Relationship between Epigenetic Maturity and Respiratory Morbidity in Preterm Infants.

OBJECTIVE: To assess associations between epigenetic maturity of extremely preterm babies (born at less than 28 weeks of gestation), neonatal interventions, and respiratory outcomes, including the administration of surfactant and postnatal corticosteroids, duration of assisted ventilation, and development of bronchopulmonary dysplasia (BPD). STUDY DESIGN: DNA was extracted from neonatal blood spots collected after birth from 143 extremely preterm infants born 1991-1992 in Victoria, Australia and used to determined DNA methylation (DNAm). A DNAm based gestational age was determined using our previously published method. The residual of DNAm gestational age and clinically estimated gestational age (referred to as "gestational age acceleration") was used as a measure to assess developmental maturity. Associations between gestational age acceleration and respiratory interventions and morbidities were determined. RESULTS: Infants with higher gestational age acceleration were less likely to receive surfactant (P = .009) or postnatal corticosteroids (P = .008), had fewer days of assisted ventilation (P = .01), and had less BPD (P = .02). Respiratory measures are known to correlate with gestational age; however, models comparing each with clinically estimated gestational age were improved by the addition of the gestational age acceleration measure in the model. CONCLUSIONS: Gestational age acceleration correlates with respiratory interventions and outcomes of extremely preterm babies. Surfactant and postnatal corticosteroid use, assisted ventilation days, and BPD rates were all lower in babies who were epigenetically more mature than their obstetrically estimated gestational age. This suggests that gestational age acceleration is a clinically relevant metric of developmental maturity.

Twin studies for the prognosis, prevention and treatment of musculoskeletal conditions.

BACKGROUND: Musculoskeletal conditions are highly prevalent in our ageing society and are therefore incurring substantial increases in population levels of years lived with disability (YLD). An evidence-based approach to the prognosis, prevention, and treatment of those disorders can allow an overall improvement in the quality of life of patients, while also softening the burden on national health care systems. METHODS: In this Masterclass article, we provide an overview of the most relevant twin study designs, their advantages, limitations and major contributions to the investigation of traits related to the domain of musculoskeletal physical therapy. CONCLUSIONS: Twin studies can be an important scientific tool to address issues related to musculoskeletal conditions. They allow researchers to understand how genes and environment combine to influence human health and disease. Twin registries and international collaboration through existing networks can provide resources for achieving large sample sizes and access to expertise in study design and analysis of twin data.