Postexercise Heart Rate Recovery in Adults Born Preterm

Objective To evaluate postexercise heart rate recovery (HRR) in adults born preterm. Study design We studied the association between preterm birth and postexercise HRR in 545 adults (267 women) at 23.3 years of age (range 19.9-26.3 years). One hundred three participants were born early preterm ( Results Mean peak HR was 159.5 bpm in the early preterm (P = .16 with controls), 157.8 bpm in the late preterm (P = .56), and 157.0 bpm in the control group. Mean HRR 30 seconds after exercise was 3.2 bpm (95% CI 1.1-5.2) lower in the early preterm group and 2.1 bpm (0.3-3.8) lower in the late preterm group than the full term controls. Mean 60s HRR was 2.5 (-0.1 to 5.1) lower in the early preterm group and 2.8 bpm (0.6-4.9) lower in the late preterm group. Mean maximum slope after exercise was 0.10 beats/s (0.02-0.17) lower in the early preterm group and 0.06 beats/s (0.00-0.12) lower in the late preterm group. Conclusions Our results suggest reduced HRR after exercise in adults born preterm, including those born late preterm. This suggests altered reactivation of the parasympathetic nervous system, which may contribute to cardiovascular risk among adults born preterm.Peer reviewe

Cardiac Autonomic Function in Adults Born Preterm

Objective To evaluate cardiac autonomic function in adults born preterm. Study design We studied the association between prematurity and cardiac autonomic function using heart rate variability measurements in 600 adults (mean age of 23.3 years) from a geographically based cohort in Northern Finland. There were 117 young adults born early preterm (= 37 weeks, controls). Autonomic function was analyzed by calculating time and frequency domain heart rate variability measurements using linear regression. Results Compared with controls, the mean difference in root mean square of successive differences (indicating cardiac vagal activity) was -12.0% (95% CI -22.2%, -0.5%, adjusted for sex, age, source cohort, and season P = .04) for the early preterm group and -7.8% (-16.8%, 2.0%, P = .12) for the late preterm group. Mean differences with controls in low frequency power (indicating cardiac vagal activity, including some sympathetic- and baroreflex-mediated effects) were -13.6% (-26.7%, 1.8%, P = .08) for the early pretermgroup and -16.4% (-27.0%, -4.3%, P = .01) for the late preterm group. Mean differences in high frequency power (quantifying cardiac vagal modulation in respiratory frequency) were -19.2% (-36.6%, 2.9%, P = .09) for the early preterm group and -13.8% (-29.4%, 5.3%, P = .15) for the late preterm group. Differences were attenuated when controlled for body mass index and physical activity. Conclusions Our results suggest altered autonomic regulatory control in adults born preterm, including those born late preterm. Altered autonomic regulatory control may contribute to increased cardiovascular risk in adults born preterm.Peer reviewe

Migraine in children and adults born preterm : A nationwide register linkage study

Objective Being born preterm is related to adverse health effects later in life. We studied whether preterm birth predicts the risk of migraine. Methods In this nationwide register study, we linked data from six administrative registers for all 235,624 children live-born in Finland (January 1987 to September 1990) and recorded in the Finnish Medical Birth Register. n = 228,610 (97.0%) had adequate data and were included. Migraine served as primary outcome variable and was stringently defined as a diagnosis from specialised health care and/or >= 2 reimbursed purchases of triptans. We applied sex- and birth year-stratified Cox proportional hazard regression models to compute hazard ratios and confidence intervals (95% confidence intervals) for the association between preterm categories and migraine. The cohort was followed up until an average age of 25.1 years (range: 23.3-27.0). Results Among individuals born extremely preterm (23-27 completed weeks of gestation), the adjusted hazard ratios for migraine was 0.55 (0.25-1.24) when compared with the full-term reference group (39-41 weeks). The corresponding adjusted hazard ratios and 95% confidence intervals for the other preterm categories were: Very preterm (28-31 weeks); 0.95 (0.68-1.31), moderately preterm (32-33 weeks); 0.96 (0.73-1.27), late preterm (34-36 weeks); 1.01 (0.91-1.11), early term (37-38 weeks); 0.98 (0.93-1.03), and post term (42 weeks); 0.98 (0.89-1.08). Migraine was predicted by parental migraine, lower socioeconomic position, maternal hypertensive disorder and maternal smoking during pregnancy. Conclusion We found no evidence for a higher risk of migraine among individuals born preterm.Peer reviewe

Risk-taking Behavior of Adolescents and Young Adults Born Preterm

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Gestational Age, Parent Education, and Education in Adulthood

BACKGROUND: Adults born preterm ( METHODS: This register-based cohort study included singletons born alive from 1987 up to 1992 in Denmark, Finland, Norway, and Sweden. In each study population, we investigated effect modification by parents' educational level (low, intermediate, high) on the association between gestational age at birth (25-44 completed weeks) and low educational attainment at 25 years (not having completed upper secondary education) using general estimation equations logistic regressions. RESULTS: A total of 4.3%, 4.0%, 4.8%, and 5.0% singletons were born preterm in the Danish (n = 331 448), Finnish (n = 220 095), Norwegian (n = 292 840), and Swedish (n = 513 975) populations, respectively. In all countries, both lower gestational age and lower parental educational level contributed additively to low educational attainment. For example, in Denmark, the relative risk of low educational attainment was 1.84 (95% confidence interval 1.44 to 2.26) in adults born at 28 to 31 weeks whose parents had high educational level and 5.25 (95% confidence interval 4.53 to 6.02) in adults born at 28 to 31 weeks whose parents had low educational level, compared with a reference group born at 39 to 41 weeks with high parental educational level. CONCLUSIONS: Although higher parental education level was associated with higher educational attainment for all gestational ages, parental education did not mitigate the educational disadvantages of shorter gestational age.Peer reviewe

Late preterm birth has direct and indirect effects on infant gut microbiota development during the first six months of life

Aim: Preterm infants display aberrant gut microbial colonisation. We investigated whether the differences in gut microbiota between late preterm and full-term infants results from prematurity or external exposures.Methods: This study comprised 43 late preterm infants (34(0/7)-36(6/7)) and 75 full-term infants based on faecal samples collected following birth and at two to four weeks and six months of age. We assessed clinically relevant bacteria using quantitative polymerase chain reaction. Logistic regression analyses were performed to determine whether the observed differences in gut microbiota were attributable to prematurity or perinatal exposure.Results: The prevalence of bifidobacteria differed in the intestinal microbiota of the fullterm and late preterm neonates. Differences in the presence of specific species were detected at the age of six months, although the microbiota alterations were most prominent following delivery. As well as prematurity, the mode of birth, intrapartum and neonatal antibiotic exposure, and the duration of breastfeeding had an additional impact on gut microbiota development.Conclusion: The gut microbiota composition was significantly different between late preterm and full-term infants at least six months after birth. Antibiotic exposure was common in late preterm infants and modulated gut colonisation, but preterm birth also affected gut microbiota development independently

Innovative metallic solutions for alpine ski bases

Ski manufacturers are interested in improving ski performance in terms of rapid sliding, excellent trajectory control, and reduced maintenance. A possible approach to achieve this goal is based on substitution of the base material, moving from the standard ultra-high-molecular-weight polyethylene to metallic solutions. Despite their elevated mechanical properties, however, metallic materials exhibit a poor sliding behavior, at least in their original manufacture condition. Although the interaction between the ski base and snow is still an open field, the authors investigated the relationship between ice friction and material hydrophobicity. The wettability behavior of surfaces can be managed by surface patterning techniques, among which laser surface texturing (LST) is a promising method, permitting surface feature modification from the micrometer- to millimeter-scale, and attractive for industrial applications. Herein, the tribological properties of two metallic materials are investigated and a process to reduce the sliding friction against snow is proposed. The LST is used to realize dimple patterning on the metallic surfaces, where the laser parameters are used to control the dimple geometry and surface wettability using untreated substrates as a reference condition. Finally, characterization using a prototype snow tribometer was performed to determine the friction coefficient and sliding performance of the laser-treated metallic surfaces

An Adaptive Approach for Online Segmentation of Multi-Dimensional Mobile Data

With increasing availability of mobile sensing devices including smartphones, online mobile data segmentation becomes an important topic in reconstructing and understanding mobile data. Traditional approaches like online time series segmentation either use a fixed model or only apply an adaptive model on one dimensional data; it turns out that such methods are not very applicable to build online segmentation for multiple dimensional mobile sensor data (e.g., 3D accelerometer or 11 dimension features like ‘mean’, ‘vari- ance’, ‘covariance’, ‘magnitude’, etc). In this paper, we design an adaptive model for segment- ing real-time accelerometer data from smartphones, which is able to (a) dynamically select suitable dimensions to build a model, and (b) adaptively pick up a proper model. In addition to using the traditional residual-style regression errors to evaluate time series segmentation, we design a rich metric to evaluate mobile data segmentation results, including (1) traditional regression error, (2) Information Retrieval style measurements (i.e., precision, recall, F-measure), and (3) segmentation time delay

Risk-taking behavior of adolescents and young adults born preterm

OBJECTIVES: To study sexually transmitted Chlamydia trachomatis infections (STCTs), teenage pregnancies, and payment defaults in individuals born preterm as proxies for engaging in risk-taking behavior. STUDY DESIGN: Our population-based register-linkage study included all 191 705 children alive at 10 years (8492 preterm [4.4%]) born without malformations in Finland between January 1987 and September 1990 as each mother's first child within the cohort. They were followed until young adulthood. We used Cox regression to assess the hazards of STCTs, teenage pregnancies, payment defaults, criminal offending, and substance abuse by gestational age. Gestational age was considered both as a continuous and categorical (extremely, very, moderately, late preterm, early term, post term, and full term as reference) exposure. RESULTS: A linear dose-response relationship existed between gestational age and STCT and teenage pregnancy; adjusted hazard for STCT decreased by 1.6% (95% CI, 0.7%-2.6%), and for teenage pregnancy by 3.3% (95% CI, 1.9%-4.8%) per each week decrease in gestational age. Those born extremely preterm (23-27 completed weeks) had a 51% (95% CI, 31%-83%) lower risk for criminal offending than their full-term born counterparts, and those born very preterm (range, 28-31 weeks) had a 28% (95% CI, 7%-53%) higher hazard for payment defaults than those born at full term. Gestational age was not associated with substance abuse. CONCLUSIONS: The lower risk-taking that characterizes people born preterm seems to generalize to sexual and to some extent criminal behavior. Those born very preterm are, however, more likely to experience payment defaults.publishedVersionPeer reviewe