title: Preterm birth may be a larger risk factor for increased blood pressure than intrauterine growth restriction.
abstract: OBJECTIVE
  Very low birthweight (VLBW) and prematurity have been associated with an increased risk of high blood pressure (BP). We compared BP and salivary cortisol responses to a stressful situation between adolescents with a VLBW and controls.
  
  
  METHODS
  We compared three groups aged 12-17 years: 30 born VLBW but appropriate for gestational age (AGA) at a mean of 27 weeks, 19 born VLBW but small for gestational age (SGA) at a mean of 31 weeks and 43 term-born AGA controls. Three consecutive BP measurements were performed before a magnetic resonance imaging (MRI) examination. Salivary cortisol and perceived stress were assessed before and after the MRI.
  
  
  RESULTS
  Systolic and diastolic BP decreased significantly for each repeated measurement in the VLBW-SGA group and controls, but remained unchanged in the VLBW-AGA group. The third systolic BP measurement was 9-12 mmHg higher in the VLBW-AGA group than the other groups (p < 0.05). There were no differences in salivary cortisol between the groups, before and after the MRI or between the sexes.
  
  
  CONCLUSIONS
  Dynamic BP responses differed between adolescents born VLBW-AGA and the other groups, indicating that extremely preterm birth may be a larger risk factor for increased BP than intrauterine growth restriction.
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden.|Department of Neonatology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Emma
authors.initials: E
authors.lastname: Steen
authors.affiliation: Department of Women's and Children's Health, Karolinska Institutet Stockholm, Stockholm, Sweden.
authors.forename: Anna-Karin
authors.initials: AK
authors.lastname: Bonamy
authors.affiliation: Department of Neonatology, Karolinska University Hospital, Stockholm, Sweden.|Department of Clinical Science, Intervention and Technology, Karolinska Institutet Stockholm, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Norman
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden.|Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Hellström-Westas
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D005317:Fetal Growth Retardation; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis; D006973:Hypertension / Q000150:complications / Q000453:epidemiology* / Q000209:etiology* / Q000378:metabolism; D007236:Infant, Small for Gestational Age; D019102:Infant, Very Low Birth Weight; D008297:Male; D047928:Premature Birth; D011446:Prospective Studies; D012307:Risk Factors; D012463:Saliva / Q000737:chemistry; D013315:Stress, Psychological / Q000150:complications / Q000378:metabolism
chemical_list: D006854:Hydrocortisone
keywords: Gender; Hypertension; Intrauterine growth restriction; Preterm; Stress