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BMJ Open Diabetes Research & Care Dec 2023This study aimed to evaluate the relationship between both low and high osmolarity and the risk of all-cause and cause-specific mortality in diabetic population.
AIMS
This study aimed to evaluate the relationship between both low and high osmolarity and the risk of all-cause and cause-specific mortality in diabetic population.
METHODS
All participants were included from the National Health and Nutrition Examination Survey 1999-2014. Baseline serum osmolality was determined from laboratory tests and cause of death from national death records. HRs and 95% CIs for all-cause mortality and cardiovascular mortality in diabetes were estimated using Cox proportional regression analysis. The non-linear relationship was explored using restricted cubic splines regression.
RESULTS
Among 7622 individuals with diabetes, 1983 (12.4%) died during a total of 3.26 thousand person-years of follow-up. Compared with the reference category (281-284 mmol/kg), the multivariable-adjusted HRs and 95% CIs for all-cause mortality were 1.27 (1.16-1.40; p<0.001) in the lowest osmolality category (<201 mmol/kg) and 1.18 (1.09-1.28; p<0.001) in the highest osmolality category (>312 mmol/kg). Restricted cubic splines results showed that serum levels of osmolality had a U-shaped association with the risk of all-cause mortality, and L-shaped relationship with the risk of cardiovascular death.
CONCLUSIONS
Both low osmolality and high osmolality were predictive of increased all-cause mortality in patients with diabetes, supporting a U-shaped relationship. Also, a lower serum osmolality increased the risk of cardiovascular mortality.
Topics: Humans; Nutrition Surveys; Risk Factors; Diabetes Mellitus; Cardiovascular Diseases; Osmolar Concentration
PubMed: 38135453
DOI: 10.1136/bmjdrc-2023-003826 -
Journal of Veterinary Internal Medicine 2023Heart failure-associated hypochloremia can be depletional from diuretics or dilutional from water retention. Serum osmolality reflects water balance but has not been...
BACKGROUND
Heart failure-associated hypochloremia can be depletional from diuretics or dilutional from water retention. Serum osmolality reflects water balance but has not been evaluated in dogs with heart disease.
HYPOTHESIS
To determine if serum osmolality is related to heart disease stage and amount of mathematical correction of serum chloride (Cl ) concentrations in healthy dogs and dogs with myxomatous mitral valve degeneration (MMVD).
ANIMALS
Seventy-seven dogs (20 healthy, 25 Stage B MMVD, 32 Stage C/D MMVD).
METHODS
Serum Cl concentrations were mathematically corrected. Osmolality was calculated (calOsm) and directly measured by freezing point depression (dmOsm) and compared by Bland-Altman analysis. Biochemical variables and osmolality were compared among healthy, Stage B, and Stage C/D dogs. Correlations were explored between osmolality and biochemical variables. Median and range are presented. P < .05 was considered significant.
RESULTS
The calOsm was different among groups (P = .003), with Stage B (310 mOsm/kg; 306, 316) and C/D dogs (312 mOsm/kg; 308, 319) having higher calOsm than healthy dogs (305 mOsm/kg; 302, 308). Osmolality methods were moderately correlated (P < .0001, r = .46) but with proportional bias and poor agreement. The amount of Cl correction was negatively correlated with calOsm (P < .0001, r = -.78) and dmOsm (P = .004, r = -.33). Serum bicarbonate concentration was negatively correlated with Cl (P < .0001, r = -.67).
CONCLUSIONS AND CLINICAL IMPORTANCE
Dogs with Stage B and Stage C/D heart disease had higher calOsm than healthy dogs. Osmolality was inversely related to the amount of Cl correction, which supports its use in assessing relative body water content. Poor agreement between calOsm and dmOsm prevents methodological interchange.
Topics: Dogs; Animals; Chlorides; Heart Diseases; Mitral Valve Prolapse; Heart Failure; Osmolar Concentration; Water; Dog Diseases
PubMed: 37702389
DOI: 10.1111/jvim.16863 -
MBio Aug 2023Changes to gut environmental factors such as pH and osmolality due to disease or drugs correlate with major shifts in microbiome composition; however, we currently...
Changes to gut environmental factors such as pH and osmolality due to disease or drugs correlate with major shifts in microbiome composition; however, we currently cannot predict which species can tolerate such changes or how the community will be affected. Here, we assessed the growth of 92 representative human gut bacterial strains spanning 28 families across multiple pH values and osmolalities . The ability to grow in extreme pH or osmolality conditions correlated with the availability of known stress response genes in many cases, but not all, indicating that novel pathways may participate in protecting against acid or osmotic stresses. Machine learning analysis uncovered genes or subsystems that are predictive of differential tolerance in either acid or osmotic stress. For osmotic stress, we corroborated the increased abundance of these genes during osmotic perturbation. The growth of specific taxa in limiting conditions in isolation correlated with survival in complex communities and in an mouse model of diet-induced intestinal acidification. Our data show that stress tolerance results are generalizable and that physical parameters may supersede interspecies interactions in determining the relative abundance of community members. This study provides insight into the ability of the microbiota to respond to common perturbations that may be encountered in the gut and provides a list of genes that correlate with increased ability to survive in these conditions. IMPORTANCE To achieve greater predictability in microbiota studies, it is crucial to consider physical environmental factors such as pH and particle concentration, as they play a pivotal role in influencing bacterial function and survival. For example, pH is significantly altered in various diseases, including cancers, inflammatory bowel disease, as well in the case of over-the-counter drug use. Additionally, conditions like malabsorption can affect particle concentration. In our study, we investigate how changes in environmental pH and osmolality can serve as predictive indicators of bacterial growth and abundance. Our research provides a comprehensive resource for anticipating shifts in microbial composition and gene abundance during complex perturbations. Moreover, our findings underscore the significance of the physical environment as a major driver of bacterial composition. Finally, this work emphasizes the necessity of incorporating physical measurements into animal and clinical studies to better understand the factors influencing shifts in microbiota abundance.
Topics: Humans; Animals; Mice; Gastrointestinal Microbiome; Microbiota; Bacteria; Osmolar Concentration; Hydrogen-Ion Concentration
PubMed: 37432034
DOI: 10.1128/mbio.00753-23 -
Microbial Cell Factories Jul 2011The filamentous fungus Aspergillus niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most...
BACKGROUND
The filamentous fungus Aspergillus niger is a widely used strain in a broad range of industrial processes from food to pharmaceutical industry. One of the most intriguing and often uncontrollable characteristics of this filamentous organism is its complex morphology, ranging from dense spherical pellets to viscous mycelia depending on culture conditions. Optimal productivity correlates strongly with a specific morphological form, thus making high demands on process control.
RESULTS
In about 50 2L stirred tank cultivations the influence of osmolality on A. niger morphology and productivity was investigated. The specific productivity of fructofuranosidase producing strain A. niger SKAn 1015 could be increased notably from 0.5 to 9 U mg(-1) h(-1) around eighteen fold, by increasing the culture broth osmolality by addition of sodium chloride. The specific productivity of glucoamylase producing strain A. niger AB1.13, could be elevated using the same procedure. An optimal producing osmolality was shown to exist well over the standard osmolality at about 3.2 osmol kg(-1) depending on the strain. Fungal morphology of all cultivations was examined by microscope and characterized by digital image analysis. Particle shape parameters were combined to a dimensionless Morphology number, which enabled a comprehensive characterization of fungal morphology correlating closely with productivity. A novel method for determination of germination time in submerged cultivations by laser diffraction, introduced in this study, revealed a decelerated germination process with increasing osmolality.
CONCLUSIONS
Through the introduction of the versatile Morphology number, this study provides the means for a desirable characterization of fungal morphology and demonstrates its relation to productivity. Furthermore, osmolality as a fairly new parameter in process engineering is introduced and found to affect fungal morphology and productivity. Osmolality might provide an auspicious and reliable approach to increase the productivity in industrial processes. Because of the predictable behavior fungal morphology showed in dependence of osmolality, a customization of morphology for process needs seems feasible.
Topics: Aspergillus niger; Glucan 1,4-alpha-Glucosidase; Microscopy; Osmolar Concentration; Sodium Chloride
PubMed: 21801352
DOI: 10.1186/1475-2859-10-58 -
Current Opinion in Critical Care Dec 2008Hyponatremia is the most common electrolyte disorder present in hospitalized patients. Acute and severe hyponatremia can cause significant morbidity and mortality. The... (Review)
Review
PURPOSE OF REVIEW
Hyponatremia is the most common electrolyte disorder present in hospitalized patients. Acute and severe hyponatremia can cause significant morbidity and mortality. The present review discusses the epidemiology, causes, and a practical approach to the diagnosis and management of acute and chronic hyponatremia, including the appropriate use of hypertonic saline and potential future use of the new V2 vasopressin receptor antagonists in critically ill patients.
RECENT FINDINGS
The increasing knowledge of aquaporin water channels and the role of vasopressin in water homeostasis have enhanced our understanding of hyponatremic disorders. Increased vasopressin secretion due to nonosmotic stimuli leads to decreased electrolyte-free water excretion with resulting water retention and hyponatremia. Vasopressin receptor antagonists induce electrolyte-free water diuresis without natriuresis and kaliuresis. Phase three trials indicate that these agents predictably reduce urine osmolality, increase electrolyte-free water excretion, and raise serum sodium concentration. They are likely to become a mainstay of treatment of euvolemic and hypervolemic hyponatremia.
SUMMARY
The correct diagnosis and management of hyponatremia is complex and requires a systematic approach. Vasopressin receptor antagonists are potential tools in the management of hyponatremia. Further studies are needed to determine their role in the treatment of acute, severe, life-threatening hyponatremia as well as chronic hyponatremia.
Topics: Acute Disease; Humans; Hyponatremia; Osmolar Concentration; Osmotic Pressure; Receptors, Vasopressin; Vasoconstrictor Agents; Vasopressins; Water-Electrolyte Balance; Water-Electrolyte Imbalance
PubMed: 19005303
DOI: 10.1097/MCC.0b013e32830e45e3 -
Investigative and Clinical Urology Sep 2023To investigate the treatment outcome of nocturnal enuresis (NE) according to first-morning urine osmolality (Uosm) before treatment.
PURPOSE
To investigate the treatment outcome of nocturnal enuresis (NE) according to first-morning urine osmolality (Uosm) before treatment.
MATERIALS AND METHODS
Ninety-nine children (mean age, 7.2±2.1 y) with NE were enrolled in this retrospective study and divided into two groups according to first-morning Uosm results, that is, into a low Uosm group (<800 mOsm/L; 38 cases, 38.4%) or a high Uosm group (≥800 mOsm/L; 61 cases, 61.6%). Baseline parameters were obtained from frequency volume charts of at least 2 days, uroflowmetry, post-void residual volume, and a questionnaire for the presence of frequency, urgency, and urinary incontinence. Standard urotherapy and pharmacological treatment were administered initially in all cases. Enuresis frequency and response rates were analyzed at around 1 month and 3 months after treatment initiation.
RESULTS
The level of first-morning Uosm was 997.1±119.6 mOsm/L in high Uosm group and 600.9±155.9 mOsm/L in low Uosm group (p<0.001), and first-morning voided volume (p=0.021) and total voided volume (p=0.019) were significantly greater in the low Uosm group. Furthermore, a significantly higher percentage of children in the low Uosm group had a response rate of ≥50% (CR or PR) at 1 month (50.0% vs. 24.6%; p=0.010) and 3 months (63.2% vs. 36.1%; p=0.009).
CONCLUSIONS
Treatment response rates are higher for children with NE with a lower first-morning Uosm.
Topics: Child; Humans; Child, Preschool; Nocturnal Enuresis; Prospective Studies; Retrospective Studies; Urinary Incontinence; Osmolar Concentration
PubMed: 37668207
DOI: 10.4111/icu.20220377 -
Comparative Biochemistry and... Sep 2021Decapod crustaceans show variable degrees of euryhalinity and osmoregulatory capacity, by responding to salinity changes through anisosmotic extracellular regulation...
Decapod crustaceans show variable degrees of euryhalinity and osmoregulatory capacity, by responding to salinity changes through anisosmotic extracellular regulation and/or cell volume regulation. Cell volume regulatory mechanisms involve exchange of inorganic ions between extra- and intra-cellular (tissue) compartments. Here, this interplay of inorganic ions between both compartments has been evaluated in four decapod species with distinct habitats and osmoregulatory strategies. The marine/estuarine species Litopenaeus vannamei (Lv) and Callinectes danae (Cd) were submitted to reduced salinity (15‰), after acclimation to 25 and 30‰, respectively. The freshwater Macrobrachium acanthurus (Ma) and Aegla schmitti (As) were submitted to increased salinity (25‰). The four species were salinity-challenged for both 5 and 10 days. Hemolymph osmolality, sodium, chloride, potassium, and magnesium were assayed. The same inorganic ions were quantified in muscle samples. Muscle hydration (MH) and ninhydrin-positive substances (NPS) were also determined. Lv showed slight hemolymph dilution, increased MH and no osmotically-relevant decreases in muscle osmolytes; Cd displayed hemolymph dilution, decreased muscular NaCl and stable MH; Ma showed hypo-regulation and steady MH, with no change in muscle ions; As conformed hemolymph sodium but hypo-regulated chloride, had stable MH and increased muscle NPS and ion levels. Hemolymph and muscle ions (especially chloride) of As were highly correlated (Pearson, +0.83). Significant exchanges between hemolymph and muscle ionic pools were more evident in the two species with comparatively less AER regulatory power, C. danae and A. schmitti. Our findings endorse that the interplay between extracellular and tissue ionic pools is especially detectable in euryhaline species with relatively lower osmoregulatory strength.
Topics: Animals; Cadmium; Decapoda; Hemolymph; Ions; Magnesium; Osmolar Concentration; Osmoregulation; Palaemonidae; Penaeidae; Potassium; Salinity; Sodium Chloride; Species Specificity; Water-Electrolyte Balance
PubMed: 34098129
DOI: 10.1016/j.cbpa.2021.111001 -
European Journal of Heart Failure Feb 2016In the EVEREST trial, tolvaptan improved symptoms and body weight during hospitalization for heart failure (HF), but did not improve post-discharge cardiovascular...
AIMS
In the EVEREST trial, tolvaptan improved symptoms and body weight during hospitalization for heart failure (HF), but did not improve post-discharge cardiovascular outcomes. We hypothesized that this disconnect between the short- and long-term effects may be related to changes in serum osmolality. We describe the longitudinal profile of osmolality and its response to tolvaptan during and after hospitalization for HF.
METHODS AND RESULTS
EVEREST enrolled 4133 patients hospitalized for HF and reduced EF. Serum osmolality data were available in 3744 (91%). We assessed the effects of tolvaptan on serum osmolality and related these effects to in-hospital changes in body weight and physician-assessed symptoms. Calculated values of osmolality, determined from serum sodium, blood urea nitrogen, and glucose, were 3-4 mOsm/kg higher than concurrently measured serum osmolality at enrolment and discharge in both treatment arms. During hospitalization in the placebo group, serum osmolality slightly increased throughout hospitalization, whereas serum sodium decreased and blood urea nitrogen increased until discharge. Tolvaptan increased osmolality by hospital day 1, but this effect diminished by post-discharge week 4-8 and disappeared by post-discharge week 56. In-hospital changes in osmolality were poorly correlated with in-hospital changes in body weight and physician-assessed dyspnoea.
CONCLUSION
Tolvaptan increased serum osmolality during hospitalization for HF, a time frame when the drug also improved signs and symptoms of HF. However, this effect on osmolality declined in the early post-discharge period, when tolvaptan failed to influence clinical outcomes. Serum osmolality, which can be estimated based on readily available laboratory parameters, may be a marker or a target of response to tolvaptan.
Topics: Antidiuretic Hormone Receptor Antagonists; Benzazepines; Heart Failure; Hospitalization; Humans; Osmolar Concentration; Randomized Controlled Trials as Topic; Tolvaptan
PubMed: 26443242
DOI: 10.1002/ejhf.415 -
Environmental Research Jan 2015For many environmental chemicals, concentrations in spot urine samples are considered valid surrogates of exposure and internal dose. To correct for urine dilution, spot...
BACKGROUND
For many environmental chemicals, concentrations in spot urine samples are considered valid surrogates of exposure and internal dose. To correct for urine dilution, spot urine concentrations are commonly adjusted for urinary creatinine. There are, however, several concerns about the use of urine creatinine. While urine osmolality is an attractive alternative; its characteristics and determinants in the general population remain unknown. Our objective was to describe the determinants of urine osmolality and to contrast the difference between osmolality and creatinine in urine.
METHODS
From the National Health and Nutrition Examination Survey (NHANES) (2009-2010), 10,769 participants aged 16 years or older with measured urine osmolality and creatinine were used in the analysis. Very dilute and very concentrated urine was defined as urine creatinine lower than 0.3g/l and higher than 3g/l, respectively. Linear and logistic regression analyses were performed to investigate the associations of interest.
RESULTS
Urine osmolality and creatinine were highly correlated (Pearson correlation coefficient=0.75) and their respective median values were 648 mOsm/kg and 1.07 g/l. The prevalence of very dilute and very concentrated urine samples was 8.1% and 3.1%, respectively. Factors associated in the same direction with both urine osmolality and urine creatinine included age, sex, race, body mass index (BMI), hypertension, water intake, and blood osmolality. The magnitude of associations expressed as percent change was significantly stronger with creatinine than osmolality. Compared to urine creatinine, urine osmolality did not vary by diabetes status but was affected by daily total protein intake. Participants with chronic kidney disease (CKD) had significantly higher urine creatinine concentrations but lower urine osmolality. Both very dilute and concentrated urine were associated with a diverse array of sociodemographic, medical conditions, and dietary factors. For instance, females were approximately 3.3 times more likely to have urine over-dilution than male [the adjusted odds ratios (95% CI)=3.27 (2.10-5.10)].
CONCLUSION
Although the determinants of urine osmolality were generally similar to those of urine creatinine, the relative influence of socio-demographic and medical conditions was less on urine osmolality than on urine creatinine. Protocols for spot urine sample collection could recommend avoiding excessive and insufficient water intake before urine sampling to improve urine adequacy. The feasibility of adopting urine osmolality adjustment and water intake recommendations before providing spot urine samples for environmental biomonitoring merits further investigation.
Topics: Environmental Exposure; Environmental Monitoring; Female; Humans; Male; Nutrition Surveys; Osmolar Concentration; United States; Urine
PubMed: 25460670
DOI: 10.1016/j.envres.2014.09.009 -
American Journal of Physiology. Cell... Apr 2009The corticomedullary osmolality gradient is the driving force for water reabsorption occurring in the kidney. In the collecting duct, this gradient allows luminal water... (Review)
Review
The corticomedullary osmolality gradient is the driving force for water reabsorption occurring in the kidney. In the collecting duct, this gradient allows luminal water to move across aquaporin (AQP) water channels, thereby increasing urine concentration. However, this same gradient exposes renal cells to great osmotic challenges. These cells must constantly adapt to fluctuations of environmental osmolality that challenge cell volume and incite functional change. This implies profound alterations of cell phenotype regarding water permeability. AQP2 is an essential component of the urine concentration mechanism whose controlled expression dictates apical water permeability of collecting duct principal cells. This review focuses on changes of AQP2 abundance and trafficking in hypertonicity-challenged cells. Intracellular mechanisms governing these events are discussed and the biological relevance of altered AQP2 expression by hypertonicity is outlined.
Topics: Adaptation, Physiological; Animals; Aquaporin 2; Cell Membrane Permeability; Cell Size; Humans; Hypertonic Solutions; Kidney; Kidney Concentrating Ability; Osmolar Concentration; Osmotic Pressure; Protein Transport; Signal Transduction; Water; Water-Electrolyte Balance
PubMed: 19211910
DOI: 10.1152/ajpcell.00655.2008