Chronic hypoxia, deficiency in the amount of oxygen reaching the tissues, is a risk factor for suicide and having multiple indicators of hypoxia confers a greater risk for suicide, indicating a dose-response relationship. This according to a recent population-based cohort study that aimed to evaluate the association between chronic hypoxia and suicide risk. Patients entered the cohort in their first year with a documented healthcare encounter and remained in the cohort until their death or the end of the study period. Generalized estimating equation methodology was used to assess the association between suicide and 3 risk markers of chronic hypoxia. Researchers found:

• Among the 9,620,944 patients in the cohort, there were 22,403 suicide deaths.
• There was a statistically significant progression of suicide risk as altitude rose in increments of 1,000 meters (OR: 1.22).
• There was a strong association between the number of hypoxic conditions and the odds of suicide.
• Patients with 3 markers of chronic hypoxia were nearly 4 times more likely to die by suicide than patients with no markers (OR: 3.96).