Associations of size at birth and postnatal catch-up growth status with clinical and biomedical characteristics in prepubertal girls with precocious adrenarche: preliminary results

The effect of metformin on low birth weight girls with precocious puberty: A protocol for systematic review and meta-analysis

BACKGROUND

In recent years, the role of metformin in girls with precocious puberty (PP) has been increasingly frequently studied. The objective of this present study is to assess the effect of metformin on low birth weight girls with precocious puberty (LBW-PP girls).

METHODS

We search the confirmed studies about circulating metformin and PP from the databases of EMBASE, PubMed, and Web of Science. Data were reported as weighted mean difference (WMD) and associated 95% confidence intervals (CIs). Analysis was performed by Review Manager 5.3 and Stata version 12.0.

RESULTS

A total of 205 cases (metformin group n = 102, untreated group n = 103) were included in this study. The meta-analysis of randomized controlled trials (RCTs) suggested that metformin had statistically significant effects on testosterone (P = .001), androstenedione (P = .022), bone mineral density (BMD; P = .151), triglycerides (P ≤ .001), body mass index Z score (BMI Z score; P ≤ .001), dehydroepiandrosterone-sulfate (DHEAS; P = .053), sex hormone-binding globulin (SHBG; P = .049), high-density lipoprotein (HDL) cholesterol (P ≤ .001), low-density lipoprotein (LDL) cholesterol (P = .021), fat mass (P ≤ .001), lean mass (P = .025), and fasting insulin (P = .002).

CONCLUSION

This meta-analysis provided evidence of the efficacy of metformin in girls with LBW-PP girls, which proved that metformin could improve metabolism and reduce weight. Metformin had a positive effect on preventing LBW-PP girls from developing into obesity and polycystic ovarian syndrome. In addition, this meta-analysis provided important reference opinions and directions for the treatment of LBW-PP girls.

Low birth weight and small for gestational age are associated with complications of childhood and adolescence obesity: Systematic review and meta-analysis

In recent decades, the incidence of type 2 diabetes (T2D) has increased dramatically in children and adolescents, posing a real public health problem. Beyond unhealthy diets and sedentary lifestyles, growing evidence suggests that some perinatal factors, such as low birth weight (LBW), are associated with higher risk of T2D in adulthood. In this regard, it remains unclear whether the increased risk is already present in childhood and adolescence. We conducted a systematic review and meta-analysis to clarify the association of LBW or being small for gestational age (SGA) with insulin resistance in childhood and adolescence. The systematic review resulted in 28 individual studies, and those with the same outcome were included within two random-effects meta-analyses. Compared with children or adolescents born with adequate size for gestational age, those SGA had 2.33-fold higher risk of T2D (95% confidence interval [CI]: 1.05-5.17). Furthermore, LBW and being SGA were associated with 0.20 higher mean homeostasis model assessment of insulin resistance (HOMA-IR) values (95% CI: 0.02-0.38). Given the high prevalence of preterm babies, from a population perspective, these results may be of great importance as they point to the existence of a potentially vulnerable subgroup of children and adolescents that could benefit from screening tests and early preventive strategies.

Effects of rapid growth on fasting insulin and insulin resistance: a system review and meta-analysis

Infants with congenital deficiency have high risk of glucose metabolism disorder, and often experience rapid growth in early childhood. However, the role of rapid growth on glucose metabolism is controversial. We conducted a systematic review and meta-analysis to examine the association of rapid growth with fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR). We searched EMBASE and Medline for English articles, and CNKI and WANFANG database for Chinese articles. Studies measuring the associations between rapid growth and insulin or HOMA-IR were included. Relevant information was extracted independently by two reviewers. Random effects model was adopted for combined and stratified analyses. At last, twenty-two relevant studies for insulin and 20 for HOMA-IR were identified. Rapid growth was associated with high insulin (weighted mean differences [WMD] 5.544, 95% confidence interval [CI] [1.436, 9.653], P = 0.008) and high HOMA-IR (WMD 0.194, 95% CI [0.098, 0.290], P < 0.001). This elevated association was statistically significant in rapid growth subjects that were >6 years old, full-term, and from developed countries. However, rapid growth among low birth weight subjects did not lead to high insulin and HOMA-IR, but decreased HOMA-IR among preterm children (WMD -0.305, 95% CI [-0.607, -0.004], P = 0.047). Follow-up age was positively correlated with HOMA-IR (r = 0.095, P < 0.001). This meta-analysis suggested that rapid growth would result in high insulin and HOMA-IR, especially for full-term infants. However, rapid growth is relatively harmless for subjects who are <6 years old, low birth weight or SGA, and is even protective for preterm subjects.

Influence of Prenatal Environment on Androgen Steroid Metabolism In Monozygotic Twins With Birthweight Differences

OBJECTIVE

Although low birthweight (bw) and unfavorable intrauterine conditions have been associated with metabolic sequelae in later life, little is known about their impact on steroid metabolism. We studied genetically identical twins with intra-twin bw-differences from birth to adolescence to analyze the long-term impact of bw on steroid metabolism.

METHODS

68 monozygotic twin pairs with a bw-difference of <1 standard deviation score (SDS; concordant; n = 41) and ≥1 SDS (discordant; n = 27) were recruited. At 14.9 years (mean age), morning urine samples were collected and analyzed with gas chromatography-mass-spectrometry.

RESULTS

No significant differences were detected in the concordant group. In contrast, in the smaller twins of the discordant group, we found significantly higher concentrations not only of the dehydroepiandrosterone sulfate (DHEAS) metabolite 16α-OH-DHEA (P = 0.001, 656.11 vs 465.82 µg/g creatinine) but also of cumulative dehydroepiandrosterone and downstream metabolites (P = 0.001, 1650.22 vs 1131.92 µg/g creatinine). Relative adrenal (P = 0.002, 0.25 vs 0.18) and overall androgen production (P = 0.001, 0.79 vs 0.65) were significantly higher in the formerly smaller discordant twins. All twin pairs exhibited significant intra-twin correlations for all individual steroid metabolites, sums of metabolites, indicators of androgen production, and enzyme activities. Multiple regression analyses of the smaller twins showed that individual steroid concentrations of the larger co-twin were the strongest influencing factor among nearly all parameters analyzed.

CONCLUSION

In monozygotic twin pairs with greater intra-twin bw-differences (≥1 SDS), we found that bw had a long-lasting impact on steroid metabolism, with significant differences regarding DHEAS metabolites and relative androgen production. However, most parameters showed significant intra-twin correlations, suggesting a consistent interrelationship between prenatal environment, genetic background, and steroid metabolism.

Pediatric endocrinology: an overview of the last decade

Over the past decade, considerable progress has been made in the field of pediatric endocrinology. However, there is still a long way to go regarding the exploration of novel avenues, such as epigenetics, the changing views on the pathophysiology and derived therapy of specific disorders, and the prevention of prevalent diseases. The next decade will hopefully bring the consolidation of most of those achievements and the development of new pathways for further progress.

Systematic review indicates postnatal growth in term infants born small-for-gestational-age being associated with later neurocognitive and metabolic outcomes

We systematically reviewed papers published in English between 1994 and October 2015 on how postnatal weight gain and growth affect neurodevelopment and metabolic outcomes in term‐born small‐for‐gestational‐age (SGA) infants. Two randomised trials reported that enriched infant formulas that promoted early growth also increased fat mass, lean mass and blood pressure (BP), but had no effect on early neurocognitive outcomes. Meanwhile, 31 observational studies reported consistent positive associations between postnatal weight gain and growth with neurocognitive outcomes, adiposity, insulin resistance and BP.

Conclusion: Few intervention studies exist, despite consistent positive associations between early growth and neurocognition in term‐born SGA infants.

Birthweight Differences in Monozygotic Twins Influence Pubertal Maturation and Near Final Height

OBJECTIVE

To evaluate the influence of unfavorable intrauterine conditions and catch-up growth, we analyzed growth and pubertal maturation in monozygotic twins with significant intra-twin birthweight differences.

STUDY DESIGN

Prospective longitudinal clinical study of 30 twin pairs at birth, prepubertally at ages 2.1, 4.0, 10.0 years, and mid-/postpubertally at age 14.6 years; 14 pairs were concordant (birthweight difference <1 SDS), 16 discordant (birthweight difference >1 SDS).

RESULTS

In 19/30 (63%) pairs, the initially smaller twin started pubertal maturation before the co-twin. In 7/8 (88%) female discordant twin pairs, the initially smaller twin experienced menarche first. Among discordant pairs, highly significant intra-twin differences for height SDS were observed up to 10 years of age, with a further decline between ages 10.0 and 14.6 years. At 10.0 years of age, significant intra-twin differences in mean dehydroepiandrostenedione sulfate were observed in all twin pairs (870.3 vs 1054 ng/mL in the smaller twin, P = .045). This was pronounced in the discordant group: 856.7 vs 1138.2 ng/mL, P = .009. In all twin pairs, highly significant intra-twin correlations were found for gonadotropins during puberty (luteinizing hormone: r = 0.67, P < .001. follicle stimulating hormone: r = 0.70, P < .001) with no significant intra-twin differences for gonadotropins, estradiol, and testosterone before or during puberty.

CONCLUSIONS

Birthweight has an impact on growth and pubertal maturation. The already decreased height in some low birthweight infants may be further impacted by an early start and fast progression of puberty. The high intra-twin correlation coefficients in our study suggest that puberty and sexual steroids are genetically determined. However, the observed adrenal androgen hypersecretion of the smaller twin during late childhood could have effected pubertal maturation and further decreased near final height.