Women with five or more live births are at increased risk of developing type 2 diabetes mellitus. This appears to be the case, even after adjusting for obesity and socioeconomic factors. Dr. Wanda K. Nicholson and colleagues at the Johns Hopkins School of Medicine in Baltimore, Maryland, came to that conclusion after conducting a prospective, population-based study of more than 7000 Caucasian and African-American women.
The subjects were between 45 and 64 years of age, and mean follow-up was for nine years. They were grouped according to parity, defined as nulliparous (including stillbirths and other non-live births), one to two live births, three to four live births, or grandmultiparous, with five or more live births.
There were 754 incident cases of type 2 diabetes during follow-up. Type 2 diabetes incidence rates were highest among the grandmultiparous, at 23 cases/1,000 person-years and lowest among women with one to two live births, at 11 cases/1,000 person-years.
The researchers acknowledge that the bulk of diabetes risk was due to obesity and lower socioeconomic status. However, after adjusting for these recognized risk factors as well as clinical status, inflammatory markers and lifestyle factors, grandmultiparity remained a risk factor for type 2 diabetes.
Whether the link between high parity and diabetes is biological or due to lifestyle is unknown. The investigators conclude that the association may be better understood after prospective studies of "specific, pregnancy-related weight gain measures, lifestyle factors and changes in socioeconomic status."
Diabetes Care Nov 2006;29:2349-2354.
DID YOU KNOW:
Working Long Hours Increases Risk Of Diabetes: A University of California study of nurses finds that working long hours increases the risk of diabetes in young and middle-aged women. The researchers, who used data from the Nurses Health Study and tracked nurses aged 29 to 46, found that those who worked 60 hours a week or more were more than twice as likely to develop Type 2 diabetes, the British newspaper, The Mirror, reported. Those who worked 40 to 60 hours were 50 percent as likely to get diabetes as those who worked 21 to 39 hours. "Results were consistent with an impact of job stress on diabetes outcome and hours worked per week may reflect the extent of exposure to stress," said Candyce Kroenke, who led the research team. Single women tended to drink and smoke more than married nurses and were also more likely to develop diabetes. Researchers believe that stress raises cortical levels, leading to higher body fat and blood pressure.
Nurses Health Study