News in Brief
Authors: Jack Williamson
Journal: The Lancet Healthy Longevity (2021)

Most commonly affecting older adults, tinnitus that interferes with daily life (bothersome tinnitus) is associated with decreased sleep, concentration, and mood in approximately 20% of patients. In a longitudinal cohort study of 5418 patients (mean age 69 years, 3131 [58%] women) with either non-bothersome tinnitus (1063 [20%] patients), bothersome tinnitus (110 [2%] patients), or without tinnitus (4245 [78%]), Berthe C Oosterloo (University Medical Center, Rotterdam, Netherlands) and colleagues used home interviews to assess tinnitus severity, depressive symptoms, anxiety symptoms, and sleep outcomes. Over a mean follow-up of 4·4 years, patients with bothersome tinnitus reported higher levels of depression (difference 0·20; 95% CI 0·11–0·28), anxiety (0·15; 0·08–0·22), and poorer sleep (0·10; 0·03–0·16) than patients with non-bothersome tinnitus and patients without tinnitus. Although a weaker association than this main finding, patients with non-bothersome tinnitus also had worse outcomes for depression (0·06; 0·03–0·09), anxiety (0·05; 0·02–0·07), and sleep (0·05; 0·03–0·08) compared with patients without tinnitus. Unexpectedly, the study also found that patients with tinnitus without hearing loss had a higher likelihood of clinically relevant mental health problems than patients with tinnitus who have hearing loss, suggesting an association between tinnitus and psychopathology. Unfortunately, due to limited power, the temporality of tinnitus to mental health was not able to be established. However, this study is the first to provide longitudinal data on tinnitus and mental health, opening new possibilities for vital investigations into tinnitus and mental health. Many age-related neurological and psychiatric disorders are characterised by myelin sheath loss and resulting damage to axonal function and integrity. In the healthy CNS, this damage is counteracted by the formation of new myelin by adult oligodendrocyte progenitor cells (aOPCs). With ageing or in disease states, this process becomes less efficient. Using DNA hydroxymethylation and transcriptomic analyses in mice, Sarah Moyon (Neuroscience Initiative Advanced Science Research Center, City University of New York, NY, USA) and colleagues explored the role of the ten-eleven-translocation (TET) enzymes, which are involved in DNA hydroxymethylation, on the ability of aOPCs to form functional new myelin after damage. Their study identified TET1 as having a major role in the expression of genes that are integral to myelin repair. Together, their findings follow on from previous studies from the same group, which showed that ablation of the DNA methyltransferases (responsible for DNA methylation) in oligodendroglial cells led to only a small effect on myelin repair, and identifies TET-mediated DNA hydroxymethylation as an epigenetic mark predictive of successful myelin repair. As the TET enzymes have previously been shown to be significantly downregulated in post-mortem brain tissue of patients with multiple sclerosis (a disease characterised by immune-mediated demyelination), Moyon and colleagues' study provides important early research for future investigations into the potential development of novel therapies targeting defective remyelination. The preference of some centres to allocate scarce heart transplants (HTs) to younger patients, as well as latent concerns that HTs might be less successful in older patients, has meant that older patients with end-stage cardiomyopathy are offered HTs less frequently or are excluded from receiving HTs altogether. However, long-term studies on the clinical outcomes of HTs in older patients with end-stage cardiomyopathy have not yet been done. In a retrospective cohort analysis of 57 285 patients (age range 18–79 years) who were listed for HT, Abhishek Jaiswal (Hartford Healthcare Heart and Vascular Institute, Hartford, CT, USA) and colleagues compared waitlist mortality and post-transplant survival after 1 year and 5 years in patients who were aged between 18 and 69 years (56 082 [97·9%] patients) and patients who were ≥70 years (1203 [2·1%] patients). Their study showed that there was no significant difference (hazard ratio [HR] 1·06, 95% CI 0·91–1·25; p=0·43) in 5-year mortality in patients who were aged 70 years or older compared with younger patients, even after adjusting for relevant recipient and donor covariates (eg, listing statuses, race, heart failure pathogenesis, and relevant medical history). Moreover, patients who were aged 70 years or older had a similar risk of death while on the HT waitlist compared with younger patients (sub-HR 0·86, 95% CI 0·68–1·08; p=0·19). Despite the low number of older patients included, taken together, these results show that age should not be considered a contraindication for HT. However, the authors recommend that careful patient selection criteria should be applied.