People who are routinely up all night working the late shift may be damaging their hearts, according to a report in the September issue of the journal Occupational and Environmental Medicine.

Dutch investigators found that shift workers are more likely to develop a condition called premature ventricular complexes (PVC), which is associated with extra heart beats and an increased risk of death due to heart disease.

Previous studies have found that shift workers have higher rates of heart disease compared with those who work in the daytime even after other risk factors - such as smoking, diet and weight - are taken into consideration.