WHAT'S KNOWN ON THIS SUBJECT: Adolescents and adults born early preterm have higher blood pressure and altered glucose metabolism compared with their term born peers. Evidence of an atherogenic lipid profile is inconsistent. Whether these risks apply to those born less preterm is not known.
WHAT THIS STUDY ADDS:In adolescence, girls have higher blood pressure and boys a more atherogenic lipid profile than their term born peers. Overall, our results are consistent with a dose-response relationship between shorter length of gestation and increasing levels of cardiovascular risk factors. abstract BACKGROUND: Adolescents and adults born as small preterm infants show more pronounced risk factors of cardiovascular disease. Whether similar risks apply across all degrees of preterm birth is poorly known.
METHODS:We studied the association between preterm birth and cardiovascular risk factors in 6642 16-year-old adolescents of the populationbased Northern Finland Birth Cohort 1986. Of these, 79 (1.2%) were born at ,34 gestational weeks (early preterm), 238 (3.6%) at 34 to 36 weeks (late preterm), and 6325 at term (controls).RESULTS: Girls born early preterm had 6.7 mm Hg (95% confidence interval: 3.1-10.2) higher systolic blood pressure (BP) and 3.5 mm Hg (1.1-5.8) higher diastolic BP, but no difference in serum lipid levels compared with control girls. Boys showed no differences in BP, but boys born early preterm had 6.7% (0.2%-13.7%) higher total cholesterol, 11.7% (2.1%-22.3%) higher low-density lipoprotein cholesterol, and 12.3% (3.1%-22.4%) higher apolipoprotein B concentrations. The differences were similar (BP) or stronger (lipids) when adjusted for maternal smoking, birth weight SD score, parental education, pubertal stage, BMI, and lifestyle. There were similar associations with length of gestation as a continuous variable. Accordingly, mean differences between late preterm and controls were in the same direction but weaker, although most were not statistically significant.
CONCLUSIONS:Preterm birth was associated with elevated BP in adolescent girls and an atherogenic lipid profile in boys. Because these associations were strongest among those born early preterm, our findings are consistent with a dose-response relationship between shorter length of gestation and cardiovascular risk factors. Dr Sipola-Leppänen carried out initial analyses and drafted the initial manuscript; Drs Vääräsmäki and Kajantie carried out initial analyses, reviewed and revised the manuscript, and supervised the writing process; Drs Tikanmäki, Hovi, and Miettola reviewed and revised the manuscript; Drs Ruokonen, Pouta, and Järvelin coordinated and supervised data collection and critically reviewed the manuscript; and all authors approved the final manuscript as submitted.www.pediatrics.org/cgi