Trend of Menarcheal Age among Korean Girls

Small for gestational age and age at menarche in a contemporary population-based U.S. sample

Children born small for gestational age (SGA) may be at risk for earlier puberty and adverse long-term health sequelae. This study investigates associations between SGA and age at menarche using secondary data on 1,027 female children in a population-based U.S. birth cohort that over-sampled non-marital births, which in the U.S. is a policy-relevant population. SGA was defined as <10th percentile of weight for gestational age compared to the national U.S. distribution. We estimated unadjusted and adjusted Ordinary Least Squares (OLS) models of associations between SGA and age at menarche in years, as well as unadjusted and adjusted logistic regression models of associations between SGA and early menarche (before age 11). SGA was not significantly associated with earlier age at menarche, even when adjusting for maternal sociodemographic characteristics, prenatal smoking, and maternal pre-pregnancy overweight and obesity. Similarly, SGA was not significantly associated with the odds of menarche occurring before age 11. However, maternal non-Hispanic Black race-ethnicity, Hispanic ethnicity, and pre-pregnancy obesity all had independent associations with average earlier age at menarche and menarche before age 11. Thus, maternal risk factors appear to play more influential roles in determining pubertal development.

Age at Menarche and Its Association With Adult-Onset Metabolic Syndrome and Related Disorders in Women: A Cross-Sectional Study of a Nationally Representative Sample Over 10 Years

The prevalence of metabolic syndrome (MetS) as well as related social costs and efforts is increasing. The purpose of this study was to investigate the association between age at menarche and the risk of MetS, obesity, diabetes, and cardiovascular disease (CVD) in women over 30 years, using data from the Korean National Health and Nutrition Examination Survey (2010-2020). The analysis of 30 916 participants showed that early menarche (before 11 years) significantly increased the risk of obesity, diabetes, and MetS compared with the median age of 14 years. Late menarche (after 17 years) was also linked to MetS and related disorders. The relationship between age at menarche (at <10 years and >19 years) and the risk of MetS and related disorders exhibited a reversed J-shaped (し) pattern characterized by a pronounced increased risk among those who experience early menarche, whereas the increased risk associated with late menarche was less consistent. These results will help to decrease the risk of MetS and related disorders by enabling early intervention in early and late menarche age groups.

Assessing medication use patterns among patients with polycystic ovary syndrome at a tertiary care teaching hospital in South Korea: A retrospective study

Polycystic ovary syndrome (PCOS) is a disease caused by excessive ovarian androgen secretion due to hypothalamic-pituitary-ovarian hormone abnormalities. We retrospectively investigated the treatment status of patients diagnosed with PCOS who visited a domestic tertiary hospital in order to analyze the use patterns and safety of drugs. Patients diagnosed with PCOS between July 2014 and September 2022 were examined, excluding patients younger than 13 years and those not receiving medication. Patients aged 21 years or younger were designated as the adolescent group and patients aged 22 years or older were designated as the adult group for comparative statistical analysis. The total number of patients was 212, including 105 adolescents (49.5%) and 107 adults (50.5%). Comorbidities were ovarian cyst in 20 (9.4%) patients, endometriosis in 19 (9%), diabetes in 14 (6.6%), thyroid dysfunction in 12 (5.7%), hypertension in 10 (4.7%), dyslipidemia in 10 (4.7%), and androgenic alopecia in 6 (2.8%). Symptoms were oligomenorrhea in 91 (42.9%) patients, amenorrhea in 72 (34%), hirsutism in 36 (17%), acne in 24 (11.3%), and infertility in 10 (4.7%). During the study period, 114 patients (53.8%) were prescribed medroxyprogesterone acetate (MPA), 66 (31.1%) were given oral contraceptives (specifically, ethinyl estradiol + drospirenone prescribed to 52 (24.5%)), and 17 (8%) were concurrently prescribed MPA and oral contraceptives. Forty-five (21.2%) patients changed prescriptions, with 10 (22.2%) switching due to side effects and 8 (17.8%) due to a therapeutic failure. A total of 5 patients (2.4%) discontinued the drug. Adverse drug reactions occurred in 15 patients (7.1%), with 5 being adolescents (4.8%) and 10 being adults (9.3%). MPA alone and ethinyl estradiol with drospirenone were the most prescribed medications for PCOS. Over the study, 45 patients changed prescriptions, 50 were lost to follow-up, and 5 adults discontinued medications.

Myopia trends among children and adolescents: a nationwide study in South Korea

PURPOSE

To evaluate gender disparities in the progression of myopia among children and adolescents in South Korea.

METHODS

Nationwide cross-sectional data of 1,190 subjects aged 10-18 years was obtained for the years of 2011 (baseline) and 2021 using the Korea National Health and Nutrition Examination Surveys. The prevalence of myopia, as well as data regarding age, household income, height, weight, body mass index, and age of menarche, were evaluated. Myopia was defined as a spherical equivalent (SE) ≤ -0.5 D.

RESULTS

The prevalence of myopia among boys was stable in 2021 compared to 2011, with rates of 53.7% and 52.8%, respectively (P = 0.372). Among girls, however, there was a statistically significant increase in myopia prevalence in 2021 compared to 2011, with rates of 73.7% and 51.6% (P < 0.001), respectively. Over 10 years, the adjusted prevalence ratio for myopia in boys was 1.11 (95% CI, 0.77-1.61), whereas myopia prevalence in girls underwent a 1.87-fold increase over the same period (95% CI, 1.30-2.69), and menarche at 12 years of age or older was associated with less myopia in girls (PR = 0.84; 95% CI, 0.72-0.99). The spherical equivalent refraction in girls increased significantly over the same 10-year period, from -1.09 ± 0.13 D to -1.58 ± 0.17 D (P < 0.017), whereas in boys, there was no significant difference (P = 0.604).

CONCLUSIONS

In our study cohort, the prevalence of myopia increased significantly among girls compared with boys over the course of decade. Additionally, an association between early menarche in girls and the prevalence of myopia was observed.

Oral Hormone Replacement Therapy and Uterine Volume in Korean Adolescents with Turner Syndrome: A Retrospective Case-Control Study

STUDY OBJECTIVE

We aimed to identify critical factors for uterine development by comparing uterine volume (UV) among patients with Turner syndrome (TS) who underwent pubertal induction (PI), patients with TS who had natural menarche (NM), and patients in a non-TS control group.

METHODS

This retrospective case-control study included patients with TS who had undergone PI with oral estrogen in a PI group (n = 31) and an NM group (n = 7). The control group included patients without TS with spontaneous puberty who underwent pelvic ultrasound at 16 years of age. For TS patients, both the UV from the first ultrasound performed at age 16 or older (1st-UV) and the UV from the most recent final ultrasound (final-UV) were obtained.

RESULTS

The 1st-UV was larger for patients in the NM group than those in the PI group (P < .001), but did not differ significantly between the NM and control groups (P = .375). The final-UV of the PI group was larger than their 1st-UV (P < .001), but still smaller than the NM group (P = .021). Hormone replacement therapy (HRT) duration and 1st-UV of PI group were positively correlated (P = .048). There were no variables that were significantly correlated with final-UV of PI group.

CONCLUSION

Patients with TS who experienced NM showed normal uterine development, but TS patients who underwent PI showed significantly smaller, undeveloped UV. While HRT duration and UV are positively correlated at the beginning of HRT, it is unclear what determines the final UV; however, late PI initiation and use of oral estrogen probably contributed to the lack of UV development.

Temporal trend of age at menarche in Korean females born between 1927 and 2004: a population-based study

Backgrounds

The age at menarche has decreased worldwide. Previous studies on Korean adolescents have reported a downward trend in age at menarche. This study aimed to investigate the current trends in age at menarche among Korean adolescents using nationally representative data.

Materials and methods

The study used data from the Korea National Health and Nutrition Examination Survey 2007-2021. A total of 50,730 females born between 1927 and 2004 with information on age at menarche were included. The trend in age at menarche was analyzed according to 15 birth-year groups (with 5-year intervals) using quantile regression analysis.

Results

The mean age at menarche decreased from 16.92 ± 0.06 years for females born before 1935 to 12.45 ± 0.04 years for females born between 2000 and 2004 (p <.001). According to the percentile group of age at menarche, mean menarche age decreased by -0.071 years per year (95% confidence interval [CI], -0.072 to -0.070) in total, -0.050 years per year (95% CI, -0.052 to -0.048) in the 3rd percentile group, -0.088 years per year (95% CI, -0.091 to -0.085) in the 97th percentile group (p <.001 for all). A decreasing trend of age at menarche was more prominent in the obesity group (-0.080 years per year, 95% CI, -0.082 to -0.078) compared to the non-obesity group (-0.069 years per year, 95% CI, -0.071 to -0.068) (p <.001 for both).

Conclusion

Ongoing downward trend in age at menarche was observed in Korean females born until 2004, decreasing by 0.71 years per decade. The downward trend was faster in individuals with a higher percentile of age at menarche and in those with obesity.

Sleep deprivation alters pubertal timing in humans and rats: the role of the gut microbiome

STUDY OBJECTIVES

Evidence implied that sleeping duration is associated with the timing of puberty and that sleep deprivation triggers early pubertal onset in adolescents. Sleep deprivation can affect metabolic changes and gut microbiota composition. This study investigated the effects of sleep deprivation on pubertal onset and gut microbiota composition in animal models and a human cohort.

METHODS

This study comprised 459 boys and 959 girls from the Taiwan Pubertal Longitudinal Study. Sleep duration was evaluated using the self-report Pittsburgh Sleep Quality Index questionnaire. Early sexual maturation was defined by pediatric endocrinologist assessments. Mediation analyses were done to examine the association between sleep parameters, obesity, and early sexual maturation. Besides, Sprague Dawley juvenile rats were exposed to 4 weeks of chronic sleep deprivation. Vaginal opening (VO) and preputial separation (PS) were observed every morning to determine pubertal onset in female and male rats.

RESULTS

The sleep-deprived juvenile rats in the sleep-deprived-female (SDF) and sleep-deprived-male (SDM) groups experienced delayed VO (mean VO days: 33 days in control; 35 days in SDF; p-value < 0.05) and PS (mean PS days: 42 days in control; 45 days in SDM; p-value < 0.05), respectively. Relative to their non-sleep-deprived counterparts, the sleep-deprived juvenile rats exhibited lower body weight and body fat percentage. Significant differences in relative bacterial abundance at genus levels and decreased fecal short-chain-fatty-acid levels were identified in both the SDF and SDM groups. In the human cohort, insufficient sleep increased the risk of early sexual maturation, particularly in girls (OR, 1.44; 95% CI: 1.09 to 1.89; p-value < 0.01). Insufficient sleep also indirectly affected early sexual maturation in girls, with obesity serving as the mediator.

CONCLUSIONS

Overall, sleep deprivation altered the timing of puberty in both animal and human models but in different directions. In the rat model, sleep deprivation delayed the pubertal onset in juvenile rats through gut dysbiosis and metabolic changes, leading to a low body weight and body fat percentage. In the human model, sleep deprivation led to fat accumulation, causing obesity in girls, which increased the risk of early puberty.

Clinical Characteristics of Gynecologic Problems During Childhood in the Korean Population

BACKGROUND

This study analyzed common gynecologic problems among Korean patients younger than ten years.

METHODS

We performed a retrospective analysis of medical records of patients younger than ten years who visited the Pediatric and Adolescent Gynecology Clinic at Samsung Medical Center between 1995 and 2020.

RESULTS

Among the 6,605 patients who visited the Pediatric and Adolescent Gynecology Clinic, data from 642 patients younger than ten years were analyzed in this study. The most common chief complaint was genital anomalies, followed by increased vaginal discharge and abnormal findings on clinical examinations. The most common disease entity was agglutination of the labia minora, which was commonly discovered incidentally during routine screenings. Vulvovaginitis, the second most common disease, was identified by symptoms of vaginal discharge, pruritus, and vaginal spotting. Neoplasm, issues with vaginal bleeding, and "other causes" were additional categories of gynecologic problems. 245 patients (38.2%) were referred from primary care sources, 175 patients (27.4%) sought care directly at the clinic, 169 patients (26.3%) were referrals from the institution's pediatric department, and the remainder were referrals from other departments.

CONCLUSION

This study provides information about the gynecologic problems most frequently encountered in pediatric patients. The study provides helpful insight for primary care physicians into the proper management and timing of referrals for these gynecologic problems of pediatric patients.

Risk of uterine leiomyomata with menstrual and reproductive factors in premenopausal women: Korea nurses' health study

BACKGROUND

Uterine leiomyomata (UL) are benign smooth muscle tumors that may cause significant morbidity in women of reproductive age. This study aimed to investigate the relationship of menstrual and reproductive factors with the risk of UL in premenopausal women.

METHODS

This prospective study included 7,360 premenopausal women aged 22-48 years who were part of the Korea Nurses' Health Study. Information on the menstrual cycle and reproductive history was assessed between 2014 and 2016, and self-reported cases of UL were obtained through 2021. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During 32,072 person-years of follow-up, 447 incident cases of UL were reported. After adjusting for other risk factors, women with late age at menarche had a lower incidence of UL (≥ 16 vs. 12-13 years: HR 0.68; 95% CI 0.47-0.99; p for trend = 0.026). The risk of UL was inversely associated with current menstrual cycle length (≥ 40 or too irregular to estimate vs. 26-31 days: HR 0.40; 95% CI 0.24-0.66) and cycle length at ages 18-22 years (HR 0.45; 95% CI 0.31-0.67; p for trend < 0.001, each). Parous women had lower risk of UL than nulliparous women (HR 0.40; 95% CI 0.30-0.53) and women who were aged 29-30 years at first birth had a lower risk of UL than those who were aged ≤ 28 years at first birth (HR 0.58; 95% CI 0.34-0.98). There was no significant association of the number of births or breastfeeding with the risk of UL among parous women. Neither a history of infertility nor oral contraceptive use was associated with the risk of UL.

CONCLUSIONS

Our results suggest that age at menarche, menstrual cycle length, parity, and age at first birth are inversely associated with the risk of UL in premenopausal Korean women. Future studies are warranted to confirm the long-term effects of menstrual and reproductive factors on women's health.

Establishment of Korean Pediatric Reference Intervals for Estradiol using Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

BACKGROUND

Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is a reliable and accurate method for measuring steroid hormone levels. There is an increasing need for sensitive and precise methods to measure estradiol in pediatric patients. Here, we established reference intervals for estradiol in healthy children using a UHPLC-MS/MS-based method for the first time in South Korea.

METHODS

Serum estradiol was measured using a Sciex Triple Quad^TM 6500 + UHPLC-MS/MS (Sciex, Framingham, MA, USA). Reference intervals for estradiol were established according to the CLSI document EP28-A3c:2008. The reference intervals were validated using serum samples from 634 pediatric patients, including neonates, children, and adolescents. Among them, 389 specimens were used in analysis of the specimen acceptance time. Statistical analysis was performed using MedCalc (MedCalc, Ostend, Belgium) and Analyse-it (Analyse-it Software Ltd., Leeds, United Kingdom) software.

RESULTS

Reference intervals for boys (n = 297) were <16.6, <7.3, <19.0, <30.5, 7.6-96.5, and 10.6-134.4 pmol/L among those aged <1, 1-5, 6-9, 10-11, 12-14, and 15-17 years, respectively. Reference intervals for girls (n = 337) were <114.7, <24.2, <34.8, 8.0-177.0, 10.4-480.5, and 9.1-486.7 pmol/L among those aged <1, 1-5, 6-9, 10-11, 12-14, and 15-17 years, respectively. Overall, there was no effect of specimen acceptance time on estradiol measurements in boys or girls, except for that in the group aged 10-11 years.

CONCLUSIONS

The reference intervals for healthy children were validated using a UHPLC-MS/MS-based method. The highly analytical sensitive UHPLC-MS/MS method may be useful for estradiol determination in pediatric patients.

Ongoing increasing trends in central precocious puberty incidence among Korean boys and girls from 2008 to 2020

BACKGROUND

Over the last few decades, there has been growing evidence of earlier onset and progression of puberty worldwide. This population-based longitudinal cohort study aimed to analyze the change in the annual incidence rate of central precocious puberty (CPP) among Korean children over the most recent decade, using the national registry data.

METHOD

The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) and insurance claims for gonadotropin-releasing hormone agonist (GnRHa) treatment were used to identify CPP patients who were using the Korean Health Insurance Review & Assessment Service (HIRA) database between 2008 and 2020. Patients who began GnRHa therapy before the age of 9 and 10 for girls and boys, respectively, were included in the study.

RESULTS

A total of 6,906 boys and 126,377 girls were diagnosed with CPP between 2008 and 2020. The annual incidence of CPP increased by 83.3 times in boys (from 1.2 to 100 per 100,000 persons) and by 15.9 times in girls (from 88.9 to 1414.7 per 100,000 persons). The age-specific annual incidence of CPP increased remarkably more in older children than in younger ones; the 2020 CPP incidence among 9-year-old boys and 8-year-old girls reached 705.2 and 7,967.3 per 100,000 persons, respectively. The annual prevalence of CPP in boys and girls increased from 2.7 to 206.5 (76.5 times) and from 141.8 to 3439.9 (24.3 times) per 100,000 persons, respectively.

CONCLUSION

Based on GnRHa treatment insurance claims, our study suggests that the annual incidence of CPP has substantially increased in Korea during the past 13 years. These findings highlight the importance of meticulous judgment by doctors in determining GnRHa treatment.

Discrete-time Survival Analysis of Risk Factors for Early Menarche in Korean Schoolgirls

OBJECTIVES

The aim of this study was to evaluate the effect of body weight status and sleep duration on the discrete-time hazard of menarche in Korean schoolgirls using multiple-point prospective panel data.

METHODS

The study included 914 girls in the 2010 Korean Children and Youth Panel Study who were in the elementary first-grader panel from 2010 until 2016. We used a Gompertz regression model to estimate the effects of weight status based on age-specific and sex-specific body mass index (BMI) percentile and sleep duration on an early schoolchild's conditional probability of menarche during a given time interval using general health condition and annual household income as covariates.

RESULTS

Gompertz regression of time to menarche data collected from the Korean Children and Youth Panel Study 2010 suggested that being overweight or sleeping less than the recommended duration was related to an increased hazard of menarche compared to being average weight and sleeping 9 hours to 11 hours, by 1.63 times and 1.38 times, respectively, while other covariates were fixed. In contrast, being underweight was associated with a 66% lower discrete-time hazard of menarche.

CONCLUSIONS

Weight status based on BMI percentiles and sleep duration in the early school years affect the hazard of menarche.

Changes in Sleep Patterns in Korean Early Adolescents during Sexual Maturation

Purpose: Teenagers’ sleep patterns show physiological delays influenced by sexual maturation and other external time-related factors. However, Korean adolescents show differences in the onset of pubertal development and have shorter sleep durations than other adolescents worldwide. Therefore, we assessed sleep patterns and sexual maturation in Korean early adolescents to evaluate changes in sleep patterns in relation to sexual maturation in early adolescents with sleep deprivation.Methods: From March to August 2017, we surveyed children aged 10 to 12 years in Seongnam (Seongnam Atopy Project). We evaluated items related to sleep and sexual maturation, assessed sleep duration and sleepiness scale scores, and analyzed the relationships of sleep parameters with sex, height, weight, and sexual maturation rating (SMR).Results: In total, 620 children were included. Sleep duration was 8.63±0.81 hours in boys and 8.40±0.98 hours in girls. Sleep started from PM 11:00±AM 0:47 in boys and PM 11:13±AM 1:06 in girls, and ended at AM 7:38±AM 0:27 in boys and AM 7:34±AM 0:27 in girls. After adjusting for sex and standardized body mass index, bedtime was delayed as the SMR increased (mean delay for each rating increase, 0.251 hours; P=0.001; 95% confidence interval [CI], 0.105 to 0.397). SMR did not influence the wake-up time, although sleep duration decreased as the SMR increased (mean decrease for each rating increase, 0.258 hours; P=0.001; 95% CI, –0.403 to –0.114). The sleepiness scale scores showed no relationship with SMR. Conclusion: Sleep patterns, especially sleep duration and bedtimes, show changes with sexual maturation in adolescents, who are vulnerable to sleep deprivation.

Genetic factors in precocious puberty

Pubertal onset is known to result from reactivation of the hypothalamic-pituitary-gonadal (HPG) axis, which is controlled by complex interactions of genetic and nongenetic factors. Most cases of precocious puberty (PP) are diagnosed as central PP (CPP), defined as premature activation of the HPG axis. The cause of CPP in most girls is not identifiable and, thus, referred to as idiopathic CPP (ICPP), whereas boys are more likely to have an organic lesion in the brain. ICPP has a genetic background, as supported by studies showing that maternal age at menarche is associated with pubertal timing in their offspring. A gain of expression in the kisspeptin gene (KISS1), gain-of-function mutation in the kisspeptin receptor gene (KISS1R), loss-of-function mutation in makorin ring finger protein 3 (MKRN3), and loss-of-function mutations in the delta-like homolog 1 gene (DLK1) have been associated with ICPP. Other genes, such as gamma-aminobutyric acid receptor subunit alpha-1 (GABRA1), lin-28 homolog B (LIN28B), neuropeptide Y (NPYR), tachykinin 3 (TAC3), and tachykinin receptor 3 (TACR3), have been implicated in the progression of ICPP, although their relationships require elucidation. Environmental and socioeconomic factors may also be correlated with ICPP. In the progression of CPP, epigenetic factors such as DNA methylation, histone posttranslational modifications, and noncoding ribonucleic acids may mediate the relationship between genetic and environmental factors. CPP is correlated with short- and long-term adverse health outcomes, which forms the rationale for research focusing on understanding its genetic and nongenetic factors.

Trajectory patterns for continuous metabolic syndrome score in childhood and the cardiovascular risk in adolescence

We explored the association between the trajectory of the continuous metabolic syndrome score (cMetS) in childhood with high-sensitivity C-reactive protein (hs-CRP) and carotid intima-media thickness (CIMT), which are known to increase cardiovascular disease risk in adolescence. The trajectory of cMetS in childhood (from 3 to 12 years of age) was identified in 833 children who participated in the Ewha Birth and Growth Study. The associations between cMetS and hs-CRP and CIMT were analyzed in 204 out of 833 children who participated in the follow-up at 13-15 years of age and measured hs-CRP and CIMT. Among the 833 children, three groups were classified: cMetS maintained at a low level (n = 198, 23.77%), middle level (n = 530, 63.63%), and at high levels (n = 105, 12.61%). The group with a stable-high cMetS trajectory showed significantly higher hs-CRP levels, and the statistical significance was maintained after adjusting for covariates. This study found that a consistently high cMetS in childhood was significantly associated with higher hs-CRP levels in adolescents, suggesting that it is necessary to intervene in metabolic risk factors early in life to reduce the risk of cardiovascular disease later in life.

The influence of endogenous and exogenous hormonal factors on migraine in spontaneous postmenopausal women: A nationwide population-based study in South Korea

BACKGROUND

Hormonal and menstrual factors are known to influence migraines in women. However, studies in the postmenopausal period are relatively insufficient for clinical translation. This study investigated the influence of endogenous and exogenous hormonal factors on migraines in spontaneous menopausal women.

METHODS

We obtained and analyzed the data related to hormonal factors from the Korean Health Examination database. A migraine diagnosis was identified using the Korean National Health Insurance Service database between 2009 and 2018. We observed migraine occurrence in spontaneous postmenopausal women. Study populations were divided into two groups depending on new diagnosis of migraine during the follow up periods. We investigated the association between endogenous and exogenous hormonal factors and migraine.

RESULTS

1,114,742 spontaneous postmenopausal women were enrolled. Migraine risk tended to increase in the shorter lifetime number of years of menstruation group compared to the group with lifetime number of years of menstruation ≥40 years. All of the hormone replacement therapy (HRT) groups showed higher risk compared with the non-HRT group. Migraine risk tends to increase with greater postmenopausal years compared to the postmenopausal <5 years group.

CONCLUSION

Our study suggests that female hormonal factors, including endogenous and exogenous estrogen exposure, may be associated with migraine occurrence in spontaneous menopausal women.