African-American women who work night shifts have an increased risk of developing diabetes, than those who have never worked night shifts, according to an ongoing study by Dr. Varsha Vimalananda from the Center for Health Organization and Implementation Research (CHOIR), Bedford, MA, USA.
28,041 African-American women who were free of diabetes were part of the study. These women were followed for incidence of diabetes during the next 8 years. 37 percent of the women reported having worked the night shift, with 5 percent having worked that shift for at least 10 years. During the 8 years of follow-up period, there were 1,786 diabetes cases.
Compared to women who never worked the night shift, the increased risk of developing diabetes was 17 percent for 1-2 years night shift work, 23 percent for 3-9 years, and 42 percent for 10 or more years. After adjustment for body mass index (BMI) and lifestyle factors such as diet and smoking, the association between years of night shift work and increased diabetes risk remained statistically significant, with a 23 percent increase in those who had worked night shifts for 10 years or more relative to those who never had worked the night shift.
The authors found that this association was stronger in younger women than in older women. Researchers found that working night shifts for 10 or more years relative to never working the night shift was associated with a 39 percent higher risk of diabetes among women aged less than 50 years compared with 17 percent higher risk in women aged 50 years or over.
The study appears in Diabetologia, the journal of the European Association for the Study of Diabetes.