Tryptophan-kynurenine metabolic pathway and daytime dysfunction in women with HIV.

Sleep disturbances are prevalent in women with HIV (WWH). Tryptophan-kynurenine (T-K) pathway metabolites are associated with alterations in actigraphy derived sleep measures in WWH, although may not always correlate with functional impairment. We investigated the relationship between T-K pathway metabolites and self-reported daytime dysfunction in WWH and women without HIV (WWoH). 141 WWH on stable antiretroviral therapy and 140 demographically similar WWoH enrolled in the IDOze Study had targeted plasma T-K metabolites measured using liquid chromatography-tandem mass spectrometry. We utilized the daytime dysfunction component of the Pittsburgh Sleep Quality Index (PSQI) to assess functional impairment across HIV-serostatus. Lower levels of 5-hydroxytryptophan and serotonin were associated with greater daytime dysfunction in all women. In WWH, daytime dysfunction was associated with increased kynurenic acid (R = 0.26, p < 0.05), and kynurenic acid-tryptophan (KA-T) ratio (R = 0.28, p < 0.01). WWH with daytime dysfunction had a 0.7 log fold increase in kynurenic acid compared to WWH without daytime dysfunction. Kynurenic acid levels and the KA-T ratio were associated with daytime dysfunction in WWH but not in WWoH. Longitudinal studies are needed to establish a causal relationship and directionality between T-K metabolic changes and sleep impairment in WWH.

Overnight urinary melatonin levels in women with and without HIV: An observational cohort study.

INTRODUCTION: Despite significant improvements in longevity and quality of life associated with antiretroviral therapy, individuals with HIV still suffer from a higher burden of sleep and circadian disruption and inflammatory-based diseases than individuals without HIV. While melatonin is a hormone that has a role in sleep and circadian regulation and has anti-inflammatory properties, the overnight concentration of the urinary melatonin metabolite has not yet been reported in people with HIV. METHODS: The aim of this study was to compare the overnight urinary melatonin metabolite levels in women aged 35-70 years with HIV (n = 151) to a well-matched comparison group of women without HIV (n = 147). All women wore a wrist actigraphy monitor and completed daily diaries documenting sleep timing and use of medications and drugs or alcohol for 10 days. Participants collected their overnight urine near the end of the monitoring period. RESULTS: Melatonin levels did not differ between women with or without HIV, but more than 40% of women had low levels of melatonin. Higher body mass index predicted lower levels of melatonin, and lower levels of melatonin were associated with lower sleep efficiency as assessed with wrist actigraphy. CONCLUSION: These data lay the foundation for exploration of the longitudinal consequences of endogenous melatonin levels for inflammatory-based diseases in aging women with and without HIV. Future studies should consider the use of supplemental melatonin to improve sleep in women with lower levels of melatonin.

The IDOze Study: The Link Between Sleep Disruption and Tryptophan-Kynurenine Pathway Activation in Women With Human Immunodeficiency Virus.

BACKGROUND: Poor sleep is associated with human immunodeficiency virus (HIV), particularly among women with HIV (WWH), although mechanisms are unclear. We explored cross-sectional associations between sleep disruption and tryptophan-kynurenine (T/K) pathway activation, measured by the kynurenine-to-tryptophan ratio (K:T). METHODS: HIV-uninfected women (HIV-) and WWH aged 35-70 years and on stable antiretroviral therapy were included. Sleep metrics were measured using wrist actigraphy. Plasma T/K pathway metabolites were measured using liquid chromatography-tandem mass spectrometry. Multivariate linear regression models examined relationships between K:T and actigraphy-based sleep metrics by HIV status. RESULTS: WWH (n = 153) and HIV- women (n = 151) were demographically similar. Among WWH, median CD4 was 751 cells/µL; 92% had undetectable HIV RNA. Compared to HIV- women, WWH had higher K:T (P < .001) and kynurenine (P = .01) levels but similar tryptophan levels (P = .25). Higher K:T was associated with more wake bouts (P = .001), more time awake after sleep onset (P = .01), and lower sleep efficiency (P = .03) in WWH only. CONCLUSIONS: HIV infection was associated with T/K pathway activation; this activation was associated with poorer sleep efficiency and more fragmented sleep. While longitudinal studies are needed to elucidate the directionality of these associations, these findings may help identify treatments to reduce sleep disruption in WWH by targeting residual inflammation and T/K pathway activation.