Low Predialysis Plasma Calculated Osmolality Is Associated with Higher All-Cause Mortality: The Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS)

The association between plasma osmolality and in-hospital mortality in the first 24 h after neonatal intensive care unit admission

Background

Perturbation of osmolality is associated with increased mortality in adults and children in critically ill conditions. However, it is still unclear whether osmolality imbalance impacts the prognosis of critically ill infants. This study aimed to investigate the relationship between plasma osmolality and prognosis in critically ill infants within 24 h of admission.

Methods

This retrospective study enrolled 1,042 infants who had plasma osmolality data from 2010 to 2018. The initial plasma osmolality (within 24 h after admission) was extracted from the pediatric intensive care database (PIC V1.1). The locally weighted scatter-plot smoothing (LOWESS) and restricted cubic splines (RCS) methods were used to explore the approximate relationship between plasma osmolality and in-hospital mortality. Univariate and multivariate logistic regression analyses were used to further analyse this relationship. Kaplan-Meier analysis was applied to estimate the probability of hospital mortality within 90 days of admission. Subgroup analysis was employed to assess the impact of potential confounders (including postnatal days, gender, and gestational age).

Results

An approximately"U"-shaped relationship between plasma osmolality and mortality was detected. In the logistic regression model, plasma osmolality <270 mmol/L (low osmolality group) was significantly associated with in-hospital mortality (P < 0.05; OR 2.52; 95% CI, 1.15-5.06). Plasma osmolality >300 mmol/L (high osmolality group) was also significantly associated with mortality (P < 0.05; OR 3.52; 95% CI, 1.16-8.83). This association remained even after multivariable adjustments. The 90-day survival rate was lower in the abnormal plasma osmolality group (including high or low osmolality groups) than in the intermediate group (log-rank test, P < 0.05). The abnormal plasma osmolality group had a significantly higher incidence of all-cause mortality in the 0-7 postnatal days subgroup (high osmolality group, P < 0.05; OR 5.25; low osmolality group, P < 0.05; OR 3.01). Infants with abnormal osmolality had a significantly higher mortality rate in the female group (P < 0.05). High osmolality was associated with a higher mortality rate in the preterm group (P < 0.05).

Conclusions

Both hypoosmolality and hyperosmolality were shown to be independently associated with increased risk of in-hospital infant mortality in NICUs.

Association of serum osmolality with all-cause and cardiovascular mortality in US adults: A prospective cohort study

BACKGROUND AND AIMS

The association between serum osmolality, an effective indicator of body hydration status, and long-term mortality in the general population remains undetermined. The present study aimed to investigate the association of serum osmolality with long-term all-cause and cardiovascular mortality among adults in the United States.

METHODS AND RESULTS

This cohort study used data from the National Health and Nutrition Examination Survey (NHANES) 2007-2014. Participants were linked to National Death Index mortality data from the survey date through December 31, 2019. Cox proportional hazards regression model was used to calculate hazard ratios (HRs) and 95% CIs, and restricted cubic spline (RCS) regression was conducted. A total of 18312 US adults were included. During a median follow-up of 8.7 years, 1353 total deaths occurred, including 379 cardiovascular deaths. After multivariable adjustments, compared with the 3rd quartile (Q3) of serum osmolality, participants in the 1st (Q1) and 4th (Q4) quartiles were at a significantly higher risk of all-cause mortality (HR 1.41 [95% CI, 1.14-1.75] and 1.29 [95% CI, 1.04-1.61], respectively). RCS revealed a nonlinear relationship of serum osmolality to all-cause and cardiovascular mortality, with an inflection point of 278 mmol/kg.

CONCLUSION

In the nationally representative cohort of US adults, serum osmolality was nonlinearly associated with all-cause and cardiovascular mortality. The risk of mortality was lowest around an osmolality of 278 mmol/kg. These findings suggest the importance of serum osmolality management for long-term health outcomes.

Serum osmolarity does not predict mortality in patients with respiratory failure

We aimed to determine the parameters that affect mortality in pulmonary intensive care units that are faster and inexpensive to determine than existing scoring systems. The relationship between serum osmolarity and prognosis was demonstrated for predialysis patients, in acute pulmonary embolism, heart failure, acute coronary syndrome, myocardial infarction, and acute spontaneous intracerebral hemorrhage in the literature. We hypothesized that serum osmolarity, which is routinely evaluated, may have prognostic significance in patients with respiratory failure.This study comprised 449 patients treated in the Pulmonary Intensive Care Clinic (PICU) of our hospital between January 1, 2020, and December 31, 2020. The modified Charlson Comorbidity Index (mCCI), Acute Physiology and Chronic Health Assessment (APACHE II), Sequential Organ Failure Evaluation Score (SOFA), Nutrition Risk Screening 2002 (NRS-2002), and hospitalization serum osmolarity levels were measured.Of the 449 patients included in the study, 65% (n = 292) were female and the mean age of all patients was 69.86 ± 1.72 years. About 83.1% (n = 373) of the patients included in the study were discharged with good recovery. About 4.9% (n = 22) were transferred to the ward because their intensive care needs were over. About 6.9% (n = 31) were transferred to the tertiary intensive care unit after their status deteriorated. About 5.1% (n = 23) died in the PICU. In the mortality group, APACHE II (P = .005), mCCI (P < .001), NRS-2002 total score (P < .001), and SOFA score (P < .001) were significantly higher. There was no statistically significant difference between the groups in terms of serum osmolarity levels.Although we could not determine serum osmolarity as a practical method to predict patient prognosis in this study, we assume that our results will guide future studies on this subject.

The Relationships between Water Intake and Hydration Biomarkers and the Applications for Assessing Adequate Total Water Intake among Young Adults in Hebei, China

Water is an essential nutrient for humans. A cross-sectional study was conducted among 159 young adults aged 18–23 years in Hebei, China. The total drinking fluids and water from food were obtained by 7-day 24 h fluid intake questionnaires and the duplicate portion method, respectively. Pearson’s correlation coefficients were performed to determine the relationship between fluid intake and 24 h urinary biomarkers and plasma biomarkers. A multivariable partial least squares (PLS) model was used to identify the key predictors in modeling the total water intake (TWI) with 24 h urine biomarkers. Logistic regressions of the TWI against binary variables were performed, and the receiver operating characteristic curve (ROC) was analyzed to determine the cutoff value of the TWI for the optimal hydration status and dehydration without adjustments to favor either the sensitivity or specificity. In total, 156 participants (80 males and 76 females) completed the study. Strong relationships were found between the total drinking fluids, TWI, and 24 h urine biomarkers among young adults, especially for the 24 h urine volume (r = 0.784, p < 0.001; r = 0.747, p < 0.001) and osmolality (r = −0.589, p < 0.001; r = −0.477, p < 0.001), respectively. As for the FMU and plasma biomarkers, no strong relationships were found. The percentages of the variance in TWI explained by the PLS model with 13 urinary biomarkers were 66.9%. The optimal TWI values for assessing the optimal hydration and dehydration were 2892 mL and 2482 mL for young males, respectively, and 2139 mL and 1507 mL for young females, respectively. Strong relationships were found between the TWI, total drinking fluids, and 24 h urine biomarkers, but not with the FMU and plasma biomarkers, among young adults, including males and females. The 24 h urine biomarkers were more sensitive than the first morning urinary biomarkers in reflecting the fluid intake. The TWI was a reliable index for assessing the hydration statuses for young adults in free-living conditions.

Evaluation of demographic and clinical risk factors for high interdialytic weight gain

Xerostomia and hyposalivation are highly prevalent in hemodialysis (HD) patients and this is effective in increased fluid intake. The aim of this study is to determine the demographic and clinical risk factors associated with high interdialytic weight gain (IDWG) in nondiabetic HD patients. In total, 52 eligible HD patients were recruited in this cross-sectional study. Patients were divided into two groups according to % IDWG: Group 1: High IDWG (≥3%) and Group 2: normal IDWG (<3%). Plasma osmolarity (POsm), unstimulated salivary flow rate (USFR), xerostomia inventory (XI), and dialysis thirst inventory (DTI) were evaluated. The mean age of the patients was 53.7 ± 15.7 years. The prevalence of xerostomia was 53.8%, and hyposalivation was in 40.3% in the patients. High IDWG was positively correlated with XI and DTI while it was negatively correlated with POsm and USFR. The area under the receiver-operating characteristics curve for POsm for high IDWG was 0.661, with sensitivity of 63.8% and specificity of 72.7% for a cut-off point of 297.4 mOsm/L. Logistic regression analysis showed that advanced age odds ratio (OR: 1.215, p = 0.019), pill burden (OR: 1.162, p = 0.031), C-reactive protein (CRP; OR: 1.308, p = 0.042), and low POsm (OR: 0.768, p = 0.046) were independently related to high IDWG. The prevalence of xerostomia and thirst was higher in HD patients with high IDWG compared to the normal IDWG group. Age, CRP, low POsm, and pill burden were independently associated with high IDWG.

Early Plasma Osmolality Levels and Clinical Outcomes in Children Admitted to the Pediatric Intensive Care Unit: A Single-Center Cohort Study

Objective: Identifying high-risk children with a poor prognosis in pediatric intensive care units (PICUs) is critical. The aim of this study was to assess the predictive value of early plasma osmolality levels in determining the clinical outcomes of children in PICUs. Methods: We retrospectively assessed critically ill children in a pediatric intensive care database. The locally weighted-regression scatter-plot smoothing (LOWESS) method was used to explore the approximate relationship between plasma osmolality and in-hospital mortality. Linear spline functions and stepwise expansion models were applied in conjunction with a multivariate logistic regression to further analyze this relationship. A subgroup analysis by age and complications was performed. Results: In total, 5,620 pediatric patients were included in this study. An approximately "U"-shaped relationship between plasma osmolality and mortality was detected using LOWESS. In the logistic regression model using a linear spline function, plasma osmolality ≥ 290 mmol/L was significantly associated with in-hospital mortality [odds ratio (OR) 1.020, 95% confidence interval (CI) 1.010-1.031], while plasma osmolality <290 mmol/L was not significantly associated with in-hospital mortality (OR 0.990, 95% CI 0.966-1.014). In the logistic regression model with plasma osmolality as a tri-categorical variable, only high osmolality was significantly associated with in-hospital mortality (OR 1.90, 95% CI 1.38-2.64), whereas low osmolality was not associated with in-hospital mortality (OR 1.28, 95% CI 0.84-1.94). The interactions between plasma osmolality and age or complications were not significant. Conclusion: High osmolality, rather than low osmolality, can predict a poor prognosis in children in PICUs.