Browsing by Author "Chiu, Hung-Wen"

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Concurrent sympathetic activation and vagal withdrawal in hyperthyroidism: Evidence from detrended fluctuation analysis of heart rate variability
(2010-05-01)
Chen, Jin-Long
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Shiau, Yuo-Hsien
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Tseng, Yin-Jiun
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Chiu, Hung-Wen
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Hsiao, Tzu-Chien
Despite many previous Studies on the association between hyperthyroidism and the hyperadrenergic state, controversies still exist. Detrended fluctuation analysis (DFA) is a well recognized method in the nonlinear analysis of heart rate variability (HRV), and it has physiological significance related to the autonomic nervous system. In particular, an increased short-term scaling exponent alpha 1 calculated from DFA is associated with both increased sympathetic activity and decreased vagal activity. No study has investigated the DFA of HRV in hyperthyroidism. This study was designed to assess the sympathovagal balance in hyperthyroidism. We performed the DFA along with the linear analysis of HRV in 36 hyperthyroid Graves' disease patients (32 females and 4 males; age 30 +/- 1 years, means +/- SE) and 36 normal controls matched by sex, age and body mass index. Compared with the normal controls, the hyperthyroid patients revealed a significant increase (P < 0.001) in alpha 1 (hyperthyroid 1.28 +/- 0.04 versus control 0.91 +/- 0.02), long-term scaling exponent alpha 2 (1.05 +/- 0.02 versus 0.90 +/- 0.01), overall scaling exponent alpha (1.11 +/- 0.02 versus 0.89 +/- 0.01), low frequency power in normalized units (LF%) and the ratio of low frequency power to high frequency power (LF/HF); and a significant decrease (P < 0.001) in the standard deviation of the R-R intervals (SDNN) and high frequency power (HF). In conclusion, hyperthyroidism is characterized by concurrent sympathetic activation and vagal withdrawal. This sympathovagal imbalance state in hyperthyroidism helps to explain the higher prevalence of atrial fibrillation and exercise intolerance among hyperthyroid patients. (C) 2010 Elsevier B.V. All rights reserved.
Fatty acid components in Asian female patients with irritable bowel syndrome
(2017-12-01)
Chua, Chian Sem
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Huang, Shih-Yi
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Cheng, Chiao-Wen
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Bai, Chyi-Huey
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Hsu, Chien-Yeh
Abdominal pain is one of the key symptoms of irritable bowel syndrome (IBS). Studies have indicated an increase in the incidence of IBS in Asia. However, yet the pathophysiology of this disease remains unknown. Women are more likely to develop the condition than men, especially the constipation-predominant type. Essential fatty acid (EFA) malnutrition is one of several theories discussing the mechanism of IBS. The authors hypothesized that significant EFA deficiency may cause abdominal pain in patients with IBS. However, because patterns in the oral intake of EFAs differ between cultures, the authors narrowed this study to examine the nutritional status of Asian female patients with IBS The authors investigated Asian female patients with IBS and compared them with a group of healthy controls. Thirty patients with IBS and 39 healthy individuals were included in this study. The participants' age, height, weight, and waist size were recorded. The 24-item Hamilton Depression Rating Scale was documented. Both erythrocyte and plasma fatty acid content were analyzed through gas-liquid chromatography. The authors found that patients with IBS exhibited significantly higher scores for depression, higher proportions of plasma saturated fatty acids and monounsaturated fatty acids, and lower proportions of docosahexaenoic acid and total omega-3 polyunsaturated fatty acids in plasma are associated with IBS in Asian female patients. Further study is indicated to confirm the causality of this association.
Negative correlation of cortical thickness with the severity and duration of abdominal pain in Asian women with irritable bowel syndrome
(2017-08-31)
Chua, Chian Sem
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Bai, Chyi-Huey
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Shiao, Chen-Yu
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Hsu, Chien-Yeh
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Cheng, Chiao-Wen
Background & aims: Irritable bowel syndrome (IBS) manifests as chronic abdominal pain. One pathophysiological theory states that the brain-gut axis is responsible for pain control in the intestine. Although several studies have discussed the structural changes in the brain of IBS patients, most of these studies have been conducted in Western populations. Different cultures and sexes experience different pain sensations and have different pain responses. Accordingly, we aimed to identify the specific changes in the cortical thickness of Asian women with IBS and to compare these data to those of non-Asian women with IBS. Methods: Thirty Asian female IBS patients (IBS group) and 39 healthy individuals (control group) were included in this study. Brain structural magnetic resonance imaging was performed. We used FreeSurfer to analyze the differences in the cortical thickness and their correlations with patient characteristics. Results: The left cuneus, left rostral middle frontal cortex, left supramarginal cortex, right caudal anterior cingulate cortex, and bilateral insula exhibited cortical thinning in the IBS group compared with those in the controls. Furthermore, the brain cortical thickness correlated negatively the severity as well as duration of abdominal pain. Conclusions: Some of our findings differ from those of Western studies. In our study, all of the significant brain regions in the IBS group exhibited cortical thinning compared with those in the controls. The differences in cortical thickness between the IBS patients and controls may provide useful information to facilitate regulating abdominal pain in IBS patients. These findings offer insights into the association of different cultures and sexes with differences in cortical thinning in patients with IBS.
Nonlinear analysis of heart rate dynamics in hyperthyroidism
(2007-04-01)
Chen, Jin-Long
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Tseng, Yin-Jiun
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Chiu, Hung-Wen
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Hsiao, Tzu-Chien
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Chu, Woei-Chyn
Studies on the physiology of the cardiovascular system suggested that the generation of the heart rate signal is governed by nonlinear chaotic dynamics. No study investigated the nonlinear dynamics of heart rate in hyperthyroidism. We examined whether the heart rate dynamics of hyperthyroid patients is different from normal controls by the nonlinear analysis of heart rate variability (HRV) with correlation dimension (CD). Thirty-three hyperthyroid Graves' disease patients (30 females and 3 males; age 31 +/- 1 years, means +/- SE) and 33 sex-, age-, and body mass index-matched normal controls were recruited to receive one-channel electrocardiogram recording for 30 min. The CD, an index of complexity, was computed from the sequence of normal R-R intervals by the Grassberger and Procaccia algorithm. Compared to the normal controls, the hyperthyroid patients showed significant reductions (P < 0.001) in the mean R-R interval (hyperthyroid 616 +/- 15 versus control 868 +/- 16 ms), the standard deviation of R-R intervals (25 +/- 2 versus 54 +/- 4 ms) and CD (5.02 +/- 0.11 versus 6.42 +/- 0.16). Our study demonstrated for the first time that hyperthyroid patients and normal controls could be distinguished by CD analysis of HRV. In addition, the decreased CD in hyperthyroid patients implies reduced complexity and impaired tolerance to cardiovascular stresses in hyperthyroidism. This finding helps to explain exercise intolerance and irritability manifested by the hyperthyroid patients.