Shift work increases diabetes and heart disease risk

With over 20% of the population in industrial countries engaging shift work – in sectors such as healthcare and transportation – we urgently need to understand its health burden (1). 

Many studies have shown that shift work is associated with heart and metabolic diseases, but new research in Experimental Physiology has clarified how shift work can have a long-term effect on the risk of heart disease and diabetes. 

The study specifically suggested that shift work has a negative impact on the way a type of fat (called triglycerides) is broken down, as well as on the way sugar is utilised in our bodies. Both of these increase the risk of heart disease and diabetes because they affect how our body processes sugar and fat. 

Researchers at the University College of Medical Sciences, University of Delhi conducted the research on two groups of healthcare workers. The first group included nurses, doctors and other healthcare workers aged 20 to 40 of both sexes who had not done night shift in the last one year or ever and had normal blood sugar levels. The second group was of the same professional background and age, but involved in rotational night shift duties (more than 4 nights duties per month at least for last one year) and had normal blood sugar levels.

Blood sugar levels were measured using an oral glucose tolerance test. Then, after 12 hours of overnight fasting, participants were given a high fat meal. Fasting insulin levels, and triglyceride levels, after fasting and after the meal, were measured in all of the study participants. These were compared between health care workers with and without night shift duties. 

Lead author on the study, SV Madhu said:

“This study gives us a better understanding of why shift work is associated, in the long-term, with heart and metabolic diseases, helping us work towards reducing the incidence of heart disease, diabetes and obesity in the future.” 

Notes for Editors

  1. Lee S, McCann D, Messenger JC. Working Time Around the World: Trends in Working Hours, Laws and Policies in a Global Comparative Perspective. London and Geneva: Routledge and ILO, 2007.
  2. Association of postprandial triglyceride responses with insulin resistance among rotational night shift healthcare workers https://physoc.onlinelibrary.wiley.com/doi/10.1113/EP087514 (link will only work after the embargo date. Before then, please email the press office for a copy of the paper)
  3. Experimental Physiology publishes advances in physiology which increase our understanding of how our bodies function in health and disease. http://ep.physoc.org
  4. The Physiological Society brings together over 3,500 scientists from over 60 countries. The Society promotes physiology with the public and parliament alike. It supports physiologists by organising world-class conferences and offering grants for research and also publishes the latest developments in the field in its three leading scientific journals, The Journal of Physiology, Experimental Physiology and Physiological Reports. www.physoc.org

Contacts:

The Physiological Society: 

Julia Turan, Communications Manager

pressoffice@physoc.org

+44 (0)20 7269 5727  

Corresponding author:

S V Madhu

Centre for Diabetes Endocrinology & Metabolism

University College of Medical Sciences (University of Delhi)

drsvmadhu@gmail.com