Early growth and carotid intima-media thickness at midlife: Northern Finland 1966 Birth Cohort study

Abstract Background Carotid intima-media thickness (CIMT) reflects atherogenesis and is a strong predictor of cardiovascular diseases. Although cardiovascular diseases have been shown to originate in foetal life and childhood, the information on the contribution of early growth to CIMT in adulthood remains limited. Purpose To assess the influence of early growth patterns on CIMT in midlife. Methods A subpopulation of the Northern Finland Birth Cohort 1966 took part in follow-up, including CIMT evaluation by ultrasound (n=1155) at the age of 46 years. Maternal pre-pregnancy body mass index (BMI) was self-reported and birth weight and gestational age were measured after delivery. BMI growth curves were modelled based on frequent anthropometric measurements in infancy and childhood. Peak weight and height velocity in infancy (0–2 years of age, n=637) as well as age and BMI at adiposity peak (AP, mean age 9 months, n=461) and at adiposity rebound (AR, mean age 5.8 years, n=562) were established. Results are reported as unstandardized beta (β) with 95% confidence intervals for one standard deviation increase in early growth variable. Associations were adjusted for sex, birth weight, maternal pre-pregnancy BMI as well as adult weight, height, systolic blood pressure, low-density lipoprotein cholesterol, physical activity, diabetes, heart diseases and antihypertensive medication. Results Infant peak weight velocity (β=0.018 (0.011, 0.025), p<0.001) was associated with a higher CIMT in midlife, independently of adjustments for sex, early life factors and adult cardiometabolic factors (β=0.011 (0.003, 0.019), p=0.010). Infant peak height velocity was also associated with adult CIMT, but only in females (β=0.012 (0.004, 0.021), p=0.004) and the association was attenuated after adjustments (β=0.010 (0.0, 0.021), p=0.055). Birth weight and gestational age were not associated with adult CIMT. BMI at AP (β=0.011 (0.003, 0.019), p=0.007) and BMI at AR (β=0.010 (0.003, 0.018), p=0.005) were directly associated with CIMT in midlife in univariate analysis, but not independently of adult cardiometabolic factors. Timing of AP and AR were not related to adult CIMT. Finally, maternal pre-pregnancy BMI (β=0.005 (0.0, 0.011), p=0.066) also tended to be associated with a higher CIMT in midlife. Conclusions Rapid growth in infancy was the most important early growth-related factor associating with CIMT in midlife, and this relationship was not fully mediated by adult anthropometrics, cardiometabolic risk factors and morbidity. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Yrjö Jahnsson Foundation, Aarne Koskelo Foundation