Adrenarche means an increase in the production of adrenal androgens in childhood. Previous studies have focused mostly on premature adrenarche, which has been linked to insulin resistance, especially in overweight children. The regulation of adrenarche is scarcely known, and its timing and intensity vary among inviduals. Adrenarche has not earlier been studied much in general populations of children. Thus, the associations of timing and intensity of adrenarche with the health of children are not known.
Adrenarche occurs some years before the onset of puberty. An increase in serum androgen levels can lead to the clinical signs of adrenarche, including adult-type body odor, oily hair and skin, acne, comedones, as well as axillary and pubic hair. Many children with adrenarche also have accelerated growth. A serum dehydroepiandrosterone sulfate (DHEAS) concentration of 1 µmol/L has been considered the cut-off level for biochemical adrenarche, particularly in research.
The purpose of Aino Mäntyselkä’s doctoral thesis was to study the presentation of adrenarche in girls and in boys, the associations of serum DHEAS with adiposity and other cardiometabolic risk factors, the associations of lifestyle factors, such as diet, physical activity and sedentary behavior with serum DHEAS and insulin-like growth factor 1 (IGF-1), and the associations of serum DHEAS and IGF-1 with cognition. The study population consisted of 437 prepubertal children aged 6-8 years participating in the Physical activity and Nutrition in Children (PANIC) study.
The clinical signs of adrenarche were more common in girls than in boys, but biochemical adrenarche without clinical signs was more common in boys. This difference between genders was probably due to a higher body fat content and more potent peripheral androgen conversion in girls. The prevalence of premature adrenarche was 8.6% in girls and 1.8% in boys. Higher serum DHEAS was associated with lower plasma low-density lipoprotein (LDL) cholesterol after adjustment for birth weight and current body mass index. The previously found association of increased cardiometabolic risk and premature adrenarche may be due to confounding factors such as low birth weight and excess weight rather than premature adrenarche. Lifestyle factors had weak or moderate associations with serum DHEAS and IGF-1 concentrations. For example, consumption of low-fiber grain products was positively associated with DHEAS and energy intake was positively associated with IGF-1. Vigorous physical activity was inversely associated with DHEAS and total sedentary behavior was positively associated with IGF-1. Serum DHEAS was not associated with cognition, but higher serum IGF-1 was related to better cognition among boys.
The doctoral dissertation of Aino Mäntyselkä, Licentiate of Medicine, entitled Adrenarche, predisposing factors, presentation and effects on health, will be examined at the Faculty of Health Sciences. The Opponent in the public examination will be Docent Päivi Keskinen of Tampere University, and the Custos will be Professor Jarmo Jääskeläinen of the University of Eastern Finland. The public examination will be held in Finnish on 30 October 2020.
Photo available for download at https://mediabank.uef.fi/A/UEF+Media+Bank/37881?encoding=UTF-8
Thesis available online: http://urn.fi/URN:ISBN:978-952-61-3596-0