Association between telomere length with alcohol use disorder and internalizing/externalizing comorbidities in a Brazilian male sample

Background Shortening telomere length (TL) is an important ageing marker associated with substance use disorder (SUD). However, the influence of psychiatric and clinical comorbidities and alcohol-related outcomes has not been much explored in the context of TL in individuals with alcohol use disorder (AUD) and may be a source of heterogeneity in AUD studies. Therefore, our aim was to investigate the influence of AUD, alcohol-related outcomes, and common psychiatric comorbidities on TL in men with AUD and healthy controls (HC). Methods Men with AUD (n=108, mean age=52.4, SD=8.6) were recruited in a detoxification unit, and HC (n=80, mean age=50.04, SD=9.1) from the blood bank, both located in Brazil. HC had no current or lifetime diagnosis of any substance use disorder. Psychiatric comorbidities were assessed using SCID-I. TL ratio was measured in triplicates using quantitative multiplex PCR. Results Telomere length did not differ between individuals with AUD and HC (p=0.073) or was associated with AUD-related outcomes, trauma, or clinical comorbidities. Individuals with externalizing disorders had longer TL when comparing with those with internalizing disorders (p=0.018) or without comorbidity (p=0.018). Conclusion Our findings indicate that TL was influenced by the presence of psychiatric comorbidity rather than case or control status. These results were adjusted for potential confounders, such as age.