The practical integration of a hybrid model of ultrasound-guided peripheral venous access in a large apheresis center.

BACKGROUND: Apheresis treatments require adequate venous access using peripheral intravenous (PIV) catheterization or central venous catheters (CVC). Ultrasound-guided PIV (USGPIV) can be used to decrease the need of CVC insertions for apheresis procedures. METHOD: A hybrid model of USGPIV and standard of care (SOC) for PIV access was developed. Nurses performed USGPIV on all patients considered for PIV access if felt SOC PIV access was not possible. Information was collected regarding nurses' confidence with access, number of attempts required, site of access, complications, and need for CVC. RESULTS: In all, 226 PIV access attempts were made during a 2-month period. All apheresis procedure types were represented. A total 65% were accessed by SOC and 35% by USGPIV. USGPIV was successful on first try on 90% draw/inlet access and 87% successful on first try on return access. Access above the antecubital fossa was required in 31% of USGPIV for draw/inlet veins, and 22% of return veins. Nurses' confidence with accessing PIV was increased by USGPIV, based on 7-point Likert scale assessments. During the recording period, 2/226 (0.9%) apheresis procedures required a CVC. In a separate cohort of only hematopoietic progenitor cell collections, CVC insertion was required in 44/238 (18.5%) patients, in 7 months prior to adoption of USGPIV and 5/152 (3.3%) patients in 7 months following adoption of USGPIV. CONCLUSION: A hybrid model of using SOC and USGPIV for PIV access for apheresis procedures resulted in decreased need for CVC access, high levels of successful initial access attempts, and increased nursing confidence in PIV access.

Ectopic serotonin production in ß-cell specific transgenic mice.

Genetically modified mice have been widely used in the field of ß-cell research. However, analysis of results gathered using genetically modified organisms should be interpreted carefully as the results may be confounded by several factors. Here, we showed the ectopic serotonin (5-HT) production in ß-cells of RIP-CreMgn, MIP-GFP, and MIP-Cre/ERT mice. These mice contained a human growth hormone (hGH) cassette to enhance transgene expression and hGH expression and Stat5 phosphorylation were detected in pancreatic islets of these mice. The expression level of tryptophan hydroxylase 1 (Tph1) was upregulated in pancreatic islets of transgenic mice with an hGH cassette but not in transgenic mice without an hGH cassette. Ectopic 5-HT production was not observed in ß-cell-specific prolactin receptor (Prlr) knockout mice or Stat5 knockout mice crossed with RIP-CreMgn. We further confirmed that 5-HT production in ß-cells of several transgenic mice was induced by hGH expression followed by the activation of the Prlr-Stat5-Tph1 pathway. These findings indicate that results obtained using transgenic mice containing the hGH cassette should be interpreted with care.

ß-cell serotonin production is associated with female sex, old age, and diabetes-free condition.

Serotonin is known to be present in pancreatic ß-cells and to play several physiological roles, including insulin secretion, ß-cell proliferation, and paracrine inhibition of α-cells. However, the serotonin production of different cell lines and islets has not been compared based on age, sex, and diabetes related conditions. Here, we directly compared the serotonin concentrations in ßTC and MIN6 cell lines, as well as in islets from mice using ultra-performance liquid chromatography tandem mass spectrometry. The average serotonin concentration was 5-10 ng/mg protein in the islets of male and non-pregnant female mice. The serotonin level was higher in females than males at 8 weeks, although there was no difference at 1 year. Furthermore, we observed serotonin by immunofluorescence staining in the pancreatic tissues of mice and human. Serotonin was detected by immunofluorescence staining in a portion of ß-cells from islets of old female mice, but not of male or young female mice. A similar pattern was observed in human pancreas as well. In humans, serotonin production in ß-cells was associated with a diabetes-free condition. Thus, serotonin production in ß-cells was associated with old age, female sex, and diabetes-free condition.

Indoor Air Quality Analysis Using Deep Learning with Sensor Data.

Indoor air quality analysis is of interest to understand the abnormal atmospheric phenomena and external factors that affect air quality. By recording and analyzing quality measurements, we are able to observe patterns in the measurements and predict the air quality of near future. We designed a microchip made out of sensors that is capable of periodically recording measurements, and proposed a model that estimates atmospheric changes using deep learning. In addition, we developed an efficient algorithm to determine the optimal observation period for accurate air quality prediction. Experimental results with real-world data demonstrate the feasibility of our approach.

Polarization-multiplexed plasmonic phase generation with distributed nanoslits.

Methods for multiplexing surface plasmon polaritons (SPPs) have been attracting much attention due to their potentials for plasmonic integrated systems, plasmonic holography, and optical tweezing. Here, using closely-distanced distributed nanoslits, we propose a method for generating polarization-multiplexed SPP phase profiles which can be applied for implementing general SPP phase distributions. Two independent types of SPP phase generation mechanisms - polarization-independent and polarization-reversible ones - are combined to generate fully arbitrary phase profiles for each optical handedness. As a simple verification of the proposed scheme, we experimentally demonstrate that the location of plasmonic focus can be arbitrary designed, and switched by the change of optical handedness.

The spatiotemporal development of adipose tissue.

Adipose tissue is a structure highly specialized in energy storage. The adipocyte is the parenchymal component of adipose tissue and is known to be mesoderm or neuroectoderm in origin; however, adipocyte development remains poorly understood. Here, we investigated the development of adipose tissue by analyzing postnatal epididymal adipose tissue (EAT) in mouse. EAT was found to be generated from non-adipose structure during the first 14 postnatal days. From postnatal day 1 (P1) to P4, EAT is composed of multipotent progenitor cells that lack adipogenic differentiation capacity in vitro, and can be regarded as being in the 'undetermined' state. However, the progenitor cells isolated from P4 EAT obtain their adipogenic differentiation capacity by physical interaction generated by cell-to-matrix and cell-to-cell contact both in vitro and in vivo. In addition, we show that impaired angiogenesis caused by either VEGFA blockade or macrophage depletion in postnatal mice interferes with adipose tissue development. We conclude that appropriate interaction between the cellular and matrix components along with proper angiogenesis are mandatory for the development of adipose tissue.

Switchable beaming from a nanoslit with metallic gratings controlled by the phase difference between incident beams.

We propose a switching method for optical beaming generated from a metal slit surrounded by surface gratings. The principle of the method is based on the interference of diffracted surface plasmon polaritons from the gratings which are controlled by the relative phases of two oblique incident beams that are illuminated on the metal slit. By adjusting the relative position of the interference pattern of the incident beams with respect to the metal slit, beaming from the proposed structure can be switched from the on- to the off-mode by virtue of the change in the symmetry of the generated surface plasmon polaritons. An experimental demonstration of the method is presented in which an electrically controlled interferometric configuration is used.

Effectiveness of a Social Networking Site Based Automatic Mobile Message Providing System on Glycemic Control in Patients with Type 2 Diabetes Mellitus.

BACKGRUOUND: This study investigated the effectiveness of a social networking site (SNS)-based automatic mobile message providing system on glycemic control in patients with type 2 diabetes mellitus (T2DM). METHODS: A 3-month, randomized, open-label, controlled, parallel-group trial was conducted. One hundred and ten participants with T2DM were randomized to a mobile message system (MMS) (n=55) or control group (n=55). The MMS group received protocolbased automated messages two times per day for 10 weeks regarding diabetes self-management through KakaoTalk SNS messenger. The primary outcome was the difference in the change in glycated hemoglobin (HbA1c) levels (%) from baseline to week 12. RESULTS: HbA1c levels were more markedly decreased in the MMS group (8.4%±0.7% to 8.0%±1.1%) than in the control group (8.5%±0.8% to 8.4%±0.8%), resulting in a significant between-group difference (P=0.027). No differences were observed in changes in fasting glucose levels, lipid profiles, and the number of participants who experienced hypoglycemia, or in changes in lifestyle behavior between groups. However, the self-monitoring of blood glucose frequency was significantly increased in the MMS group compared to the control group (P=0.003). In addition, sleep duration was increased in the MMS group, but was not changed in the control group. CONCLUSION: An SNS-based automatic mobile message providing system was effective in improving glycemic control in patients in T2DM. Studies which based on a more individualized protocol, and investigate longer beneficial effect and sustainability will be required in the future.

Tunable subwavelength hot spot of dipole nanostructure based on VO2 phase transition.

We propose a novel approach to generate and tune a hot spot in a dipole nanostructure of vanadium dioxide (VO2) laid on a gold (Au) substrate. By inducing a phase transition of the VO2, the spatial and spectral distributions of the hot spot generated in the feed gap of the dipole can be tuned. Our numerical simulation based on a finite-element method shows a strong intensity enhancement difference and tunability near the wavelength of 678 nm, where the hot spot shows 172-fold intensity enhancement when VO2 is in the semiconductor phase. The physical mechanisms of forming the hot spots at the two-different phases are discussed. Based on our analysis, the effects of geometric parameters in our dipole structure are investigated with an aim of enhancing the intensity and the tunability. We hope that the proposed nanostructure opens up a practical approach for the tunable near-field nano-photonic devices.

Glucose Regulation after Partial Pancreatectomy: A Comparison of Pancreaticoduodenectomy and Distal Pancreatectomy in the Short and Long Term.

BACKGRUOUND: Long term quality of life is becoming increasingly crucial as survival following partial pancreatectomy rises. The purpose of this study was to investigate the difference in glucose dysregulation after pancreaticoduodenectomy (PD) or distal pancreatectomy (DP). METHODS: In this prospective observational study from 2015 to 2018, 224 patients who underwent partial pancreatectomy were selected: 152 (67.9%) received PD and 72 (32.1%) received DP. Comprehensive assessment for glucose regulation, including a 75 g oral glucose tolerance test was conducted preoperatively, and 1, 12, and 52 weeks after surgery. Patients were further monitored up to 3 years to investigate development of new-onset diabetes mellitus (NODM) in patients without diabetes mellitus (DM) at baseline or worsening of glucose regulation (≥1% increase in glycosylated hemoglobin [HbA1c]) in those with preexisting DM. RESULTS: The disposition index, an integrated measure of ß-cell function, decreased 1 week after surgery in both groups, but it increased more than baseline level in the PD group while its decreased level was maintained in the DP group, resulting in a between-group difference at the 1-year examination (P<0.001). During follow-up, the DP group showed higher incidence of NODM and worsening of glucose regulation than the PD group with hazard ratio (HR) 4.29 (95% confidence interval [CI], 1.49 to 12.3) and HR 2.15 (95% CI, 1.09 to 4.24), respectively, in the multivariate analysis including dynamic glycemic excursion profile. In the DP procedure, distal DP and spleen preservation were associated with better glucose regulation. DP had a stronger association with glucose dysregulation than PD. CONCLUSION: Proactive surveillance of glucose dysregulation is advised, particularly for patients who receive DP.

Effect of olmesartan and amlodipine on serum angiotensin-(1-7) levels and kidney and vascular function in patients with type 2 diabetes and hypertension.

BACKGROUND: Recent studies suggest that angiotensin-converting enzyme 2 (ACE2) and angiotensin-(1-7) [Ang-(1-7)] might have beneficial effects on the cardiovascular system. We investigated the effects of olmesartan on the changes in serum ACE2 and Ang-(1-7) levels as well as kidney and vascular function in patients with type 2 diabetes and hypertension. METHODS: This was a prospective, randomized, active comparator-controlled trial. Eighty participants with type 2 diabetes and hypertension were randomized to receive 20 mg of olmesartan (N = 40) or 5 mg of amlodipine (N = 40) once daily. The primary endpoint was changes of serum Ang-(1-7) from baseline to week 24. RESULTS: Both olmesartan and amlodipine treatment for 24 weeks decreased systolic and diastolic blood pressures significantly by > 18 mmHg and > 8 mmHg, respectively. Serum Ang-(1-7) levels were more significantly increased by olmesartan treatment (25.8 ± 34.5 pg/mL → 46.2 ± 59.4 pg/mL) than by amlodipine treatment (29.2 ± 38.9 pg/mL → 31.7 ± 26.0 pg/mL), resulting in significant between-group differences (P = 0.01). Serum ACE2 levels showed a similar pattern (6.31 ± 0.42 ng/mL → 6.74 ± 0.39 ng/mL by olmesartan treatment vs. 6.43 ± 0.23 ng/mL → 6.61 ± 0.42 ng/mL by amlodipine treatment; P < 0.05). The reduction in albuminuria was significantly associated with the increases in ACE2 and Ang-(1-7) levels (r = - 0.252 and r = - 0.299, respectively). The change in Ang-(1-7) levels was positively associated with improved microvascular function (r = 0.241, P < 0.05). Multivariate regression analyses showed that increases in serum Ang-(1-7) levels were an independent predictor of a reduction in albuminuria. CONCLUSIONS: These findings suggest that the beneficial effects of olmesartan on albuminuria may be mediated by increased ACE2 and Ang-(1-7) levels. These novel biomarkers may be therapeutic targets for the prevention and treatment of diabetic kidney disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT05189015.

Associations of polyneuropathy with risk of all-cause and cardiovascular mortality, cardiovascular disease events stratified by diabetes status.

AIMS/INTRODUCTION: We investigated the association of polyneuropathy (PN) with all-cause and cardiovascular (CV) mortality and with cardiovascular disease (CVD) events stratified by diabetes status. MATERIALS AND METHODS: This prospective cohort study used the UK Biobank. Polyneuropathy was defined based on nurse-led interviews or ICD codes for polyneuropathy. Cox proportional hazards models were used to investigate the association of polyneuropathy with clinical outcomes. RESULTS: A total of 459,127 participants were included in the analysis. Polyneuropathy was significantly associated with all-cause and cardiovascular mortality, and with CVD events even after adjusting for CVD risk factors across all diabetes statuses. Metabolic parameters HbA1c , waist circumference, BMI and the inflammatory parameter C-reactive protein showed significant mediation effects for the association between polyneuropathy and CVD. Adherence to a favorable lifestyle was associated with a lower risk of all-cause and cardiovascular mortality regardless of polyneuropathy status. CONCLUSIONS: Polyneuropathy was associated with all-cause and cardiovascular mortality, and with CVD events in subjects with diabetes or prediabetes, even those having normal glucose tolerance. This study suggests the importance of polyneuropathy as a risk factor for death and highlights the necessity of early diagnosis and lifestyle intervention for those with type 2 diabetes and polyneuropathy.

Diabetes Mellitus in the Elderly Adults in Korea: Based on Data from the Korea National Health and Nutrition Examination Survey 2019 to 2020.

BACKGRUOUND: We evaluated the prevalence and management of diabetes mellitus (DM) in elderly Korean patients based on data from the Korea National Health and Nutrition Examination Survey (KNHANES). METHODS: A total of 3,068 adults aged 65 years and older (19.8% of total population) were analyzed using KNHANES from 2019 to 2020. Prevalence, awareness, treatment, and control rates, and comorbidities were analyzed. Lifestyle behaviors and energy intake were also measured. RESULTS: The prevalence of DM and prediabetes was 29.6% and 50.5%, respectively. The awareness, treatment and control rates were 76.4%, 73.3%, and 28.3%, respectively. The control rate was 77.0% if A1C <7.5% criteria was used. The mean A1C value of individuals with known DM was 7.1%, and 14.5% of the known DM patients had A1C ≥8.0%. Abdominal obesity, hypertension, and hypercholesterolemia were combined with DM in 63.9%, 71.7%, and 70.7%, respectively, and the rate of integrated management was 36.0% (A1C <7.5% criteria). A total of 40.1% of those with DM walked regularly. The percentage of energy intake from carbohydrates was higher in those with DM than in those without DM (P=0.044), while those of fat (P=0.003) and protein (P=0.025) were lower in those with DM than in those without DM in women. CONCLUSION: In 2019 to 2020, three of 10 adults aged 65 years and older in Korea had DM, and approximately 70% of them had comorbidities. A strategy for more individualized comprehensive care for the elderly patients with DM is urgently needed.

The impact of diabetes status on total and site-specific cancer risk in the elderly population: A nationwide cohort study.

AIMS: We aimed to evaluate the association of prediabetes, diabetes, and diabetes duration with risk of total and site-specific cancer in the Korean population aged 65 years and above. METHODS: This study included 1,232,173 subjects aged ≥ 65 years who underwent a general health screening program. Diabetes status was categorized as normal glucose tolerance, impaired fasting glucose, new-onset diabetes, diabetes duration of < 5 years, and diabetes duration of ≥ 5 years. Cox proportional hazards models were used to investigate the association of diabetes status with cancer risk. RESULTS: The risk of total cancer increased as diabetes status worsened, as did the risks of liver, biliary, and pancreatic cancer. Risks of liver, biliary, and pancreatic cancer were significantly higher in subjects aged 65-74 years than in those aged ≥ 75 years. The relationship of diabetes status with overall cancer incidence was found to significantly interact with sex. Among subjects with diabetes, the risks of liver and lung cancer were significantly higher in men than in women regardless of diabetes duration. CONCLUSIONS: Diabetes status is associated with increased risk of cancer in the elderly. There are age and sex differences in the risk of total and site-specific cancers, including liver, biliary, and pancreatic cancer. This study highlights the importance of cancer screening for elderly subjects with diabetes.

A New Modality in Dyslipidemia Treatment: Antisense Oligonucleotide Therapy.

There are unmet needs for pharmacologic agents beyond current medications, such as statins, to effectively lower low-density lipoprotein cholesterol levels to target goals, especially in patients with very high or extremely high risk. Pharmacological targeting of mRNA represents an emerging, innovative approach with the potential to expand upon current therapies. In RNA-targeted therapeutics, a novel approach is the use of chemically modified oligonucleotides to inhibit the production of target proteins at their sites of gene coding. There are two main classes of RNA-targeted therapeutics: single-stranded antisense oligonucleotides (ASOs) and double-stranded small inhibiting RNAs. ASOs are synthetic molecules with a length of 15-30 nucleotides that are designed specifically to bind to a target mRNA in a sequence-specific manner. Using these agents to inhibit the translation of key regulatory proteins, such as apolipoprotein CIII, apolipoprotein(a), and angiopoietin-like protein 3, has demonstrated treatment efficacy for dyslipidemia. Many cardiovascular outcome trials with ASOs are ongoing. As clinicians, we must carefully monitor the long-term safety and efficacy of this new modality through large clinical trials in the future.

New, Novel Lipid-Lowering Agents for Reducing Cardiovascular Risk: Beyond Statins.

Statins are the cornerstone of the prevention and treatment of atherosclerotic cardiovascular disease (ASCVD). However, even under optimal statin therapy, a significant residual ASCVD risk remains. Therefore, there has been an unmet clinical need for novel lipid-lowering agents that can target low-density lipoprotein cholesterol (LDL-C) and other atherogenic particles. During the past decade, several drugs have been developed for the treatment of dyslipidemia. Inclisiran, a small interfering RNA that targets proprotein convertase subtilisin/kexin type 9 (PCSK9), shows comparable effects to that of PCSK9 monoclonal antibodies. Bempedoic acid, an ATP citrate lyase inhibitor, is a valuable treatment option for the patients with statin intolerance. Pemafibrate, the first selective peroxisome proliferator-activated receptor alpha modulator, showed a favorable benefit-risk balance in phase 2 trial, but the large clinical phase 3 trial (PROMINENT) was recently stopped for futility based on a late interim analysis. High dose icosapent ethyl, a modified eicosapentaenoic acid preparation, shows cardiovascular benefits. Evinacumab, an angiopoietin-like 3 (ANGPTL3) monoclonal antibody, reduces plasma LDL-C levels in patients with refractory hypercholesterolemia. Novel antisense oligonucleotides targeting apolipoprotein C3 (apoC3), ANGPTL3, and lipoprotein(a) have significantly attenuated the levels of their target molecules with beneficial effects on associated dyslipidemias. Apolipoprotein A1 (apoA1) is considered as a potential treatment to exploit the athero-protective effects of high-density lipoprotein cholesterol (HDL-C), but solid clinical evidence is necessary. In this review, we discuss the mode of action and clinical outcomes of these novel lipid-lowering agents beyond statins.

Lipoprotein Lipase: Is It a Magic Target for the Treatment of Hypertriglyceridemia.

High levels of triglycerides (TG) and triglyceride-rich lipoproteins (TGRLs) confer a residual risk of cardiovascular disease after optimal low-density lipoprotein cholesterol (LDL-C)-lowering therapy. Consensus has been made that LDL-C is a non-arguable primary target for lipid lowering treatment, but the optimization of TGRL for reducing the remnant risk of cardiovascular diseases is urged. Omega-3 fatty acids and fibrates are used to reduce TG levels, but many patients still have high TG and TGRL levels combined with low high-density lipoprotein concentration that need to be ideally treated. Lipoprotein lipase (LPL) is a key regulator for TGs that hydrolyzes TGs to glycerol and free fatty acids in lipoprotein particles for lipid storage and consumption in peripheral organs. A deeper understanding of human genetics has enabled the identification of proteins regulating the LPL activity, which include the apolipoproteins and angiopoietin-like families. Novel therapeutic approach such as antisense oligonucleotides and monoclonal antibodies that regulate TGs have been developed in recent decades. In this article, we focus on the biology of LPL and its modulators and review recent clinical application, including genetic studies and clinical trials of novel therapeutics. Optimization of LPL activity to lower TG levels could eventually reduce incident atherosclerotic cardiovascular disease in conjunction with successful LDL-C reduction.

Glucose Profiles Assessed by Intermittently Scanned Continuous Glucose Monitoring System during the Perioperative Period of Metabolic Surgery.

BACKGROUND: Continuous glucose monitoring (CGM) has been widely used in the management of diabetes. However, the usefulness and detailed data during perioperative status were not well studied. In this study, we described the immediate changes of glucose profiles after metabolic surgery using intermittently scanned CGM (isCGM) in individuals with type 2 diabetes mellitus (T2DM). METHODS: This was a prospective, single-center, single-arm study including 20 participants with T2DM. The isCGM (FreeStyle Libre CGM) implantation was performed within 2 weeks before surgery. We compared CGM metrics of 3 days before surgery and 3 days after surgery, and performed the correlation analyses with clinical variables. RESULTS: The mean glucose significantly decreased after surgery (147.0±40.4 to 95.5±17.1 mg/dL, P<0.001). Time in range (TIR; 70 to 180 mg/dL) did not significantly change after surgery in total. However, it was significantly increased in a subgroup of individuals with glycosylated hemoglobin (HbA1c) ≥8.0%. Time above range (>250 or 180 mg/dL) was significantly decreased in total. In contrast, time below range (<70 or 54 mg/dL) was significantly increased in total and especially in a subgroup of individuals with HbA1c <8.0% after surgery. The coefficient of variation significantly decreased after surgery. Higher baseline HbA1c was correlated with greater improvement in TIR (rho=0.607, P=0.005). CONCLUSION: The isCGM identified improvement of mean glucose and glycemic variability, and increase of hypoglycemia after metabolic surgery, but TIR was not significantly changed after surgery. We detected an increase of TIR only in individuals with HbA1c ≥8.0%.

Association Between Fat Mass or Fat Fibrotic Gene Expression and Polyneuropathy in Subjects With Obesity: A Korean Metabolic Bariatric Surgery Cohort.

Aim: We aimed to investigate the association between obesity-related parameters and polyneuropathy (PN) and to evaluate inflammatory and fibrotic gene expression of fat as a potential mediator in subjects scheduled to undergo metabolic bariatric surgery (MBS). Methods: This was a cross-sectional study of MBS cohort. Body composition and visceral fat area (VFA) were quantified by bioimpedance analysis and computed tomography scan. PN was defined by Michigan Neuropathy Screening Instrument-Physical Examination score was > 2. We measured mRNA expression level of FN1, TIMP1, CCL2, and CXCL8 in omental fat tissue. Results: Of 189 subjects (mean age, 39.4 years; 69 [36.5%] male; mean body mass index, 38.5 kg/m2), prevalence of PN was 9.1% in subjects without diabetes (n = 110) and 20.3% in those with diabetes (n = 79). Nondiabetic subjects with PN had higher homeostatic model assessment-insulin resistance (6.8 ± 3.5 vs 4.5 ± 2.8, p = 0.041), and increased fat mass (58.5 ± 12.5 kg vs 50.5 ± 10.7 kg, p = 0.034), and VFA (309.4 ± 117.6 cm2vs 243.5 ± 94.2 cm2, p = 0.046) compared to those without PN. These obesity-related parameters were significantly associated with the presence of PN after adjusting for conventional risk factors of PN only in subjects without diabetes. In contrast, a fibrotic gene such as TIMP1 was independently associated with PN (adjusted odds ratio of 1.56; 95% confidence interval 1.06, 2.30) only in subjects with diabetes. Conclusion: Increased adiposity was independently associated with PN in obese subjects without diabetes. In contrast, this association was not significant after adjusting conventional risk factors of PN in obese subjects with diabetes but increased fibrotic gene expression in fat was associated with PN in this group.

Comparison of Bioelectrical Impedance Analysis and Computed Tomography on Body Composition Changes Including Visceral Fat After Bariatric Surgery in Asian Patients with Obesity.

PURPOSE: The accuracy of bioelectrical impedance analysis (BIA) in patients with obesity has been controversial. This study aimed to validate the use of BIA in detecting body composition changes, especially for visceral fat, before and after bariatric surgery using computed tomography (CT) as a reference method. MATERIALS AND METHODS: This retrospective study included Korean patients with a BMI of ≥ 35, or ≥ 30 with metabolic comorbidities. All patients underwent bariatric surgery, and underwent BIA and CT evaluation before and 6 months after the operation. The skeletal muscle index (SMI) and visceral fat index (VFI), variables corrected for height, were compared between BIA and CT. RESULTS: Forty-eight patients (18 men, 30 women) demonstrated a mean weight loss of 27.5 kg. Significant decreases in both VFI and SMI were observed in both BIA and CT (all p<0.001), with greater VFI change compared to SMI (48.2% vs. 10.4% in CT, respectively). Both pre- and post-operative measurements of VFI and SMI were significantly correlated between BIA and CT (all p<0.05). However, the percent decrease was significantly correlated only with VFI (ρ=0.71, p<0.001). The Bland-Altman analysis showed that BIA underestimated VFI, with a greater degree of underestimation in subjects with higher VFI. CONCLUSION: Despite the underestimation of BIA in measuring visceral fat, BIA VFI was associated with CT VFI. The SMI values showed significant correlations before and after surgery, but not with the percent decrease. Our results suggest that BIA can be a reliable tool for measuring body composition, especially for visceral fat, after bariatric surgery.