Hong Kong, Jan 27: Do you frequently work in night shifts? Lack of proper sleep and night-time wakefulness can cause damage to the structure of the human DNA and lead to many diseases, including cancer and diabetes, as well as cardiovascular, neurological and pulmonary diseases, warns a study.The study, published in the Anesthesia academic journal, shows that DNA repair gene expression is lower at baseline among night workers and further decreases after acute sleep deprivation, which supports the postulation that night workers demonstrate impaired DNA repair.The findings showed that people who are required to work overnight demonstrate 30 per cent higher DNA breaks as compared with those not required to work overnight, and this DNA damage is further increased by over 25 per cent after a night of acute sleep deprivation."DNA damage is a change in the basic structure of DNA that is not repaired when the DNA is replicated," said S. W. Choi, Research Associate at The University of Hong Kong. "Double-strand breaks are particularly hazardous as repair failure causes genomic instability and cell death, whereas disrepair can lead to inappropriate end-joining events that commonly underlie oncogenic transformation," Choi added. For the study, the team examined a small group of healthy full-time doctors, average age between 28 and 33, who donated a sample of blood after three days of adequate sleep. Doctors who worked the night shift then had additional blood sampled the morning after, following acute sleep deprivation."The study demonstrates that disrupted sleep is associated with DNA damage," Choi said.Furthermore, larger prospective studies looking at relationships between DNA damage and chronic disease development are warranted, and methods to relieve or repair DNA damage linked to sleep deprivation should be investigated, Choi suggested.