Development of a Sham Protocol to Investigate Transcutaneous Tibial Nerve Stimulation in Randomised, Sham-Controlled, Double-Blind Clinical Trials.

Transcutaneous tibial nerve stimulation (TTNS) is a promising treatment for neurogenic lower urinary tract symptoms. However, the evidence is limited due to a general lack of randomised controlled trials (RCTs) and, also, inconsistency in the sham and blinding conditions. In the context of much-needed RCTs, we aimed to develop a suitable sham-control protocol for a clinical setting to maintain blinding but avoid meaningful stimulation of the tibial nerve. Three potential electrode positions (lateral malleolus/5th metatarsal/plantar calcaneus) and two electrode sizes (diameter: 2.5 cm/3.2 cm) were tested to determine which combination provided the optimal sham configuration for a TTNS approach, based on a visible motor response. Sixteen healthy volunteers underwent sensory and motor assessments for each sham configuration. Eight out of them came back for an extra TTNS visit. Sensory thresholds were present for all sham configurations, with linear regression models revealing a significant effect regarding electrode position (highest at plantar calcaneus) but not size. In addition, motor thresholds varied with the position-lowest for the 5th metatarsal. Only using this position and 3.2 cm electrodes attained a 100% response rate. Compared to TTNS, sensory and motor thresholds were generally higher for the sham configurations; meanwhile, perceived pain was only higher at the lateral malleolus. In conclusion, using the 5th metatarsal position and 3.2 cm electrodes proved to be the most suitable sham configuration. Implemented as a four-electrode setup with standardized procedures, this appears to be a suitable RCT protocol for maintaining blinding and controlling for nonspecific TTNS effects in a clinical setting.

bTUNED: transcutaneous tibial nerve stimulation for neurogenic lower urinary tract dysfunction.

OBJECTIVE: To present the protocol for a randomized controlled trial (RCT) evaluating the efficacy and safety of transcutaneous tibial nerve stimulation (TTNS) for refractory neurogenic lower urinary tract dysfunction (NLUTD). STUDY DESIGN AND RESULTS: bTUNED (bladder and TranscUtaneous tibial Nerve stimulation for nEurogenic lower urinary tract Dysfunction) is an international multicentre, sham-controlled, double-blind RCT investigating the efficacy and safety of TTNS. The primary outcome is success of TTNS, defined as improvements in key bladder diary variables at study end compared to baseline values. The focus of the treatment is defined by the Self-Assessment Goal Achievement (SAGA) questionnaire. Secondary outcomes are the effect of TTNS on urodynamic, neurophysiological, and bowel function outcome measures, as well as the safety of TTNS. CONCLUSIONS: A total of 240 patients with refractory NLUTD will be included and randomized 1:1 into the verum or sham TTNS group from March 2020 until August 2026. TTNS will be performed twice a week for 30 min during 6 weeks. The patients will attend baseline assessments, 12 treatment visits and follow-up assessments at the study end.

Lower urinary tract electrical sensory assessment: a systematic review and meta-analysis.

OBJECTIVES: To summarize the current literature on lower urinary tract electrical sensory assessment (LUTESA), with regard to current perception thresholds (CPTs) and sensory evoked potentials (SEPs), and to discuss the applied methods in terms of technical aspects, confounding factors, and potential for lower urinary tract (LUT) diagnostics. METHODS: The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Medline (PubMed), Embase and Scopus were searched on 13 October 2020. Meta-analyses were performed and methodological qualities of the included studies were defined by assessing risk of bias (RoB) as well as confounding. RESULTS: After screening 9925 articles, 80 studies (five randomized controlled trials [RCTs] and 75 non-RCTs) were included, comprising a total of 3732 patients and 692 healthy subjects (HS). Of these studies, 61 investigated CPTs exclusively and 19 reported on SEPs, with or without corresponding CPTs. The recording of LUTCPTs and SEPs was shown to represent a safe and reliable assessment of LUT afferent nerve function in HS and patients. LUTESA demonstrated significant differences in LUT sensitivity between HS and neurological patients, as well as after interventions such as pelvic surgery or drug treatments. Pooled analyses showed that several stimulation variables (e.g. stimulation frequency, location) as well as patient characteristics might affect the main outcome measures of LUTESA (CPTs, SEP latencies, peak-to-peak amplitudes, responder rate). RoB and confounding was high in most studies. CONCLUSIONS: Preliminary data show that CPT and SEP recordings are valuable tools to more objectively assess LUT afferent nerve function. LUTESA complements already established diagnostics such as urodynamics, allowing a more comprehensive patient evaluation. The high RoB and confounding rate was related to inconsistency and inaccuracy in reporting rather than the technique itself. LUTESA standardization and well-designed RCTs are crucial to implement LUTESA as a clinical assessment tool.

Sacral Neuromodulation for Neurogenic Lower Urinary Tract Dysfunction.

BACKGROUND: Neurogenic lower urinary tract dysfunction (NLUTD) is a highly prevalent and disabling condition; nevertheless, standard treatments often remain unsatisfactory. Sacral neuromodulation (SNM) is a well-established therapy for non-NLUTD, but there is a lack of randomized controlled trials to show benefit in patients with NLUTD. METHODS: For this sham-controlled, double-blind, multicenter trial, patients with refractory NLUTD (and intended SNM) were recruited at four Swiss SNM referral centers. After lead placement into the sacral foramina S3 (rarely, S4), all participants underwent SNM testing. If successful (≥50% improvement in key bladder diary variables), the neurostimulator was implanted for permanent stimulation. For 2 months, neuromodulation was optimized using subsensory stimulation with individually adjusted parameters. Thereafter, the neurostimulator remained on or was switched off (1:1 random allocation to group SNM ON or SNM OFF, respectively) for 2 months, followed by a neurourologic reevaluation. The primary outcome was success, as defined above, of SNM compared with baseline. RESULTS: Of 124 patients undergoing SNM testing, 65 (52%) had successfully improved lower urinary tract function. Of these, 60 patients (median age, 49.5 years; 43 women) were randomly assigned to the intervention. After 2 months of intervention, the SNM ON group demonstrated a success rate of 76%. In the SNM OFF group, 42% of patients showed sustained SNM effects despite their neurostimulator being switched off during the last 2 months (odds ratio, 4.35; 95% confidence interval, 1.43 to 13.21; P=0.009). During the entire study period, there were 11 adverse events (6 dropouts; no dropouts during the intervention phase). CONCLUSIONS: SNM effectively corrected refractory NLUTD in the short term in well-selected neurologic patients. (Funded by the Swiss National Science Foundation, Vontobel­Stiftung, Gottfried und Julia Bangerter­Rhyner Stiftung, Dr. Urs Mühlebach, and the Swiss Continence Foundation; ClinicalTrials.gov number, NCT02165774.)

Optimizing clinical trial design using prospective cohort study data: a case study in neuro-urology.

STUDY DESIGN: Simulations using data from a prospective cohort study. OBJECTIVES: To illustrate how prospective cohort data can be employed in randomized controlled trial (RCT) planning to assess feasibility and operational challenges, using TASCI (Transcutaneous tibial nerve stimulation in patients with Acute Spinal Cord Injury to prevent neurogenic detrusor overactivity: a nationwide randomized, sham-controlled, double-blind clinical trial) as a case study. SETTING: Spinal cord injury (SCI) rehabilitation centers in Switzerland. METHODS: TASCI is nested in the multicenter Swiss Spinal Cord Injury Cohort Study (SwiSCI), which prospectively includes patients with acute SCI. In simulations, data from 640 patients, collected by SwiSCI, were used to investigate different scenarios of patient eligibility and study consent, as well as the performance of the randomization list. Descriptive analysis was used to describe the population of interest and the simulation results; multivariable logistic regression analysis was performed to identify predictors of discharge within the TASCI intervention time period. RESULTS: The recruitment target of 114 patients is obtainable within the originally envisioned 3-year time period under the most favorable recruitment scenario examined. The distribution of the primary prognostic factor produced imbalance in the randomization lists and informed further discussion of the cut-off values used in stratification. Influxes of patients resulted in overlapping intervention periods for multiple participants, which guided resource allocation. Early discharge was related to the primary prognostic factor and study center, but is only anticipated in about 8% of participants. CONCLUSIONS: Prospective cohort data are a very valuable resource for planning RCTs.

Scalp Topography of Lower Urinary Tract Sensory Evoked Potentials.

Impaired lower urinary tract (LUT) afferents often cause LUT symptoms. Assessment of LUT afferent pathways is possible using bipolar cortical sensory evoked potential (SEP) recordings with the active electrode at the vertex during electrical stimulation in the LUT. This study aimed to investigate the topographical distribution and microstates of lower urinary tract sensory evoked potentials (LUTSEPs) using different stimulation frequencies. Ninety healthy subjects (18-36 years old, 40 women) were randomly assigned to one of five stimulation locations [bladder dome; trigone; proximal, membranous (men only) or distal urethra]. Cycles of 0.5 Hz/1.1 Hz/1.6 Hz electrical stimulation were applied using a custom-made catheter. Cortical activity was recorded from 64 surface electrodes. Marker setting was performed manually on an individual subject-level for the P1, N1, and P2 components of vertex recordings. N1 and P2 topographies presented with central negativities and positivities around the vertex. Regarding topographical distribution, Randomization Graphical User interface (RAGU) analyses revealed consistent frequency effects and microstates for N1/P2. Higher stimulation frequencies resulted in decreasing map strength for P1, N1, and P2. LUTSEP topographies suggest central generators in the somatosensory cortex, which are not detectable in a bipolar set-up. The observed frequency effect indicates fiber refractoriness at higher frequencies. The multichannel approach allows more comprehensive assessment of LUTSEPs and might therefore be sensitive to pathological changes. Examinations in patients with LUT symptoms are needed to further investigate this biomarker.

TASCI-transcutaneous tibial nerve stimulation in patients with acute spinal cord injury to prevent neurogenic detrusor overactivity: protocol for a nationwide, randomised, sham-controlled, double-blind clinical trial.

INTRODUCTION: Neurogenic lower urinary tract dysfunction (NLUTD), including neurogenic detrusor overactivity (NDO) and detrusor sphincter dyssynergia, is one of the most frequent and devastating sequelae of spinal cord injury (SCI), as it can lead to urinary incontinence and secondary damage such as renal failure. Transcutaneous tibial nerve stimulation (TTNS) is a promising, non-invasive neuromodulatory intervention that may prevent the emergence of the C-fibre evoked bladder reflexes that are thought to cause NDO. This paper presents the protocol for TTNS in acute SCI (TASCI), which will evaluate the efficacy of TTNS in preventing NDO. Furthermore, TASCI will provide insight into the mechanisms underlying TTNS, and the course of NLUTD development after SCI. METHODS AND ANALYSIS: TASCI is a nationwide, randomised, sham-controlled, double-blind clinical trial, conducted at all four SCI centres in Switzerland. The longitudinal design includes a baseline assessment period 5-39 days after acute SCI and follow-up assessments occurring 3, 6 and 12 months after SCI. A planned 114 participants will be randomised into verum or sham TTNS groups (1:1 ratio), stratified on study centre and lower extremity motor score. TTNS is performed for 30 min/day, 5 days/week, for 6-9 weeks starting within 40 days after SCI. The primary outcome is the occurrence of NDO jeopardising the upper urinary tract at 1 year after SCI, assessed by urodynamic investigation. Secondary outcome measures assess bladder and bowel function and symptoms, sexual function, neurological structure and function, functional independence, quality of life, as well as changes in biomarkers in the urine, blood, stool and bladder tissue. Safety of TTNS is the tertiary outcome. ETHICS AND DISSEMINATION: TASCI is approved by the Swiss Ethics Committee for Northwest/Central Switzerland, the Swiss Ethics Committee Vaud and the Swiss Ethics Committee Zürich (#2019-00074). Findings will be disseminated through peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT03965299.

Neuroimaging in Neuro-Urology.

Neuroimaging allows in vivo visualization of neuronal structures/processes to assess their involvement in bodily functions. This is particularly valuable for the assessment of complex, multilevel neuronal controlled functions, such as urine storage and micturition. Using positron emission tomography or functional magnetic resonance imaging, significant alterations of supraspinal lower urinary tract (LUT) control have been described in patients with neurogenic LUT dysfunction due to spinal cord injury, Parkinson's disease, and multiple sclerosis. Severity of such alterations often correlates with symptom/dysfunction severity, both of which could be partly mitigated by therapeutic interventions. However, the overall evidence and study quality are presently very limited, and a multidisciplinary approach will be required to achieve clinical relevance in the long term. PATIENT SUMMARY: We reviewed the findings of neuroimaging studies in patients with bladder dysfunction due to neurological trauma/disease. Changes in the nervous systems of these patients alter bladder control, and neuroimaging may become a valuable tool for assessing these alterations.

Transcutaneous Tibial Nerve Stimulation for Treating Neurogenic Lower Urinary Tract Dysfunction: A Pilot Study for an International Multicenter Randomized Controlled Trial.

BACKGROUND: Tibial nerve stimulation (TNS) is an effective and safe treatment for idiopathic lower urinary tract dysfunction (LUTD), but its value in neurological patients is unclear. OBJECTIVE: To test the feasibility, acceptability, and safety of a randomized, sham-controlled, double-blind transcutaneous TNS (TTNS) setup for treating neurogenic LUTD. DESIGN, SETTING, AND PARTICIPANTS: A pilot study including nine patients with refractory neurogenic LUTD investigated prospectively at a university neuro-urology department. INTERVENTION: Randomized, sham-controlled, double-blind verum and sham TTNS was performed for 30min twice a week, for 6 wks. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Outcomes were feasibility, acceptability, and safety of the TTNS protocol. Secondarily, potential efficacy was investigated. Descriptive statistics were used. RESULTS AND LIMITATIONS: All procedures were feasible and well tolerated by all nine patients. Using verum TTNS, a motor response could be triggered in all patients and a sensory response in all but one. At the beginning and end of treatment, seven and six (78% and 67%) patients believed to receive verum TTNS, and five and six (56% and 67%) correctly guessed their group allocation, respectively. No treatment-related adverse events occurred. A comparison of baseline versus 6 wks of verum and sham TTNS led to relevant symptom and functional changes in only a limited number of piloted patients. CONCLUSIONS: Verum and sham TTNS combined with the blinding procedures proved feasible and safe. Both interventions and procedures, as well as the randomization process, were well accepted by the patients. While the subsensory threshold TTNS approach in combination with the sham condition is advantageous for patients' blinding, the clinical findings raised some doubt regarding sufficient TNS. Hence, relevant methodological adjustments concerning the adequate stimulation current and corresponding sham condition are needed before starting randomized controlled trials to clarify the value and role of TTNS in neuro-urology. PATIENT SUMMARY: Transcutaneous tibial nerve stimulation is a promising treatment option for neurogenic lower urinary tract dysfunction, but methodological adjustments in treatment application are required before further prospective studies can be initiated.

Quantitative electrical pain threshold assessment in the lower urinary tract.

AIMS: Assessing the reliability of electrical pain threshold (PT) and evaluating the impact of stimulation frequency at different locations in the healthy lower urinary tract (LUT). METHODS: Ninety subjects (age: 18.3-35.8 years, 40 females, 50 males) were randomly allocated to one stimulation site (bladder dome [BD], trigone, proximal, membranous (only males), or distal urethra). Using 0.5 Hz/1.1 Hz/1.6 Hz electrical stimulation (square wave, pulse width:1 ms), current perception thresholds (CPTs), PTs and tolerance thresholds were assessed at two visits. Analyses were performed using linear mixed models, intraclass correlation coefficients (ICC) and Bland-Altman method. RESULTS: PTs vary in relation to stimulation frequency, location and between genders. PT decreased with higher stimulation frequency. The highest PTs were measured at the BD and membranous urethra with males reporting higher PTs than females. Reliability of PT assessments according to ICC was good to excellent across all frequencies, locations, and genders (ICC = 0.61-0.97), except for BD and distal urethra in females showing poor to fair reliability (BD: all frequencies, distal urethra: 0.5 Hz). CONCLUSIONS: PTs can be safely and reliably assessed from bladder and urethral locations. Semi-objective PT assessment may provide additional information on functionality and sensitivity of the LUT slow fiber afferents and complement findings from urodynamic investigations and CPT assessments. In conclusion, the developed methodology may open new opportunities for using electrical stimulation paradigms for LUT PT assessments and diagnostics. All this allows a more precise, location-specific characterization of pain origin and pain reaction towards therapy.

Update from TASCI, a Nationwide, Randomized, Sham-controlled, Double-blind Clinical Trial on Transcutaneous Tibial Nerve Stimulation in Patients with Acute Spinal Cord Injury to Prevent Neurogenic Detrusor Overactivity.

Transcutaneous tibial nerve stimulation has the potential to revolutionize the management of lower urinary tract dysfunction in patients with acute spinal cord injury. TASCI is a nationwide randomized, sham-controlled, double-blind clinical trial for which the preparatory phase has been successfully completed.

Optimized Measurement Parameters of Sensory Evoked Cortical Potentials to Assess Human Bladder Afferents - A Randomized Study.

Overactive bladder and voiding dysfunction are highly prevalent and often associated with malfunction of the bladder afferent pathways. Appropriate diagnostic tools for an objective assessment of afferent nerve function of the human bladder are currently missing. One promising possibility is the assessment of sensory evoked potentials (SEP) during repetitive electrical bladder stimulation, which proved feasible in healthy subjects. For an implementation into clinical practice, however, further refinements for efficient and reliable data acquisition are crucial. The aim of this randomized study was to find the optimal measurement settings regarding stimulation frequency, repetition number, and data acquisition. Forty healthy subjects underwent two visits of SEP (Cz-Fz) assessments using repetitive (500 stimuli) electrical stimulation of 0.5 Hz, 1.1 Hz, and 1.6 Hz and pulse width of 1 ms at the bladder dome or trigone. SEP analyses revealed higher amplitudes and better signal-to-noise ratio (SNR) with lower stimulation frequencies, while latencies remained unchanged. Decreasing amplitudes and SNR were observed with continuing stimulation accompanied by decreasing responder rate (RR). When applying stimuli at a frequency of 0.5 Hz, averaging across 200 stimuli revealed optimal reliability with best SNR, RR and sufficiently high amplitudes. This constitutes an optimal compromise between the duration of the assessment and SEP peak-to-peak amplitudes.

Does electrical stimulation in the lower urinary tract increase urine production? A randomised comparative proof-of-concept study in healthy volunteers.

TRIAL DESIGN: During electrical stimulation in the lower urinary tract for the purpose of current perception threshold and sensory evoked potential recording, we observed that bladder volume increased rapidly. The aim of this prospective randomised comparative proof-of-concept study was to quantify urine production per time during stimulation of the lower urinary tract using different stimulation frequencies. METHODS: Ninety healthy subjects (18 to 36 years old) were included. Forty females and 50 males were randomly assigned to one of the following study groups: dome, trigone or proximal, membranous (males only) or distal urethra. Starting from 60mL prefilling, stimulation was performed at two separate visits with a 14 French custom-made catheter using randomly applied frequencies of 0.5Hz, 1.1Hz, 1.6Hz (each with 500 stimuli). After each stimulation cycle per frequency, urine production was assessed. Main outcome measures represented urine production during stimulation, daily life and their ratio. RESULTS: Lower urinary tract electrical stimulation increased urine production per time compared to bladder diary baseline values. Linear mixed model showed that frequency (p<0.001), stimulation order (p = 0.003), intensity (p = 0.042), and gender (p = 0.047) had a significant influence on urine production. Location, visit and age had no significant influence. CONCLUSIONS: Urine production is increased during electrical stimulation with a bigger impact of higher frequencies. This might be relevant for methodological aspects in the assessment of lower urinary tract afferent function and for patients with impaired renal urine output. Inhibition of renal sympathetic nerve activity by vagal afferents may be the underlying mechanism.

Sensory evoked cortical potentials of the lower urinary tract in healthy men.

AIMS: To assess the afferent innervation of various locations in the male lower urinary tract (LUT) using sensory evoked cortical potentials (SEPs). METHODS: Twelve healthy men (mean age: 29.6 ± 7.2 years, mean height: 1.8 ± 0.1 m) underwent repetitive slow (0.5 Hz/1 ms) and fast (3 Hz/0.2 ms) electrical stimulations of bladder (dome/trigone) and urethral (proximal/membranous/distal) locations with simultaneous cortical SEP recording (Cz-Fz). Latencies (ms) and peak-to-peak amplitudes (µV) for SEP components P1, N1, and P2 were analyzed. Tibial SEPs were assessed as methodological control. The reproducibility was investigated from between visits and inter-rater assessments using Bland-Altman plots. Statistical tests comprised analysis of variance (ANOVA), linear regressions, and paired t-tests. Values are given as mean ± standard deviation. RESULTS: Typical LUTSEPs with P1, N1, and P2 components were successfully detected (100% responder rate) for slow but less successfully for fast stimulation. The slow stimulation provided reproducible LUTSEPs with position specific N1 latencies: dome 125.6 ± 21.3 ms, trigone 122.9 ± 20.5 ms, proximal- 116.1 ± 21.4 ms, membraneous- 118.8 ± 29.3 ms, and distal urethra 108.8 ± 17.8 ms. Despite good inter-rater agreement, latency variability between and within subjects was higher for LUTSEPs than for tibial SEPs. N1 latencies became shorter (P < 0.01) with increasing subject age for bladder dome and distal urethra stimulation. CONCLUSIONS: LUTSEPs can be successfully obtained for different LUT locations in men using slow electrical stimulation. Location specific differences in N1 latencies may indicate different local afferent innervation. Larger variability of LUTSEPs versus tibial SEPs may be related to the more challenging approach and afferent fibre access within the LUT. Further studies optimizing measurement and analysis approach are required.

Protocol for a prospective, randomized study on neurophysiological assessment of lower urinary tract function in a healthy cohort.

BACKGROUND: Lower urinary tract symptoms are highly prevalent and a large proportion of these symptoms are known to be associated with a dysfunction of the afferent pathways. Diagnostic tools for an objective and reproducible assessment of afferent nerve function of the lower urinary tract are missing. Previous studies showed first feasibility results of sensory evoked potential recordings following electrical stimulation of the lower urinary tract in healthy subjects and patients. Nevertheless, a refinement of the methodology is necessary. METHODS: This study is a prospective, randomized trial conducted at Balgrist University Hospital, Zürich, Switzerland. Ninety healthy subjects (forty females and fifty males) without lower urinary tract symptoms are planned to be included in the study. All subjects will undergo a screening visit (including standardized questionnaires, 3-day bladder diary, urinalysis, medical history taking, vital signs, physical examination, neuro-urological examination) followed by two measurement visits separated by an interval of 3 to 4 weeks. Electrical stimulations (0.5Hz-5Hz, bipolar, square wave, pulse width 1 ms) will be applied using a custom-made transurethral catheter at different locations of the lower urinary tract including bladder dome, trigone, proximal urethra, membranous urethra and distal urethra. Every subject will be randomly stimulated at one specific site of the lower urinary tract. Sensory evoked potentials (SEP) will be recorded using a 64-channel EEG cap. For an SEP segmental work-up we will place additional electrodes on the scalp (Cpz) and above the spine (C2 and L1). Visit two and three will be conducted identically for reliability assessment. DISCUSSION: The measurement of lower urinary tract SEPs elicited by electrical stimulation at different locations of the lower urinary tract has the potential to serve as a neurophysiological biomarker for lower urinary tract afferent nerve function in patients with lower urinary tract symptoms or disorders. For implementation of such a diagnostic tool into clinical practice, an optimized setup with efficient and reliable measurements and data acquisition is crucial. In addition, normative data from a larger cohort of healthy subjects would provide information on variability, potential confounding factors and cut-off values for investigations in patients with lower urinary tract dysfunction/symptoms. TRIAL REGISTRATION: Clinicaltrials.gov; Identifier: NCT02272309 .

The interrelationships of birthweight, inflammation and body composition in healthy adults.

BACKGROUND: Lower birthweight is associated with an increased risk of cardiovascular diseases and diabetes. We hypothesized that inflammation and body fat may be potential mediators for these inverse relationships. MATERIALS AND METHODS: Healthy adults aged 25-41 years were enrolled in a prospective population-based cohort study in the Principality of Liechtenstein. Main exclusion criteria were diabetes, overt cardiovascular disease or a body mass index > 35 kg/m(2) . Birthweight was self-reported by the study participants. White blood cell (WBC) count and high-sensitivity C-reactive protein (hs-CRP) levels were assayed from fresh blood samples. Body composition was determined by bioelectrical impedance analysis. Multivariable linear regression models were constructed to assess the relationships between birthweight, inflammation and body composition. RESULTS: Our sample consisted of 1774 participants (53·4% females) with a median age of 37 years. Median birthweight was 3355 g. In multivariable models, we found an inverse relationship of birthweight with hs-CRP levels (ß -0·010 (95% CI -0·02; -0·002), P = 0·01) and WBC count (ß -0·002 (95% CI -0·004; -0·0002), P = 0·03). Additional adjustment for body fat mass attenuated these relationships (ß -0·008 (95% CI -0·02; 0·0003), P = 0·06 for hs-CRP levels and (ß -0·002 (95% CI -0·004; 0·0006), P = 0·16 for WBC count. Body fat mass itself was strongly associated with birthweight (ß -0·06 (95% CI -0·10; -0·03), P < 0·0001). CONCLUSION: Birthweight is inversely associated with inflammation in adulthood. This relationship may be mediated by an elevated body fat mass among individuals with lower birthweight.

Plasma copeptin levels and ambulatory blood pressure characteristics in healthy adults.

OBJECTIVE: We investigated whether copeptin - a well characterized vasopressin-related stress hormone - is associated with circadian ambulatory blood pressure (BP) variability and/or mean BP levels in young adults. METHOD AND RESULTS: We studied a population-based sample of healthy adults aged 25-41 years. Individuals with diabetes, treated hypertension, and cardiovascular disease were excluded. Ambulatory 24-h BP monitoring was performed using validated devices. To evaluate the relationships of copeptin with mean ambulatory BP levels and BP variability during daytime and night-time, multivariable adjusted regression models were constructed. BP variability was defined as SD of all intraindividual BP values. Of the 2012 individuals included in this study, 53% were women and the median age was 37 years. Median plasma copeptin levels were 3.9 (interquartile range 2.7, 5.8) in men and 2.3 pmol/l (interquartile range 1.6, 3.6) in women (P < 0.0001). In multivariable linear regression models, log-transformed copeptin was significantly associated with systolic and diastolic night-time BP levels among men [ß = 1.9, 95% confidence interval (CI) 0.6, 3.1, P = 0.003; and ß = 1.4, 95% CI 0.6, 2.3, P = 0.001, respectively], but not among women. In addition, copeptin was strongly associated with an increased systolic and diastolic daytime (ß = 0.5, 95% CI 0.2, 0.7, P = 0.001; ß = 0.5, 95% CI 0.3, 0.8, P < 0.0001, respectively) and night-time BP variability (ß = 0.6, 95% CI 0.3, 0.9, P = 0.0002; ß = 0.4, 95% CI 0.2, 0.7, P = 0.002, respectively). CONCLUSION: In this large population-based study of young and healthy adults, plasma levels of copeptin were significantly associated with an increased BP variability in both sexes and an elevated night-time BP among men.

Plasma endothelin-1 and cardiovascular risk among young and healthy adults.

OBJECTIVES: Endothelial dysfunction is a major precursor of atherosclerosis. The aim of this study was to assess the interrelationships between plasma endothelin-1 (ET-1) levels and cardiovascular risk among young and healthy individuals. METHODS: We performed a population-based study among 2160 healthy adults aged between 25 and 41 years in the Principality of Liechtenstein. Individuals with prevalent cardiovascular disease, diabetes or a body mass index >35 kg/m(2) were excluded. Plasma ET-1 was measured using a novel high-sensitive, single-molecule counting technology. The relationships between plasma levels of ET-1 and various cardiovascular risk factors were assessed by multivariable regression analyses. RESULTS: Median age of our population was 37 years. Median ET-1 levels across ET-1 quartiles were 1.86, 2.33, 2.76 and 3.48 pg/mL. After multivariable adjustment, there were significant correlations of ET-1 with systolic blood pressure (ß per 1-unit increase in log transformed ET-1 2.30 (95% confidence interval (CI) 1.03; 3.58, p = 0.0004), C-reactive protein (ß 0.19 (95% CI 0.03; 0.34, p = 0.021), glomerular filtration rate (ß -1.73 (95% CI -3.17; -0.29, p = 0.019), and current smoking (Odds ratio 1.94 (95% CI 1.39; 2.71, p < 0.0001). We also found a highly significant association between ET-1 levels and overall cardiovascular risk estimated by the "Prospective Cardiovascular Münster" (PROCAM) and the Framingham score (ß 0.18 (95% CI 0.06; 0.31, p = 0.004, and ß 0.11 (95% CI 0.05; 0.16), p < 0.0001, respectively). CONCLUSIONS: Plasma ET-1 levels are easily measurable in healthy adults and correlate with major cardiovascular risk factors and global cardiovascular risk.

Relationship between high-sensitivity cardiac troponin I and blood pressure among young and healthy adults.

BACKGROUND: The aim of this study was to evaluate the relationship of cardiac troponin (cTn) levels with conventional and ambulatory blood pressure (BP) in young and healthy adults. METHODS: We performed a population based cross-sectional analysis among 2,072 young and healthy adults aged 25-41 years free of cardiovascular disease and diabetes mellitus. cTnI was measured using a highly sensitive (hs) assay. The relationships of high sensitivity cardiac tropononin I (hs-cTnI) with office and 24-hour BP were assessed using multivariable regression analyses. RESULTS: Median age was 37 years and 975 (47%) participants were male. hs-cTnI levels were detectable in 2,061 (99.5%) individuals. Median (interquartile range) hs-cTnI levels were 0.98 (0.71; 1.64) ng/L among men and 0.48 (0.33; 0.71) ng/L among women. Systolic BP, but not diastolic BP, gradually increased across hs-cTnI quartiles (118, 120, 121, and 122 mm Hg for conventional BP; P = 0.0002; 122, 123, 124, and 124 mm Hg for 24-hour BP, P = 0.0001). In multivariable linear regression analyses, the ß estimates for systolic BP per 1-unit increase in log transformed hs-cTnI were 2.52 for conventional BP (P = 0.0001); 2.75 for 24-hour BP (P < 0.0001); 2.71 and 2.41 (P < 0.0001 and P = 0.0002) for day and nighttime BP, respectively. There was a significant relationship between hs-cTnI and the Sokolow-Lyon Index (odds ratio (95% confidence interval): 2.09 (1.37; 3.18), P < 0.001). CONCLUSION: Using a hs assay, hs-cTnI was detectable in virtually all participants of a young and healthy population. hs-cTnI was independently associated with systolic BP and left ventricular hypertrophy.

Blue blocker glasses as a countermeasure for alerting effects of evening light-emitting diode screen exposure in male teenagers.

PURPOSE: Adolescents prefer sleep and wake times that are considerably delayed compared with younger children or adults. Concomitantly, multimedia use in the evening is prevalent among teenagers and involves light exposure, particularly in the blue-wavelength range to which the biological clock and its associated arousal promotion system is the most sensitive. We investigated whether the use of blue light-blocking glasses (BB) during the evening, while sitting in front of a light-emitting diode (LED) computer screen, favors sleep initiating mechanisms at the subjective, cognitive, and physiological level. METHODS: The ambulatory part of the study comprised 2 weeks during which the sleep-wake cycle, evening light exposure, and multimedia screen use were monitored in thirteen 15- to 17-year-old healthy male volunteers. BB or clear lenses as control glasses were worn in a counterbalanced crossover design for 1 week each, during the evening hours while using LED screens. Afterward, participants entered the laboratory and underwent an evening blue light-enriched LED screen exposure during which they wore the same glasses as during the preceding week. Salivary melatonin, subjective sleepiness, and vigilant attention were regularly assayed, and subsequent sleep was recorded by polysomnography. RESULTS: Compared with clear lenses, BB significantly attenuated LED-induced melatonin suppression in the evening and decreased vigilant attention and subjective alertness before bedtime. Visually scored sleep stages and behavioral measures collected the morning after were not modified. CONCLUSIONS: BB glasses may be useful in adolescents as a countermeasure for alerting effects induced by light exposure through LED screens and therefore potentially impede the negative effects modern lighting imposes on circadian physiology in the evening.