Evaluation of neutrophile-to-lymphocyte ratio and lipid profile in non-violent suicide attempters: a mechanistic study.

Background: Suicide is one of the most common causes of juvenile death. Screening suicide risk is quite challenging and even more difficult in subjects who have no psychiatric disorder or other suicide risk factors in their medical history. To date, the association of serum lipid profile and suicidal risk has been evaluated in patients with different psychiatric disorders, yielding conflicting results. Here, we aimed to investigate the lipid panel and neutrophil-to-lymphocyte ratio in the sera of people with a first episode of suicide attempt in western Iran.

Methods: A total of 159 suicide attempters and 186 volunteers without history of suicide, aged 18-35 years, were evaluated in this experiment. Blood samples were collected between 8-10 AM and kept at 37 °C for blood clotting. We then analyzed the concentration of various lipid markers, including triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and high-density lipoprotein (HDL), using a series of enzymatic reactions. Additionally, we determined the neutrophil-to-lymphocyte ratio (NLR) by dividing the total number of neutrophils by the total number of lymphocytes after conducting peripheral blood cell counts.

Results: The concentration of TG was 94.2±5.8 mg/dL in males and 92.3±5.3 mg/dL in females. TC was 136.3±3.6 mg/dL in males and 152.7±4.4 in females, with a significant decrease in comparison with the control subjects (p less than 0.0001). NLR was 4.34±0.9 with a significant increase compared with the controls (P less than 0.002). (TG), (TC) and (LDL) levels in suicide attempters were significantly lower than in the control groups. Nevertheless, serum (HDL) levels in male and female suicide attempters were significantly higher than in the control group. Furthermore, NLR was significantly lower in the subjects with suicide attempts compared with the controls.

Conclusions: Lower concentrations of (TG), (TC) and (LDL) along with higher NLR were associated with non-violent suicide attempts. These findings might be an effective tool in screening suicide risk in young adults.