Background/Objective: Chronic sleep deprivation can lead to adverse health effects and therefore represents a public health burden While caffeine is a widely used stimulant, the relationship between caffeine consumption and sleep remains uncertain. Moreover, many studies might be subject to methodological bias, as invasive sleep measurements may themselves serve as confounders. The aim of the SleepSmart study was to assess the impact of caffeine consumption through coffee and energy drinks, utilizing both smartwatch data and questionnaire responses. Methods: The SleepSmart study is an observational cohort study conducted at LMU Hospital Munich, Germany, from July 2024 to January 2025. The study investigated two intervention groups: (1) coffee and (2) energy drink consumption. Each intervention lasted 1 week, with days 1 to 3 serving as a reference period (water consumption to adjust for increased fluid intake) and days 4 to 6 serving as the intervention period (consumption of an equivalent of 240 mg of caffeine per day, 3 h before bedtime). Data was collected through self-administered questionnaires and wearable devices. The primary endpoint was sleep duration. Objective measures of sleep (duration of light/deep sleep, duration of wake phases, heart rate) and self-assed quality of sleep (Pittsburgh Sleep Quality Index) served as secondary endpoints. Results: For the primary endpoint, we did not find a significant difference in average sleep duration (baseline [hours] 6.7, coffee 6.9, energy drink 6.7, p-value 0.183). Similarly, secondary endpoints related to sleep measures showed no significant changes in the duration of light/deep sleep (coffee [min]: 242.2, reference coffee [ref_C] 255.7 I energy drink: 237.5, reference energy drink [ref_E] 261.3), time awake (coffee 22.7, ref_C 23.4 I energy drink 21.3, ref_E 18.9), time to fall asleep/wake up (coffee 4.2, ref_C 4.0 I energy drink 4.4, ref_E 2.7), or average heart rate (coffee [bpm] 62.2, ref_C 62.1 I energy drink 62.6, ref_E 62.3)—neither between the two intervention groups nor compared to the reference period. However, self-assessed sleep quality revealed a decrease in perceived sleep quality, with reports of poor sleep increasing by 8% after coffee consumption (rather bad/very bad sleeping quality: 29.7%) and 20% after energy drink consumption (46.6%), compared to baseline data (21.6%). Conclusions: The SleepSmart study introduces wearable sleep tracking as an innovative, low-interference method for objectively recording sleep data. While wearable data did not indicate significant sleep deterioration in the group of young, healthy adults, caffeine appeared to negatively impact the subjective perception of sleep in the study cohort.

Several medications for treatment of Juvenile Idiopathic Arthritis (JIA) are considered to be carcinogenic. Therefore, the aim was to assess whether there is an association between therapeutic interventions and malignancies in JIA patients. A nested case–control study was carried out within a retrospective cohort study of 3698 JIA patients diagnosed between 1952 and 2010. All 48 JIA patients with a diagnosis of a malignant tumour and up to four matched controls for each received a questionnaire about their use of medication. Subsequently treatment was compared between cases and controls and analyses performed for 37 cases and 125 controls (response 88.5 %). Treatment with DMARD (84 %) was most frequently used, followed by glucocorticoids (66 %) and immunosuppressives (65 %). Twenty percent reported to have ever been taking biologics. Medication use did not differ significantly between cases and controls. Our results did not show an association between medications used and malignancies in JIA patients.

Background: Heat induces a thermoregulatory strain that impairs cardiopulmonary exercise capacity. The aim of the current study is to elucidate the effect of isolated dehydration on cardiopulmonary exercise capacity in a model of preparticipating hypohydration. Methods: Healthy recreational athletes underwent a standardised fluid deprivation test. Hypohydration was assessed by bioelectrical impedance analysis (BIA) and laboratory testing of electrolytes and retention parameters in the blood and urine. The participants underwent cardiopulmonary exercise testing (CPET) with a cycle ramp protocol. Each participant served as their own control undergoing CPET in a hypohydrated [HYH] and euhydrated [EUH] state. Results: Fluid deprivation caused a mild (2%) but significant reduction of body water (38.6 [36.6; 40.7] vs. 39.4 [37.4; 41.5] %; p < 0.01) and an increase of urine osmolality (767 [694; 839] vs. 537 [445; 629] mosm/kg; p < 0.01). Hypohydration was without alterations of electrolytes, serum osmolality or hematocrit. The oxygen uptake was significantly lower after hypohydration (−4.8%; p = 0.02 at ventilatory threshold1; −2.0%; p < 0.01 at maximum power), with a corresponding decrease of minute ventilation (−4% at ventilatory threshold1; p = 0.01, −3.3% at maximum power; p < 0.01). The power output was lower in hypohydration (−6.8%; p < 0.01 at ventilatory threshold1; −2.2%; p = 0.01 at maximum power). Conclusion: Isolated hypohydration causes impairment of workload as well as peak oxygen uptake in recreational athletes. Our findings might indicate an important role of hypohydration in the heat-induced reduction of exercise capacity.

Background: Sports-related concussion is a relevant risk of contact sports, with several million cases per year worldwide. Prompt identification is crucial to prevent complications and late effects but may be impeded by an overlap with dehydration-associated impairment of cognitive function. Researchers have extensively studied the effects of pronounced dehydration in endurance sports, especially in the heat. However, little is known about the effects of isolated and mild dehydration. Methods: Healthy recreational athletes underwent a standardized fluid deprivation test. Hypohydration was assessed by bioelectrical impedance analysis (BIA) and laboratory testing of electrolytes and retention parameters. Participants underwent cardiopulmonary exercise testing (CPET) with a cycle ramp protocol. Each participant served as their own control undergoing CPET in a hypohydrated [HYH] and a euhydrated [EUH] state. Effects were assessed using a shortened version of Sport Concussion Assessment Tool 3 (SCAT3). Results: Fluid deprivation caused a mild (2%) reduction in body water, resulting in a calculated body mass loss of 0.8% without alterations of electrolytes, serum-osmolality, or hematocrit. Athletes reported significantly more (1.8 ± 2.2 vs. 0.4 ± 0.7; p < 0.01) and more severe (4.4 ± 6.2 vs. 1.0 ± 1.9; p < 0.01) concussion-like symptoms in a hypohydrated state. Balance was worse in HYH by trend with a significant difference for tandem stance (1.1 ± 1.3 vs. 0.6 ± 1.1; p = 0.02). No relevant differences were presented for items of memory and concentration. Conclusions: Mild dehydration caused relevant alterations of concussion-like symptoms and balance in healthy recreational athletes in the absence of endurance exercise or heat. Further research is needed to clarify the real-life relevance of these findings and to strengthen the differential diagnosis of concussion.

Introduction: Hypertension is a major cause of premature death worldwide as it is an important risk factor for coronary artery disease, myocardial infarction, heart failure and stroke. Although an estimated 1.3 billion adults suffer from hypertension, less than half of them are diagnosed correctly and therefore receive sufficient treatment. Furthermore, only one fifth of those treated reach the therapy target of normotension. This significant deficit underlines the need for new therapy concepts to improve long-term health outcomes. Several studies have shown positive effects of digital health programmes in the disease management of ambulatory, long-term hypertension treatment. More research is needed to explore the abilities of digital health programmes as an innovative pathway in ambulatory healthcare. The eXPLORE study aims to evaluate the feasibility of a clinical trial on the impact of a supplementary digital therapy programme for the treatment of primary arterial hypertension. Methods and analyses: The eXPLORE study collects data in the setting of a prospective randomised controlled trial to evaluate methodological feasibility for larger-scaled follow-up research. The study compares a digital therapy programme using a smartphone application that is based on functions and algorithms creating tasks and recommendations based on individual health data to standard care for the treatment of primary arterial hypertension. The study period is 180 days, with a 90-day in-life phase followed by a 90-day follow-up phase. Baseline and follow-up data (3 months, 6 months follow-up) of all participants included is collected via questionnaire surveys as well as self-administered blood pressure monitoring. Patient inclusion, initial data acquisition and follow-up were carried out in an innovative remote setting. The study was initiated in November 2022 and is currently ongoing. Study outcome measures are changes in mean blood pressure, health literacy and self-sufficient health behaviour. Ethics and dissemination: The eXPLORE study is carried out in accordance with all applicable legal regulations. Cost-effectiveness is assured by continuous evaluation and documentation over the course of the study. All health-relevant data from the eXPLORE study will be provided for analyses and publication to the investigators of LMU Hospital. The study was approved by the local ethics committee of LMU Munich (project nr.: 22–0115). Trial registration: NCT05580068 . Protocol Version: 1.5, 28.08.2023.

Munich?s Oktoberfest (OF) is the world?s largest fair, attracting 6 to 7 million visitors every year (1). Owing to excessive alcohol consumption, the Oktoberfest represents an annual stress test for acute care in the emergency departments,...