Blunted heart rate circadian rhythms in small for gestational age infants during the early neonatal period.

Infants born with intrauterine growth restriction are at increased risk for adverse cardiovascular outcomes in neonatal and later life. Although circadian rhythm is a prognostic marker of cardiovascular health, the concern over the circadian rhythm of these infants is rarely observed. To determine the influence of intrauterine growth retardation on the pattern of circadian rhythm, heart rate (HR) circadian rhythmicity was analyzed in 39 small for gestational age (SGA; birth weight and height below <-2.0 standard deviation score [SDS]) and 117 appropriate for gestational age (AGA; >-1.5 to <1.5 SDS) infants within 72 hours of birth using spectral analysis and cosinor analysis. Amplitude, midline estimating statistic of rhythm, and acrophase calculated from circadian rhythm were analyzed with clinical variables. A significant HR circadian rhythm was observed in 23.1% of the SGA and 24.8% of the AGA group without significant differences; however, SGA infants exhibited remarkable smaller amplitudes compared with AGA in all gestational age (GA) groups (p < 0.001). Amplitudes in AGA infants were positively correlated with the GA or body composition relevant variables (p < 0.001, respectively), but not SGA infants. The blunted HR circadian rhythmicity in SGA infants showed in this study might indicate the vulnerability to pathophysiological condition and could potentially refer to cardiovascular disease in later life.

Prevalence of Mycoplasma IgM in children with lower respiratory tract illness.

BACKGROUND: Few data are available for the recent occurrence of Mycoplasma infections in children in Japan. The purpose of the present study was therefore to identify the prevalence of Mycoplasma infections in children in Japan. METHODS: IgM antibodies to M. pneumoniae were prospectively determined using the Meridian ImmunoCard Mycoplasma test in hospitalized patients with lower respiratory tract infections between January 2004 and June 2007. A total of 858 hospitalized patients aged 0-15 years (445 male, 413 female), diagnosed as having acute pneumonia or bronchitis, were enrolled. The number of patients with pneumonia or bronchitis was 331 (male/female, 167/164) and 527 (male/female/ 278/249), respectively. Two hundred and five of the 858 patients (23.9%) were ImmunoCard positive. Of the 205 patients, 121 children and 84 children were diagnosed as having pneumonia and bronchitis, respectively. One hundred and forty-three of the 727 patients (19.7%) <5 years of age were ImmunoCard test positive. CONCLUSIONS: M. pneumoniae infection is not rare in children aged <5 years in Japan.