Serum zinc and pneumonia in nursing home elderly.
BACKGROUND
Zinc plays an important role in immune function. The association between serum zinc and pneumonia in the elderly has not been studied.


OBJECTIVE
The objective was to determine whether serum zinc concentrations in nursing home elderly are associated with the incidence and duration of pneumonia, total and duration of antibiotic use, and pneumonia-associated and all-cause mortality.


METHODS
This observational study was conducted in residents from 33 nursing homes in Boston, MA, who participated in a 1-y randomized, double-blind, and placebo-controlled vitamin E supplementation trial; all were given daily doses of 50% of the recommended dietary allowance of essential vitamins and minerals, including zinc. Participants with baseline (n = 578) or final (n = 420) serum zinc concentrations were categorized as having low (<70 microg/dL) or normal (>or=70 microg/dL) serum zinc concentrations. Outcome measures included the incidence and number of days with pneumonia, number of new antibiotic prescriptions, days of antibiotic use, death due to pneumonia, and all-cause mortality.


RESULTS
Compared with subjects with low zinc concentrations, subjects with normal final serum zinc concentrations had a lower incidence of pneumonia, fewer (by almost 50%) new antibiotic prescriptions, a shorter duration of pneumonia, and fewer days of antibiotic use (3.9 d compared with 2.6 d) (P <or= 0.004 for all). Normal baseline serum zinc concentrations were associated with a reduction in all-cause mortality (P = 0.049).


CONCLUSIONS
Normal serum zinc concentrations in nursing home elderly are associated with a decreased incidence and duration of pneumonia, a decreased number of new antibiotic prescriptions, and a decrease in the days of antibiotic use. Zinc supplementation to maintain normal serum zinc concentrations in the elderly may help reduce the incidence of pneumonia and associated morbidity.
Meydani
Simin N
SN
Nutritional Immunology Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA. simin.meydani@tufts.edu
Barnett
Junaidah B
JB
Dallal
Gerard E
GE
Fine
Basil C
BC
Jacques
Paul F
PF
Leka
Lynette S
LS
Hamer
Davidson H
DH
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001900:Boston / Q000453:epidemiology; D002423:Cause of Death; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006707:Homes for the Aged; D006801:Humans; D015994:Incidence; D008297:Male; D009735:Nursing Homes; D009752:Nutritional Status; D011014:Pneumonia / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology* / Q000401:mortality; D013997:Time Factors; D014810:Vitamin E / Q000008:administration & dosage*; D014815:Vitamins / Q000008:administration & dosage; D015032:Zinc / Q000097:blood* / Q000276:immunology
D000900:Anti-Bacterial Agents; D014815:Vitamins; D014810:Vitamin E; D015032:Zinc