Work, stress, and bodily reactions

Åse Marie HansenNational Research Centre for the

Working Environment

• What is stress?• How to measure stress? • The bodily reaction to workrelated stress?• When is stress unhealthy?• Biological variation

Work, stress, and bodily reactions

Model

Exposure

Biological response

Effect

Concept of biomarkers

Stressor

Acute physiological response

Long term effects

Strain Train

Individual factorsPerceived psykosocialwork environment

What is stress?

Example:Stress is a series of reactions, which may

lead to a chronic individual state characterized by a combination of high arousal, aversion and negative expectation about solving the challenge

What is stress?

Stress is your body's way of responding to any kind of demand. It can be caused by both good and bad experiences.

Stress is the emotional and physical strain causedby our response to pressure from the outside world.

What is workrelated stress?

Stressors at the work place

Physical strain

Job demands,heavy work load

Chemical exposure

Job demands,mental demands

Job control

Physical work placee.g. noise and temperatur

Reactions to stress

• Cognitive and emotional reactions

• Behavioral reactions/symptoms

• Somatic reactions

• Physiological reactions

Cognitive and emotional reactions

Lack of motivation

Tiredness

Difficulty to remember

Difficulty to concentrate

Anxiety

Irritability

Depression

Low self-worth

Lack of appetite

Sleep problems

Reservation

Anger

Behavioral symptoms

Aggression

Low performance

Behavioral reactions to stress

Alcohol

Coffee

Smoking

Abuse

Physical activity

Sick leave

Indecisive

Somatic symptoms of stress

Headache

Sweating

Often infections

Hyperventilation

Stomach problems

Loss of weight

Palpitation/ Pain in the breast

How to measure stress?• Questionnaire, e.g.

– Demand/control– Effort /reward– COPSOQ– Perceived stress and energy

• Observations• Bodily reactions to stress

(physiological reactions), e.g.– cortisol in saliva– adrenaline and noradrenaline in urine

How do you feel after a normal workday?

S: CalmE: PassiveS: PressureE: FocusedS: RelaxedE: IneffectiveE: EnergeticS: StressedE: SadS: TenseE: ActiveS: Refreshed

Very often

OftenSome-times

To some degree

Very littleNot at all

Translated from Kjellberg and Iwanowski 1989

Responses from approx. 600 officeworkers

5 %xE: Passive5 %xE: Ineffective3 %xE: Sad

x5 %E: Focusedx3 %E: Energetic

x2 %E: Active14 %xS: Pressure15 %xS: Stressed15 %xS: Tense

x1,5 %S: Calmx5 %S: Relaxed

x17 %S: Refreshed

Very often

OftenSome-times

To some degree

Very littleNot at all

Stress scale = 2.3 Energy scale = 3.0

0.0

0.5

1.0

1.5

2.0

2.5

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

Time

Tuesday Wednesday Thursday Friday Saturday Sunday

Stre

ss In

dex

Scor

eStress index

Ener

gyIn

dex

Scor

e

0.0

1.0

2.0

3.0

4.0

5.0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

06:0

0

12:0

0

18:0

0

00:0

0

Time

Energy index

Tuesday Wednesday Thursday Friday Saturday Sunday

How the body responds to work-related stress

The sympathetic nervous system

• Adrenaline/noradrenaline increase

• Heart frequency increase

• Blood pressure increase

• More blood to the muscles

• Less blood to the skin

• Low digestion

• Increased brain activity

Biomarkers for catabolicand anabolic metabolism

Catecholamines(adrenaline and noradrenaline)

CortisolGlycated hemoglobin

(HbA1c)

TestosteroneGrowth hormoneDehydroepiandrosterone

(DHEA)

Unwinding after work overload

0

50

100

150

200

250

0 5 10 15 20

Weeks

% o

f pre

-ove

rtim

e va

lue

061218

Evening Daytime Extra working hours

061218

Hours

Frankenhaueser and Johansson. Int.Rev.Appl.Psychol. (1986)

Total serum cholesterol

200205210215220225230235240

31-12

-56

20-01

-57

09-02

-57

01-03

-57

21-03

-57

10-04

-57

30-04

-57

20-05

-57

09-06

-57

29-06

-57

mg/

100

mL

plas

ma

Group A Group B

A A and B BB

Perceived stress Friedman et al. 1958

Noise

0.050

0.060

0.070

0.080

0.090

06:00 08:00 10:00 12:00 14:00

Cor

tisol

(µgr

am/m

g cr

eatin

ine)

Without hearing protectionWith hearing protection

Melamed et al., Psychom.Res.1995

HbA1c

KolesterolDHEA-STestosteronIgAProlaktin

1

AdrenalinNoradrenalinKortisol

Helbredsundersøgelse

Generelt stress niveauOplevet si tuation

Monotonous work

Hansen et al 2003

** p<0.05

Unpublished results

4,50

4,55

4,60

4,65

4,70

4,75

low demand/low control

low demand/high control

high demand/low control

high demand/high control

% o

f tot

al h

emog

lobi

nJob strain and HbA1c

Outsourcing

Outsourcing

-20 0 20 40 60Percent increase

Adrenaline

Noradrenal ine

Cortisol

HbA1c

DHEA-S

**

*

Netterstrøm et al. (2000)

Threat of closing

Erikssen et al. 1990

80

90

100

110

120

130

140

150

160

1982 1983 1984 1985 1986 1987 1988586062646668707274767880BP (mm Hg)

Norwegian metal workers(N = approx. 180) Pulse

SBP

Pulse

DBP

129 129130135

142 145 143

63 63

6970

84 85 8690

94 9691

Organisational downsizing and death

7,5 years follow-up study among 22.430 employeesin the public sector, who kept their jobs

Vahtera et al. BMJ 2004;328:555-558.*Controlled for age, gender, SES og job

0

1

2

1.0

1.5

1.01.2

2.0

1.2

RR*

None Minor Major None Minor Major

Extent of downsizing

2.0

1.0

0

CVD Otherdeaths

When are the physiologicalreactions unhealthy?

Models for health risk

• Cognitive activation theory• Allostasis• Lack of restitution• Shift of rhythms• Stress-disequilibrium theory

(Not included)

Bullying and cortisol in saliva

3.00

7.00

11.00

15.00

19.00

00:00 06:00 12:00 18:00 00:00

Time of day

Cor

tisol

in s

aliv

a(n

mol

/l)

Reference group bullied individuals

AllostasisThe ability to

achieve stabilitythrough change.

McEwen New England Journal of Medicine (1998)

Size of response

Exposure

The wear and tear that result from chronic

overactivity or underactivityof allostatic

systems

Allostatic load

Successful aging

• Systolic blood pressure (>148 mm Hg)• Diastolic blood pressure (>83 mm Hg)• Waist-hip ratio (>0.94)• Total cholesterol-HDL ratio (>5.9)• Total HbA1c (>7.1%)• Urinary cortisol (>25.7 mg/g creatinine)• Urinary norepinephrine (>48 mg/g creatinine)• Urinary epinephrine (>5 mg/g creatinine)• HDL cholesterol (< 1.45 mmol/L)• DHEA-S (<2.5 µmol/L)

T.E. Seeman et al. (1997)

Successful aging

0

5

10

15

0 1-2 >=3

Allostatic load category

New

car

diov

ascu

lar

dise

ase,

%

T.E. Seeman et al. (1997)

Cortisol and memory

0

2

4

6

8

10

12

-10 -5 0 5 10 15 20 25

Cortisol response (nmol/L)

No.

ofc

orre

ctly

reca

lled

wor

ds

Kirschbaum et al. Life Sci. 1996

Cortisol and memory

0

1

2

3

4

5

6

7

8

9

Declarative memory Procedural memory

No.

ofr

ecal

led

orco

mpl

eted

wor

ds

10 mg cortisolPlacebo

*

Kirschbaum et al. Life Sci. 1996

Cortisol and memory

45

50

55

60

65

0 2 4 6 8 10Days

Imm

edia

tere

call

bits

placebo40 mg/d160 mg/d

Newcomer et al. Arch.Gen.Psychiatry 1999

Rate of recovery

Exposure

Unwinding after work overload

0 5 10 15 20

Weeks

0

50

100

150

200

250

% o

f pre

-ove

rtim

e va

lue

of e

pine

phrin

e

EveningDaytimeExtra working hours

Frankenhaueser and Johansson. Int.Rev.Appl.Psychol. (1986)

061218

Hours

Reduced reactivity

Stressor

Serum cortisol after stress test

400

450

500

Base 16 20 30 40

Minutes after stress test

Seru

m c

ortis

ol (n

mol

/L)

Vilnius

Linköping

M. Kristensson et al. (1998)

Stress test ***

* ***

Lack of variability

HighFlatNormal

Construction workers

0.00

5.00

10.00

15.00

20.00

25.00

03:00 09:00 15:00 21:00Time (hours)

nmol

cor

tisol

/l sa

liva

Reference group

Construction workers - normal day

Construction workers - long day

Cortisol in saliva during a working day

Significantly higher concentration of saliva cortisol observed in construction workers compared to reference group. No difference was observed between construction workers having long and normal days

Hansen, 2006

Relative variability in salivary cortisol

* Coefficient of variance# 95% Confidence interval

[91-108]

99

[91-108]

99

Reference group

[65-92]CI (%) #

0.00476CV (%) *

0.0437282CV (%) *

[57-95][64-112]CI (%) #

Normal daysLong days

P-valueConstruction workers

Hansen, 2006

Conclusion

• Construction workers had higher concentrations of cortisol in saliva during a work day compared to white collar workers.

• Construction workers had lower relative variability in cortisol compared to whi te collar workers

Restitution

Catabolic metabolismAnabolic metabolism

Demands DemandsRest

Restitution

Catabolic metabolismAnabolic metabolism

Demands DemandsRest

Outsourcing

-20 0 20 40 60Percent increase

Adrenaline

Noradrenal ine

Cortisol

HbA1c

DHEA-S

**

*

Netterstrøm et al. (2000)

Working hours and bloodpressure

Yang et al. 2006

00.20.40.60.8

11.21.41.6

11-39 40 41-51 > 51Weekly working hours

Ris

cof

incr

ease

dbl

ood

pres

sure

Contolled for diabetes, tobacco, physical activty, SES, gender, age(n=24.205, 18-64 år)

Øresundsbron

Building the bridge between Sweden and Denmark

14

16

18

20

22

0 5 10

Test

oste

rone

(nm

ol/L

)

Pylon workersControls

Days

Ørbæk et al. 2000

Øresundsbron

Exhaustion

0

5

10

15

0 5 10 15Dag

% o

f the

day

Pylon workers Track workers

Ørbæk et al. 2000

Typical sleep

Gerlach: Søvn, 2003

Hormones respond to sleep

• Growth hormone, prolactin and testosterone ↑

• Thyroid hormoneand adrenaline ↓

• Cortisol ↑ duringterminal sleep

• CRH reduces sleepquality

• Melatonin stimulatessleep

Sleep → hormones: Hormones → sleep:

Stress and sleep

Stress

Physiologicalarousal

Increased cortisoland adrenaline

Difficultiesfalling asleep

Sleep loss

Need for increased effort

Sleep problems -> illness• Increased risk of heart disease

– Review of 10 studies– High quality studies found increased risk of

coronary events after adjusting for age and otherrisk factors

– The combined risk was 1.7 (range 1.5 -3.9)• Increased risk of diabetes

– 6599 non-diabetic men at baseline, aged 44.5 ±4.0 years

– 281 (4.3%) developed diabetes during follow-up(14.8 years)

– Men with difficulties falling asleep or regular use of hypnotics had increased risk of 1.52 [95% CI: 1.05-2.20] Schwarts S et al., J Psychosom Res, 1999

Nilsson PM et al., Diabetes Care, 2004

Sleep and heart diseaseA study of 71,617 American nurses followed for 10 years

Ayas et al. Arch Intern Med 2003;163:205-9. The Nurses’ Health Study

0.0

0.5

1.0

1.5

2.0

2.5

1.8

1.31.1 1.0

-5

RR

1.61.4

1.2 1.1 1.0

1.4

6 7 8 9+ - 5 6 7 8 9+

Adjusted for 14 factorsAge-adjusted

Psychosocial work and sleep

• High demands• Low control• Keep thinking of

work• Expect difficult

workday

• Unsolved conflicts• Unsolved problems

• Social support

Decreasessleep problems:

Increasessleep problems:

Kalimo et al., Stress Med, 2000Åkerstedt et al., J Psychosom Res 53(1), 2002Åkerstedt et al., J Psychosom Res 53(3), 2002Kecklund et al., Biol Psychol, 2004

Shift of rhytms

Melatonin - workdayMelatonin - day off

KSS - workdayKSS - day off Working hours

Time

Fixed shift day

Very alert

Alert

Neither alert nor sleepy

Sleepy

Extremely sleepy

06:00 12:00 18:00 24:000

2

4

6

8

10

12

14

16

18 Fixed shift night

06:00 12:00 18:00 24:00

Time

0

2

4

6

8

10

12

14

16

18

µmol

aMT6

/mol

creati

nine

Hansen et al., 2006Garde et al., unpublished data

Biological variation

PhysiologicalAge, sex, height, health etc.

GeneticMetabolism & Genotype

LifestyleSmoking, alcohol, medicine etc.

Biological variation

Individual factorsIndividual factors

Body mass indexBody mass index

AgeAge

GenderGender

Age

Stevens, Wilson, et al. 1997

Age

0

10

20

30

40

19-39 40-49 50-59 >60

Women

Men

DH

EA (n

mol

/L)

Years of age

AR Genazzani (1998)

Age and BMI

30 6020

300

1

2

3

4

5

6

7

8

Age (years)

BMI (kg/m2)

S-DHEA-S (nmol/L)

Hansen et al 2002

Age and smoking

30 60Non-smoker

Smoker

4

5

Age (years)

B-HbA1c (%)

Hansen et al 2002

GenderTe

stos

tero

ne(n

mol

/L)

302520151050

H Olesen et al. (1987)

CoffeeCoffeeCoffee

AlcoholAlcoholAlcohol

SmokingSmokingSmoking

MedicineMedicine

Individual factors related to life style

Individual factors related to life style

Evening coffee steels yoursleep

One cup of coffeecontains enoughcoffein to half theamount of melatonin

Ingeniøren No 22, Maj 2002, (part of a note from New Scientist)

Urinary adrenaline: Smoking and BMI

0

1

2

3

4

5

6

05:45 11:45 17:45 23:45

Hour

µmol

/mol

cre

atin

ine

SmokerNon-smoker

Women BMI 19-20

0123456

05:45 11:45 17:45 23:45

Hour

µmol

/mol

cre

atin

ine Smoker

Non-smokers

Women BMI 28-30

Hansen et al. 2001

Genetic factorsGenetic factors

Ethnic background:20% higher levels of S -testosterone in black subjects% HbA1c lower in Caucasian compared to black subjects

Ethnic background:20% higher levels of S -testosterone in black subjects% HbA1c lower in Caucasian compared to black subjects

Other Interactions

Exercise

Food

Artificiel light

Wake up

Circadian rhytm

Seasonal variation

Circadian variation

Medicinsk Kompendium (1994)

1000

750

500

250

012 16 20 24 4 8 12

Time

Plas

ma

corti

sol (

nmol

/L)

Circadian variation

Medicinsk Kompendium (1994)

Seasonal variation -epinephrine

0

2

4

6

8

10

Hour

µmol

/mol

cre

atin

ine

June and July August to May

0 06.00 12.00 18.00 24.00

Hansen et al 2001

Garde et al, 2000

Seasonal variationof DHEAS

4

5

6

7

8

9

June July Aug Sep Oct Nov Dec Jan Feb Mar Apr May

Pla

sma

DH

EA

S(µ

mol

/L)

WinterSummer

Within and between subjectvariation

02468

1012

0 5 10 15 20

Plasma DHEA-S (µmol/L)

Garde et al, 2000

Within and between subjectvariation

02468

1012

3.0 3.5 4.0 4.5 5.0 5.5

Blood HbA1c (% of total hemoglobin)

Garde et al, 2000

Questions?

• Åse Marie Hansen aamh@arbejdsmiljoforskning.dk