Twenty-four-hour Urinary Salt Excretion on Admission Predicts Significant Weight Loss with Seven-day Dietary Salt Restriction in Hospitalized Patients with Chronic Kidney Disease: A Single-center Study.

In patients with chronic kidney disease (CKD), restricting dietary salt is recommended to prevent fluid retention. Rapid weight loss is often observed when CKD patients with a high salt intake are hospitalized and started on a low-salt diet. We investigated the effects of 7-day dietary salt restriction on weight loss in hospitalized patients with CKD. During the 7-day hospitalization, a low-salt (6 g/day) and low-protein (0.6-0.8 g/kg/day ideal body weight) diet was served to all patients. Urine samples were collected for the first 24 h after admission, and patients were divided into quartiles (Q1-Q4) by urinary salt excretion. Body weight was measured on days 1 and 7. Weight loss after admission was compared among the groups. Factors associated with weight loss were evaluated by multivariate logistic regression. The mean age of the patients was 70.3 ± 11.7 years, and 73% were male. Mean weight loss was 1.6 ± 1.7 kg on day 7. Weight loss was significantly greater in Q3 and Q4 than in Q1 (P = 0.009 and P <0.001, respectively). In the univariate analysis, weight loss correlated positively with 24-h urinary salt excretion on admission (γ2 = 0.146) and body mass index (γ2 = 0.223). The 24-h urinary salt excretion on admission and BMI were independently associated with weight loss of >2 kg. The adjusted odds ratios (95% confidence interval) were 1.24 (1.13-1.36) and 1.15 (1.07-1.22), respectively. Twenty-four-hour urinary salt excretion on admission is useful for predicting significant weight loss with short-term dietary salt restriction.

Hypouricemia in the emergency department: A retrospective, single-center study.

Backgrounds: Few studies have reported the prevalence and characteristics of hypouricemia in the emergency department (ED). We investigated the prevalence and characteristics of hypouricemia in the ED of a university-affiliated hospital in Japan. Methods: This is a retrospective cross-sectional single-center study. All adult patients (18 years old or older) who had their serum uric acid (SUA) measured at the ED between 2011 and 2021 were included. Information collected included age, sex, SUA, and serum creatinine. Hypouricemia was defined as an SUA level ≦2.0 mg/dL. Results: A total of 10,551 patients were included in the study. Fifty-one percent were male. The median SUA levels were significantly higher in men than in women (6.0 [4.8-7.4] vs. 4.7 [3.7-6.1], p < 0.001). The prevalence of hypouricemia was higher in women than in men (2.0% vs. 0.9%, p < 0.001). A possible cause of hypouricemia was identified in 88 patients. Malignancy and diabetes were the major possible cause of hypouricemia (p < 0.001). Conclusion: The distribution of SUA levels and prevalence of hypouricemia differed significantly by sex and age in the ED. Malignancy was the leading cause of hypouricemia in the ED.

Impact of early initiation of renin-angiotensin blockade on renal function and clinical outcomes in patients with hypertensive emergency: a retrospective cohort study.

BACKGROUND: Hypertensive emergency is a critical disease that causes multifaceted sequelae, including end-stage kidney disease and cardiovascular disease. Although the renin-angiotensin-aldosterone (RAA) system is enormously activated in this disease, there are few reports that attempt to characterize the effect of early use of RAA inhibitors (RASi) on the temporal course of kidney function. METHODS: This retrospective cohort study was conducted to clarify whether the early use of RASi during hospitalization offered more favorable benefits on short-term renal function and long-term renal outcomes in patients with hypertensive emergencies. We enrolled a total of 49 patients who visited our medical center with acute severe hypertension and multiple organ dysfunction between April 2012 and August 2020. Upon admission, the patients were treated with intravenous followed by oral antihypertensive drugs, including RASi and Ca channel blockers (CCB). Kidney function as well as other laboratory and clinical parameters were compared between RASi-treated and CCB- treated group over 2 years. RESULTS: Antihypertensive treatment effectively reduced blood pressure from 222 ± 28/142 ± 21 to 141 ± 18/87 ± 14 mmHg at 2 weeks and eGFR was gradually restored from 33.2 ± 23.3 to 40.4 ± 22.5 mL/min/1.73m2 at 1 year. The renal effect of antihypertensive drugs was particularly conspicuous when RASi was started in combination with other conventional antihypertensive drugs at the early period of hospitalization (2nd day [IQR: 1-5.5]) and even in patients with moderately to severely diminished eGFR (< 30 mL/min/1.73 m2) on admission. In contrast, CCB modestly restored eGFR during the observation period. Furthermore, renal survival probabilities were progressively deteriorated in patients who had manifested reduced eGFR (< 15 mL/min/1.73 m2) or massive proteinuria (urine protein/creatinine ≥ 3.5 g/gCr) on admission. Early use of RASi was associated with a favorable 2-year renal survival probability (0.90 [95%CI: 0.77-1.0] vs. 0.63 [95%CI: 0.34-0.92] for RASi ( +) and RASi (-), respectively, p = 0.036) whereas no apparent difference in renal survival was noted for CCB. CONCLUSIONS: Early use of RASi contributes to the renal functional recovery from acute reduction in eGFR among patients with hypertensive emergencies. Furthermore, RASi offers more favorable effect on 2-year renal survival, compared with CCB.

Incidence and risk factors of overcorrection in patients presenting with severe hyponatremia to the emergency department.

BACKGROUND: Hyponatremia is one of the most common electrolyte abnormalities. Overcorrection of severe hyponatremia can result in serious neurological complications such as osmotic demyelination syndrome, but the incidence and risk factors of overcorrection and osmotic demyelination have not been thoroughly investigated. METHODS: This is a single-center retrospective cohort study of 50 patients admitted through the emergency department with initial serum sodium (serum Na) < 125 mEq/L between January 2015 and December 2017. Incidence and risk factors of overcorrection and osmotic demyelination were examined. Overcorrection was defined as an increase in serum sodium concentration > 10 mEq/L at 24 h and/or > 18 mEq/L at 48 h, respectively. RESULTS: Six patients (12%) and one patient (2%) had overcorrection at 24 h and 48 h, respectively. A total of 5 (10%) patients had a brain MRI completed after overcorrection, and no patient showed radiologic evidence of osmotic demyelination. Symptomatic hyponatremia at presentation and 3% saline use were associated with the risk of overcorrection in univariable analysis (p < 0.001; p = 0.006, respectively). CONCLUSIONS: Among patients admitted with severe hyponatremia, overcorrection occurred in 14%. Symptomatic hyponatremia at presentation and 3% saline use were associated with the risk of overcorrection.

Severe hypokalemia in the emergency department: A retrospective, single-center study.

Background and Aims: Hypokalemia is one of the most common problems in the emergency department (ED). Severe hypokalemia, defined as a serum potassium level ≤2.5 mEq/L, is a relatively uncommon electrolyte disorder, and few studies have reported its prevalence, etiology, symptoms, and management in the ED. Therefore, we aimed to investigate them in this study. Methods: This retrospective single-center study included adult patients whose serum potassium levels were measured in the ED between 2012 and 2019. Data including age, sex, serum potassium levels, and serum creatinine levels were collected from the electronic medical records. Results: The serum potassium levels of 21,616 adult patients were measured. The median age of these patients was 73 years (range: 57-83 years), and 38% were men. The prevalence of severe hypokalemia was 0.4%. The most common symptom of symptomatic severe hypokalemia was weakness (p = 0.001). Malnutrition, use of Japanese herbal medicine, and use of diuretics were the main causes of severe hypokalemia. Sixty-one patients (70%) underwent electrocardiography. Fifty-nine patients (68%) received treatment for severe hypokalemia within one day of the visit. Conclusion: The management of severe hypokalemia in the ED may be suboptimal. Emergency physicians should be vigilant to avoid missing hypokalemia.

Seasonal Changes in the Prevalence of Hyperkalemia in the Emergency Department: A Single Center Study.

Background: Hyperkalemia is an electrolyte disorder frequently encountered in the emergency department. There are few studies on seasonal variation in the prevalence of hyperkalemia. The aim of this study was to investigate the seasonal changes in the prevalence of hyperkalemia in the emergency department. Materials and Methods: We retrospectively reviewed a total of 24,085 patients presented to the emergency department between January 2012 and December 2020. Age, gender, serum potassium level, and serum creatinine level were recorded. The definition used for hyperkalemia was a serum potassium level of ≥ 5.5 mEq/L. Renal function was divided into two categories: preserved (eGFR ≥ 60 mL/min/1.73 m2) or reduced (eGFR < 60 mL/min/1.73 m2). Results: The prevalence of hyperkalemia was 2.1% in patients with preserved renal function and was 11.9% in patients with reduced renal function (p < 0.001). The prevalence of hyperkalemia was highest in winter, followed by spring, autumn, and summer in patients with preserved renal function (p < 0.001) and those with reduced renal function (p < 0.001). There was a linear correlation between monthly weather temperature and the prevalence of hyperkalemia in patients with preserved renal function (r = -0.392; p < 0.001) and those with reduced renal function (r = -0.487; p < 0.001). Conclusions: we found that the prevalence of hyperkalemia was significantly higher in winter for both patients with preserved renal function and those with reduced renal function.

Tonicity Matters, Especially in Complex Hyponatremia Resulting from Pseudo-, Trans-locational, and True Hypotonic Hyponatremia: An Educational Case Report.

Serum tonicity is defined by the serum concentrations of sodium (sNa) and glucose, which can promote free water movement across intra/extracellular compartments. Rapid changes in serum tonicity can cause brain damage. We herein report an educational case of a patient with hyponatremia (sNa: 112 mEq/L) concomitant with acute alcoholic pancreatitis. The cause of hyponatremia was considered complex. Pseudo- and trans-locational natremia was secondary to hyperglycemia (721 mg/dL) and hypertriglyceridemia (1,768 mg/dL), respectively, and true hypotonic hyponatremia. Regarding sNa correction, rapid correction was suspected. However, this was safely managed by monitoring tonicity (not sNa or osmolarity), thereby avoiding brain damage.

Renal hypouricemia in a recipient of living-donor kidney transplantation: a case report and literature review.

Hypouricemia in kidney transplant (KT) recipients is rare since they usually have subnormal kidney function which raises serum uric acid level. Recently, interests in pathogenesis of hypouricemia have been increasing due to the understanding of the role of uric acid transporter in renal hypouricemia (RHUC). We herein report the case of RHUC consequently developed in a KT recipient from a living donor with RHUC diagnosed by the detailed urinary and genetic test. A 73-year-old Japanese man underwent KT, and the donor was his wife who had hypouricemia [serum uric acid (S-UA) 0.6 mg/dL]. Nine months after KT, the recipient's S-UA was low (1.5 mg/dL) with serum creatinine (S-Cr) of 1.56 mg/dL, and fractional excretion of UA (FEUA) was high (59.7%; normal < 10%), indicating RHUC. Regarding the donor's information, S-Cr, S-UA, and FEUA were 0.95 mg/dL, 1.0 mg/dL, and 54.5%, respectively. To investigate further on the pathogenesis of RHUC in both the recipient and the donor, we performed genetic tests. The donor had a homozygous mutation of W258X in the SLC22A12 gene and the recipient had a wild type of W258X. Finally, we reviewed the previous literature on RHUC among KT recipients and discussed the strategy of follow-up for these patients.

Seasonal variation in emergent hemodialysis initiation in the late elderly: A single-center study.

BACKGROUND: The number of new dialysis patients, particularly among the elderly population, has been globally increasing. In Japan, patients aged ≥65 years and ≥75 years comprised 72% and 45% of patients on dialysis in 2018, respectively. Few studies have reported seasonal variations in the initiation of dialysis. We investigated the seasonal prevalence of the emergent hemodialysis initiation in the elderly. METHODS: We reviewed 479 elderly patients who initiated hemodialysis between January 2006 and December 2018. Early elderly patients were defined as patients aged between 65 and 74 years, and late elderly patients were defined as those aged ≥75 years. Emergent hemodialysis initiation was defined as initiation with a temporary vascular catheter without elective permanent vascular access or unplanned hemodialysis initiation due to patients requiring critical care regardless of elective permanent vascular access. The information collected included age, sex, and details of the initiation of hemodialysis. RESULTS: The early elderly group consisted of 199 patients, and the late elderly group consisted of 279 patients. In the late elderly group, hemodialysis initiation was most frequent in winter, followed by spring, autumn, and summer (p = 0.018). Moreover, emergent hemodialysis initiation was most frequent in winter, followed by spring, autumn, and summer (p = 0.009). Emergent hemodialysis initiation due to fluid overload was most frequent in winter, followed by autumn, spring, and summer (p < 0.001). Among late elderly patients who initiated hemodialysis, 78% did not have permanent hemodialysis access at the time of the initiation of hemodialysis. CONCLUSION: In the late elderly group, hemodialysis initiation and emergent hemodialysis initiation were significantly more frequent in the winter than in the remaining seasons. In addition, emergent hemodialysis initiation due to fluid overload was most frequent in winter in the late elderly group.

Association Between Kidney Function Decline and Baseline TNFR Levels or Change Ratio in TNFR by Febuxostat Chiefly in Non-diabetic CKD Patients With Asymptomatic Hyperuricemia.

Background: The levels of circulating tumor necrosis factor receptor (TNFR) 1 and 2 help predict the future decline of estimated glomerular filtration rate (eGFR) chiefly in patients with diabetes. It has been recently reported that the change ratio in TNFR1 by SGLT2 inhibitor treatment is also related with future GFR decline in patients with diabetes. The aims of this study are to investigate the association between baseline TNFR levels and early change in TNFR levels by the non-purine selective xanthine oxidase inhibitor, febuxostat, and future eGFR decline chiefly in chronic kidney disease (CKD) patients without diabetes. Methods: We conducted a post-hoc analysis of the FEATHER study on patients with asymptomatic hyperuricemia and CKD stage 3, who were randomly assigned febuxostat 40 mg/day or matched placebo. This analysis included 426 patients in whom baseline stored samples were available. Serum TNFR levels at baseline were measured using enzyme-linked immunosorbent assay. Those levels were also measured using 12-week stored samples from 197 randomly selected patients. Results: Compared with placebo, short-term febuxostat treatment significantly decreased the median percent change from baseline in serum uric acid (-45.05, 95% CI -48.90 to -41.24 mg/dL), TNFR1 (1.10, 95% CI-2.25 to 4.40), and TNFR2 (1.66, 95% CI -1.72 to 4.93), but not TNFR levels. Over a median follow-up of 105 weeks, 30 patients (7.0%) experienced 30% eGFR decline from baseline. In the Cox multivariate model, high levels of baseline TNFR predicted a 30% eGFR decline, even after adjusting for age, sex, systolic blood pressure, high sensitivity C-reactive protein, uric acid, and presence or absence of febuxostat treatment and diabetes, in addition to baseline albumin to creatinine ratio and eGFR. Conclusion: Early change in circulating TNFR levels failed to predict future eGFR decline; however, regardless of febuxostat treatment, the elevated baseline level of TNFR was a strong predictor of 30% eGFR decline even in chiefly non-diabetic CKD patients with asymptomatic hyperuricemia.

Association between pill burden and interdialytic weight gain in patients with hemodialysis: A multi-center cross-sectional study.

High daily pill burden affects quality of life and mortality. High interdialytic weight gain (IDWG) is associated with increased mortality. We examined the association between pill burden and IDWG in hemodialysis patients. This cross-sectional study was conducted in six dialysis centers in Japan in June 2017. The exposure was the number of daily tablets, and outcome was defined as 1 day of relative IDWG divided by post-dialysis weight from the previous session. Among 188 outpatients (mean age, 68.7 [SD, 10.3] years; men, 67.0%; median dialysis vintage, 76.0 [interquartile range, 36.5, 131.5] months), the mean number of daily tablets was 19.7 ± 9.9, and mean relative weight gain was 3.5 ± 1.2%. Multiple linear regression analysis showed a regression coefficient of 0.021 (95% confidence interval: 0.004-0.039), indicating that one additional tablet prescription increased the IDWG by 0.021%. In hemodialysis patients, the daily pill burden was a significant, independent risk for increased relative IDWG.

Nephrotic syndrome due to preeclampsia before 20 weeks of gestation: a case report.

BACKGROUND: Preeclampsia (PE) refers to the development of hypertension and new-onset proteinuria or progressive organ damage (especially kidney) in a previously normotensive pregnant women after 20 weeks of gestation. Thus, new-onset nephrotic syndrome due to PE before 20 weeks of gestation seems to be rare, making its diagnosis difficult in this time period. CASE PRESENTATION: A 28-year-old woman presented with a new-onset nephrotic syndrome at 16 weeks of gestation. A high dose of oral glucocorticoids (prednisolone, 40 mg) was initiated for presumed glomerulonephritis since she presented with severe nephrotic syndrome before 20 weeks of gestation, however, the treatment was not effective. At 21 weeks of gestation, we confirmed that the soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio was very high (sFlt-1, 13,400 pg/mL; PlGF, 21.9 pg/mL; serum sFlt-1/PlGF ratio 611.9). Therefore, we diagnosed nephrotic syndrome due to PE, and oral glucocorticoids were discontinued. After she underwent a cesarean section at 24 weeks & 3 days, we performed a kidney biopsy. Focal segmental sclerotic lesions with epithelial cell hyperplasia and foam cells in the tubular poles were seen on light microscopy. On immunofluorescence tests, C4d staining showed linear peripheral patterns in the glomeruli. Electron microscopy revealed diffuse subendothelial edema with focal foot process effacement. The histological diagnosis was severe glomerular endotheliosis with focal segmental glomerulosclerosis. Furthermore, the histology of placenta was consistent with PE. Eight months after delivery, her proteinuria disappeared completely. CONCLUSIONS: We not only confirmed an abnormal serum sFlt-1/PlGF ratio but also presented the histology compatible with pure PE in the kidney and placenta in a case of nephrotic syndrome before 20 weeks of gestation. The serum sFlt-1/PlGF ratio may be useful in determining the treatment strategy for atypical cases of pregnant women with nephrotic syndrome, particularly before 20 weeks of gestation.

Arteriovenous fistulas after ultrasound-guided needle biopsy of kidney allografts and treatment outcomes after transcatheter embolization: A single-center experience in Japan.

BACKGROUND: Arteriovenous fistula (AVF) is one of the vascular complications after allograft biopsy, and their reported incidence rates range widely. Transcatheter embolization (TE) is a common AVF treatment in kidney allografts. However, information on AVF incidence and features and TE outcomes in Japanese kidney transplant (KT) recipients is lacking. METHODS: This study investigated 270 protocol or clinically indicated kidney allograft biopsies in 129 KT recipients during 2010-2016 at a single-center using standardized methods (16-gauge needle and ultrasound guidance). We recorded the incidence and clinical features of AVF using currently recommended standardized methods of allograft biopsy and TE outcomes regarding allograft function up to 12 months after the procedure in Japanese KT recipients. RESULTS: AVF incidence was 2.6% (seven cases). The time from biopsy to AVF diagnosis was 7 (median, interquartile range: 5-117, range: 1-318) days. The time from biopsy to AVF diagnosis was significantly shorter in symptomatic cases (gross hematuria) than in asymptomatic cases (median 6 vs. 117 days, p = 0.034). Symptomatic patients underwent TE within a shorter time (0-6 days) than asymptomatic patients (25-104 days). There were no complications, and allograft function was stable up to 12 months after TE despite using contrast media and partial renal infarction. CONCLUSIONS: AVF does occur in certain probabilities. AVF formation can occur without apparent bleeding and exist for a long time after allograft biopsy. TE is a safe and immediate treatment for AVF in kidney allograft.

Morphological Features of Minimal Change Disease and Focal Segmental Glomerulosclerosis Using Repeat Biopsy and Parietal Epithelial Cell Marker.

INTRODUCTION: Minimal change disease (MCD) and primary focal segmental glomerulosclerosis (FSGS) are representative podocyte diseases. The clinical cause of MCD and FSGS has not been clearly elucidated yet. However, it is important to distinguish MCD and FSGS because their prognoses and responses to treatment are quite different. OBJECTIVE: This study aimed to examine whether parietal epithelial cell (PEC) marker and repeat biopsy are useful for diagnosing primary FSGS. METHODS: Clinicopathological features of 17 patients with the nephrotic syndrome, who underwent kidney biopsy ≥2 times from 1975 to 2017, and had MCD or FSGS were analyzed using PAX8. We defined patients with PAX8+ cells as PAX8+ and the remainder as PAX8- patients. Three cases of sample insufficiency and 1 non-steroid-resistant or frequently relapsing case indicated for repeat biopsy were excluded. RESULTS: Among the 13 patients studied, 4 were PAX8+ and 9 were PAX8- (median age: 41 and 46 years, -respectively, at first biopsy). PAX8+ and PAX8- patients showed no significant differences in clinical data and histological diagnosis except for a significant difference in histological diagnosis at the second biopsy. The number of PAX8+ patients increased to 6. Unlike the first biopsy results, FSGS was present in 5 of 6 (83.3%) PAX8+ patients; MCD occurred in all 7 (100%) PAX8- patients. Three of 6 (50.0%) PAX8+ patients undergoing repeat biopsy were steroid resistant; no (0%) PAX8- patient was steroid resistant. All cases of final FSGS diagnosis were PAX8+ at the first or second biopsy. Only 1 PAX8+ MCD patient was steroid resistant. All PAX8- MCD patients were frequently relapsing. CONCLUSIONS: More PAX8+ patients were diagnosed with FSGS than PAX8- patients. Clinical presentation of MCD in PAX8- patients was frequently relapsing. PEC marker staining in patients with the nephrotic syndrome, e.g., MCD, may help to diagnose FSGS.

Effect of Long-term Peritoneal Dialysis on Change in Visceral Fat Area: A Single-Center Experience.

INTRODUCTION: Visceral fat area (VFA) is known to increase after initiation of peritoneal dialysis (PD). However, the factors contributing to the increase in VFA in long-term PD patients have not been sufficiently elucidated. The present study investigated factors that affect VFA in patients who continue PD for ≥3 years. METHODS: Twenty patients (63.1 ± 10.3 years, 9 men, 11 diabetic patients) between January 2008 and January 2015 were included. VFA, subcutaneous fat area (SFA) and waist circumference at initiation and follow-up were measured at the level of the umbilicus by computed tomography using an image analysis system. Change in VFA was defined as the value obtained by dividing VFA at the final follow-up by that at the initiation. The correlations between clinical parameters at initiation and changes in VFA were analyzed. RESULTS: There was no significant change in body weight (57.6 ± 10.4 vs 58.3 ± 7.8 kg, P = 0.296) during the mean final follow-up period of 55 ± 13 months, although VFA increased significantly (103.6 ± 39.2 vs 122.6 ± 38.3 cm2, P = 0.030). Although subcutaneous fat area (SFA) did not change (124.7 ± 52.3 vs 124.5 ± 49.2 cm2, P = 0.989), waist circumference increased significantly (79.4 ± 8.4 vs 83.7 ± 6.9 cm, P = 0.010). SFA (r = -0.735, P < 0.001), waist circumference (r = - 0.644, P = 0.002), high-density lipoprotein cholesterol (HDL-C) (r = 0.487, P = 0.029), and age (r = 0.507, P = 0.023) correlated significantly with changes in VFA. CONCLUSIONS: VFA might increase with long-term PD in patients with end-stage kidney disease who have high HDL-C, small SFA, and small waist circumference at initiation.

Impact of age on the seasonal prevalence of hypernatremia in the emergency department: a single-center study.

BACKGROUND: Hypernatremia is one of the most commonly encountered electrolyte disorders in the emergency department (ED). Few studies have reported the seasonal fluctuations of the prevalence of hypernatremia with conflicting results. We investigated the seasonal prevalence of hypernatremia in an emergency department in Japan. METHODS: A total of 12,598 patients presented to the ED between January 2015 and December 2017 were reviewed. The adult group aged between 18 and 64 years old consisted of 5427 patients and the elderly group aged over 65 years consisted of 7171 patients. Information collected included age, sex, serum sodium, and serum creatinine. Hypernatremia was defined as a serum sodium leve1 > 145 mEq/L, and moderate to severe hypernatremia was defined as a serum sodium level ≥ 150 mEq/L. RESULTS: The prevalence of hypernatremia was significantly higher in the elderly group than in the adult group (2.6% vs. 0.7%; p < 0.001). Similarly, the prevalence of moderate to severe hypernatremia was significantly higher in the elderly group than in the adult group (1.0% vs. 0.1%; p < 0.001). The prevalence of hypernatremia and moderate to severe hypernatremia was significantly higher in the elderly group than in the adult group in all seasons. In the elderly group, the seasonal prevalence of moderate to severe hypernatremia was significantly higher during the winter. Also, there was a correlation between weather temperature and the prevalence of moderate to severe hypernatremia in the elderly group (r = - 0.34, p = 0.04). CONCLUSIONS: Hypernatremia is prevalent in the elderly and the prevalence is highest during the winter. Special attention should be paid in the elderly patients to prevent hypernatremia especially in the winter.