The response of circulating brain natriuretic peptide to academic stress in college students

Figures & data

Table I.  Subjects' physical characteristics.

	Male (n = 70)	Female (n = 95)	p Value
Age (years)	24 ± 4	27 ± 4	0.0003
Height (cm)	178 ± 7	165 ± 7	< 0.0001
Weight (kg)	76 ± 10	57 ± 8	< 0.0001
BMI (kg/m^2)	20.9 ± 2.0	23.9 ± 2.3	< 0.0001

Values are means ± SD; n, no. of individuals.

Table II.  Subjects' hormonal and hemodynamic variables at rest and in response to stress.

	Male (n = 70)	Female (n = 95)	p Value (male–female)
Cortisol (nmol/l)
Exam	433 (377–490)	588 (504–671)	0.0008
Rest	314 (268–360)	406 (356–456)	< 0.0001
p Value (exam–rest)	0.003	< 0.001
NT-proBNP (ng/l)
Exam	28 (18–37)	72 (57–88)	< 0.0001
Rest	52 (33–71)	115 (89–140)	< 0.0001
p Value (exam–rest)	0.02	< 0.001
HR (beats/min)
Exam	71 (67–74)	75 (72–78)	0.01
Rest	68 (65–70)	67 (65–70)	0.79
p Value (exam–rest)	0.10	< 0.001
DBP (mm/Hg)
Exam	71 (68–73)	67 (65–70)	0.05
Rest	61 (59–64)	60 (57–62)	0.16
p Value (exam–rest)	< 0.001	< 0.001
SBP (mm/Hg)
Exam	117 (114–120)	109 (106–112)	< 0.0001
Rest	107 (104–109)	98 (95–100)	< 0.0001
p Value (exam–rest)	< 0.001	< 0.001

Multivariate analysis using ANOVA for repeated measures, included in the model, were age and BMI. Results demonstrate the estimated marginal means (95% CI) of cortisol and NT-proBNP concentrations, HR, and DBP, SBP, adjusted for age and BMI.

Figure 1  The change in circulating concentrations of NT-proBNP from rest to stress in relation to the change in circulating cortisol concentrations. The change in circulating concentrations of NT-proBNP from rest to stress in relation to the change in circulating cortisol concentrations. Male (n = 70 (A)) and female (n = 95 (B)) students were divided into two groups according to their absolute change in circulating levels of cortisol (below median and above median). Multivariate analysis using ANOVA for repeated measures revealed in males a significant interaction (p = 0.02): male students with the above median difference in cortisol between stress and rest have lower stress-day level and higher rest-day concentrations of NT-proBNP than students with below median differences. In females (B), no interaction was found: female students with the above median difference in cortisol between stress and rest have higher stress-day and higher rest-day concentrations of NT-proBNP than students with below median differences. The error bars indicate s.e.m.