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Huang WL, Hwang BT, Lai CT, Li JY, Kuo TBJ, Yang CCH. Is Heart Rate Variability Related to Season of Birth? Clin Cardiol 2015. [PMID: 26212374 DOI: 10.1002/clc.22410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Season of birth (SOB) has been found to be related to cardiovascular mortality, but the mechanisms are unclear. It is suggested that birth in winter is a protective factor for the circulatory system, and this should be able to be observed using heart rate variability (HRV) measurements. The phenomenon may have a sex difference and is likely to be modulated by climatic factors. This study focused on this problem and investigates healthy school-age children to minimize confounding factors. HYPOTHESIS Birth in winter is protective to cardiovascular system via autonomic modulation. There is a gender difference in the relationship between SOB and autonomic activity. Climatic factors are the cause of SOB effects on autonomic system. METHODS A total of 381 healthy school-age children were recruited for this study. Their HRV profiles were measured once and climatic information related to their month of birth was gathered. The HRV profiles of the 2 sexes and 4 seasons of birth were compared. Correlation and regression analysis were performed to clarify the relationship between climatic factors and the HRV results. RESULTS Boys born in winter have higher high-frequency power (HF) but a lower ratio of low-frequency power to high-frequency power (LF/HF) than do males born in other seasons. This result is not found for girls. Age and the temperature of the SOB are predictive factors for HF among boys. The humidity of SOB is a predictive factor for normalized low-frequency power (LF%) and LF/HF among girls. CONCLUSIONS Season of birth is related to both parasympathetic and sympathetic activity among school-age children, especially boys. Temperature and humidity are potential causes of this SOB phenomenon.
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Affiliation(s)
- Wei-Lieh Huang
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Department of Psychiatry, National Taiwan University Hospital, Yun-Lin Branch, Yunlin, Taiwan.,Department of Psychiatry, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Be-Tau Hwang
- Department of Pediatrics, Taipei City Hospital, Taipei, Taiwan
| | - Chun-Ting Lai
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Sleep Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Jia-Yi Li
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Sleep Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Terry B J Kuo
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Sleep Research Center, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Department of Education and Research, Taipei City Hospital, Taipei, Taiwan
| | - Cheryl C H Yang
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.,Sleep Research Center, National Yang-Ming University, Taipei, Taiwan.,Brain Research Center, National Yang-Ming University, Taipei, Taiwan.,Department of Education and Research, Taipei City Hospital, Taipei, Taiwan
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Wright CI, Kroner CI, Draijer R. Non-invasive methods and stimuli for evaluating the skin's microcirculation. J Pharmacol Toxicol Methods 2006; 54:1-25. [PMID: 16256378 DOI: 10.1016/j.vascn.2005.09.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Accepted: 09/21/2005] [Indexed: 11/17/2022]
Abstract
Vessels in the skin are arranged into superficial and deep horizontal plexuses and they are involved in thermoregulation, oxygen and nutritional support. The skin has a large number of functions and broad appeal spanning basic mechanistic and clinical research. Indeed, the skin can be used as a marker of normal and impaired vascular control and, owing to its accessibility and frequent involvement, is easy to investigate non-invasively. A large number of non-invasive methods are available for investigating the skin, ranging from those that permit the visualisation of microvessels, to those that monitor blood flow or one of its derivatives (e.g., skin temperature and transcutaneous oxygen). Such methods can be combined with non-invasive, dynamic stimuli (e.g., the use of cold or warm stimuli, activation of the peripheral nervous system or local neuronal systems, and the topical application of vasoactive drugs) and this potentially enables the differentiation of underlying disorders (e.g., primary from secondary Raynaud's phenomenon) and also to quantify changes over time or following intervention. The present article outlines the non-invasive methods and dynamic tests that can be used to investigate the microcirculation of the skin.
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Affiliation(s)
- C I Wright
- Unilever Food and Health Research Institute, Unilever R&D Vlaardingen, Olivier van Noortlaan 120, PO Box 114, 3130 AC Vlaardingen, The Netherlands.
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