Helen C. Atkinson

Summary: Objective: We examined parental and early‐life variables in order to identify risk factors for adulthood overweight and obesity in offspring. We report here on the longitudinal prevalence of overweight and obesity in Australian children born between 1989 and 1991 and followed from birth to age 22.Methods: Data were analysed on 1355 participants from the Western Australian Pregnancy Cohort (Raine) Study, with anthropometry collected during pregnancy, at birth, one year and at three yearly intervals thereafter. Multivariate analyses and cross‐sectional logistic regression quantified the timing and contribution of early‐life risk factors for overweight and obesity in young‐adulthood.Results: At five years of age 12.6% of children were overweight and 5.2% were obese. By early adulthood, the prevalence of obesity had increased to 12.8%, whilst overweight remained relatively stable at 14.2% (range from early childhood to adulthood 11–16%). Parental pre‐pregnancy body mass index (BMI) was the strongest determinant of adult offspring BMI. Although rapid first year weight gain was associated with increased offspring BMI, the impact of first year weight‐gain diminished over childhood, whilst the impact of parental BMI increased over time.Conclusions: Parental pre‐pregnancy BMI and rapid early‐life weight gain predispose offspring to obesity in adulthood.

Molecular mechanisms responsible for abnormal endometrial vasculature in women receiving long-acting progestin-only contraceptives (LAPCs) are unknown. We hypothesize that LAPCs impair vascular smooth muscle cell (VSMC) and pericyte proliferation and migration producing thin-walled hyperdilated fragile microvessels prone to bleeding. Proliferating cell nuclear antigen (PCNA) and α-smooth muscle actin (αSMA) double-immunostaining assessed VSMC differentiation and proliferation in endometria from women before and after DepoProvera (Depo) treatment and from oophorectomized guinea pigs (OVX-GPs) treated with vehicle, estradiol (E2), medroxyprogesterone acetate (MPA), or E2+MPA. Whole-genome profiling, proliferation, and migration assays were performed on cultured VSMCs treated with MPA or etonogestrel (ETO). Endometrial vessels of Depo-administered women displayed reduced αSMA immunoreactivity and fewer PCNA (+) nuclei among αSMA (+) cells (P < 0.008). Microarray analysis of VSMCs identified several MPA- and ETO-altered transcripts regulated by STAT1 signaling (P < 2.22 × 10⁻⁶), including chemokine (C-C motif) ligand 2 (CCL2). Both MPA and ETO reduce VSMC proliferation and migration (P < 0.001). Recombinant CCL2 reversed this progestin-mediated inhibition, whereas a STAT1 inhibitor abolished the CCL2 effect. Similarly, the endometria of MPA treated OVX-GPs displayed decreased αSMA staining and fewer PCNA (+) nuclei in VSMC (P < 0.005). In conclusion, LAPCs promote abnormal endometrial vessel formation by inhibiting VSMC proliferation and migration. Significance Over a million unintended pregnancies occur in the United States each year because of either discontinuation or misuse of contraceptives. The major reason for discontinuation of long-acting progestin-only contraceptives (LAPCs) is the occurrence of abnormal uterine bleeding (AUB). Uncovering the mechanisms underlying LAPC-induced AUB is essential to prevent their discontinuation. We found that LAPCs reduce proliferation of human and guinea pig endometrial vascular smooth muscle cells (VSMCs), resulting in production of thin-walled hyperdilated fragile microvessels. In cultured VSMCs, chemokine (C-C motif) ligand 2 reverses LAPC-mediated inhibition of VSMC proliferation, suggesting that LAPCs impair endometrial vascular integrity and that chemokine ligand 2 administration may prevent LAPC-induced AUB.

The hypothalamic-pituitary-adrenal (HPA) axis regulates stress responses and HPA dysfunction has been associated with several chronic diseases. Low birthweight may be associated with HPA dysfunction in later life, yet human studies are inconclusive. The primary study aim was to identify genetic variants associated with HPA axis function. A secondary aim was to evaluate if these variants modify the association between birthweight and HPA axis function in adolescents. Morning fasted blood samples were collected from children of the Western Australia Pregnancy Cohort (Raine) at age 17 (n = 1077). Basal HPA axis function was assessed by total cortisol, corticosteroid binding globulin (CBG), and adrenocorticotropic hormone (ACTH). The associations between 124 tag single nucleotide polymorphisms (SNPs) within 16 HPA pathway candidate genes and each hormone were evaluated using multivariate linear regression and penalized linear regression analysis using the HyperLasso method. The penalized regression analysis revealed one candidate gene SNP, rs11621961 in the CBG encoding gene (SERPINA6), significantly associated with total cortisol and CBG. No other candidate gene SNPs were significant after applying the penalty or adjusting for multiple comparisons; however, several SNPs approached significance. For example, rs907621 (p = 0.002) and rs3846326 (p = 0.003) in the mineralocorticoid receptor gene (NR3C2) were associated with ACTH and SERPINA6 SNPs rs941601 (p = 0.004) and rs11622665 (p = 0.008), were associated with CBG. To further investigate our findings for SERPINA6, rare and common SNPs in the gene were imputed from the 1,000 genomes data and 8 SNPs across the gene were significantly associated with CBG levels after adjustment for multiple comparisons. Birthweight was not associated with any HPA outcome, and none of the gene-birthweight interactions were significant after adjustment for multiple comparisons. Our study suggests that genetic variation in the SERPINA6 gene may be associated with altered CBG levels during adolescence. Replication of these findings is required.

Diagnosing polycystic ovary syndrome (PCOS) in adolescence is clinically challenging. The prevalence of clinical, ultrasound and biochemical features of PCOS in a community-based adolescent population using current diagnostic criteria has not previously been described. This was a prospective cohort study with 244 unselected post-menarchal girls, mean age 15.2 years, of whom 91% were Caucasian. Subjects were recruited from a large population-based birth cohort (the Raine cohort). Clinical hyperandrogenism (HA) was quantified using Ferriman–Gallwey scores. In the early follicular phase (Day 2–6), we measured circulating androgens and sex hormone-binding globulin by immunoassay, and ovarian morphology was assessed by transabdominal ultrasound examination. BMI and waist–hip ratio were measured. Normal ranges for early follicular phase androgens in adolescence were derived for this population. The top 5 and 10% of circulating free testosterone levels were 45.6 and 34.5 pmol/l, respectively. Fifty-one percent of girls reported menstrual irregularity. Clinical HA was uncommon, being observed in only 3.5% of girls. Mean ovarian volume was greater than that reported by others in adult women and 35% of girls had polycystic ovary morphology on transabdominal ultrasound. Taking the upper 5% of free testosterone as HA, 42 girls (18.5%) would have met the Rotterdam criteria for PCOS, 11 girls (5%) the Androgen Excess Society criteria and 7 girls (3.1%) the National Institutes of Health criteria. Menstrual irregularity is common in adolescence and does not relate to clinical or biochemical HA. Diagnostic criteria for PCOS which include ovarian volume and morphology may be of limited use in adolescence.

We have examined the effects of acute administration of the cannabinoid receptor type 1 (CB₁) antagonist AM251 on the rat hypothalamic-pituitary-adrenal (HPA) axis with respect to both gender and time of day. Blood samples were collected from conscious male and female rats every 5 min using an automated blood sampling system, and corticosterone concentrations were determined. In male rats, there was a distinct diurnal effect of AM251 with a greater activation of the HPA axis in the morning (diurnal trough) compared with the evening (diurnal peak). At both times of the day, circulating corticosterone concentrations were elevated for approximately 4 h after AM251 administration. In female rats, there was also diurnal variation in the activation of the HPA axis; however, these effects were not as profound as those in males. Corticosterone concentrations were only slightly elevated at the diurnal trough and for a shorter time period than in males (2 compared with 4 h). Moreover, there was no effect of AM251 on corticosterone concentrations when administered at the diurnal peak. Subsequent studies, only in males, in which both ACTH and corticosterone were measured, confirmed that the effects of AM251 on corticosterone were mediated by ACTH. Moreover, the elevation of both ACTH and corticosterone could be replicated using another CB₁ antagonist, AM281. These data demonstrate that the extent and duration of HPA axis activation after CB₁ blockade are clearly dependent on both gender and time of day.

Context: Adequate uterine volume and ovarian reserve are essential for reproductive health. Antenatal events such as restricted fetal growth and maternal tobacco smoking are hypothesized to impact on reproductive function in later life, although not studied in a large prospective normal pregnancy population to date. Objective: The objective of the study was to determine the relationship between intrauterine growth, birth weight, and maternal tobacco smoking on uterine volume and ovarian reserve in adolescence. Design and Setting: This was a prospective study in which half the cohort underwent intensive ultrasound monitoring in utero. Participants: Intrauterine growth was measured using ultrasound at 18, 24, 28, and 34/36 wk gestation (n = 115 girls). Maternal smoking data were prospectively collected at 18 and 34/36 wk from the whole cohort. Uterine (n = 229) and early follicular ovarian volume and antral follicle count (n = 225) were measured using transabdominal ultrasound (n = 230). Ovarian reserve was estimated using early follicular phase anti-Mullerian hormone, inhibin B, and FSH (n = 213). Main Outcome Measures: The relationship between maternal tobacco smoking, intrauterine growth trajectories, and markers of ovarian reserve and uterine size in adolescence was measured. Results: Linear regression showed that daughters of mothers who smoked had a significantly smaller uterus compared with nonsmokers (P = 0.019). No significant relationship between maternal tobacco smoking and ovarian volume (P = 0.164) or markers of ovarian reserve (antral follicle count, plasma FSH, anti-Mullerian hormone, and inhibin B) in adolescence was determined. Conclusions: Our findings indicate that maternal smoking, but not variations in fetal growth, may lead to a reduction in uterine volume and does not appear to impact ovarian reserve.

Context: The prenatal antecedents of polycystic ovary syndrome (PCOS) are not known, but prenatal androgen exposure is thought to contribute. This has not previously been investigated in large prospective studies of normal human pregnancy. Objective: The aim of the study was to establish the prospective relationship between early life androgen exposure and PCOS in adolescence. Design and Setting: A prospective cohort study was conducted in the general community. Patients or Other Participants: A total of 2900 pregnant women were recruited at 18 wk gestation. Prenatal androgen exposure was measured from maternal blood samples (at 18 and 34–36 wk) and umbilical cord blood. Timed (d 2–5 menstrual cycle) blood samples were collected, clinical hyperandrogenism was assessed, and transabdominal ultrasound examination of ovarian morphology was performed in 244 unselected girls from the Raine cohort aged 14–17 yr. Main Outcome Measure(s): We examined the relationship between early life androgen exposure and PCOS in adolescence. Results: We did not observe a statistically significant relationship between early life androgen exposure and PCOS in adolescence. Conclusions: This is the first prospective study to evaluate the relationship between prenatal androgen exposure and PCOS in adolescence in normal pregnancy. Our findings do not support the hypothesis that maternal androgens, within the normal range for pregnancy, directly program PCOS in the offspring. This large prospective study of maternal and umbilical cord androgen levels failed to demonstrate a relationship between early life androgen exposure and PCOS in adolescence.

The inhibitory effect of androgens on the hypothalamic‐pituitary‐adrenal (HPA) axis in basal and stress conditions in adult male rats is well documented. Major sex‐related neuroendocrine changes take place during puberty. There is a robust rise in production and secretion of gonadal steroids, which is thought to underlie numerous neural and behavioural changes brought on after puberty. The present study investigated the effect of the pubertal rise in gonadal steroid levels on the subsequent adult corticosterone profile, particularly the sensitivity of the adult HPA axis to testosterone. Animals were castrated either prepubertally (28 days) or in adulthood (11 weeks) and adult animals were subsequently treated with subcutaneous implants containing either testosterone or cholesterol. Using an automated blood sampling system, blood was collected from each freely moving, conscious rat every 10 min (i) over a 24 h period; (ii) in response to 10 min of noise stress, and (iii) following an immunological challenge with lipopolysaccharide (LPS). Analysis revealed that testosterone treatment did not significantly affect overall corticosterone release over the 24 h period in adult animals castrated before puberty in contrast to animals castrated in adulthood in which testosterone significantly suppressed corticosterone secretion. Following either a noise stress or LPS injection, testosterone treatment did not affect the hypothalamic or adrenal stress response in animals castrated prepubertally. Testosterone significantly suppressed the corticotrophin‐releasing hormone and arginine vasopressin mRNA as well as the corticosterone response to LPS in castrated animals that had had their testes intact over puberty. These data provide evidence that puberty is a critical organizational period during which rising levels of gonadal steroids programme the sensitivity of the adult HPA axis to gonadal steroids in adulthood.