Background: There is increasing awareness of the physiological effects of Ramadan intermittent fasting (RIF) in obese subjects. However, there are no data on the effects of RIF on plasma volume changes (ΔPV) in individuals with different body weights. Background and Objectives: This study investigated the effects of RIF on ΔPV in normal-weight (NW) and overweight (OW) adult men, and adult men with obesity (OB) and severe obesity (SO). Materials and Methods: Thirty-two male subjects (32) were divided into four groups (n = 8 per group) according to their body mass index (BMI): normal weight (NW) (BMI < 25 kg/m2; age = 27.4 ± 3.8), overweight (OW) (BMI between 25 and 29.9 kg/m2; age = 26.8 ± 3.7), obese subjects (OB) (BMI between 30 and 34.9 kg/m2; age = 25.6 ± 2.9), and severely obesity (SO) (BMI between 35 and 40 kg/m2; age = 24.0 ± 4.1). Blood samples were collected for 24 h on 4 different occasions, at T0 before the start of the Ramadan month, at T1 15 days after the start of Ramadan, at T2 one day after the end of Ramadan, and at T3 on the 21st day after the end of Ramadan to determine ΔPV. All groups completed their fasting rituals for the 30 days of Ramadan. Results: A significant group × time effect occurred for body mass (p = 0.001; ES = 0.53), BMI (p = 0.001; ES = 0.53), and body fat percentage (p = 0.001; ES = 0.52). Post hoc tests indicated reductions in body mass in OB and SO at T1 (p = 0.03; ES = 0.21 and p = 0.002; ES = 0.12) and T2 (p = 0.03; ES = 0.31 and p = 0.02; ES = 0.23), reductions in BMI in OB and SO at T1 (p = 0.04; ES = 0.35 and p = 0.03; ES = 0.42) and T2 (p = 0.03; ES = 0.52 and p = 0.005; ES = 0.48), and reductions in body fat percentage only in OB AT T1 (p = 0.002; ES = 0.31) and T2 (p = 0.001; ES = 0.17). A significant group × time effect occurred for hematocrit (p = 0.02; ES = 0.34), hemoglobin (p = 0.01; ES = 0.35), and ΔPV (p = 0.02; ES = 0.18). Post hoc tests indicated increases in hematocrit in OB at T2 (p = 0.03; ES = 0.36) and hemoglobin in OB and SO at T1 (p = 0.03; ES = 0.35 and p = 0.002; ES = 0.32) and T2 (p = 0.003; ES = 0.21 and p = 0.002; ES = 0.33). There were also increases in ΔPV in OB at T1 and T2 (p = 0.002; ES = 0.25 and p = 0.003; ES = 0.22) and in SO only at T2 (p = 0.02; ES = 0.37). Contrast analysis indicated that NW was significantly lower than the grand mean of OW, Ob, and SO for all anthropometric and PVV variables (all p < 0.05). Conclusions: The effects of RIF on ΔPV and anthropometric characters was greater in obese individuals compared to normal-weight and overweight participants, suggesting that the improvements in body composition and ΔPV produced by RIF could positively influence obesity.

BACKGROUND: The increased diuresis after sodium-glucose cotransporter 2 inhibitor (SGLT2i) was associated with a reduction of the estimated plasma volume (ePV) in type 2 diabetic patients.
OBJECTIVE: We hypothesized that the early effect of SGLT2i on ePV may be monitored by the change of biomarkers of hemoconcentration.
METHODS: We analyzed the early- and long-term effect of SGLT2i empagliflozin on the ePV as assessed by biomarkers of hemoconcentration in a nondiabetic patient with heart failure and reduced ejection fraction (HFrEF) and a nondiabetic patient with heart failure and preserved ejection fraction (HFpEF). The ePV was calculated from hemoglobin and hematocrit levels by Duarte formula and ePV change was calculated by Strauss formula.
RESULTS: The ePV change was -22.56% between baseline and 1 month, and -37.60% between baseline and 12 months follow-up in a patient with HFrEF, and -6.18% and -16.40% in a patient with HFpEF, respectively.
CONCLUSIONS: The early effect of SGLT2i on ePV in patients with heart failure may be monitored by biomarkers of hemoconcentration.

We previously reported that sodium-glucose cotransporter 2 (SGLT2) inhibitors exert sustained fluid homeostatic actions through compensatory increases in osmotic diuresis-induced vasopressin secretion and fluid intake. However, SGLT2 inhibitors alone do not produce durable amelioration of fluid retention. In this study, we examined the comparative effects of the SGLT2 inhibitor dapagliflozin (SGLT2i group, n = 53) and the combined use of dapagliflozin and conventional diuretics, including loop diuretics and/or thiazides (SGLT2i + diuretic group, n = 23), on serum copeptin, a stable, sensitive, and simple surrogate marker of vasopressin release and body fluid status. After six months of treatment, the change in copeptin was significantly lower in the SGLT2i + diuretic group than in the SGLT2i group (-1.4 ± 31.5% vs. 31.5 ± 56.3%, p = 0.0153). The change in the estimated plasma volume calculated using the Strauss formula was not significantly different between the two groups. Contrastingly, changes in interstitial fluid, extracellular water, intracellular water, and total body water were significantly lower in the SGLT2i + diuretic group than in the SGLT2i group. Changes in renin, aldosterone, and absolute epinephrine levels were not significantly different between the two groups. In conclusion, the combined use of the SGLT2 inhibitor dapagliflozin and conventional diuretics inhibited the increase in copeptin levels and remarkably ameliorated fluid retention without excessively reducing plasma volume and activating the renin-angiotensin-aldosterone and sympathetic nervous systems.

BACKGROUND: Acute kidney injury (AKI) remains a common complication of coronary revascularization and increases poor outcomes in critically ill surgical patients. Compared to the plasma volume status (PVS), estimated plasma volume status (ePVS) has the advantages of being noninvasive and simple and has been shown to be associated with worse prognosis in patients undergoing coronary revascularization. This study was to evaluate the association of ePVS with the risk of AKI in patients who underwent coronary revascularization.
METHODS: In this retrospective cohort study, data of patients who underwent coronary revascularization were extracted from the Medical Information Mart for Intensive Care (MIMIC)-IV database (2008-2019). The outcome was the occurrence of AKI after ICU admission. The covariates were screened via the LASSO regression method. Univariate and multivariate Logistic regression models were performed to assess the association of ePVS and PVS and the odds of AKI in patients who underwent coronary revascularization, with results shown as odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses of age, surgery, and anticoagulation agents and sequential organ failure assessment (SOFA) score were performed to further explore the association of ePVS with AKI.
RESULTS: A total of 3,961 patients who underwent coronary revascularization were included in this study, of whom 2,863 (72.28%) had AKI. The high ePVS was associated with the higher odds of AKI in patients who received coronary revascularization (OR = 1.06, 95%CI: 1.02-1.10), after adjusting for the covariates such as age, race, SAPS-II score, SOFA score, CCI, weight, heart rate, WBC, RDW-CV, PT, BUN, glucose, calcium, PH, PaO2, mechanical ventilation, vasopressors, and diuretic. Similar results were found in patients who underwent the CABG (OR = 1.07, 95%CI: 1.02-1.11), without anticoagulation agents use (OR = 1.07, 95%CI: 1.03-1.12) and with high SOFA score (OR = 1.10, 95%CI: 1.04-1.17). No relationship was found between PVS and the odds of AKI in patients who underwent the coronary revascularization.
CONCLUSIONS: The ePVS may be a promising parameter to evaluate the risk of AKI in patients undergoing coronary revascularization, which provides a certain reference for the risk stratification management of ICU patients who underwent coronary revascularization.

In chronic heart failure, dilutional anemia and hypervolemia may occur due to plasma volume expansion, the latter sometimes exacerbated by an increase in red cell volume. Diagnosis and a therapeutic strategy require determination of vascular volumes.

UNASSIGNED: Blood volume (BV) profiles vary markedly in patients with heart failure (HF), but how HF phenotypes and patient sex impact volume profiles remain to be explored. The aim of the study was to differentiate BV, plasma volume, and red blood cell mass profiles by phenotypes of preserved and reduced left ventricular ejection fractions and assess the impact of patient sex on profile heterogeneity.
UNASSIGNED: Retrospective analysis of clinical and BV data was undertaken in patients with chronic New York Heart Association II-III heart failure. BV was quantitated using the nuclear medicine indicator-dilution methodology.
UNASSIGNED: A total of 530 BV analyses (360 HF with reduced ejection fraction and 170 HF with preserved ejection fraction) were identified in 395 unique patients. Absolute BV was greater in HF with reduced ejection fraction (6.7±1.8 versus 5.9±1.6 liters: P<0.001); however, large variability in frequency distribution of volume profiles was observed in both phenotypes (-22% deficit to +109% excess relative to normal volumes). HF with reduced ejection fraction was characterized by a higher prevalence of BV expansion ≥+25% of normal (39% versus 26%; P=0.003), and HF with preserved ejection fraction was characterized a by more frequent normal BV (42% versus 24%; P<0.001). Male sex in both phenotypes was associated with a larger absolute BV (7.0±1.6 versus 5.1±1.3 liters; P<0.001) and higher frequency of large BV and plasma volume expansions above normal (both P<0.001), while females in both phenotypes demonstrated a higher prevalence of normal BV and plasma volume (both P<0.001).
UNASSIGNED: Findings support significant differences in BV, plasma volume, and red blood cell mass profile distributions between heart failure phenotypes, driven in large part by sex-specific factors. This underscores the importance of identifying and distinguishing individual patient volume profiles to help guide volume management strategies.

OBJECTIVE: Plasma volume status (PVS), a measure of plasma volume, has been evaluated as a prognostic marker for chronic heart failure. Although the prognostic value of PVS has been reported, its significance in patients with acute decompensated heart failure (ADHF) admitted to the cardiovascular intensive care unit (CICU) remains unclear. In this study, we examined the relationship between PVS and long-term mortality in patients with ADHF admitted to the CICU.
METHODS: Between January 2018 and December 2020, 363 consecutive patients with ADHF were admitted to the Nippon Medical School Hospital CICU. Of the 363 patients, 206 (mean age, 74.9 ± 12.9 years; men, 64.6%) were enrolled in this study. Patients who received red blood cell transfusions, underwent dialysis, were discharged from the CICU or died in the hospital were excluded from the study. We measured the PVS of the patients at admission, transfer to the general ward (GW) and discharge using the Kaplan-Hakim formula. The patients were assigned to four groups according to the quartiles of their PVS measured at each of the three abovementioned timepoints. We examined the association between PVS and all-cause mortality during the observation period (1134 days). The primary endpoint of this study was all-cause mortality.
RESULTS: The Kaplan-Meier analysis showed that the high PVS group had a significantly higher mortality rate at admission, transfer to the GW and discharge than the other groups (log-rank test: P = 0.016, P = 0.005 and P < 0.001, respectively). Univariate Cox regression analysis showed that age, body mass index, history of heart failure, use of beta-blockers, albumin level, blood urea nitrogen level, N-terminal pro-brain natriuretic peptide level and left ventricular ejection fraction were significantly different among the PVS groups and thus were not significant prognostic factors for ADHF. Furthermore, the multivariate analysis revealed that PVS at discharge [hazard ratio (HR) = 1.06 (1.00-1.12), P = 0.048] was an independent poor prognostic factor for ADHF.
CONCLUSIONS: This study highlights the effect of PVS measured at different timepoints on the prognoses of ADHF patients. Regular assessment of PVS, particularly at discharge, is crucial for optimising patient management and achieving favourable outcomes in cases of ADHF.

暂无摘要。

Orthostatic hypertension, defined by an increase of systolic blood pressure (SBP) of ≥20 mmHg upon standing, harbors an increased cardiovascular risk. We pooled data from two rigorously conducted head-down tilt bedrest studies to test the hypothesis that cardiopulmonary deconditioning and hypovolemia predispose to orthostatic hypertension. With bedrest, peak VO2 decreased by 6 ± 4 mlO2/min/kg (p < 0.0001) and plasma volume by 367 ± 348 ml (p < 0.0001). Supine SBP increased from 127 ± 9 mmHg before to 133 ± 10 mmHg after bedrest (p < 0.0001). In participants with stable hemodynamics following head-up tilt, the incidence of orthostatic hypertension was 2 out of 67 participants before bedrest and 2 out of 57 after bedrest. We conclude that in most healthy persons, cardiovascular deconditioning and volume loss associated with long-term bedrest are not sufficient to cause orthostatic hypertension.

BACKGROUND: Patients with cirrhosis often develop hyperdynamic circulation with increased cardiac output, heart rate, and redistribution of the circulating volume with expanded plasma volume (PV). PV determination is part of the evaluation of patients with cirrhosis, but gold-standard methods are invasive, expensive, and time-consuming. Therefore, other estimations of PV would be preferable, and the aim of this study was therefore to study if PV, as assessed by a simplified algorithm based on hematocrit and weight, can replace the gold-standard method.
METHODS: We included 328 patients with cirrhosis who had their PV assessed by the indicator dilution technique as the gold-standard method (PVI-125). Actual PV was estimated as PVa = (1 - hematocrit)·(a + (b·body weight)). Ideal PV was estimated as PVi = c · body weight, where a, b, and c are constants.
RESULTS: PVI-125, PVa, and PVi were 3.99 ± 1.01, 3.09 ± 0.54, and 3.01 ± 0.65 (Mean ± SD), respectively. Although PVI-125 correlated significantly with PVa (r = 0.72, p < 0.001), a Bland-Altman plot revealed wide limits of confidence.
CONCLUSIONS: The use of simplified algorithms does not sufficiently estimate PV and cannot replace the indicator dilution technique.