Salivary immunoglobulin A (IgA) and lysozyme have been studied as possible
biomarkers of stress. This study examined the stress levels among female nu
rses in various units and the relationship between these stress levels and
salivary IgA and lysozyme secretion. One hundred ninety-five (43 %) of 457
eligible female nurses from surgical wards/operating theaters (SURG), medic
al wards (MED), and outpatient clinics/day-surgery theaters (OPD) completed
a self-administered questionnaire. From this group of 195 nurses, 124 prov
ided a salivary sample accumulated over 5 minutes. Stress levels were asses
sed with a ten-point Stress Assessment Score (SAS) for Asians and a direct
question on perceived life stress. Enzyme-linked immunosorbent assay and ly
so-plate methods were used to determine salivary IgA and lysozyme levels. F
orty-five percent of SURG, 35 % of MED, and 17% of OPD nurses scored at lea
st four points on the SAS. SURG nurses had the lowest IgA secretion (geomet
ric mean; 95% confidence interval [CI]) rates (43 mu g/min; 36 to 51 mu g/m
in). The other groups had significantly higher salivary IgA secretion rates
: MED (96 mu g/min; 80 to 116 mu g/min) and OPD (77 mu g/min; 60 to 98 mu g
/min) Findings for salivary lysozyme (mu g/min) were similar; SURG (9 mu g/
min; 6 to 13 mu g/min) MED (19 mu g/min; 12 to 28 mu g/min) and OPD (16 mu
g/min; 9 to 28 mu g/min). The salivary IgA (Spearman's r = -0.22, P = 0.01)
but not the lysozyme (Spearman's r = -0.01, P = 0.9) secretion rate correl
ated negatively with SAS. Nurses working in various units under different c
onditions experienced dissimilar levels of stress. Salivary IgA, but not ly
sozyme, correlated inversely with self-reported levels of stress. It may th
us be a potential biomarker in future studies on stress.