Plasma Osmolality Research Articles

Sex Differences in Hydration Biomarkers and Test-Retest Reliability Following Passive Dehydration.

This study investigated (a)differences between males and females for changes in serum, tear, and urine osmolality, hematocrit, and urine specific gravity following acute passive dehydration and (b)assessed the reliability of these biomarkers separately for each sex. Fifteen males (age: 26.3 ± 3.5years, body mass: 76 ± 7kg) and 15 females (age: 28.8 ± 6.4years, body mass: 63 ± 7kg) completed a sauna protocol twice (5-28days apart), aiming for 4% body mass loss (BML). Urine, blood, and tear markers were collected pre- and postdehydration, and change scores were calculated. Male BML was significantly greater than that of females in Trial 1 (3.53% ± 0.55% vs. 2.53% ± 0.43%, p < .001) and Trial 2 (3.36% ± 0.66% vs. 2.53% ± 0.44%, p = .01). Despite significant differences in BML, change in hematocrit was the only change marker that displayed a significant difference in Trial 1 (males: 3% ± 1%, females: 2% ± 1%, p = .004) and Trial 2 (males: 3% ± 1%, females: 1% ± 1%, p = .008). Regression analysis showed a significant effect for sex (male) predicting change in hematocrit (β = 0.8, p = .032) and change in serum osmolality (β = -3.3, p = .005) when controlling for BML but not for urinary or tear measures. The intraclass correlation coefficients for females (ICC 2, 1) were highest for change in urine specific gravity (ICC = .62, p = .006) and lowest for change in tear osmolarity (ICC = -.14, p = .689), whereas for males, it was posthematocrit (ICC = .65, p = .003) and post tear osmolarity (ICC = .18, p = .256). Generally, biomarkers showed lower test-retest reliability in males compared with females but, overall, were classified as poor-moderate in both sexes. These findings suggest that the response and reliability of hydration biomarkers are sex specific and highlight the importance of accounting for BML differences.

Secondary polycythemia in acutely ill COVID-19 patients is associated with higher mortality but not markedly higher thrombotic risk

Secondary polycythemia is commonly observed among patients with chronic pulmonary diseases. However, its significance in the context of Coronavirus disease 2019 (COVID-19) is unknown. We retrospectively evaluated a total of 5872 hospitalized COVID-19 patients with mostly severe and critical symptoms, and without prior or subsequently diagnosed myeloproliferative neoplasm. Patients were stratified based on admission hemoglobin into four subgroups: anemia (hemoglobin <120 g/L for females and 130 g/L for males), normal hemoglobin, mild (hemoglobin 160–165 g/L for females and 165–185 g/L for males) and severe polycythemia (hemoglobin >165 g/L for females and >185 g/L for males). Among 5872 patients, a total of 158 (2.7%) had mild and 25 (0.4%) severe polycythemia. Polycythemia was significantly associated with higher respiratory and functional impairment, reduced plasma volume, higher serum osmolarity and comorbidity burden specific to the degree of polycythemia. Patients presenting with mild (odds ratio (OR) = 1.63, p = .003) and severe polycythemia (OR = 4.98, p < .001) had increased risk of death in comparison to patients with normal hemoglobin, whereas no significant associations with venous thromboembolism, arterial thrombosis nor major bleeding were observed. Anemia was associated with higher risk of death (OR = 1.42, p < .001), venous thromboembolism (OR = 1.34, p < .006) and major bleeding (OR = 2.27, p < .001) in comparison to normal hemoglobin. Associations of polycythemia and anemia with mortality diminished, and anemia with venous thromboembolism and major bleeding persisted, after multivariate adjustments for age, sex, comorbidities, COVID-19 severity and functional status. Secondary polycythemia in hospitalized COVID-19 patients without prior of subsequently diagnosed myeloproliferative neoplasm is rare and is associated with high mortality, increasing with degree of polycythemia, but not markedly higher thrombotic risk.

Biochemical profile of diabetic ketoacidosis in type 2 diabetes patients: an observational study

Background: The present study was conducted to assess the clinical profile of type 2 diabetes patients presenting with diabetic ketoacidosis and review their biochemical parameters at the time of presentation. Methods: The present study was an analytical, cross-sectional study conducted over the period of two years. All the type 2 diabetes patients with diabetic ketoacidosis admitted during the study period constituted the study population, after being subjected to prefixed selection criteria. All the participants were subjected to detailed clinical examination and biochemical analysis during hospitalization and parameters were monitored. Results: Out of the total 60 type 2 DM patients with DKA studied, 53.3% patients belonged to 51 to 60 years age group and 55% were males. One patient died and 59 survived (mortality rate-1.6%). Comparatively higher mean RBS, higher mean serum osmolality and lower pH were observed in the death case in comparison with those who survived. The patient who died had no statistically significant difference in serum sodium, potassium, calcium and magnesium but had lower serum HCO3- than alive patients on admission. Conclusions: DKA is a serious metabolic complication even in cases of type 2 diabetes and higher RBS, higher Sr Osmolality and lower pH at the time of presentation correlate directly with poorer outcomes.

Ad libitum dehydration is associated with poorer performance on a sustained attention task but not other measures of cognitive performance among middle-to-older aged community-dwelling adults: A short-term longitudinal study.

Hydration status and water intake are critical to physiological health. Despite a popular narrative that dehydration impairs cognitive performance, results are mixed in the literature. Therefore, we tested how hydration status was associated with cognitive performance in an ad libitum state over the course of 3 months. Data come from a short-term longitudinal study among middle-to-older aged US adults (n = 78) measured three times (207 observations). All participants were scheduled for 8:00 a.m. visits for the baseline, two-week, and 3-month examinations where they completed surveys, neuropsychological tests to measure cognitive performance, anthropometrics, and a blood draw for biomarker analysis. Serum osmolality (Sosm) was measured as a biomarker of hydration status using osmometry. Four cognitive performance tasks were assessed, including inhibition, working memory, cognitive flexibility, and sustained attention. Panel random effects linear regressions demonstrate that there was an inverse association between dehydration and sustained attention, whereas there were no significant relationships between dehydration and inhibition, working memory, and cognitive flexibility. Adults who were dehydrated (defined as Sosm >300 mOsm/kg) performed substantially worse (B = 0.65 z-score; SE = 0.28; p = .020) on the sustained attention task than those who were not dehydrated adjusting for time fixed effects, age, body mass index, sex, and educational attainment. This short-term longitudinal study found that dehydration was only associated with poorer performance on a cognitive performance task that required sustained attention. Maintaining adequate hydration may be increasingly important for middle-to-older aged adults to ensure proper cognitive function, particularly as water needs increase in future climatic scenarios.

Identifying Baseline Predictors of Selective Laser Trabeculoplasty Effectiveness: An Alternative Mathematical Approach.

Selective laser trabeculoplasty (SLT) emerges as a first-line treatment for newly diagnosed open-angle glaucoma and ocular hypertension. However, the interindividual response to SLT considerably varied. Large-scale clinical investigations concerning predictive factors for SLT effectiveness are limited. This study aimed to identify baseline predictors of the percentage intraocular pressure (IOP)-lowering effectiveness of SLT using an alternative mathematical approach. Mathematical equations of IOP under the steady state of aqueous humour flow were formulated. The conclusive equation integrates physiological variables, including trabecular outflow facility, uveoscleral outflow fraction, plasma protein concentration, albumin/globulin ratio, mean arterial pressure, episcleral venous pressure, and plasma osmolarity. The equation was employed to estimate the percentage of IOP reduction following SLT and subsequently subjected to global sensitivity analysis to determine significant predictors of the IOP-lowering effect of SLT using the Monte Carlo simulation of 8,192 samples. In the current model, a 50% improvement in the trabecular outflow facility impacted by SLT is associated with a mean percentage IOP reduction of 16.6%. Lower baseline trabecular outflow facilities were the strongest predictors, showing a correlation with greater effectiveness of SLT in terms of percentage of IOP reduction. The second most influential factor includes baseline uveoscleral outflow fraction, followed by baseline episcleral venous pressure. Specifically, lower baseline uveoscleral outflow fraction and episcleral venous pressure were found to be correlated with increased effectiveness of SLT. Baseline levels of plasma protein concentration, albumin/globulin ratio, mean arterial pressure, and plasma osmolarity have minimal impact on SLT success or failure. This study identifies baseline trabecular outflow facilities as the strongest predictor of SLT effectiveness. The results suggested that pre-SLT medical treatment that augments uveoscleral outflow and/or trabecular outflow facilities could compromise the effectiveness of subsequent SLT in terms of percentage IOP reduction compared to those who never received pre-SLT medication.

Physiologic responses of Cownose Rays following freshwater dips for treatment of capsalid monogeneans.

Two Cownose Rays Rhinoptera bonasus were presented for management of a severe capsalid monogenean infection Benedeniella posterocolpa in a mixed species habitat at an aquarium. A series of freshwater (FW) dips were elected to mitigate parasite resistance to praziquantel due to the endemic monogenean population in the system. A pretreatment blood sample was opportunistically obtained, and subsequent samples were processed due to development of clinical signs. While the first FW dip was tolerated well and did not induce abnormal behavior, the second led to one individual presenting with tachypnea, pallor, and lethargy. Marked hematological abnormalities requiring medical intervention occurred in both individuals after the second dip. After treatment with elasmobranch Ringer's fluid therapy, sodium bicarbonate, prednisolone acetate, and vitamin E/selenium in the more severely affected ray, and elasmobranch Ringer's alone in the second ray, hematologic derangements and symptoms resolved. Hemoconcentration, hyperproteinemia, hyperlactatemia, and hyperglycemia were attributed to a stress response. A selective loss of urea after exposure to FW resulted in decreased plasma osmolality. Given the severity of the stress response and associated complications observed, hyposalinity treatments should be utilized with caution in this species. If this therapy is employed, the clinician is advised to be prepared to administer supportive care coinciding with the FW dip if necessary.

The Changes in Relative Blood Volume during Dialysis Are Characterized by Ultrafiltration Rate and Predialysis Blood Test Values

Introduction: Continuous monitoring of relative blood volume (percentage BV) in hemodialysis (HD) is critical for determining dry weight and preventing intradialytic hypotension. However, the cause of the BV variation remains unknown. This research aimed to examine factors that influence the percentage BV. Methods: We devised a formula based on coefficients (“a,” “τ,” and “b”) to predict changes in percentage BV. “a” denotes a significant decrease in percentage BV in the early stages of HD. “τ” represents the transition from early to late phase of HD. “b” denotes the slope of the decrease in percentage BV in the late phase of HD. We measured the percentage BV in 18 patients with end-stage renal disease. The coefficients were estimated by fitting experimental data from patients using a least squares optimization algorithm. A correlation analysis of these parameters and patient predialysis data was performed. Results: Ultrafiltration rate (UFR) was found to be negatively correlated with “b” (r = −0.851, p < 0.01). However, UFR was not significantly related to “a.” Predialysis serum total protein level was negatively correlated with “a” (r = −0.531, p = 0.042). Predialysis serum albumin and predialysis sodium were not significantly correlated with “a” and “τ.” Plasma osmolarity did not have a significant relationship with “a” and “τ.” Discussion/Conclusion: UFR influenced the decrease in percentage BV in the late phase but did not influence the decrease of percentage BV in the early phase. “a” was associated with predialysis serum total protein level but not with plasma osmolality or predialysis sodium. This implies that colloid oncotic pressure is important for plasma refilling immediately after dialysis begins. During the change of percentage BV, the decrease in the early phase of dialysis was not related to UFR, but related to other parameters, especially predialysis total protein level. A decrease in the late phase of dialysis is related to UFR.

The Impact of a Single Haemodialysis Session on the Retinal Thickness and Optic Nerve Morphology

Background: The aim of the study was to assess the influence of a single haemodialysis (HD) session on the retinal and optic nerve morphology in end-stage kidney disease (ESKD) patients. Methods: It is a prospective study including only the right eye of 35 chronic kidney disease (CKD) patients subjected to HD. Each patient underwent a full eye examination 30 min before HD (8 a.m.) and 15 min after HD. Optical coherence tomography (OCT) was used to assess the peripapillary retinal nerve fibre layer (pRNFL) thickness, macular nerve fibre layer (mRNFL) thickness, ganglion cell layer with inner plexiform layer thickness (GCL+), GCL++ (mRNFL and GCL+) thickness, total retinal thickness (RT) and total macular volume (TMV). The correlation was tested between such systemic parameters changes as systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), body weight, plasma osmolarity and ocular perfusion pressure (OPP) and ultrafiltration volume with total RT and pRNFL thickness changes during HD. Results: In the results of a single HD session, we could observe a statistically significant increase in the total RT thickness (pre-HD 270.4 ± 19.94 μm, post-HD 272.14 ± 20.11 μm; p = 0.0014), TMV (pre-HD 7.48 ± 0.53 mm3, post-HD 7.52 ± 0.55 mm3; p = 0.0006), total pRNFL thickness (pre-HD 97.46 ± 15.71 μm, post-HD 100.23 ± 14.7 μm; p = 0.0039), total GCL+ thickness (pre-HD 70.11 ± 9.24 μm, post-HD 70.6 ± 9.7 μm; p = 0.0044), and GCL++ thickness (pre-HD 97.46 ± 12.56 μm, post-HD 97.9 ± 12.94 μm; p = 0.0081). We observed a significant correlation between the change in total RT and DBP change, as well as between body weight change and the change in total pRNFL thickness. There was also a correlation between total pRNFL thickness change and the presence of diabetes mellitus. Conclusion: Even a single HD session affects the retinal and pRNFL thickness, which should be taken into account when interpreting the OCT results in patients subjected to HD. The impact of changes after a single HD session on selected parameters requires further assessment in subsequent studies, including long-term observation.

Association of Retinal Vein Occlusion With Serum Osmolality and Hydration Status.

The aim of this study was to evaluate serum osmolality and hydration status in patients with retinal vein occlusion (RVO). This cross-sectional study consisted of 79 patients with RVO and 81 age- and sex-matched peers without ocular disease. Data were collected from patient records and included a comprehensive ophthalmological examination, laboratory data of fasting blood test results, and internal medicine outpatient examination. Complete blood count and levels of fasting glucose, sodium, blood urea nitrogen (BUN), creatinine, triglyceride, low-density lipoprotein, high-density lipoprotein, HbA1c, and serum osmolality were evaluated. BUN/creatinine ratios were calculated. Mean serum sodium and serum osmolality levels were 142.53 ± 2.13 and 139.74 ± 2.16 mEq/L and 286.58 ± 4.40 and 280.57 ± 4.39 mOsmol/kg H2O in the RVO and control groups, respectively. Serum osmolality and serum sodium levels, and BUN/creatinine ratio were significantly higher in the RVO group than in controls (P < 0.05 for all). We found that serum osmolality, sodium levels, and the BUN/creatinine ratio increased significantly in the RVO group. The results suggest dehydration status may affect the genesis of vessel occlusion in RVO. [Ophthalmic Surg Lasers Imaging Retina 2024;55:130-135.].

Neural control of fluid homeostasis is engaged below 10°C in hibernation.

Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) hibernate for several months each winter without access to water,1 but the mechanisms that maintain fluid homeostasis during hibernation are poorly understood. In torpor, when body temperature (TB) reaches 4°C, squirrels decrease metabolism, slow heart rate, and reduce plasma levels of the antidiuretic hormones arginine vasopressin (AVP) and oxytocin (OXT).1 Squirrels spontaneously undergo interbout arousal (IBA) every 2weeks, temporarily recovering an active-like metabolism and a TB of 37°C for up to 48 h.1,2 Despite the low levels of AVP and OXT during torpor, profound increases in blood pressure and heart rate during the torpor-IBA transition are not associated with massive fluid loss, suggesting the existence of a mechanism that protects against diuresis at a low TB. Here, we demonstrate that the antidiuretic hormone release pathway is activated by hypothalamic supraoptic nucleus (SON) neurons early in the torpor-arousal transition. SON neuron activity, dense-core vesicle release from the posterior pituitary, and plasma hormone levels all begin to increase before TB reaches 10°C. Invivo fiber photometry of SON neurons from hibernating squirrels, together with RNA sequencing and c-FOS immunohistochemistry, confirms that SON is electrically, transcriptionally, and translationally active to monitor blood osmolality throughout the dynamic torpor-arousal transition. Our work emphasizes the importance of the antidiuretic pathway during the torpor-arousal transition and reveals that the neurophysiological mechanism that coordinates the hormonal response to retain fluid is active at an extremely low TB, which is prohibitive for these processes in non-hibernators.

Assessment of osmotic adaptation and seawater readiness in juvenile Chinook salmon reared at the Malkinskiy salmon hatchery

Aim: to assessed the readiness of Chinook salmon fingerlings reared at the Malkinskiy salmon hatchery (Kamchatka region) to seawater run and to reverse water-salt transport; to develop a rapid and effective method to determine the readiness of juvenile Chinook salmon to seawater run.Methods: the dynamics of haemoglobin, glucose, haematocrit, blood osmolarity and body weight were studied in juvenile of Chinook salmon of a different sizes exposed in water with salinities of 30 and 40% (experiments in fresh water under the same conditions served as a control, all experiments were carried out in three repetitions).Novelty: a method is described to assess the readiness of juvenile salmonids with a prolonged freshwater period of life to sea water run.Results: the standard “salinity test” does not always reflect the readiness of juveniles to run, and to clarify their physiological state, it is worth studing the dynamics of blood osmolarity during exposure to water with a salinity of 30% (the critical indicator is 340 mOsm l‑1 after a day of experiment). Blood levels of glucose, hemoglobin and hematocrit, as well as the dynamics of body weight are not suitable for assessing salt resistance because off the excessive sensitivity of these indicators. It was shown that juvenile Chinook weighing ≥ 7 g were physiologically ready for run, whereas juveniles weighing ≤ 5 g were not. The intermediate group (5–7 g) exhibited different physiological states in different years.Practical importance: determining the minimum size of fully transformed smolts and finding ways to increase the salt tolerance of juveniles is the way to increase the profitability of the hatchery.

Prevalence and risk factors associated with dehydration of patients with dysphagia in eastern China: A cross-sectional study.

Dehydration is one of the common complications of dysphagia and poses significant risks including hospitalization and mortality, but the relationship between dysphagia and dehydration has received little attention. This study aims to determine the prevalence and risk factors for dehydration of patients with dysphagia in eastern China, and to provide reference for early identification and prevention of dehydration. A descriptive, cross-sectional design was conducted. Three hundred and thirty-seven (n = 337) patients with dysphagia participated in the study between August and December 2022. Information relating to participants' demographic variables, nutrition, cognition, functional, hydration status and fluid intake was collected. Univariate analysis was used to examine related impact factors, and then binary logistic regression analysis was conducted to determine reliable impact factors. Among 337 patients with dysphagia, the average age was 63.47 ± 16.96, most participants were male (72.1%) and married (91.7%). The prevalence of dehydration was calculated to be 43.9%, the mean plasma osmolality score was 293.53 mmol/L. Diseases with the highest prevalence were stroke (78.3%), followed by hypertension (63.5%). The risk for dehydration increased with older age, usage of more medicines such as diuretics and beta-blockers, worse functional status and lower fluid intake. This study found a high percentage of dehydration in patients with dysphagia. Findings can provide a basis for targeted nursing interventions for clinical prevention and treatment of dehydration.

Spontaneous hydropneumothorax with unknown origin and new onset hyperosmolar hyperglycemic state: case report in limited health facility

Introduction: Hydropneumothorax and Hyperosmolar Hyperglycaemic State (HHS) are uncommon disorders with serious mortality. Both conditions need appropriate intervention and monitoring in comprehensive health facilities. Reports on the occurrence of spontaneous hydropneumothorax accompanied by HHS are still limited, due to the rarity of these two disorders.Case Presentation: A 42-year-old woman with abrupt shortness of breath started 1 day ago. No coughing or chest pain. Losing weight in last six months. There was no history of any disease and medication. Physical findings were drowsy consciousness with tachycardia and weak pulse, asymmetrical chest expansion with retraction, vesicular breath sounds diminished in the left lung following hyper resonant in percussion. The extremities were cold and dry. Skin turgor was reduced. Plain CXR revealed air and fluid in left pleural cavity. Laboratory test revealed very high blood glucose with hyperosmolarity.Discussion: Hydropneumothorax is the presence of air in the pleural space accompanied by ipsilateral effusion. The manifestations include shortness of breath, increased work of breathing, and sharp chest pain, or asymptomatic. It is unclear whether this patient's hyperglycaemia is related to the occurrence of spontaneous hydropneumothorax. HHS can be diagnosed by effective serum osmolality with glucose levels plus appropriate medical presentation. The management is based on the correction of dehydration, hyperglycaemia, hyperosmolarity, and precipitating conditions.Conclusion: Both hydropneumothorax and HHS have high mortality rates, particularly when the two conditions coexist. This case met some challenging issues that might increase the mortality.

Association between serum osmolality and risk of in-hospital mortality in patients with intracerebral hemorrhage.

This study aimed to analyze the association between serum osmolality and the risk of in-hospital mortality in intracerebral hemorrhage (ICH) patients. In this retrospective cohort study, data of a total of 1,837 ICH patients aged ≥18 years were extracted from the Medical Information Mart for Intensive Care-IV (MIMIC-IV). Serum osmolality and blood urea nitrogen (BUN)-to-creatinine (Cr) ratio (BCR) were used as the main variables to assess their association with the risk of in-hospital mortality in ICH patients after first intensive care unit (ICU) admission using a univariable Cox model. Univariable and multivariable Cox regression analyses were applied to explore the associations between serum osmolality, BCR, and in-hospital mortality of ICH patients. Hazard ratio (HR) and 95% confidence intervals (CIs) were calculated. The median survival duration of all participants was 8.29 (4.61-15.24) days. Serum osmolality of ≥295 mmol/L was correlated with an increased risk of in-hospital mortality in patients with ICH (HR = 1.43, 95%CI: 1.14-1.78). BCR of >20 was not significantly associated with the risk of in-hospital mortality in ICH patients. A subgroup analysis indicated an increased risk of in-hospital mortality among ICH patients who were women, belonged to white or Black race, or had complications with acute kidney injury (AKI). High serum osmolality was associated with an increased risk of in-hospital mortality among ICH patients.

Seasonal variation in vascular dehydration risk: insights from the Kobe Orthopedic and Biomedical Epidemiologic (KOBE) study.

Dehydration, a risk factor for ischemic cerebrovascular diseases, is common in summer; however, the incidence of ischemic diseases is not necessarily higher in summer. Therefore, this study aimed to clarify the relationships between serum osmolarity, hematocrit, daily non-alcohol drink (NAD) intake and factors such as season and age as risk factors for dehydration. Participants (703 women and 306 men) in the follow-up survey, in 2012 and 2013, of the Kobe Orthopedic and Biomedical Epidemiologic (KOBE) Study, consisting of healthy individuals living in Kobe, Japan, were categorized into two groups based on the examination month: the warmer and colder seasons. Multivariate analyses were conducted to examine disparities in serum osmolarity, hematocrit, and NAD intake between these two groups. The colder season was found to be negatively correlated with serum osmolarity and NAD intake, but positively correlated with hematocrit, even after adjusting for relevant factors. Age was independently associated with serum osmolarity, but not with hematocrit and NAD intake. This study suggests that intra-vascular volume depletion is more likely in the colder season despite lower serum osmolarity compared to the warmer season. Age-related increases in serum osmolarity without a corresponding rise in water intake may contribute to this. These findings support the importance of addressing dehydration in the colder season, particularly in older adults.

Hydric physiology and ecology of a federally endangered desert lizard.

Animals can respond to extreme climates by behaviourally avoiding it or by physiologically coping with it. We understand behavioural and physiological thermoregulation, but water balance has largely been neglected. Climate change includes both global warming and changes in precipitation regimes, so improving our understanding of organismal water balance is increasingly urgent. We assessed the hydric physiology of US federally endangered blunt-nosed leopard lizards (Gambelia sila) by measuring cutaneous evaporative water loss (CEWL), plasma osmolality and body condition. Measurements were taken throughout their active season, the short period of year when these lizards can be found aboveground. Compared to a more mesic species, G. sila had low CEWL which is potentially desert-adaptive, and high plasma osmolality that could be indicative of dehydration. We hypothesized that throughout the G. sila active season, as their habitat got hotter and drier, G. sila would become more dehydrated and watertight. Instead, CEWL and plasma osmolality showed minimal change for females and non-linear change for males, which we hypothesize is connected to sex-specific reproductive behaviours and changes in food availability. We also measured thermoregulation and microhabitat use, expecting that more dehydrated lizards would have lower body temperature, poorer thermoregulatory accuracy and spend less time aboveground. However, we found no effect of CEWL, plasma osmolality or body condition on these thermal and behavioural metrics. Finally, G. sila spends considerable time belowground in burrows, and burrows may serve not only as essential thermal refugia but also hydric refugia.

Diabetes Insipidus: Types, Diagnosis and Management

Diabetes insipidus (DI) is an acquired or hereditary water imbalance disorder characterized by polydipsia and polyuria. It is a condition that involves the excretion of dilute urine in large volumes. The illness can strike at any age, with males and females have identical rates of occurrence of the disease. The two main mechanisms responsible for diabetes insipidus are either insufficient release or production of ADH (antidiuretic hormone) from the hypothalamus (central diabetes insipidus) or ADH resistance in which the kidneys are unable to respond to ADH (nephrogenic diabetes insipidus). Another form of DI is transient diabetes insipidus commonly known as gestational diabetes insipidus that occurs in the second/third trimester of pregnancy due to increased levels of placental vasopressinase that occurs progressively during pregnancy and increases metabolic clearance of vasopressin. The fourth type of DI is primary polydipsia, characterized by elevated levels of water intake that physiologically lower vasopressin and may be psychogenic, iatrogenic or dipsogenic. Signs and symptoms of DI often include water electrolyte-imbalance, excessive or severe thirst, frequent and excessive urination, fatigue, dehydration, and weight loss. Diabetes insipidus (DI) should be distinguished from primary polydipsia, and whether it is caused by a central, nephrogenic, or gestational cause. This distinction is critical since incorrect treatment can result in serious repercussions. Diagnosis of DI includes measurement of plasma sodium and osmolality, baseline copeptin, hypertonic saline stimulation and arginine stimulation test. The treatment for DI includes the use of drugs such as desmopressin, thiazide diuretics, indomethacin and amiloride.

A case of central diabetes insipidus after COVID-19 as a probable diagnosis of lymphocytic infundibulo-neurohypophysitis with positive anti-rabphilin-3A antibodies with review of literature.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2, and various complications have been reported. Furthermore, there have been increasing reports of endocrinopathy related to COVID-19 following the pandemic. We report a 49-year-old healthy woman who developed rapid onset of polydipsia and polyuria three weeks after COVID-19. Laboratory tests indicated low urine osmolarity and increased serum osmolarity, and antidiuretic hormone (ADH) was undetectable. Urine osmolality remained low with water deprivation. Similarly, plasma ADH responses to hypertonic-saline infusion were blunted and urine osmolality increased in response to desmopressin. There was no clear evidence of anterior pituitary dysfunction. T1-weighted magnetic resonance imaging (MRI) showed pituitary stalk thickening and absence of posterior pituitary bright signal spots, suggesting the presence of hypophysitis. Based on these results, we made a probable diagnosis of lymphocytic infundibulo-neurohypophysitis (LINH) which have caused central diabetes insipidus. Positive findings for serum anti-rabphilin-3A antibodies, reported as a potential diagnostic marker for LINH, were also noted. Following oral desmopressin administration, polydipsia and polyuria were quickly improved, though treatment with desmopressin was still required over four months. This is the first report of a patient with a probable diagnosis of LINH after COVID-19 who tested positive for anti-rabphilin-3A antibodies. Positive findings for those antibodies suggest that pituitary dysfunction associated with COVID-19 is hypophysitis involving an abnormal immune mechanism. The presence of anti-rabphilin-3A antibodies may be useful as a non-invasive diagnostic marker of LINH and potentially serve as a valuable diagnostic aid in cases of LINH associated with COVID-19.

The diagnostic role of arginine-stimulated copeptin in the differential diagnosis of polyuria-polydipsia syndrome (PPS) in pediatric age.

In recent years, copeptin stimulation through arginine administration has been evaluated as a new potential tool in the differential diagnosis of polyuria-polydipsia syndrome (PPS) in adults; to date very few data, all retrospective, exist in pediatric age. The aim of this prospective study is to evaluate the diagnostic performance of the arginine-stimulation test for copeptin in a cohort of pediatric patients affected by PPS. All children (<18 years) referred to the Department of Pediatric Endocrinology of the Regina Margherita Children Hospital for polyuria-polydipsia in the period January 2021-June 2023 were enrolled. The Arginine-stimulation test for copeptin was performed in all patients presenting PPS after water deprivation test (WDT). Patients with polyuria-polydipsia were then classified as having primary polyuria (PP), complete and partial central diabetes insipidus (CDI), according to the standardized interpretation. Arginine-stimulation test for copeptin was also performed in a control cohort. A significant difference in arginine-stimulated copeptin values was observed at baseline (p = 0.005), at 60 min (p = 0.01), and at 90 min (p = 0.005) in 7 subjects presenting PP, 6 patients affected by CDI and 50 subjects of the control cohort. Plasma osmolality values remained stable at all measurements. The arginine-stimulated copeptin test demonstrated sensitivity and specificity of 100%, whereas the sensitivity of the WDT test was 83.3% and the specificity was 85.7%. Given the reliability and the minor adverse effects and costs, the copeptin level after arginine administration could replace the WDT in the diagnostic workup of these in pediatric age.

Caffeine Intake and its Effect on Hydration Status Among Workers: A Literature Review

Introduction: caffeine is one of a compound that is widely found in coffee, tea, energy drink, and chocolate. Their consumption is high among adults, especially workers during working hours. The diuretic effect from caffeine, caffeinated beverages’ density, and drink behavior change due to the consumption of caffeinated beverages might alter the hydration status. Moreover, low hydration status is associated with work performance where heat strain may worsen it. The objective of this study is to review the original studies on the association of caffeine intake and hydration status among workers. Methods: studies were obtained from 4 electronic databases which are Scopus, PubMed, EBSCO, and google scholar. Inclusion criteria were published in English or Bahasa Indonesia, between January 2000 and February 2023. Only originals studies included with the method of experimental or observational studies.Results: there were eighteen studies found regarding the association between caffeine intake and hydration status. The indicator of hydration status varied from urine specific gravity, urine or serum osmolality, urine color, glomerular filtration rate, urine pH, urine volume, body water, and rehydration capability. Most of the intervention was caffeine intake, but two studies involved tea consumption instead. Conclusions: Recent studies suggested inconclusive results between caffeine intake and hydration status in adults where some studies showed insignificant change between intervention and control groups and some others showed the poor quality of hydration status among caffeine consumers. More studies are necessary to conduct, especially among workers since their specifically high consumption of caffeine and the risky environment of working.