Awareness of Fluid Losses Does Not Impact Thirst during Exercise in the Heat: A Double-Blind, Cross-Over Study

Background: Thirst has been used as an indicator of dehydration; however, as a perception, we hypothesized that it could be affected by received information related to fluid losses. The purpose of this study was to identify whether awareness of water loss can impact thirst perception during exercise in the heat. Methods: Eleven males participated in two sessions in random order, receiving true or false information about their fluid losses every 30 min. Thirst perception (TP), actual dehydration, stomach fullness, and heat perception were measured every 30 min during intermittent exercise until dehydrated by ~4% body mass (BM). Post exercise, they ingested water ad libitum for 30 min. Results: Pre-exercise BM, TP, and hydration status were not different between sessions (p > 0.05). As dehydration progressed during exercise, TP increased significantly (p = 0.001), but it was the same for both sessions (p = 0.447). Post-exercise water ingestion was almost identical (p = 0.949) in the two sessions. Conclusion: In this study, thirst was a good indicator of fluid needs during exercise in the heat when no fluid was ingested, regardless of receiving true or false water loss information.

Helichrysum italicum ssp. italicum Infusion Promotes Fat Oxidation in Hepatocytes and Stimulates Energy Expenditure and Fat Oxidation after Acute Ingestion in Humans: A Pilot Study

Helichrysum italicum is an aromatic plant with promising pharmacological activities. Bioactive compounds found in plants represent an important alternative treatment for weight loss and an infusion of H. italicum contains compounds which could have such effect. Our aim was, therefore, to investigate its acute effects on resting energy expenditure (REE) and possible differences in substrate oxidation in a pilot study. A dried, ground plant material of H. italicum ssp. italicum was infused with hot water and chemically characterized with HPLC-MS analysis. Sensory evaluation of herbal tea was performed. A randomized, crossover, controlled pilot study was then conducted on eleven healthy male subjects. The REE and substrate oxidation were measured by indirect calorimetry at baseline and 30 and 120 min after ingestion of infusion or hot water. The expression of genes involved in lipid metabolism was examined in H. italicum infusion-treated hepatocytes. Several phenolic classes were identified in the infusion, caffeoylquinic acids were the most abundant, followed by pyrones and flavonols. A single ingestion of H. italicum infusion significantly increased REE by 4% and fat oxidation by 12% compared to hot water ingestion. A significant 2-fold up-regulation of β-oxidation-related genes in HepG2 cells, exposed to H. italicum infusion, was detected. This pilot study suggests that H. italicum infusion possesses bioactive substances with potential application in obesity prevention, which could, with additional studies, become an economically interesting novel application of the plant. Clinical trial registration number: NCT04818905

Retinal microvascular density modifications during the water drinking test

Purpose: The water drinking test (WDT) is a well-known stress test that increases intraocular pressure (IOP) momentarily and can indicate risk of glaucoma progression. This study focuses on correlating changes in the retinal microvascular plexus with the WDT in young healthy subjects. Methods: A total of 20 eyes of 20 healthy young subjects (mean age 24.37 ± 2.17 years) were included in this study. In our protocol, WDT consisted of drinking 1 L of water within 5 min. Outcome measures in this prospective observational study were mean arterial pressure (MAP), heart rate (HR), IOP, and retinal vessel density of both superficial and deep macular retina using optical coherence tomography angiography (OCTA), which were assessed before water ingestion and four times after at 15-min intervals. OCTA images were later quantified by fractal analysis (box counting [ Dbox]). One-way repeated measures analysis of variance (ANOVA) was used to assess the effects of WDT on each of the parameters. Results: The WDT resulted in significant peak changes of the following parameters compared to baseline: IOP: 15.63 ± 3.37 versus 18.38 ± 4.53 mmHg at 30 min, p < 0.001; HR: 75.74 ± 12.23 versus 64.95 ± 11.37 bpm at 15 min, p < 0.001; deep retinal vessel density 1.758 ± 0.14 versus 1.749 ± 0.16 at 15 min, p = 0.040. Conclusions: Besides IOP elevation and systemic effects in HR, WDT is associated with temporary modifications of the deep vascular plexus in young healthy subjects.

Renal Health: Providing Information and Technological Tools to Empower Patients to Live Better with Kidney Disease

Chronic kidney disease (CKD) is a growing Public Health problem. Recent evidence points that low education and poor socio-economic conditions are associated with higher risk of developing CKD and progressing to dialysis or transplantation need. Hence patient empowerment through health education and qualification with technological tools that allows better treatment adherence may play an important role in the achievement of optimal clinical outcomes. The Renal Health is a multidisciplinary project created at the University of Fortaleza, northeast Brazil, in 2015, aiming to create novel educational material and technological tools for people with CKD, in different treatment modalities, including dialysis and transplant. The products developed so far in the project include an application for smartphones aiming to help patients in dialysis and transplant in their treatments, including schedule for medications, with alarms, water ingestion control, laboratory tests results, and medical appointments’ agenda, besides all information regarding CKD. The other tools include a medication box, an insole for weight control (both are in the prototype phase), connection with smartbands (for vital signs monitoring) and multimedia educational tools, including a profile in the Instagram and a channel in YouTube. Since the first release of the application in the virtual stores, there were more than 1,000 downloads, predominantly in Brazil, although the app is also available in English and Spanish. All these tools represent innovative ways of patient empowerment and may be increasingly present in daily life. Further studies are required to assess the impact of these tools in patients’ outcomes, including CKD progression and mortality.

FC 054FUNCTIONAL SODIUM MAGNETIC RESONANCE IMAGING OF THE HUMAN KIDNEY

Background and Aims Maintenance of a cortico-medullary concentration gradient (CMG) required for urine concentration, is one of most important tubular function. However, we are lacking of functional tubular parameters to explore this function. The only tool available to assess it currently, is urinary osmolarity that is an indirect and nonspecific maker of CMG. In this study, we explore the ability of 23NaMRI in measuring 1) the dynamics of CMG for the first time compared to urinary osmolarity after a water load 2) the CMG in kidney disease. Method We conducted an exploratory pilot study for 10 healthy controls with water load then 5 cardiorenal patients with kidney disease. 1) Healthy controls were asked to be fasting since midnight. Urines sample were collected to measure fasting osmolarity and a first MRIscan were performed to acquire baseline anatomical and sodium images. Once the baseline was completed, healthy participants were asked to ingest water (15 mL/kg) within 15 minutes. Four subsequent sodium pictures were acquired an hour after water ingestion. Urine samples were obtained after each sodium acquisition every 15 min during one hours. 2) Cardiorenal patients underwent an MRI scan, provided a spot urine sample and have blood work collected. All MR experiments were carried out on a GE MR750 3T (GE Healthcare, WI). A custom-built two-loop (18cm in diameter) butterfly radiofrequency surface coil tuned for 23Na frequency (33.786 MHz) was used to acquire renal 23Na images. Results Mean age of the 10 healthy controls was 41.8 ± 15.3 years, mean body mass index (BMI) was 24.3 ± 3.8 kg/m2. Mean water intake was 1092 ± 233 mL, total water excreted was 1250 ± 301 mL . Mean age of the 5 cardiorenal patients was 76.6 ± 12.2 years, mean BMI was 28.1 ± 6.9 kg/m2. eGFR was 54 ± 37 mL/min/1.73m2. Urinary osmolarity was 498 ± 145 mosm/L and medulla/cortex ratio was 1.35 ± 0.11. Sodium imaging was successfully acquired in all volunteers. In the morning fasting, medulla/cortex ratio was 1.55 ± 0.11 regarding to a urinary osmolarity to 814 ± 121 mosm/L. Mean ± SD fasting urinary osmolarity dropped significantly to 73 ± 14 mosm/L for maximal dilution, p=0.001. Mean medulla/cortex ratio dropped significantly to 1.31 ± 0.09 mosm/L for maximal dilution, p=0.002. Figure 1 displays changes of 23NaMRI pictures before (A) then 1h (B), 1H15 (C), 1h30 (D) and 1h45 (E) after a water load. Urinary osmolarity and medulla/cortex ratio are significantly correlated, r=0.54, p=0.0001. We measured corticomedullary gradient in cardiorenal patient with different level of eGFR to show the ability and feasibility to measure this gradient in pathological settings. We were able to measure medulla/cortex ratio in patients with CKD with a mean SNR of 20.45 ± 9.45. Conclusion We explored CMG dynamically every 15 min and we were able to discriminate significant changes after a water load. We were also able to provide efficient 23NaMRI pictures in cardiorenal patients with kidney disease. CMG exploration would provide a relevant assessment of tubular dysfunction independently of glomerular alteration and thus could be of prognostic value.

Role of LncRNA score and PVT1 in primary hyperparathyroidism-- a preliminary study

Background Dysregulated lncRNA score and PVT1 expression may be involved in cancer. However, relationships of lncRNAs with hyperparathyroidism and parathyroid cancer (PC) diagnosis remain mysterious. Methods Using quantitative real-time polymerase chain reaction (RT-qPCR), expression profile of PVT1 was evaluated in 57 patients with primary hyperparathyroidism, including 11 with parathyroid cancer (PC) and 46 with parathyroid adenoma (PA). Results Higher levels of lncRNA score and PVT1 expression were associated with increased serum calcium level after water ingestion and PC risk (P < 0.05). Accordingly, lncRNA score and PVT1 expression were increased with varying degrees of hypercalcemia in PC. A higher level of lncRNA score (but not PVT1) was an independent risk factor of PC, with an AUC up to 0.872 (95% CI: 0.756–0.945, P < 0.001). Moreover, lncRNA score was more valuable (with AUC 0.974, sensitivity of 85.71% and specificity of 100%, respectively) than intact parathyroid hormone (iPTH) in predicting risk of PC among patients with hypercalcemia (especially based on greater AUC, P = 0.010). Conclusion Increased lncRNA score is correlated with an elevated level of serum calcium, which may serve as a potential biomarker for PC diagnosis, especially with hypercalcemia. Graphical abstract