Background: The purpose of this study was to report the radiographic results and complications of magnetically controlled growing rod (MCGR) treatment in patients with early-onset scoliosis (EOS).

Methods: Patient records and radiographs from a consecutive series of patients treated with MCGR for EOS at two Swedish institutions were reviewed retrospectively. Radiographic analysis included Cobb angle, T1-T12 height, T1-S1 height, thoracic kyphosis, and lung height. Subgroup analyses were performed on primary versus conversion cases and single versus dual rods using one-way analysis of variance (ANOVA) and independent samples t-test.

Results: Fifty-two cases treated with MCGR (24 single rods, 28 dual rods) were included from local surgical records into this cohort study, 32 primary and 20 converted from other growth friendly surgical treatment. Mean age at MCGR implantation was 7.4 (2.0-14.6) years old in the primary group and 9.3 (5.0-16.1) years old in the converted group. Mean follow-up time was 3.7 (2.0-7.6) years. Mean (standard deviation; SD) Cobb angle of the major curve changed from 62° (17°) preoperatively to 42° (16°) postoperatively to 46° (18°) at final follow-up (P<0.001). Mean (SD) overall thoracic kyphosis changed from 41° (19°) preoperatively to 32° (14°) postoperatively to 39° (17°) at final follow-up (P=0.018). Mean T1-T12 height was 177 mm (34 mm) preoperatively, 183 mm (35 mm) immediate postoperative and 199 mm (35 mm) at final follow-up (P=0.047). The mean T1-T12 height increased significantly in the primary group but not in the converted group. The number of surgeries was 114 (78 planned, 36 unplanned). The rate of unplanned surgeries did not differ significantly between single and dual rods. The total number of complications was 70 of which 38 were implant related. The overall mean complication rate was 1.4 (0-4). There were no significant differences in complication rates between subgroups.

Conclusions: MCGR treatment enabled and maintained correction of spinal deformity while allowing spinal growth. There were no significant differences in complication rates or unplanned surgeries between the groups treated with single or dual rods.

OBJECTIVES: To investigate at what age preterm infants develop a salivary cortisol circadian rhythm and identify whether it is dependent on gestational age and/or postnatal age. To evaluate whether salivary cortisol circadian rhythm development is related to behavioral regularity. To elucidate salivary cortisol levels in preterm infants during the first year of life.

METHODS: This prospective, longitudinal study included 51 preterm infants. 130 healthy full-term infants served as controls. Monthly salivary cortisol levels were obtained in the morning (07:30-09:30), at noon (10:00-12:00), and in the evening (19:30-21:30), beginning at gestational age week 28-32 and continuing until twelve months corrected age. Behavioral regularity was studied using the Baby Behavior Questionnaire.

RESULTS: A salivary cortisol circadian rhythm was established by one month corrected age and persisted throughout the first year. The preterm infants showed a cortisol pattern increasingly more alike the full-term infants as the first year progressed. The preterm infants increase in behavioral regularity with age but no correlation was found between the development of salivary cortisol circadian rhythm and the development of behavior regularity. The time to establish salivary cortisol circadian rhythm differed between preterm and full-term infants according to postnatal age (p = 0.001) and was dependent on gestational age. Monthly salivary cortisol levels for preterm infants from birth until twelve months are presented. Additional findings were that topical corticosteroid medication was associated with higher concentrations of salivary cortisol (p = 0.02) and establishment of salivary cortisol circadian rhythm occurred later in infants treated with topical corticosteroid medication (p = 0.02).

CONCLUSIONS: Salivary cortisol circadian rhythm is established by one month corrected age in preterm infants. Establishment of salivary cortisol circadian rhythm is related to gestational age rather than to postnatal age. Salivary cortisol circadian rhythm development is not related to behavioral regularity.

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BACKGROUND:

Cortisol concentrations in plasma display a circadian rhythm in adults and children older than one year. Earlier studies report divergent results regarding when cortisol circadian rhythm is established. The present study aims to investigate at what age infants develop a circadian rhythm, as well as the possible influences of behavioral regularity and daily life trauma on when the rhythm is established. Furthermore, we determine age-related reference intervals for cortisol concentrations in saliva during the first year of life.

METHODS:

130 healthy full-term infants were included in a prospective, longitudinal study with saliva sampling on two consecutive days, in the morning (07:30-09:30), noon (10:00-12:00) and evening (19:30-21:30), each month from birth until the infant was twelve months old. Information about development of behavioral regularity and potential exposure to trauma was obtained from the parents through the Baby Behavior Questionnaire and the Life Incidence of Traumatic Events checklist.

RESULTS:

A significant group-level circadian rhythm of salivary cortisol secretion was established at one month, and remained throughout the first year of life, although there was considerable individual variability. No correlation was found between development of cortisol circadian rhythm and the results from either the Baby Behavior Questionnaire or the Life Incidence of Traumatic Events checklist. The study presents salivary cortisol reference intervals for infants during the first twelve months of life.

CONCLUSIONS:

Cortisol circadian rhythm in infants is already established by one month of age, earlier than previous studies have shown. The current study also provides first year age-related reference intervals for salivary cortisol levels in healthy, full-term infants.

A functional stress-response system is essential for survival at birth, as well as for health and further development. Altered cortisol response and hypothalamic-pituitary-adrenal system function may have both short and long-term effects on health and development throughout life. Cortisol secretion follows a circadian rhythm in adults. Data in the literature concerning basal cortisol levels is scant, with divergent results regarding the timeframe for establishment of cortisol circadian rhythm in children. Nevertheless, cortisol is often studied in stress-related research concerning preterm infants, full-term infants, and infants at high psychosocial risk.

This thesis aimed to investigate at what age cortisol circadian rhythm develops in healthy full-term infants, preterm infants, and infants at high psychosocial risk and to identify whether such development is dependent on gestational or postnatal age. A secondary aim was to investigate whether either behavioral regularity or daily life trauma are associated with establishment of cortisol circadian rhythm. The last two interventional studies explored whether a) parental participation in the Hagadal daycare attachment program in one  study and b) oral administration of glucose during nasopharyngeal suctioning in the other study influenced development of salivary cortisol circadian rhythm and/or cortisol levels. The effects, if any, of the Hagadal daycare attachment program on caregiver sensitivity to infants were also investigated.

The present thesis includes four original studies. Papers I, II, and III describes prospective, longitudinal studies extending over a year, including a survey of the cortisol levels and development of cortisol circadian rhythm in three infant groups. Paper III also included an intervention component addressing the possible effects of the Hagadal daycare attachment program. Paper IV describes a case-control study designed to generate paired baseline-response data concerning the effects of oral glucose administration during nasopharyngeal suctioning as an interventional procedure.

Cortisol circadian rhythm in salivary cortisol secretion was similarly established at one month postnatal age in full-term infants and at one month corrected age in preterm infants, reflecting a process dependent on gestational age. This rhythm persisted throughout the first year of life in all infants and consolidated over time in healthy full-term and preterm infants, but not in infants at high psychosocial risk, who displayed higher variability in cortisol levels. The infants in paper IV had not yet reached one month of corrected age and therefore had not yet developed cortisol circadian rhythm at the time of the investigation. No correlation was found between development of cortisol circadian rhythm and either behavioral regularity or reported traumatic life events. This thesis presents data on salivary cortisol levels among three different groups of infants during the first year of life. Cortisol circadian rhythm among infants in study III evolved in response to parental participation in the Hagadal daycare attachment program, which increased caregiver sensitivity to infants. Study IV found that nasopharyngeal suctioning was not a sufficiently stressful stimulus to increase salivary cortisol or impact pain score. Oral glucose administration had no effect on salivary cortisol levels.

This thesis concludes that cortisol circadian rhythm is already established in infants by one month of age, earlier than previous studies have shown, and further that this process is dependent on gestational age. The Hagadal daycare attachment program enhances parental sensitivity toward children, which helps to stabilize development of cortisol circadian rhythm.

Background Cortisol concentrations in plasma display a circadian rhythm in adults and children older than one year. Earlier studies report divergent results regarding when cortisol circadian rhythm is established. The present study aims to investigate at what age infants develop a circadian rhythm, as well as the possible influences of behavioral regularity and daily life trauma on when the rhythm is established. Furthermore, we determine age-related reference intervals for cortisol concentrations in saliva during the first year of life. Methods 130 healthy full-term infants were included in a prospective, longitudinal study with saliva sampling on two consecutive days, in the morning (07:30-09:30), noon (10:00-12:00) and evening (19:30-21:30), each month from birth until the infant was twelve months old. Information about development of behavioral regularity and potential exposure to trauma was obtained from the parents through the Baby Behavior Questionnaire and the Life Incidence of Traumatic Events checklist. Results A significant group-level circadian rhythm of salivary cortisol secretion was established at one month, and remained throughout the first year of life, although there was considerable individual variability. No correlation was found between development of cortisol circadian rhythm and the results from either the Baby Behavior Questionnaire or the Life Incidence of Traumatic Events checklist. The study presents salivary cortisol reference intervals for infants during the first twelve months of life. Conclusions Cortisol circadian rhythm in infants is already established by one month of age, earlier than previous studies have shown. The current study also provides first year age-related reference intervals for salivary cortisol levels in healthy, full-term infants.

Aim: To investigate whether nasopharyngeal suctioning produces a physiological and behavioural stress reaction in preterm infants and if a possible reaction can be dampened by sweet solution. Methods: Eleven preterm infants were randomly assigned to receive either 30% oral glucose or nothing prior to morning nasopharyngeal suctioning; the procedure was reversed in the afternoon. The study included a total of 44 samples from preterm infants evaluated with salivary cortisol, pain score (Visual Analogue Scale), heart rate, oxygen saturation and recovery time through the Newborn Individualized Developmental Care and Assessment Program. For reference, 44 samples from eleven full-term infants were evaluated for salivary cortisol. Results: Regardless of whether or not preterm infants received glucose before nasopharyngeal suctioning, no statistically significant difference was found in salivary cortisol reactivity, pain score, heart rate, oxygen saturation or recovery time. Nor were any statistically significant differences between salivary cortisol baseline and response values found in full-term infants after nasopharyngeal suctioning. Conclusion: In the present setting, nasopharyngeal suctioning was not stressful enough to increase salivary cortisol or pain score. Oral glucose did not alter salivary cortisol levels.