Influence of prone sleep position on arousal response as a risk factor for SIDS

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671066
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Embryonic/Neonatal medicine
• Research Institution: Nagoya City University
• Principal Investigator: KATO Ineko Nagoya City University, Medical School, Research Associate, 医学部, 助手 (00305541)
• Co-Investigator(Kenkyū-buntansha): TOGASHI Hajime Nagoya City University, Medical School, Professor, 医学部, 教授 (50106233)
• Project Period (FY): 2000 – 2001
• Keywords: Sudden Infant Death Syndrome / SIDS / arousal response / sucking prone spectral analysis / うつぶせ寝 / 心拍スペクトル解析

Research Abstract

Cause of SIDS (Sudden Infant Death Syndrome) is still unknown, Recently, the relationship between a lack of arousal and prone sleep position has been reported as a risk factor for SIDS. Use of pacifier during sleep has been known to reduce a threshold of arousal response. It is still unknown whether sympathetic nerves are activated by using pacifier. It will be important for protection of SIDS to know if sympathetic nerves are activated by using pacifier, or if pone sleep position reduces the sympathetic nerve activation compared with supine position when the use of pacifier. In this study, thirteen newborn infants were investigated by simultaneous monitoring of sucking pressure, electrocardiogram, respiratory wave during rest and non-nutritive sucking. Heart rate spectral analysis was performed both during rest and non-nutritive sucking, and compared between supine position and prone position. Complex demodulation analysis method of Time Series Analysis System (NCU version) was used for the heart rate spectral analysis. Decrease of HF power and increase of LF/HF were observed during non-nutritive sucking compared with during rest. HF represents parasympathetic activity, and LF/HF represents sympathetic activity. In this present study, it was revealed that activation of sympathetic nerve of reduction of parasympathetic nerve occurs during non-nutritive sucking. There was no difference in decrease of HF and increase of LF/HF power between supine position and prone position. The activation of sympathetic nerve during non-nutritive sucking did not affected by sleep position.