Heart Rate Variability, Deceleration Capacity of Heart Rate, and Death: A Veteran Twins Study.

BACKGROUND: Autonomic function can be measured noninvasively using heart rate variability (HRV), which indexes overall sympathovagal balance. Deceleration capacity (DC) of heart rate is a more specific metric of vagal modulation. Higher values of these measures have been associated with reduced mortality risk primarily in patients with cardiovascular disease, but their significance in community samples is less clear. METHODS AND RESULTS: This prospective twin study followed 501 members from the VET (Vietnam Era Twin) registry. At baseline, frequency domain HRV and DC were measured from 24-hour Holter ECGs. During an average 12-year follow-up, all-cause death was assessed via the National Death Index. Multivariable Cox frailty models with random effect for twin pair were used to examine the hazard ratios of death per 1-SD increase in log-transformed autonomic metrics. Both in the overall sample and comparing twins within pairs, higher values of low-frequency HRV and DC were significantly associated with lower hazards of all-cause death. In within-pair analysis, after adjusting for baseline factors, there was a 22% and 27% lower hazard of death per 1-SD increment in low-frequency HRV and DC, respectively. Higher low-frequency HRV and DC, measured during both daytime and nighttime, were associated with decreased hazard of death, but daytime measures showed numerically stronger associations. Results did not substantially vary by zygosity. CONCLUSIONS: Autonomic inflexibility, and especially vagal withdrawal, are important mechanistic pathways of general mortality risk, independent of familial and genetic factors.

Validation of the RBD Symptom Severity Scale in the North American Prodromal Synucleinopathy Consortium.

BACKGROUND AND OBJECTIVES: REM sleep behavior disorder (RBD) is a parasomnia characterized by dream enactment. The International RBD Study Group developed the RBD Symptom Severity Scale (RBDSSS) to assess symptom severity for clinical or research use. We assessed the psychometric and clinimetric properties of the RBDSSS in participants enrolled in the North American Prodromal Synucleinopathy (NAPS) Consortium for RBD. METHODS: NAPS participants, who have polysomnogram-confirmed RBD, and their bedpartners completed the RBDSSS (participant and bedpartner versions). The RBDSSS contains 8 questions to assess the frequency and severity/impact of (1) dream content, (2) vocalizations, (3) movements, and (4) injuries associated with RBD. Total scores for participant (maximum score = 54) and bedpartner (maximum score = 38) questionnaires were derived by multiplying frequency and severity scores for each question. The Clinical Global Impression Scale of Severity (CGI-S) and RBD symptom frequency were assessed by a physician during a semistructured clinical interview with participants and, if available, bedpartners. Descriptive analyses, correlations between overall scores, and subitems were assessed, and item response analysis was performed to determine the scale's validity. RESULTS: Among 261 study participants, the median (interquartile range) score for the RBDSSS-PT (participant) was 10 (4-18) and that for the RBDSSS-BP (bedpartner) was 8 (4-15). The median CGI-S was 3 (3-4), indicating moderate severity. RBDSSS-BP scores were significantly lower in women with RBD (6 vs 9, p = 0.02), while there were no sex differences in RBDSSS-PT scores (8 vs 10.5, p = 0.615). Positive correlations were found between RBDSSS-PT vs RBDSSS-BP (Spearman rs = 0.561), RBDSSS-PT vs CGI-S (rs = 0.556), and RBDSSS-BP vs CGI-S (rs = 0.491, all p < 0.0001). Item response analysis showed a high discriminatory value (range 1.40-2.12) for the RBDSSS-PT and RBDSSS-BP (1.29-3.47). DISCUSSION: We describe the RBDSSS with adequate psychometric and clinimetric properties to quantify RBD symptom severity and good concordance between participant and bedpartner questionnaires and between RBDSSS scores and clinician-assessed global severity.

Comorbid neurotrauma increases neurodegenerative-relevant cognitive, motor, and autonomic dysfunction in patients with REM sleep behavior disorder: A substudy of the North American Prodromal Synucleinopathy Consortium.

STUDY OBJECTIVES: Rapid eye movement (REM) sleep behavior disorder (RBD) is strongly associated with phenoconversion to an overt synucleinopathy, e.g., Parkinson's disease (PD), Lewy Body Dementia (LBD), and related disorders. Comorbid traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD) - henceforth "neurotrauma" (NT) - increase the odds of RBD by ~2.5-fold and is associated with an increased rate of service-connected PD in Veterans. Thus, RBD and NT are both independently associated with PD; however, it is unclear how NT influences neurological function in patients with RBD. METHODS: Participants ≥18 years with overnight-polysomnogram-confirmed RBD were enrolled between 8/2018 to 4/2021 through the North American Prodromal Synucleinopathy (NAPS) Consortium. Standardized assessments for RBD, TBI, and PTSD history, as well as cognitive, motor, sensory and autonomic function were completed. This cross-sectional analysis compared cases (n=24; RBD+NT) to controls (n=96; RBD), matched for age (~60 years), sex (15% female), and years of education (~15 years). RESULTS: RBD+NT reported earlier RBD symptom onset (37.5±11.9 vs. 52.2±15.1 years of age) and a more severe RBD phenotype. Similarly, RBD+NT reported more severe anxiety and depression, greater frequency of hypertension, and significantly worse cognitive, motor, and autonomic function compared to RBD. No differences in olfaction or color vision were observed. CONCLUSION: This cross-sectional, matched case:control study shows individuals with RBD+NT have significantly worse neurological measures related to common features of an overt synucleinopathy. Confirmatory longitudinal studies are ongoing; however, these results suggest RBD+NT may be associated with more advanced neurological symptoms related to an evolving neurodegenerative process.

Hypoglossal Nerve Stimulation and Cardiovascular Outcomes for Patients With Obstructive Sleep Apnea: A Randomized Clinical Trial.

Importance: Sham-controlled trials are needed to characterize the effect of hypoglossal nerve stimulation (HGNS) therapy on cardiovascular end points in patients with moderate-severe obstructive sleep apnea (OSA). Objective: To determine the effect of therapeutic levels of HGNS, compared to sham levels, on blood pressure, sympathetic activity, and vascular function. Design, Setting, and Participants: This double-blind, sham-controlled, randomized crossover therapy trial was conducted from 2018 to 2022 at 3 separate academic medical centers. Adult patients with OSA who already had an HGNS device implanted and were adherent and clinically optimized to HGNS therapy were included. Participants who had fallen asleep while driving within 1 year prior to HGNS implantation were excluded from the trial. Data analysis was performed from January to September 2022. Interventions: Participants underwent a 4-week period of active HGNS therapy and a 4-week period of sham HGNS therapy in a randomized order. Each 4-week period concluded with collection of 24-hour ambulatory blood pressure monitoring (ABPM), pre-ejection period (PEP), and flow-mediated dilation (FMD) values. Main Outcomes and Measures: The change in mean 24-hour systolic blood pressure was the primary outcome, with other ABPM end points exploratory, and PEP and FMD were cosecondary end points. Results: Participants (n = 60) were older (mean [SD] age, 67.3 [9.9] years), overweight (mean [SD] body mass index, calculated as weight in kilograms divided by height in meters squared, 28.7 [4.6]), predominantly male (38 [63%]), and had severe OSA at baseline (mean [SD] apnea-hypopnea index, 33.1 [14.9] events/h). There were no differences observed between active and sham therapy in 24-hour systolic blood pressure (mean change on active therapy, -0.18 [95% CI, -2.21 to 1.84] mm Hg), PEP (mean change on active therapy, 0.11 [95% CI, -5.43 to 5.66] milliseconds), or FMD (mean change on active therapy, -0.17% [95% CI, -1.88% to 1.54%]). Larger differences between active and sham therapy were observed in a per-protocol analysis set (n = 20) defined as experiencing at least a 50% reduction in apnea-hypopnea index between sham and active treatment. Conclusions and Relevance: In this sham-controlled HGNS randomized clinical trial, mean 24-hour systolic blood pressure and other cardiovascular measures were not significantly different between sham and active HGNS therapy. Several methodologic lessons can be gleaned to inform future HGNS randomized clinical trials. Trial Registration: ClinicalTrials.gov Identifier: NCT03359096.

Contemporary diagnostic visual and automated polysomnographic REM sleep without atonia thresholds in isolated REM sleep behavior disorder.

STUDY OBJECTIVES: Accurate diagnosis of isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is crucial due to its injury potential and neurological prognosis. We aimed to analyze visual and automated REM sleep without atonia (RSWA) diagnostic thresholds applicable in varying clinical presentations in a contemporary cohort of patients with iRBD using submentalis (SM) and individual bilateral flexor digitorum superficialis (FDS) and anterior tibialis electromyography limb recordings during polysomnography. METHODS: We analyzed RSWA in 20 patients with iRBD and 20 age-, REM-, apnea-hypopnea index-matched controls between 2017 and 2022 for phasic burst durations, density of phasic, tonic, and "any" muscle activity (number of 3-second mini-epochs containing phasic or tonic muscle activity divided by the total number of REM sleep 3-second mini-epochs), and automated Ferri REM atonia index (RAI). Group RSWA metrics were comparatively analyzed. Receiver operating characteristic curves determined optimized area under the curve (AUC) and maximized specificity and sensitivity diagnostic iRBD RSWA thresholds. RESULTS: All mean RSWA metrics were higher in patients with iRBD than in controls (P < .05), except for selected anterior tibialis measures. Optimized, maximal specificity AUC diagnostic cutoffs for coprimary outcomes were: SM "any" 6.5%, 14.0% (AUC = 92.5%) and combined SM+FDS "any" 15.1%, 27.4% (AUC = 95.8%), while SM burst durations were 0.72, and 0.72 seconds (AUC 90.2%) and FDS RAI = 0.930, 0.888 (AUC 92.8%). CONCLUSIONS: This study provides evidence for current quantitative RSWA diagnostic thresholds in chin and individual 4 limb muscles applicable in different iRBD clinical settings and confirms the key value of SM or SM+FDS to assure accurate iRBD diagnosis. Evolving iRBD recognition underscores the necessity of continuous assessment with future large, prospective, well-harmonized, multicenter polysomnographic analyses. CITATION: Leclair-Visonneau L, Feemster JC, Bibi N, et al. Contemporary diagnostic visual and automated polysomnographic REM sleep without atonia thresholds in isolated REM sleep behavior disorder. J Clin Sleep Med. 2024;20(2):279-291.

The Effect of Tele-Savvy on Sleep Quality and Insomnia in Caregivers of Persons Living with Dementia.

Introduction: Sleep disturbance is prevalent in caregivers of persons living with dementia (PLwD). Tele-Savvy, a 7-week virtual psychoeducational intervention, enhances caregivers' competence and self-care, and reduces depression. While not explicitly designed to do so, Tele-Savvy can potentially improve caregivers' disturbed sleep. The present study aimed to examine the longitudinal effects of Tele-Savvy on caregivers' sleep quality and insomnia. Methods: This was a secondary data analysis of a 3-arm randomized control trial [Tele-Savvy (active treatment), Healthy Living (attention control), and usual care (waitlist control)]. Multilevel mixed modeling with intent-to-treat principles tested for group, time, and group-by-time effects. Effect sizes were estimated for all changes from baseline to the initial 6-month post-intervention point. Following completion of the 6-month post-randomization delay, we examined combined outcomes for Tele-Savvy. Results: Participants (n=137; mean age 64.7 years) were predominantly female (68.6%) and White (68.6%). We found no initial group-by-time effects for the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI). For the combined Tele-Savvy group, there was a statistically significant improvement in ISI scores across time (p=0.050). The combined Tele-Savvy effect size for PSQI was d=0.126 and ISI was d=0.310. Discussion: Tele-Savvy resulted in a significant long-term reduction in insomnia symptoms in this sample of caregivers of PLwD and demonstrated a positive trend for improvement in their sleep quality. Since sleep disturbance is so prevalent among caregivers of PLwD, the inclusion of sleep health education into psychoeducation caregiver interventions may yield even better outcomes for caregivers.

From nocturnal awakenings to nocturnal voiding: the relationship between insomnia and nocturia - a systematic review.

INTRODUCTION: The aim of this study was to systematically evaluate relevant literature regarding 1) the prevalence of nocturia in patients with insomnia; 2) sleep characteristics of insomniacs with and without nocturia; 3) interventions for the treatment of insomnia and their effect on nocturia. EVIDENCE ACQUISITION: A systematic review of literature was performed through EMBASE, MEDLINE, CLINICALTRIALS.GOV and CENTRAL databases up until November 2022 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. From the identified reports, 11 studies were retained, of which 7 were eligible for meta-analysis. Bias assessment was performed using the ROBINS tools as per the Cochrane collaboration guidelines. EVIDENCE SYNTHESIS: A total of 5396 older adults were included in the meta-analysis. The pooled estimate of the OR was 1.958 (95% CI: 1.609-2.384) for nocturia in patients with insomnia based on 7 studies in a random effects model with nonsignificant heterogeneity (I2=50.83%, P=0.06). Wake after sleep onset (WASO) was longer in people with insomnia and nocturia compared to those without and sleep efficiency (SE) declined. Interventions with melatonin, diet and behavioral therapy were beneficial on nocturia frequency in insomniacs. A limiting factor of our analysis was the scarcity of available data, potentially causing an important selection bias. CONCLUSIONS: The overall odds for nocturia in older adults is higher in patients with insomnia than those without and is associated with worse sleep outcomes. Interventions for treating insomnia such as melatonin, behavioral therapy and diet show beneficial results on nocturnal voiding frequency. We advocate for further research in which uniform definitions and questionnaires are used. Routine screening for nocturia in patients with insomnia could be beneficial to maximize sleep quality improvement.

Frequency of Orthostatic Hypotension in Isolated REM Sleep Behavior Disorder.

BACKGROUND AND OBJECTIVES: Although orthostatic hypotension (OH) can be an early feature of autonomic dysfunction in isolated REM sleep behavior disorder (iRBD), no large-scale studies have examined the frequency of OH in iRBD. In this study, we prospectively evaluated the frequency of OH in a large multicenter iRBD cohort. METHODS: Participants 18 years or older with video polysomnogram-confirmed iRBD were enrolled through the North American Prodromal Synucleinopathy consortium. All participants underwent 3-minute orthostatic stand testing to assess the frequency of OH, and a Δ heart rate/Δ systolic blood pressure (ΔHR/ΔSBP) ratio <0.5 was used to define reduced HR augmentation, suggestive of neurogenic OH. All participants completed a battery of assessments, including the Scales for Outcomes in Parkinson Disease-Autonomic Dysfunction (SCOPA-AUT) and others assessing cognitive, motor, psychiatric, and sensory domains. RESULTS: Of 340 iRBD participants (65 ± 10 years, 82% male), 93 (27%) met criteria for OH (ΔHR/ΔSBP 0.37 ± 0.28; range 0.0-1.57), and of these, 72 (77%) met criteria for OH with reduced HR augmentation (ΔHR/ΔSBP 0.28 ± 0.21; range 0.0-0.5). Supine hypertension (sHTN) was present in 72% of those with OH. Compared with iRBD participants without OH, those with OH were older, reported older age of RBD symptom onset, and had worse olfaction. There was no difference in autonomic symptom scores as measured by SCOPA-AUT. DISCUSSION: OH and sHTN are common in iRBD. However, as patients may have reduced autonomic symptom awareness, orthostatic stand testing should be considered in clinical evaluations. Longitudinal studies are needed to clarify the relationship between OH and phenoconversion risk in iRBD. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov: NCT03623672; North American Prodromal Synucleinopathy Consortium.

Simultaneous Recording of Objective Sleep in Mothers and School-aged Children with Developmental Disabilities: A Pilot Study of Actigraphy and Videosomnography.

Mothers of school-aged children ages 3 to 17 years with developmental disabilities (DDs) commonly report sleep problems in their children associated with impaired maternal sleep. However, existing research relies heavily on mothers' self-reported sleep. This study aimed to determine the feasibility of objectively measuring child and mother sleep-wake patterns using actigraphy and videosomnography. This was an observational pilot study. Mothers wore actigraphy watches and video-recorded their child's sleep for 7 nights. Mothers also completed a 7-day sleep diary and questionnaires on sleep quality, depressive symptoms, stress, and child sleep problems. Ten mothers (32-49 years) and ten children with DDs (8-12 years) completed this study. Half of the children were boys with autism spectrum disorders. We successfully recruited 77% of eligible mothers for the study during the pandemic. Eight mothers successfully wore the actigraphy, and nine successfully video-recorded their child's sleep. Mothers rated their participation positively and considered the data collection protocol acceptable. While mothers' sleep patterns from actigraphy were mostly within recommendations, self-reported sleep quality was poor. Child's sleep estimates from videosomnography showed children slept substantially less than recommended sleep hours. Mothers also reported a high frequency of child sleep problems. Consistent with this pattern, mothers also endorsed elevated stress and depression. The use of actigraphy and videosomnography is feasible. Objective sleep measurement for mothers' and children's sleep is needed with self-report to measure multidimensional aspects of sleep and discrepancies between objective and self-report sleep measures. Future studies can use multi-methods sleep measures and work toward interventions that can improve family sleep and reduce mothers' stress and depression.

Racial/ethnic differences in the beneficial effect of social support on sleep duration.

STUDY OBJECTIVES: Social support (SS) is associated with better health outcomes, including sleep health. However, the specific sources of SS that benefit sleep are unclear, and whether these associations vary by race/ethnicity or age is unknown. The aim of this study was to examine cross-sectional associations between sources of SS (number of friends, financial, church attendance, and emotional support) and self-reported short sleep duration (< 7 hours) overall and by race/ethnic groups and age among a representative sample. METHODS: Using National Health and Nutrition Examination Survey (NHANES) data, logistic regression (marginal standardization) and linear regression models were fit accounting for survey design and weights to test associations between sources of SS (number of friends, financial, church attendance, emotional support) and self-reported short sleep duration (< 7 hours) overall and by race/ethnic groups (Black, Hispanic, and White) and age (< 65 vs ≥ 65 years). RESULTS: Among 3,711 participants, the mean (standard error) age was 57 (0.3) years and 37% slept < 7 hours. Black adults had the highest prevalence of short sleep (55%). Overall, participants with financial support compared with those without financial support had a lower prevalence of short sleep: 23% (confidence interval [CI]: 0.68, 0.87). As the number of SS sources increased, the prevalence of short sleep duration decreased and the racial disparity in sleep duration narrowed. Associations between financial support and sleep were most pronounced among Hispanic and White adults and adults < 65 years. CONCLUSIONS: In general, financial support was associated with a healthier sleep duration, particularly among those < 65 years of age. Individuals with numerous sources of SS were less likely to be short sleepers. The benefits of SS on sleep duration varied by race. Targeting specific sources of SS may help to improve sleep duration among those most at risk. CITATION: Johnson DA, Prakash-Asrani R, Lewis BD, Bliwise DL, Lewis TT. Racial/ethnic differences in the beneficial effect of social support on sleep duration. J Clin Sleep Med. 2023;19(7):1231-1238.

Baseline characteristics of the North American prodromal Synucleinopathy cohort.

OBJECTIVE: Rapid eye movement (REM) sleep behavior disorder (RBD) is widely considered a prodromal synucleinopathy, as most with RBD develop overt synucleinopathy within ~10 years. Accordingly, RBD offers an opportunity to test potential treatments at the earliest stages of synucleinopathy. The North American Prodromal Synucleinopathy (NAPS) Consortium has created a multisite RBD participant, primarily clinic-based cohort to better understand characteristics at diagnosis, and in future work, identify predictors of phenoconversion, develop synucleinopathy biomarkers, and enable early stage clinical trial enrollment. METHODS: Participants ≥18 years of age with overnight polysomnogram-confirmed RBD without Parkinson's disease, dementia, multiple system atrophy, or narcolepsy were enrolled from nine sites across North America (8/2018 to 4/2021). Data collection included family/personal history of RBD and standardized assessments of cognitive, motor, sensory, and autonomic function. RESULTS: Outcomes are primarily reported based on sex (361 total: n = 295 male, n = 66 female), and secondarily based on history of antidepressant use (n = 200 with, n = 154 without; with correction for sex differences) and based on extent of synucleinopathy burden (n = 56 defined as isolated RBD, n = 305 defined as RBD+ [i.e., exhibiting ≥1 abnormality]). Overall, these participants commonly demonstrated abnormalities in global cognition (MoCA; 38%), motor function (alternate tap test; 48%), sensory (BSIT; 57%), autonomic function (orthostatic hypotension, 38.8%), and anxiety/depression (BAI and PHQ-9; 39.3% and 31%, respectively). INTERPRETATION: These RBD participants, assessed with extensive history, demographic, cognitive, motor, sensory, and autonomic function demonstrated a lack of sex differences and high frequency of concomitant neurological abnormalities. These participants will be valuable for future longitudinal study and neuroprotective clinical trials.

Sleep Disorders, Comorbidities, Actions, Lower Urinary Tract Dysfunction, and Medications ("Sleep C.A.L.M.") in the evaluation and management of nocturia: A simple approach to a complex diagnosis.

INTRODUCTION: Nocturia arises from a fundamental mismatch between nocturnal urine production, storage capacity, and sleep architecture, which may be driven by abnormalities of the genitourinary tract, but also by sleep disorders, medical diseases, patient actions/lifestyle factors, or medications. This article introduces a novel system for organizing the complex differential diagnosis for nocturia, as proposed by an international collective of practicing urologists, physician specialists, and sleep experts: "Sleep CALM"-Sleep Disorders, Comorbidities, Actions, Lower Urinary Tract Dysfunction, and Medications. METHODS: Narrative review of current evidence regarding the relevance of each "Sleep CALM" factor to nocturia pathogenesis, evaluation, and management. RESULTS: Nocturia and sleep disorders are highly intertwined and often bidirectional, such that nocturnal awakenings for reasons other than a sensation of bladder fullness should not be used as grounds for exclusion from nocturia treatment, but rather leveraged to broaden therapeutic options for nocturia. Nocturia is an important potential harbinger of several serious medical conditions beyond the genitourinary tract. Urologists should have a low threshold for primary care and medical specialty referral for medical optimization, which carries the potential to significantly improve nocturnal voiding frequency in addition to overall health status. Adverse patient actions/lifestyle factors, lower urinary tract dysfunction, and medication use commonly coexist with disordered sleep and comorbid medical conditions, and may be the primary mediators of nocturia severity and treatment response, or further exacerbate nocturia severity and complicate treatment. CONCLUSION: "Sleep CALM" provides a memorable and clinically relevant means by which to structure the initial patient history, physical exam, and clinical testing in accordance with current best-practice guidelines for nocturia. Although not intended as an all-encompassing diagnostic tool, the "Sleep CALM" schema may also be useful in guiding individualized ancillary testing, identifying the need for specialty referral and multidisciplinary care, and uncovering first-line treatment targets.

Comparison of polysomnography in people with Alzheimer's disease and insomnia versus non-demented elderly people with insomnia.

BACKGROUND: We used baseline polysomnography (PSG) data obtained during the clinical program development for suvorexant to compare the PSG profiles of people with Alzheimer's disease and insomnia (ADI) versus age-matched elderly individuals with insomnia (EI). METHODS: Sleep laboratory baseline PSG data from participants age 55-80 years from 2 trials in people with insomnia and a trial in people with ADI were included. ADI participants had dementia of mild-to-moderate severity. Diagnostic criteria for insomnia, exclusion for other sleep problems, PSG recording procedures, and endpoint derivations were similar across the trials. All participants underwent a night of in-laboratory PSG prior to the baseline night to allow for screening/adaptation. Participants in the EI and ADI groups were compared with regard to sleep architecture, sleep micro-structure, and quantitative EEG power spectral endpoints. The analysis was performed on a post hoc basis using propensity score matching to compare sleep parameters separately in women and men while accounting for age group and total sleep time. RESULTS: A total of 837 EI and 239 ADI participants were included, with the majority in each population (∼65%) being women. Compared to EI, those with ADI had a lower percentage of time spent in slow wave sleep (and a corresponding higher percentage of time spent in the lighter N1 sleep), a lower number of spindles per minute of N2 sleep, and lower absolute EEG power during NREM sleep, particularly in the lower-frequency bands. Trends for lower REM sleep percentage in ADI did not reach statistical significance. CONCLUSIONS: Our findings in this large data set, in which the influence of sleep problems was effectively subtracted out (since both groups had insomnia), provide strong confirmatory support of results from previous smaller studies in indicating that AD of mild-to-moderate severity is associated with less slow wave sleep, spindles, and lower-frequency EEG power. TRIAL REGISTRATION: ClinicalTrials.gov, numbers NCT01097616, NCT01097629, NCT02750306.