Mixing early rises and long weekend lie-ins is damaging for our health

    19 November 2015

    Routine sleep changes, such as waking up early for work during the week, could raise your risk of developing diabetes and heart disease, according to a study in the Endocrine Society’s Journal of Clinical Endocrinology and Metabolism.

    Previous studies have shown that shift workers are more likely to develop metabolic syndrome, coronary heart disease and type 2 diabetes. It is believed that this is caused by the continual disruption to the circadian system, which regulates our sleep and wake phases.

    Sleep disruption is thought to be a contributing factor in the rising rates of diabetes and obesity globally.

    Patricia Wong, the study’s lead author, said: ‘Social jetlag refers to the mismatch between an individual’s biological circadian rhythm and their socially imposed sleep schedules. Other researchers have found that social jetlag relates to obesity and some indicators of cardiovascular function.’

    ‘However, this is the first study to extend upon that work and show that even among healthy, working adults who experience a less extreme range of mismatches in their sleep schedule, social jetlag can contribute to metabolic problems. These metabolic changes can contribute to the development of obesity, diabetes and cardiovascular disease.’

    The researchers looked at the sleep patterns of 447 men and women between the ages of 30 and 54, all of whom worked at least 25 hours a week. Participants wore a wristband that measured their movement and sleep for a week.

    Almost 85 per cent had a later halfway point in their sleep cycle on free days compared to work days. It was found that those with a greater misalignment between their sleep schedules on free and work days tended to have poorer cholesterol profiles, higher fasting insulin levels, larger waist circumference, higher BMI and greater insulin resistance.

    Wong said: ‘If future studies replicate what we found here, then we may need to consider as a society how modern work and social obligations are affecting our sleep and health. There could be benefits to clinical interventions focused on circadian disturbances, workplace education to help employees and their families make informed decisions about structuring their schedules, and policies to encourage employers to consider these issues.’