Micromapping testicular sperm extraction: A new technique for microscopic testicular sperm extraction in nonobstructive azoospermia.

Purpose: In microscopic testicular sperm extraction (mTESE) for nonobstructive azoospermia (NOA), sperm can be recovered relatively easily in some cases, and mTESE may be retrospectively considered excessive. However, mTESE is routinely performed in the majority of NOA patients because of the difficulty in predicting tissue status. A minimally invasive and comprehensive sperm retrieval method that allows on-the-spot tissue assessment is needed. We have developed and evaluated a novel sperm retrieval technique for NOA called micromapping testicular sperm extraction (MMTSE). Methods: MMTSE involves dividing the testis into four sections and making multiple small needle holes in the tunica albuginea to extract seminiferous tubules and retrieve sperm. The sperm-positive group by MMTSE (Group I) underwent additional tissue collection (ATC) via a small incision, whereas the sperm-negative group by MMTSE (Group 0) underwent mTESE. Results: In total, 40 NOA participants underwent MMTSE. Group I included 15 patients and Group 0 included 25 patients. In Group 1, sperm were recovered from all patients by ATC. In Group 0, sperm were recovered in 4 of 25 cases using mTESE. Conclusions: MMTSE shows promise as a simple method that comprehensively searches testicular tissue and retrieves sperm using an appropriate method while minimizing patient burden.

Non-medical oocyte cryopreservation at a single center in Japan: 8 years of experience.

Purpose: Increasing numbers of women are opting to undergo non-medical oocyte cryopreservation (NMOC). In this report, we present experience at our clinic and discuss NMOC in Japan. Methods: We followed the progress of 403 women who underwent NMOC at our clinic between 2014 and 2021, totaling 592 reproductive cycles. Results: In total, 61 women underwent oocyte warming and fertility treatment. Of these, 13 women gave birth to 14 children. The median age at first oocyte cryopreservation was 38.3 years, and the oldest pregnant woman was 42 years. Most clients (60%) were in their late 30s. The median time between first oocyte cryopreservation and warming was 3.0 years. One woman was able to achieve a live birth with four vitrified oocytes. Conclusions: This is the first report in Japan documenting pregnancies and childbirths resulting from NMOC. Ideally, women hope to achieve natural pregnancy between 20 and 32 years of age. NMOC is an option for individuals who are unable to pursue pregnancy during optimal reproductive years and wish to preserve their fertility for future attempts. NMOC is recommended in cases with few indications, and it is necessary to continue accumulating data on its long-term safety and effectiveness.

Immobilization of Arg-Gly-Asp peptides on silk fibroin via Gly-Ala-Gly-Ala-Gly-Ser sequences.

A simple method by which the functional peptide of Gly-Arg-Gly-Asp-Ser (GRGDS) is immobilized on the surface of silk fibroin (SF) films via Gly-Ala-Gly-Ala-Gly-Ser (GAGAGS) sequences is proposed. GAGAGS, a repeating amino acid sequence in the crystal region of Bombyx mori SF, performs a key role in interacting with and immobilizing SF molecules. Immobilization by this proposed method involves no chemical reaction, thereby preserving the original properties of the SF molecule. The density of GRGDS peptides existing on SF film was found to be higher in the GAGAGS-bound type than in the non-GAGAGS-bound type. Furthermore, results showed that the amount of immobilized (GAGAGS)GRGDS peptide increased as the ß-sheet crystallization was promoted in the SF film. Fibroblasts, which adhered to the surface of the SF film, showed more extensibility because of the (GAGAGS)GRGDS immobilization, which suggests that the cell adhesion activity of RGD is functioning effectively.

Structure-Activity Relationship and In Silico Evaluation of cis- and trans-PCPA-Derived Inhibitors of LSD1 and LSD2.

trans-2-Phenylcycloproylamine (trans-PCPA) has been used as the scaffold to develop covalent-binding inhibitors against lysine-specific demethylase 1 (LSD1/KDM1A), a therapeutic target for several cancers. However, the effects of different structural moieties on the inhibitory activity, selectivity, and reactivity of these derivatives, including the cis isomers, against LSD1 and its paralogue LSD2/KDM1B are not fully understood. Here we synthesized 65 cis- and trans-PCPA derivatives and evaluated their inhibitory activity against LSD1 and LSD2. One of the derivatives, 7c (cis-4-Br-2,5-F2-PCPA; S1024), inhibited LSD1 and LSD2 with K i values of 0.094 µM and 8.4 µM, respectively, and increased the level of dimethylated histone H3 at K4 in CCRF-CEM cells. A machine learning-based regression model (Q 2 = 0.61) to predict LSD1-inhibitory activity was also constructed and showed a good prediction accuracy (R 2 = 0.81) for 12 test-set compounds, including 7c. The present methodology would be useful when designing covalent-binding inhibitors for other enzymes.

Discovery of Carbono(di)thioates as Indoleamine 2,3-Dioxygenase 1 Inhibitors.

A structure-activity relationship study unexpectedly showed that carbonothioates 4a and 4b, obtained by a unique alkaline hydrolysis of 2-alkylthio-oxazolines 3a and 3b, respectively, are a novel scaffold for indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors. Derivatization of the carbonothioates enhanced inhibitory activity against IDO1 and cellular kynurenine production without cytotoxicity and led to the discovery of the related scaffolds carbonodithioates 5 and cyanocarbonimidodithioates 6 as IDO1 inhibitors. Incorporation of an OH group provided the most potent analogue 5i. UV-visible absorption spectroscopy of the Soret band, as well as docking and peptide mapping studies, suggested that these molecules bind to the heme in the active site of IDO1. Our unique IDO1 inhibitors are potential leads for future development.

Six-year follow-up of children born from vitrified oocytes.

RESEARCH QUESTION: Are children born from vitrified-warmed oocytes physically or mentally different from naturally conceived children? DESIGN: Intracytoplasmic sperm injection (ICSI) of vitrified-warmed oocytes was performed for 282 patients (307 cycles) from August 2000 to March 2020. Long-term follow-up of children born from vitrified-warmed oocytes was performed via a questionnaire that was sent to the parents at regular intervals from 3 to 72 months after the child's birth. Questionnaires were sent 11 times from birth to the age of 6 years. The development of motor function and mental status was evaluated as the primary outcome, based on the reported data. Subsequently, patients were divided into four groups by age at oocyte retrieval (20-29, 30-34, 35-39, and 40 years or older). Clinical outcomes were calculated as a secondary outcome. RESULTS: For the 282 patients, the birth of 116 babies was reported (110 singletons and three sets of twins), and seven cases are, at the time of writing, unconfirmed. The results of the survey found physical parameters in singletons to be equivalent to the nationally reported average data issued by the Ministry of Health, Labor and Welfare of Japan. CONCLUSION: This is the first follow-up report of children born from vitrified-warmed oocytes followed by ICSI. The data suggested that the responses from the study participants on the mental and physical development of children were comparable to the data reported by the government, although more responses from patients should be collected to allow further study.

Analysis of the risk factors and treatment for repeated implantation failure: OPtimization of Thyroid function, IMmunity, and Uterine Milieu (OPTIMUM) treatment strategy.

PROBLEM: What are the pregnancy outcomes after the OPtimization of Thyroid function, Immunity, and Uterine Milieu (OPTIMUM) treatment strategy in patients with repeated implantation failure (RIF)? METHOD OF STUDY: Infertile women with a history of RIF after more than three embryo transfer (ET) cycles underwent implantation testing, including a hysteroscopy, endometrial biopsy for CD138 immunostaining and bacterial culture, and serum 25-hydroxyvitamin D3 , interferon-γ-producing helper T (Th1) cell, IL-4-producing helper T (Th2) cell, thyroid-stimulating hormone, thyroid peroxidase antibody, and thrombophilia screening between April 2017 and August 2018. We treated chronic endometritis with antibiotics, aberrant high Th1/Th2 cell ratios with vitamin D and/or tacrolimus intake, overt/subclinical hypothyroidism with levothyroxine, and thrombophilia with low-dose aspirin. Of the 116 RIF women, 88 women with 133 ET cycles were recruited from a questionnaire-based survey regarding pregnancy outcomes. Fifty-nine consecutive RIF patients without the OPTIMUM treatment strategy were also recruited as a control. RESULTS: The 116 women with RIF after the OPTIMUM treatment strategy were 38.3 ± 3.8 years old and had an implantation failure history over 5 (3-19) ET cycles. Implantation testing identified impaired intrauterine circumstances in 75 women (64.7%), an aberrant elevated Th1/Th2 cell ratio in 56 women (48.3%), and thyroid abnormalities in 33 women (28.4%). Cumulative ongoing pregnancy rates including spontaneous pregnancy in the patients aged < 40 and ≥ 40 years were 72.7% and 45.5% within two ET cycles, respectively. The pregnancy outcomes in the OPTIMUM group were significantly higher than those in the control. CONCLUSIONS: The OPTIMUM treatment strategy improved pregnancy outcomes in patients with RIF.

Accuracy and Reliability of the Ankle Brachial Index Measurement Using a Multicuff Oscillometric Device Versus the Doppler Method.

OBJECTIVE: Ankle brachial index (ABI) is widely used for the diagnosis of lower extremity artery disease (LEAD). The purpose of this prospective study was to validate the diagnostic ability and reproducibility of a four cuff automated oscillometric device vs. the Doppler method. METHODS: Patients with suspected LEAD or asymptomatic individuals at risk because of the presence two or more cardiovascular risk factors were enrolled. For each patient, Doppler and oscillometric ABI measurements were repeated by two observers to address intra- and interobserver reproducibility. RESULTS: In total, 118 patients were evaluated. The prevalence of Doppler ABI (Dop-ABI) ≤ 0.90 was 45.8%. Taking the Dop-ABI as the reference, the sensitivity, specificity, accuracy, positive and negative predictive values of oscillometric ABI (Osc-ABI) during the first measurement by the first observer were 89.1%, 94.4%, 94.1%, 91.8%, and 92.4%, respectively. The concordance for diagnosing ABI ≤0.90 between methods was excellent (kappa coefficients ranging from 0.80 to 0.88 with different observers). Intra-observer reproducibility assessed by intraclass correlation coefficient (ICC) between methods were 0.94 for observer 1 and 0.96 for observer 2. The intra-observer reproducibility using the same method was also excellent (ICC 0.94, 95% confidence interval [CI] 0.91-0.95) for Dop-ABI and 0.95 (95% CI 0.93-0.97) for Osc-ABI). The ICC for interobserver reproducibility using the same method was 0.95 (95% CI 0.92-0.96) for Dop-ABI and 0.96 (95% CI 0.94-0.97) for Osc-ABI. CONCLUSION: This study validates the excellent diagnostic performances of a four cuff oscillometric device specifically designed for screening for LEAD. The simple measurement method could therefore be advocated in primary care where fast, easy, and reliable methods are suitable.

Higher Gene Expression Related to Wound Healing by Fibroblasts on Silk Fibroin Biomaterial than on Collagen.

Silk fibroin (SF), which offers the benefits of biosafety, biocompatibility, and mechanical strength, has potential for use as a good biomedical material, especially in the tissue engineering field. This study investigated the use of SF biomaterials as a wound dressing compared to commercially available collagen materials. After human fibroblasts (WI-38) were cultured on both films and sponges, their cell motilities and gene expressions related to wound repair and tissue reconstruction were evaluated. Compared to the collagen film (Col film), the SF film induced higher cell motility; higher expressions of genes were observed on the SF film. Extracellular matrix production-related genes were up-regulated in WI-38 fibroblasts cultured on the SF sponges. These results suggest that SF-based biomaterials can accelerate wound healing and tissue reconstruction. They can be useful biomaterials for functional wound dressings.

Does dysbiotic endometrium affect blastocyst implantation in IVF patients?

PURPOSE: To analyze the pregnancy outcomes of IVF patients presenting eubiotic or dysbiotic endometrium at the time of embryo transfer and to analyze what bacterial profiles are suitable for embryo implantation. METHODS: Ninety-nine IVF patients under 40 years old undergoing vitrified-warmed blastocyst transfer in HRT cycle had concurrent endometrial microbiome analysis. Samples from the endometrium were taken from the participants at the time of mock transfer; the bacterial profiles at genus level and percentage of lactobacilli in the endometrium of the patients were analyzed. RESULTS: Thirty-one cases (31.3%) had dysbiotic endometrium. The background profiles, pregnancy rates per transfer (52.9% vs 54.8%), and miscarriage rates (11.1% vs 5.9%) were comparable between patients with eubiotic or dysbiotic endometrium. Major bacterial genera other than Lactobacillus detected in the dysbiotic endometrium were Atopobium, Gardnerella, and Streptococcus. Some patients achieved ongoing pregnancies with 0% Lactobacillus in the endometrium. The endometrial bacterial profiles of pregnant cases with dysbiotic endometrium were comparable with those of non-pregnant cases. CONCLUSION: Analyzing microbiota at the species-level resolution may be necessary for identifying the true pathogenic bacteria of the endometrium and avoiding over-intervention against non-Lactobacillus microbiota. Further studies are necessary for analyzing the mechanism of how the pathogenic bacteria affect embryo implantation.

A pilot study and case reports on endometrial microbiota and pregnancy outcome: An analysis using 16S rRNA gene sequencing among IVF patients, and trial therapeutic intervention for dysbiotic endometrium.

PURPOSE: The present study aimed to analyze the pregnancy outcomes of IVF patients presenting Lactobacillus-dominated microbiota (LDM) or non-Lactobacillus-dominated microbiota (NLDM) of their endometrium and to report cases who were treated for NLDM concurrently with antibiotics and prebiotic/probiotic supplements in a Japanese infertile population. METHODS: Ninety-two IVF patients were recruited from August 2017 to March 2018. Endometrial fluid samples for sequencing were collected using an IUI catheter. The bacterial status of the endometrium and the pregnancy outcomes were analyzed. For cases with NLDM, antibiotics and prebiotics/probiotics were administered according to their individual microbial conditions. RESULTS: Forty-seven cases (51.1%) presented LDM and 45 cases (48.9%) presented NLDM at initial analysis. Nine Patients with NLDM were treated by antibiotics and prebiotics/probiotics, and successfully became Lactobacillus-dominant. Pregnancy rates by single vitrified-warmed blastocyst transfers were higher in the LDM group (58.9% per patient and 36.3% per FBT) than in the NLDM group (47.2% per patient and 34.7% per FBT) but not significantly different. CONCLUSION: The results of this study could not necessarily prove the clear benefit of establishing Lactobacillus-dominated endometrium in terms of pregnancy outcome, but there is significance in searching for endometrial microbial status of infertile patients and recovering Lactobacillus-dominated endometrium might benefit implantation.

Influence of Negative Emotional Expressions on the Outcomes of Shared Decision Making During Oncofertility Consultations in Japan.

This report examines how negative emotional expressions (NEE) influence the consequences of shared decision making (SDM) in oncofertility treatment among 32 young female cancer patients and 19 family members. Using a cross-sectional observational study, results showed that NEE influence the outcome consequences of SDM related to patients' decisions about desired treatment(s) and that the absence of negative emotional reactions to information from doctors was related to willingness to receive the desired treatment. This suggests that healthcare providers need to be sensitive to NEE of patients and their families, and highlights the need for psychological counseling before oncofertility consultation.

Analysis of endometrial microbiota by 16S ribosomal RNA gene sequencing among infertile patients: a single-center pilot study.

PURPOSE: The present study aimed to analyze the endometrial and vaginal microbiome among a Japanese infertile population by sequencing and the impact of the endometrial and vaginal environment on implantation. METHODS: In total, 102 infertile (79 in vitro fertilization [IVF] and 23 non-IVF) patients and seven healthy volunteers were recruited from August to December, 2017. Endometrial fluid and vaginal discharge samples for sequencing were collected by using an intrauterine insemination catheter. The bacterial status of the endometrium and vagina were analyzed. RESULTS: The Lactobacillus-dominated microbiota (>90% Lactobacillus spp.) in the endometrium vs vagina was 38% (30/79) vs 44.3% (44/79) in the IVF patients, 73.9% (17/23) vs 73.9% (17/23) in the non-IVF patients, and 85.7% (6/7) vs 85.7% (6/7) in the healthy volunteers. The percentage of endometrial Lactobacillus in the healthy volunteers was highly stable within the same menstrual cycle and even in the following cycle. The major taxonomies were Gardnerella, Streptococcus, Atopobium, Bifidobacterium, Sneathia, Prevotella, and Staphylococcus. Fifteen patients achieved pregnancy by a single vitrified-warmed blastocyst transfer during this study; the median percentage of Lactobacillus in the pregnant women was 96.45 ± 33.61%. CONCLUSION: A considerable percentage of non-Lactobacillus-dominated (NLD) microbiota was found in the endometrium of Japanese infertile women. Increasing the endometrial level of the Lactobacilli to >90% might favor the implantation outcome of NLD infertile patients.

Cyclic analogue of S-benzylisothiourea that suppresses kynurenine production without inhibiting indoleamine 2,3-dioxygenase activity.

Kynurenine is biosynthesised from tryptophan catalysed by indoleamine 2,3-dioxygenase (IDO). The abrogation of kynurenine production is considered a promising therapeutic target for immunological cancer treatment. In the course of our IDO inhibitor programme, formal cyclisation of the isothiourea moiety of the IDO inhibitor 1 afforded the 5-Cl-benzimidazole derivative 2b-6, which inhibited both recombinant human IDO (rhIDO) activity and cellular kynurenine production. Further derivatisation of 2b-6 provided the potent inhibitor of cellular kynurenine production 2i (IC50 = 0.34 µM), which unexpectedly exerted little effect on the enzymatic activity of rhIDO. Elucidation of the mechanism of action revealed that compound 2i suppresses IDO expression at the protein level by inhibiting STAT1 expression in IFN-γ-treated A431 cells. The kynurenine-production inhibitor 2i is expected to be a promising starting point for a novel approach to immunological cancer treatment.

Crystal Structure of LSD1 in Complex with 4-[5-(Piperidin-4-ylmethoxy)-2-(p-tolyl)pyridin-3-yl]benzonitrile.

Because lysine-specific demethylase 1 (LSD1) regulates the maintenance of cancer stem cell properties, small-molecule inhibitors of LSD1 are expected to be useful for the treatment of several cancers. Reversible inhibitors of LSD1 with submicromolar inhibitory potency have recently been reported, but their exact binding modes are poorly understood. In this study, we synthesized a recently reported reversible inhibitor, 4-[5-(piperidin-4-ylmethoxy)-2-(p-tolyl)pyridin-3-yl]benzonitrile, which bears a 4-piperidinylmethoxy group, a 4-methylphenyl group, and a 4-cyanophenyl group on a pyridine ring, and determined the crystal structure of LSD1 in complex with this inhibitor at 2.96 Å. We observed strong electron density for the compound, showing that its cyano group forms a hydrogen bond with Lys661, which is a critical residue in the lysine demethylation reaction located deep in the catalytic center of LSD1. The piperidine ring interacts with the side chains of Asp555 and Asn540 in two conformations, and the 4-methylphenyl group is bound in a hydrophobic pocket in the catalytic center. Our elucidation of the binding mode of this compound can be expected to facilitate the rational design of more-potent reversible LSD1 inhibitors.

Long-term clinical outcomes of testicular sperm extraction and intracytoplasmic sperm injection for infertile men.

Purpose: To find the best methods to achieve the highest pregnancy and birth rates for couples needing testicular sperm extraction (TESE)-intracytoplasmic sperm injection (ICSI). Methods: Retrospectively studied were 801 patients with male factor infertility who had undergone TESE-ICSI between April, 1996 and July, 2016 and who had been categorized into four groups: obstructive azoospermia (OA); non-obstructive azoospermia (NOA); Klinefelter syndrome (KS); and cryptozoospermia (Crypt). The sperm retrieval rate, hormone levels, fertilization rate (FR), pregnancy rate (PR), and birth rate (BR) after ICSI among three groups were compared: fresh testicular sperm (FS)-fresh oocytes (FO) (Group I); frozen-thawed testicular sperm-FO (Group II); and FS-vitrified-warmed oocytes (Group III). Results: The testicular sperm recovery rate was 57.8% (463/801): 89.6% in the Crypt, 97.1% in the OA, 28.9% in the NOA, and 42.2% in the KS groups. The follicle-stimulating hormone levels were significantly higher in the NOA and KS groups and the testosterone levels were significantly lower in the KS group. The FR, PR, and BR were: 65.2%, 43.2%, and 28.5% in group I; 59.2%, 33.4%, and 18.7% in group II; and 56.4%, 33.8%, and 22.1% in group III. Conclusion: Intracytoplasmic sperm injection with FS-FO achieved the best PR and BR. It should be considered what to do in cases with no testicular sperm by TESE. The authors hope that ICSI with donor sperm will be allowed in Japan in the near future.

Preliminary Evaluation of Aortic Aneurysm Screening Using Oscillometric Device Equipped With Novel Algorithm Analyzing Pulse Wave Transfer.

BACKGROUND: Detection of aortic aneurysm (AA) prior to rupture is crucial to decreasing its mortality. Towards this purpose, a novel detection algorithm was developed from pulse volume recording (PVR), analyzing the propagation loss of pulse waves caused by expansion of the aortic wall. The diagnostic ability of the algorithm was evaluated in this prospective study.Methods and Results:PVR were measured for 30 s using the oscillometric device designed for automatic measurement of the ankle-brachial index (ABI). The algorithm processed the data automatically and assessed whether the patient had an AA. CT angiography was used as the reference standard. Sensitivity and specificity of the algorithm were evaluated. A total of 152 AA patients, including 21 patients with thoracic AAs (TAA), and 64 non-aneurysm control subjects were enrolled. The mean diameter of all AAs was 47.2±10.3 mm. After measurements, 121 AA patients and 33 control subjects were judged by the algorithm as having or not having AAs, resulting in sensitivity of 80% and specificity of 52%. The sensitivity was higher for larger AAs. There was no sensitivity difference according to the location of the AA. CONCLUSIONS: The new diagnostic algorithm installed in the oscillometric device detected AAs with high sensitivity, especially larger aneurysms. For application as a screening tool, the specificity needs to be improved.

Efficacy of the endometrial receptivity array for repeated implantation failure in Japan: A retrospective, two-centers study.

Aim: This study aimed to assess the efficacy of the endometrial receptivity array (ERA) as a diagnostic tool and the impact of personalized embryo transfer (pET) for the treatment of patients with recurrent implantation failure (RIF) in Japan. Methods: Fifty patients with a history of RIF with frozen-thawed blastocyst transfers were recruited from July, 2015 to April, 2016. Endometrial sampling for the ERA and histological dating and a pET according to the ERA were performed. The receptive (R) or non-receptive (NR) status of the endometrium as a result of the first ERA, endometrial dating, and pregnancy rates after the pET were analyzed. Results: Of the patients with RIF, 12 (24%) were NR. Among them, eight (66.7%) were prereceptive. A clinical follow-up was possible in 44 patients who underwent the pET. The pregnancy rates were 58.8% per patient and 35.3% per first pET in the R patients and 50.0% per patient and 50.0% per first pET in the NR patients. Discrepancies between the ERA results and histological dating were seen more in the NR patients than in the R patients. Conclusions: For patients with unexplained RIF, there is a significance in searching for their personal window of implantation (WOI) using the ERA, considering the percentage of those who were NR and the pregnancy rates that resulted from the pET. By transferring euploid embryos in a personal WOI, much better pregnancy rates are expected.

Effects of fertility preservation in patients with breast cancer: A retrospective two-centers study.

Purpose: To assess the efficacy of fertility preservation (FP) and the impact of chemotherapy on the reproductive potential of Japanese patients with breast cancer. Methods: Sixty-two patients with breast cancer visited the authors' centers from October, 2003 to June, 2015. They were divided into two groups according to the treatment: oocyte or embryo vitrification for FP before cancer treatment (group A) or infertility treatment after cancer treatment (group B). Group B was divided into two subgroups, B1 (no chemotherapy) and B2 (postchemotherapy), in order to analyze the effect of anticancer drugs on ovarian reserves and assisted reproductive technology outcomes. The number of retrieved oocytes, vitrified oocytes or embryos, and pregnancy rates were analyzed and compared: group A compared to group B1 compared to group B2. Results: The patients in groups A and B1 underwent egg collection without any chemotherapy. The numbers of collected oocytes and vitrified embryos were significantly higher in groups A and B1 than in group B2. Nearly 50% of the in vitro fertilization patients who underwent an embryo transfer (ET) became pregnant, including two patients in group A who underwent a vitrified-warmed ET. Among the pregnant women, 70% did not have chemotherapy. Conclusion: For patients with breast cancer, FP with unfertilized oocytes or embryos before chemotherapy seems to be promising for achieving higher pregnancy rates, with no risk of minimal residual disease.

Seasonal Variation in the Daily Urinary Sodium Excretion in Outpatients from the Morioka Region of Northern Japan.

Objective Although the daily urinary sodium excretion (UNaV) is considered to provide the most reliable estimate of the daily sodium intake, it may be affected by salt loss due to sweating in summer. However, the seasonal variation in the daily UNaV associated with a normal lifestyle is unknown. Methods This study was performed in 348 outpatients from the Morioka region during three seasons: summer (summer 1), winter, and the following summer (summer 2). The daily UNaV (g salt/day) was estimated by the second morning urine method three times during each season. Seasonal variation was defined as a significant trend across the three seasons together with a significant difference between winter and both summers. Results In women, the daily UNaV was higher in winter (11.8±3.0 g salt/day) than in summer 1 (11.2±2.9 g salt/day) or summer 2 (11.0±2.9 g salt/day). In contrast, there was no marked seasonal variation in men. An analysis stratified by age (4 quartiles) identified seasonal variation in the older 2 quartiles of women (aged ≥68 years). In these women, the mean seasonal difference in the daily UNaV was 0.9 g of salt/day for both winter vs. summer 1 and winter vs. summer 2, while it was 0.1-0.8 g of salt/day in the other groups. Conclusion Seasonal variation in the daily UNaV only occurred in older female patients and was relatively small. This is evidence for restricting salt intake throughout the year and should reassure patients who are anxious about salt loss due to sweating in summer.