 21 patients (7 females), median age 8.9 (interquartile range 13.1) years, received 5 mg/kg Zn sulfate/day (maximum 150 mg). The number of infections decreased from 3 (1.25) to 2 (2.0) (tied p < 0.02) and the forced expiratory volume in 1 s (FEV(1)) increased from 72.0 (38.4) to 76.5 (52)% (p < 0.02). Energy intake improved (92.3 (14.5) to 117.0 (28.5)%; tied p < 0.02), as did weight for height (W/H; 90 (9.4) to 94 (8.5)%; tied p = 0.043). In the CF control patients the number of infections (2.0 (2.0)), energy intake (116 (43.3)%) and nutritional status remained stable (W/H 99 (17.2)%), but pulmonary function decreased significantly (DeltaFEV(1) loss of 2.0 (8.0)%). There was a significantly different evolution for the change in forced vital capacity (p < 0.004) and DeltaFEV(1) (p < 0.001) between supplemented and control patients.

Conclusions: Analysis of the clinical data on Zn supplementation in CF showed beneficial effects in Zn-deficient CF patients. These results must be confirmed in a prospective double-blind randomized control trial.