Hair cortisol as a biomarker of stress in the 2011 Libyan war

There is a substantial body of research that utilizes saliva cortisol levels to examine wartime stress; however, there is a paucity of literature that utilizes hair cortisol levels, which allows for long-term assessment of chronic stress, to investigate the stress of war. The present study aimed to evaluate changes in hair cortisol concentrations before, during, and after the 2011 Libyan war.

This study examined hair cortisol concentrations of young adult women who were living in Tripoli, Libya during the 2011 war. The participants were recruited at the campus of Tripoli University. Participants needed to have at least 24 cm of hair and to have resided in Tripoli before, during and after the 2011 Libyan war. Hair was sectioned to reflect 3 month windows of cortisol exposure corresponding to periods before, during and after the war. Hair cortisol concentrations were quantified using a modified salivary ELISA test. The women were also asked to complete the Perceived Stress Scale pertaining to the post-war period.

Median hair cortisol concentrations in the post-war period (226.11 ng/g; range 122.95-519.85 ng/g) were significantly higher than both the pre-war (180.07 ng/g; 47.13-937.85 ng/g) and wartime (186.65 ng/g; 62.97-771.79 ng/g) periods (P<0.05). The mean PSS score (24) was in the range of “much higher than the mean” for this test and the vast majority of participants were either in the “much higher than the mean” or “slightly higher than the mean” ranges. Hair cortisol determination suggests that in Tripoli, the post-war period appears to have been more stressful than the war itself. This is consistent with the fact that during the war the civilian participants were not directly involved with warfare, nor were they targeted by the international coalition fighting Gaddafi. In contrast, the post-war period was characterized by chaos and total lack of authority, with the participants exposed to injury, lack of food and destruction.

This study documents the utility of hair cortisol levels to retrospectively assess stress before, during, and after an armed conflict.