Serum zinc, bronchiectasis, and bronchial carcinoma.

, , 21-25. Serum zinc levels were measured by atomic absorption spectrophotometry in 65 patients with proven bronchiectasis; the mean level was 93 μg/100 ml, while the levels in two groups of healthy control subjects were 88·6 and 92·7 μg/100 ml respectively. The range of individual values was similar in all groups and the differences between the mean serum zinc levels of the two groups of control subjects and the mean level of the group of patients with bronchiectasis were small and did not attain significance at the conventional 0·05 level. In contrast, the mean level in bronchial carcinoma patients (75·9 μg/100 ml) was significantly less than in each of the other groups of subjects. Zinc sulphate was administered for six weeks on a double-blind cross-over basis to patients with bronchiectasis and, although serum zinc levels rose, no detectable clinical improvement resulted. No definitive evidence of zinc deficiency in bronchiectasis has been established.