Brown adipose tissue in young adults who were born preterm or small for gestational age

• Published in: JOURNAL OF PEDIATRIC ENDOCRINOLOGY & METABOLISM Vol. 31; no. 6; pp. 641 - 647
• Main Authors: Kistner, Anna, Rydén, Henric, Anderstam, Björn, Hellström, Ann, Skorpil, Mikael
• Format: Journal Article
• Language: English
• Published: Germany De Gruyter 27.06.2018; Walter de Gruyter GmbH
• Subjects: Adipose Tissue, Brown - diagnostic imaging; Adipose Tissue, Brown - metabolism; Adult; adults and pediatrics; appropriate; Birth weight; Birth Weight - physiology; blood-pressure; Case-Control Studies; children; cold-exposure; endocrine disorders; Endocrinology & Metabolism; Endocrinology and Diabetes; Endokrinologi och diabetes; Female; Gestational Age; growth; Growth factors; Humans; Infant, Newborn; Infant, Premature - growth & development; Infant, Premature - metabolism; Infant, Small for Gestational Age - growth & development; Infant, Small for Gestational Age - metabolism; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medicin och hälsovetenskap; Metabolism; mri; Obesity - diagnosis; Obesity - etiology; Obesity - metabolism; Pediatrics; Pediatrik; positron-emission-tomography; Pregnancy; Risk Factors; spectrum; water-fat separation; Young Adult; Young adults; endocrine disorders; magnetic resonance imaging; adults and pediatrics
• ISSN: 0334-018X; 2191-0251; 2191-0251
• DOI: 10.1515/jpem-2017-0547

Brown adipose tissue (BAT) is present and functions to dissipate energy as heat in young adults and can be assessed using magnetic resonance imaging (MRI) to estimate the voxel fat fraction, i.e. proton density fat fraction (PDFF). It is hypothesized that subjects born preterm or small for gestational age (SGA) may exhibit disrupted BAT formation coupled to metabolic factors. Our purpose was to assess the presence of BAT in young adults born extremely preterm or SGA in comparison with controls. We studied 30 healthy subjects (median age, 21 years): 10 born extremely preterm, 10 full term but SGA and 10 full term with a normal birth weight (controls). We utilized an MRI technique combining multiple scans to enable smaller echo spacing and an advanced fat-water separation method applying graph cuts to estimate B0 inhomogeneity. We measured supraclavicular/cervical PDFF, R2*, fat volume, insulin-like growth factor 1, glucagon, thyroid stimulating hormone and the BAT-associated hormones fibroblast growth factor 21 and irisin. The groups did not significantly differ in supraclavicular/cervical PDFF, R2*, fat volume or hormone levels. The mean supraclavicular/cervical PDFF was equivalent between the groups (range 75-77%). Young adults born extremely preterm or SGA show BAT development similar to those born full term at a normal birth weight. Thus, the increased risk of cardiovascular and metabolic disorders in these groups is not due to the absence of BAT, although our results do not exclude possible BAT involvement in this scenario. Larger studies are needed to understand these relationships.