Preterm birth as a predicting factor for health and disease later in life : Growth, cardiometabolic risk, and cognitive functioning
Year: 2023
Type: dissertation
Study design: Observational Study
Abstract: Background and aims. Children and adults born preterm (<37 gestational weeks) are mostly healthy and live normal lives; however, preterm birth is associated with several long-term health risks. The three papers upon which this thesis is based evaluate these risks from different perspectives. Study I. Especially very preterm (<32 gestational weeks) birth is associated with cardiometabolic risks: higher blood pressure, problems at glucose and insulin metabolism, and changes in cardiac function in childhood and young adult age. We evaluated whether early nutrition or growth are associated on later cardiometabolic risks in preterm and very low birth weight (<1,500 g, VLBW) individuals. Study II. Cognitive and executive function defects among very preterm born children and adults are well established. We evaluated if adults born late preterm (34 to <37 weeks) also have cognitive or executive function deficits. Study III. Growth of preterm children differs from those born at term during the first years of life. However, not much is known about timing of pubertal growth in children born preterm. In adults born at term, early puberty is associated with higher body mass index, mental health problems, and shorter final height. We evaluated if preterm birth is associated with earlier pubertal growth compared to those born at term. Methods. Study I. The Helsinki Study of Very Low Birth Weight Adults (HeSVA) includes 166 preterm and VLBW participants born between 1978 and 1985 and treated at Helsinki University Hospital HUS. The adult assessments included measurements of blood pressure, heart rate, and lipid levels, and performance of oral glucose tolerance test (including insulin concentrations) and intravenous glucose tolerance test. To study the effects of early energy and macronutrient intakes and growth on later cardiometabolic risk factors, we used multiple linear regression models. Analyses included 125 participants who had specific nutritional data available and did not have neurosensory impairment. Study II. The ESTER preterm birth study is a cohort including 149 moderately or very preterm (<34 gestational weeks), 248 late preterm, and 356 term-born adults, born 1985 to 1989 in Northern Finland. Adult health assessment included cognitive testing by Cogstate Research™. Our test battery evaluated executive functioning, working memory, learning, and reaction times. Effects of very or moderately preterm and late preterm birth on Cogstate test results were analyzed with multiple linear regression models. Analyses were also performed in predefined subgroups according to small for gestational age (SGA) or appropriate for gestational age birth weight. Study III. As part of the ESTER study, the effect of preterm birth on the timing of pubertal growth was analyzed with the SuperImposition by Translation And Rotation (SITAR) model. The most important outcomes of these analyses were the differences at age of peak height velocity (PHV) and PHV itself. We also studied differences at age of menarche and age of voice break with student’s t test. Results. Study I. Compared to recommendations today, participants received a low amount of protein, 1.4 g/kg/d during weeks 1–3. Weeks 1–3, 4–6, or 7–9 macronutrient or energy intakes were not associated with blood pressure, heart rate, or lipid levels in adult age (mean 22.4 years). Higher macronutrient and energy intakes during weeks 1–3 of life were associated with higher fasting insulin (and therefore also homeostatic model assessment for insulin resistance index, HOMA-IR). However, no associations were found between early nutrition and intravenous glucose tolerance test (at 25.1 years) results. Greater head growth during weeks 3–6 was associated with lower diastolic blood pressure, but growth parameters were not otherwise associated with cardiometabolic outcomes. Study II. Adults born very or moderately preterm and adults born both late preterm and SGA performed weaker than term-born participants on a spatial memory efficiency test All gestational age groups performed equally well on other cognitive function tests. Study III. Very or moderately preterm, late preterm, and term-born participants reached their PHV at the same age, and PHV was similar between groups. Women had their menarche at the same age, and men had their voice break at same age. Conclusions. Although some previous studies have found associations with early nutrition or early growth and later cardiometabolic outcomes, this was mostly not established in our study. Opposite to our hypothesis, pubertal growth does not seem to be affected by preterm birth. We and others have shown that very or moderately preterm birth is a risk factor for cognitive defects. Accompanied with late preterm birth, those having other risk factors—SGA in our study—are at risk for mild cognitive defects.
Source: Työväentutkimus Vuosikirja
Author: Suikkanen, Julia
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W6995925386