• Journal of Genetic Medicine
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• v.14 no.1
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• pp.8-17
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• 2017

Purpose: Pulse wave velocity (PWV) is an indicator of arterial stiffness, and is considered a marker of vascular damage. However, a genome-wide association study analyzing single nucleotide polymorphisms (SNPs) associated with brachial-ankle PWV (baPWV) has not been conducted in healthy populations. We performed this study to identify SNPs associated with baPWV in healthy populations in Korea. Materials and Methods: Genomic SNPs data for 2,407 individuals from three sites were analyzed as part of the Korean Genomic Epidemiologic Study. Without replication samples, we performed multivariable analysis as a post hoc analysis to verify the findings in site adjusted analysis. Healthy subjects aged between 40 and 70 years without self-reported history or diagnosis of hypertension, diabetes, hyperlipidemia, heart disease, cerebrovascular disease and cancer were included. We excluded subjects with a creatinine level >1.4 mg/dL (men) and 1.2 mg/dL (women). Results: In the site-adjusted association analysis, significant associations (P<$5{\times}10^{-8}$) with baPWV were detected for only 5 SNPs with low minor allele frequency. In multivariable analysis adjusted by age, sex, height, body mass index, mean arterial pressure, site, smoking, alcohol, and exercise, 11 SNPs were found to be associated (P<$5{\times}10^{-8}$) with baPWV. The 5 SNPs (P<$5{\times}10^{-8}$) linked to three genes (OPCML, PRR35 and RAB40C) were common between site-adjusted analysis and multivariable analysis. However, meta-analysis of the result from three sites for the 11 SNPs showed no significant associations. Conclusion: Using the recent standard for genome-wide association study, we did not find any evidence of significant association signals with baPWV.

• Korean Journal of Radiology
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• v.25 no.4
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• pp.384-394
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• 2024

Objective: To evaluate the image quality of novel dark-blood computed tomography angiography (CTA) imaging combined with deep learning reconstruction (DLR) compared to delayed-phase CTA images with hybrid iterative reconstruction (HIR), to visualize the cervical artery wall in patients with Takayasu arteritis (TAK). Materials and Methods: This prospective study continuously recruited 53 patients with TAK (mean age: 33.8 ± 10.2 years; 49 females) between January and July 2022 who underwent head-neck CTA scans. The arterial- and delayed-phase images were reconstructed using HIR and DLR. Subtracted images of the arterial-phase from the delayed-phase were then added to the original delayed-phase using a denoising filter to generate the final-dark-blood images. Qualitative image quality scores and quantitative parameters were obtained and compared among the three groups of images: Delayed-HIR, Dark-blood-HIR, and Dark-blood-DLR. Results: Compared to Delayed-HIR, Dark-blood-HIR images demonstrated higher qualitative scores in terms of vascular wall visualization and diagnostic confidence index (all P < 0.001). These qualitative scores further improved after applying DLR (Dark-blood-DLR compared to Dark-blood-HIR, all P < 0.001). Dark-blood DLR also showed higher scores for overall image noise than Dark-blood-HIR (P < 0.001). In the quantitative analysis, the contrast-to-noise ratio (CNR) values between the vessel wall and lumen for the bilateral common carotid arteries and brachiocephalic trunk were significantly higher on Dark-blood-HIR images than on Delayed-HIR images (all P < 0.05). The CNR values were significantly higher for Dark-blood-DLR than for Dark-blood-HIR in all cervical arteries (all P < 0.001). Conclusion: Compared with Delayed-HIR CTA, the dark-blood method combined with DLR improved CTA image quality and enhanced visualization of the cervical artery wall in patients with TAK.

• Korean Journal of Radiology
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• v.24 no.4
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• pp.349-361
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• 2023

Objective: To quantitatively assess the pulmonary vasculature using non-contrast computed tomography (CT) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) pre- and post-treatment and correlate CT-based parameters with right heart catheterization (RHC) hemodynamic and clinical parameters. Materials and Methods: A total of 30 patients with CTEPH (mean age, 57.9 years; 53% female) who received multimodal treatment, including riociguat for ≥ 16 weeks with or without balloon pulmonary angioplasty and underwent both non-contrast CT for pulmonary vasculature analysis and RHC pre- and post-treatment were included. The radiographic analysis included subpleural perfusion parameters, including blood volume in small vessels with a cross-sectional area ≤ 5 mm² (BV5) and total blood vessel volume (TBV) in the lungs. The RHC parameters included mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and cardiac index (CI). Clinical parameters included the World Health Organization (WHO) functional class and 6-minute walking distance (6MWD). Results: The number, area, and density of the subpleural small vessels increased after treatment by 35.7% (P < 0.001), 13.3% (P = 0.028), and 39.3% (P < 0.001), respectively. The blood volume shifted from larger to smaller vessels, as indicated by an 11.3% increase in the BV5/TBV ratio (P = 0.042). The BV5/TBV ratio was negatively correlated with PVR (r = -0.26; P = 0.035) and positively correlated with CI (r = 0.33; P = 0.009). The percent change across treatment in the BV5/TBV ratio correlated with the percent change in mPAP (r = -0.56; P = 0.001), PVR (r = -0.64; P < 0.001), and CI (r = 0.28; P = 0.049). Furthermore, the BV5/TBV ratio was inversely associated with the WHO functional classes I-IV (P = 0.004) and positively associated with 6MWD (P = 0.013). Conclusion: Non-contrast CT measures could quantitatively assess changes in the pulmonary vasculature in response to treatment and were correlated with hemodynamic and clinical parameters.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.506-520
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• 2022

Purpose: Physical activity (PA) has a beneficial effect on the prevention of arteriosclerosis in healthy adults. The purpose of this study was to analyze the relationship between PA measured using an accelerometer and arterial stiffness in healthy Korean adults. Methods: This study involved 87 subjects (36.8% women) aged 20-64 years. PA was evaluated using an accelerometer (wGT3X-BT, ActiGraph, Florida, USA) for 7 days. Based on the results of the accelerometer measurement, subjects were classified into active and inactive groups according to the World Health Organization (WHO) PA guidelines. The brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) to assess arterial stiffness were measured by a non-invasive vascular screening device (VP-1000 Plus, Omron). Results: The average age of the study subjects was 47.7 ± 11.3 years and the WHO PA guideline achievement rate was 29.9%. There was no significant difference in arterial stiffness (baPWV and ABI) between the active and inactive groups. In females, the time spent in light PA were positively correlated with ABI (r = 0.396; p < 0.05) and the number of sedentary bouts over 50 minutes was inversely correlated with ABI (r = -0.402; p < 0.05). However, there was no significant correlation between PA and arterial stiffness in males. Conclusions: The results of this study suggest that light PA and sedentary behavior have a positive correlation with arterial stiffness in females.

• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.220-226
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• 2009

Purpose : Macrovascular complications are the main cause of mortality in type 1 diabetes mellitus (T1DM). The purpose of this study was to clarify the presence of early vascular changes and to assess the risk factors of macrovascular complications in young adults with T1DM diagnosed in childhood and adolescence. Methods : Seventy-two patients ($23.9{\pm}2.4$ years) with T1DM diagnosed before 18 years of age and twenty normal controls were included. The incidence of hypertension, dyslipidemia, and other risk factors of macrovascular complication were reviewed. Flow-mediated vasodilation (FMD) and mean intima-media thickness (IMT) measured by ultrasound were compared between patients and control subjects, and their correlations with macrovascular risk factors were analyzed. Results : Of the 72 patients, 32 (44.4%) had hypertension. The proportions of maleness (P=0.03) and mean body mass index (P=0.04) were higher in the hypertensive patients than in normotensive patients. Thirty-one (N=69, 44.9%) patients had dyslipidemia and LDL-cholesterol was positively correlated with mean HbA1c (r=0.32, P=0.008) and total daily insulin dose (r=0.27, P=0.02). The mean IMT was significantly higher in patients than in control subjects ($0.43{\pm}0.06$ mm vs $0.39{\pm}0.06$ mm, P=0.03). There was no difference in the value of FMD between patients and controls, but the duration of the disease after pubertal onset was negatively correlated with FMD (r=-0.34, P=0.01). Conclusion : Hypertension, dyslipidemia and atherosclerotic vascular change were observed in young adults with T1DM diagnosed during childhood and adolescence; this strongly suggests that meticulous screening of macrovascular complications and control of their risk factors should be conducted.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.8-16
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• 2008

Purpose: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using $^{99m}Tc$-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). Materials and Methods: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. Results: Seventeen patients (M:F =12:5, mean age $53{\pm}2yr$) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p = 0.003) and decreased to the preoperative level at 3-6 months (p = 0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. Conclusion: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.3
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• pp.92-95
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• 2017

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by an ${\alpha}$-galactosidase A (GLA, MIM 300644) enzyme deficiency due to pathogenic variants in the ${\alpha}$-galactosidase A gene (GLA). The disease leads to accumulation of globotriaosylceramide (Gb3) and related glycophospholipids affecting nearly all major organ systems, with the primary sites damaged by Gb3 including renal glomeruli, myocardium, neurons of the dorsal ganglion and autonomic nervous system, and vascular endothelial and smooth muscle. Progressive deposition in these organ systems present with various clinical manifestations including acroparesthesia, renal failure and heart failure. Here, we report a Chinese male diagnosed with Fabry disease in his late $4^{th}$ decades showing improvement of acroparesthesia during enzyme replacement therapy (ERT). A 48-year-old Chinese man who presented with chronic recurrent severe burning pain in his fingers and toes since the age of 10, with worse involvement of the former visited to our clinic for further evaluation. His medical history included a transient ischemic attack aged 40 and diagnosed with stage 4-5 chronic kidney disease aged 47. In the family history, the patient's brother was found to be have Fabry disease 1 month before his visit. Except for his brother, all other members of the family are healthy. Based on his medical history and family history, he was strongly suspicious for Fabry disease. He was found to have a galactose-alpha-1,3-galactose level 4.96 (Reference range, 42.5-67.9) suggestive of Fabry disease. The followed sequencing of GLA coding region in our patient revealed hemizyosity for the mutation c.988C>T (Q330X) in Exon 7. Since ERT start, he showed significant improvement in his symptoms of burning sensation of fingers and toes. On the contrary, due to deteriorating kidney function even with ERT, he is considered for kidney transplantation. Despite of diagnostic delay until late 4th decades, ERT showed a potential improvement of acroparesthesia in our patient. However, late start of ERT can lead to poor outcome in multiorgan function. Therefore, early diagnosis with high index of suspicion followed by continuous ERT with regular monitoring have an impact on quality of life in Fabry disease.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.192-200
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• 2008

To evaluate the hemodynamic changes and the predictive factors of the clinical outcome in pediatric patients with moyamoya disease, we analyzed pre/post basal/acetazolamide stress brain perfusion SPECT with automated volume of interest (VOIs) method. Methods: Total fifty six (M:F = 33:24, age $6.7{\pm}3.2$ years) pediatric patients with moyamoya disease, who underwent basal/acetazolamide stress brain perfusion SPECT within 6 before and after revascularization surgery (encephalo-duro-arterio-synangiosis (EDAS) with frontal encephalo-galeo-synangiosis (EGS) and EDAS only followed on contralateral hemisphere), and followed-up more than 6 months after post-operative SPECT, were included. A mean follow-up period after post-operative SPECT was $33{\pm}21$ months. Each patient's SPECT image was spatially normalized to Korean template with the SPM2. For the regional count normalization, the count of pons was used as a reference region. The basal/acetazolamide-stressed cerebral blood flow (CBF), the cerebral vascular reserve index (CVRI), and the extent of area with significantly decreased basal/acetazolamide- stressed rCBF than age-matched normal control were evaluated on both medial frontal, frontal, parietal, occipital lobes, and whole brain in each patient's images. The post-operative clinical outcome was assigned as good, poor according to the presence of transient ischemic attacks and/or fixed neurological deficits by pediatric neurosurgeon. Results: In a paired t-test, basal/acetazolamide-stressed rCBF and the CVRI were significantly improved after revascularization (p<0.05). The significant difference in the pre-operative basal/acetazolamide-stressed rCBF and the CVRI between the hemispheres where EDAS with frontal EGS was performed and their contralateral counterparts where EDAS only was done disappeared after operation (p<0.05). In an independent student t-test, the pre-operative basal rCBF in the medial frontal gyrus, the post-operative CVRI in the frontal lobe and the parietal lobe of the hemispheres with EDAS and frontal EGS, the post-operative CVRI, and ${\Delta}CVRI$ showed a significant difference between patients with a good and poor clinical outcome (p<0.05). In a multivariate logistic regression analysis, the ${\Delta}CVRI$ and the post-operative CVRI of medial frontal gyrus on the hemispheres where EDAS with frontal EGS was performed were the significant predictive factors for the clinical outcome (p =0.002, p =0.015), Conclusion: With probabilistic map, we could objectively evaluate pre/post-operative hemodynamic changes of pediatric patients with moyamoya disease. Specifically the post-operative CVRI and the post-operative CVRI of medial frontal gyrus where EDAS with frontal EGS was done were the significant predictive factors for further clinical outcomes.