Presentation Indranil Das.

HIGHER INCIDENCE OF TYPE 2 DIABETES AMONG WOMEN

WORKING NIGHT SHIFTS

A REVIEW

Researchers

• Das Indranil. MBBS, DIH, MPH (on-going) University of Eastern Finland.

• Heikkinen Jarmo. Clinical Lecturer, University of Eastern Finland.

• Järvelin-Pasanen Susanna. University Teacher, University of Eastern Finland.

Introduction

Type 2 diabetes• Insulin resistance• Relative lack of Insulin• Polyuria, polydipsia and

polyphagia

Night shift• 24 x7 work schedules and

round the clock service• Working schedules during

night hours• Graveyard shift

Type 2 diabetes and melatonin

• Diurnal changes of insulin, related to circadian rhythm and sleep

• The synchronization is linked to melatonin• Risk related to genotype and lifestyle

Epidemiology

• Ice berg phenomenon• In 2010, 285 million affected world wide • Expected prevalence 4.4% by 2030• Mostly a disease of urban obese population

Complications of type 2 diabetes

• Cardiovascular complications

• Renal diseases• Ophthalmic

complications

• Obstetric complications- High Perinatal mortality, Congenital malformations, higher incidence of operative procedures.

Night Shift and HealthComplex interaction.Circadian Rhythm disruptionSocial disruption

Objectives

• Summarize the studies on incidence of type 2 diabetes among women working in night shifts

• Study the effect of number of years worked on the risk of type 2 diabetes among women working in night shifts

Importance of this study

• Less studies on women

• Women are at added risk

• Increasing participation of women 24X7 jobs

Selection of Studies

Result: Selected studies.Study Design Study population Follow Up

Exposure assesment

Pan et al. 2011 Cohort study (NHS I) N= 69269 Age group: 42-67 years

18-20 yrs.

Self-reported T2DM confirmed by validated questionnaire.

Cohort study (NHS II) N=107915 Age group: 25-42 years

18-20 yrs. Self-reported T2DM confirmed by validated questionnaire.

Kroenke et al. 2007 Cohort study (NHS II) N=62574 Age group: 29-46 years.

6 yrs. Biennial mailed questionnaire. Supplementary validated questionnaire.

Result: Association & incidenceStudy Nightshift Work Incidence Hazard Ratio (95% CI) Conclusion

Pan A et al. 2011 3 nights per month in addition to day and evening shift

6165 ( in NHS I)3961 (in NHS II)

1.58 (1.43-1.74) (working in night shift more than or equal to 20 years)

Positive association. Association mediated by BMI

Kroenke CH et al. 2007

No exclusion criteria

365 1.41 (0.96-2.06)(working in night shift >10 years)

No association when adjusted for BMI (Obesity)

Result: Risk and number of years worked

(Pan et al. 2011)

Number of years worked in Night Shift Unadjusted Hazard Ratio (95% CI) Hazard Ratio after adjustment for BMI

1 -2 years 1.05 (1.00-1.11) 1.03 (0.98-1.08)

3- 9 years 1.20 (1.14-1.26) 1.06 (1.01-1.11)

10-19 years 1.40 (1.30-1.51) 1.10 (1.02-1.18)

More than 20 years 1.58 (1.43-1.74) 1.24 (1.13-1.37)

Conclusions

• Incidence of type 2 diabetes is higher among women working in night shifts, BMI plays an important role in the association. But more studies are required to establish cause effect relationship.

• Risk increases with the number of years worked in night shift, significantly after 10 years of night shift working.

Recommendations

• Health education: diet, life style adjustments, screening

• Occupational health facilities• Pre employment, and regular health check up• Research with different cohort, better case

identification and longer follow up

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