Women who experience the most symptoms of posttraumatic stress disorder (PTSD) were found to have a two-fold increased risk of developing type 2 diabetes mellitus (T2D) compared with women who had not been exposed to trauma.

Past studies have suggested a link between the two conditions, but it has been unclear whether PTSD increased the risk of T2D or if both conditions were linked to associated outside factors, the JAMA Network Journals reported.

To make their findings the researchers conducted one of the "first longitudinal studies of PTSD and the incidence of T2D in a civilian group of women."

The study included a 22 year follow-up period; during this time, 3,091 of the 49,739 women in the study developed T2D. The data suggested women who had PTSD symptoms had a higher rate of TD2.

In the study sample there were "4.6 cases of T2D per 1,000 person-years among women with six or seven PTSD symptoms; 3.9 cases among women with four to five symptoms; 3.7 cases among women with one to three symptoms; 2.8 cases among women exposed to trauma but with no PTSD symptoms; and 2.1 cases among women unexposed to trauma," the researchers reported.

The findings suggest high body mass index and antidepressant use associated with PTSD were linked to nearly half of the observed increased risk of T2D in this group. Factors such as smoking, diet quality, and alcohol intake did not appear to contribute to the increase in P2D risk.

"Our findings have implications for research and practice. Further research must identify the biochemical and possible additional behavioral changes, such as sleep disturbance, that mediate the relationship between PTSD and onset of T2D. A better understanding of pathways will facilitate interventions to prevent this disabling disease," the study concluded.

The findings were published in a recent edition of the journal JAMA Psychiatry.