Effects of short-term zinc supplementation on cellular immunity, respiratory symptoms, and growth of malnourished Equadorian children.
OBJECTIVE
To assess the effect of zinc supplementation on respiratory tract disease, immunity and growth in malnourished children.


METHODS
A randomized double-blind placebo-controlled trial.


METHODS
A day-care center in Quito, Ecuador.


METHODS
Fifty children (12-59 months old) recruited by height-for-age and weight-for-age deficit.


METHODS
Twenty-five children (supplemented, S group) received 10 mg/day of zinc as zinc sulfate, and 25 (nonsupplemented, NS group) received a placebo during 60 days. All were also observed during a 60-day postsupplementation period. Two children of the S group dropped out. Daily the clinical presence of cough, respiratory tract secretions, and fever, was recorded. On days 0,60 and 120, the cutaneous delayed-type hypersensitivity (DTH) to multiple antigens, and anthropometric parameters were assessed. On days 0 and 60 serum zinc levels were also measured.


RESULTS
On day 60, DTH was significantly larger (20.8 +/- 7.1 vs 16.1 +/- 9.7 mm), and serum zinc levels were significantly higher (118.6 +/- 47.1 vs 83.1 +/- 24.5 micrograms/dl) in the S group than in the NS group (P <0.05 for each). The incidence of fever [relative risk (RR): 0.30, c.i. = 0.08- 0.95, P =0.02], cough (RR): 0.52, c.i. = 0.32-0.84, P = 0.004) and upper respiratory tract secretions (RR):0.72, c.i. = 0.59-0.88, P = 0.001) was lower in the S group than in the NS group at day 60. At the end of the postsupplementation observation period (day 120), the incidence of fever and upper respiratory tract secretions was the same in both the S and NS groups. The incidence of cough was higher at day 120 in the S group than in the NS group (RR): 2.28, c.i. = 1.37-3.83, P = 0.001).


CONCLUSIONS
This study supports a role for zinc in immunity, and immunity to respiratory infections, while pointing out the need for larger studies.
Sempértegui
F
F
National Research Institute of Health, Ministry of Public Health, Quito, Ecuador.
Estrella
B
B
Correa
E
E
Aguirre
L
L
Saa
B
B
Torres
M
M
Navarrete
F
F
Alarcón
C
C
Carrión
J
J
Rodríguez
Griffiths
J K
JK
D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D015362:Child Nutrition Disorders / Q000188:drug therapy*; D002675:Child, Preschool; D003371:Cough / Q000188:drug therapy; D004311:Double-Blind Method; D004484:Ecuador; D005260:Female; D005334:Fever / Q000175:diagnosis; D006130:Growth Disorders / Q000188:drug therapy*; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000188:drug therapy; D007111:Immunity, Cellular / Q000187:drug effects; D007223:Infant; D008297:Male; D012141:Respiratory Tract Infections / Q000188:drug therapy* / Q000276:immunology; D012306:Risk; D013431:Sulfates / Q000627:therapeutic use*; D017967:Zinc Compounds / Q000627:therapeutic use*; D019287:Zinc Sulfate
D000276:Adjuvants, Immunologic; D013431:Sulfates; D017967:Zinc Compounds; D019287:Zinc Sulfate