Premature thelarche: An Updated Review

BACKGROUND

Premature thelarche is the most common pubertal disorder in girls. The condition should be differentiated from central precocious puberty which may result in early epiphyseal fusion and reduced adult height, necessitating treatment.

OBJECTIVE

The purpose of this article is to familiarize physicians with the clinical manifestations of premature thelarche and the clinical features and laboratory tests that may help distinguish premature thelarche from central precocious puberty.

METHODS

A search was conducted in September 2022 in PubMed Clinical Queries using the key term " Premature thelarche". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used to compile the present article.

RESULTS

Premature thelarche denotes isolated breast development before the age of 8 years in girls who do not manifest other signs of pubertal development. The condition is especially prevalent during the first two years of life. The majority of cases of premature thelarche are idiopathic. The condition may result from an unsuppressed hypothalamic-pituitary-gonadal axis in the early years of life, an "overactivation" of the hypothalamic-pituitary axis in early childhood secondary to altered sensitivity to steroids of the hypothalamic receptors controlling sexual maturation, increased circulating free estradiol, increased sensitivity of breast tissue to estrogens, and exposure to exogenous estrogens. The cardinal feature of premature thelarche is breast development which occurs without additional signs of pubertal development in girls under 8 years of age. The enlargement may involve only one breast, both breasts asymmetrically, or both breasts symmetrically. The breast size may fluctuate cyclically. The enlarged breast tissue may be transiently tender. There should be no significant changes in the nipples or areolae and no pubic or axillary hair. The vulva, labia majora, labia minora, and vagina remain prepubertal. Affected girls have a childlike body habitus and do not have mature contours. They are of average height and weight. Growth and osseous maturation, the onset of puberty and menarche, and the pattern of adolescent sexual development remain normal. Most cases of premature thelarche can be diagnosed on clinical grounds. Laboratory tests are seldom indicated. No single test can reliably differentiate premature thelarche from precocious puberty.

CONCLUSION

Premature thelarche is benign, and no therapy is necessary apart from parental reassurance. As enlargement of breasts may be the first sign of central precocious puberty, a prolonged follow-up period every 3 to 6 months with close monitoring of other pubertal events and linear growth is indicated in all instances.

Lifetime Cumulative Effect of Reproductive Factors on Stroke and Its Subtypes in Postmenopausal Chinese: A Prospective Cohort Study

BACKGROUND

Multiple reproductive factors are associated with stroke. Little is known about the cumulative effects of reproductive factors during a reproductive life course on stroke and its subtypes, especially among female Chinese.

OBJECTIVE

To assess the associations of lifetime cumulative estrogen exposure due to reproductive factors with stroke and its etiological subtypes among postmenopausal Chinese .

METHODS

From the China Kadoorie Biobank (CKB) study, postmenopausal females without prior stroke at baseline (2004-2008) were selected. Lifetime cumulative estrogen exposure due to reproductive factors was assessed using three composite indicators: reproductive lifespan (RLS), endogenous estrogen exposure (EEE), and total estrogen exposure (TEE). Stroke and its subtypes, ischemic stroke (IS), intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), were identified via linkage to a disease registry system and health insurance data during follow-up (2004-2015). Multivariable-adjusted Cox proportional hazards regression models were applied to estimate the adjusted hazard ratio (aHR) and 95% confidence intervals (CI) for the risk of stroke by quartiles of RLS, EEE, and TEE respectively.

RESULTS

A total of 122,939 postmenopausal participants aged 40 to 79 years without prior stroke at baseline were included. During a median follow-up period of 8.9 years, 15,139 new-onset stroke cases were identified, including 12,853 IS, 2,580 ICH, and 269 SAH cases. Compared with the lowest quartile (Q1) of RLS, the highest quartile (Q4) had a lower risk of total stroke (aHR: 0.95, 95% CI: 0.92-0.98), IS (aHR: 0.95, 95% CI: 0.92-0.98), and ICH (aHR: 0.87, 95% CI: 0.81-0.94). Both EEE and TEE displayed a graded association with the subsequent descending risk of total stroke (aHR for Q4 vs Q1: EEE: 0.85, 95% CI: 0.82-0.89; TEE: 0.87, 95% CI: 0.84-0.90), IS (aHR for Q4 vs Q1: EEE: 0.86, 95% CI: 0.83-0.90; TEE: 0.86, 95% CI: 0.83-0.89), and ICH (EEE: 0.73, 95% CI: 0.65-0.81; TEE: 0.83,95% CI: 0.76-0.91), with a P-trend<0.001 for all of these associations.

CONCLUSIONS

Patients' cumulative estrogen exposure due to reproductive factors could potentially be a valuable indicator for risk stratification of stroke events following menopause.

Association of life-course reproductive duration with mortality: a population-based twin cohort study

BACKGROUND

Although age at menopause has been linked to mortality, the association between the entire reproductive lifespan and mortality remains unclear.

OBJECTIVE

This study aimed to examine to what extent life-course reproductive duration is associated with all-cause mortality and explore the role of a healthy lifestyle and familial background in such an association.

STUDY DESIGN

A total of 11,669 women (mean age, 63.54 years) from the Swedish Twin Registry were followed for up to 19 years. Information on reproductive duration (the interval between ages at menarche and menopause) and lifestyle factors (including smoking, alcohol consumption, and physical activity; divided into unfavorable/intermediate/favorable) was collected on the basis of a structured questionnaire. Survival status was obtained from the Sweden Cause of Death Register. The data were analyzed using generalized estimating equation models, Laplace regression, and conditional logistic regression.

RESULTS

In the generalized estimating equation model, compared with those with ≤34 reproductive years, the odds ratio (95% confidence interval) of all-cause mortality was 0.79 (0.68-0.90) for those with ≥40 reproductive years, which prolonged survival time by 0.84 (0.24-1.43) years. Women with ≥40 reproductive years plus a favorable lifestyle (odds ratio, 0.28; 95% confidence interval, 0.23-0.35) were at a lower risk of all-cause mortality than those with <40 reproductive years plus an unfavorable lifestyle. An additive interaction between ≥40 reproductive years and a favorable lifestyle on all-cause mortality was observed (attributable proportion, 0.584; 95% confidence interval, 0.016-1.151). The odds ratios in conditional logistic regression and generalized estimating equation models did not differ significantly (P=.67).

CONCLUSION

A longer reproductive lifespan is associated with reduced all-cause mortality and prolongs survival by 0.84 years. A favorable lifestyle may amplify the beneficial effect of longer reproductive lifespan on mortality. Familial background does not account for the observed association.

Duration of estrogen exposure during reproductive years, age at menarche and age at menopause, and risk of cardiovascular disease events, all-cause and cardiovascular mortality: a systematic review and meta-analysis

BACKGROUND

Little is known about the estrogen exposure measurement and mutual effect of age at menarche and age at menopause in the risk of cardiovascular disease (CVD) events.

OBJECTIVES

To evaluate estrogen exposure measurement and describe mutual effect of age at menarche and age at menopause in the risk of CVD events.

SEARCH STRATEGY

Systematic review of literature in PubMed, Embase and Web of Science for studies published up to 28 June 2020.

SELECTION CRITERIA

Observational studies related to estrogen exposure measurement, including mutual effect of age at menarche and age at menopause and risk of CVD events.

DATA COLLECTION AND ANALYSIS

Synthesis of evidence was conducted by reviewing individual estimates, followed by meta-analysis. The study received no external funding.

MAIN RESULTS

A total of 75 studies were included in synthesis of evidence, of which 17 studies were included in meta-analysis. Reproductive lifespan (age at menopause - age at menarche), endogenous estrogen exposure and total estrogen exposure were used for estrogen exposure measurement. Reproductive lifespan was by far the most commonly used method for estrogen exposure measurement. A shorter reproductive lifespan was associated with a higher risk of CVD events; the pooled relative risk (95% CI) was 1.31 (1.25-1.36) for stroke events. Robust epidemiological studies with measurement of estrogen exposure and associated health risk would strengthen the evidence.

CONCLUSIONS

Reproductive lifespan was the most commonly used method for estrogen exposure measurement in epidemiological studies. A shorter reproductive lifespan was associated with a higher risk of CVD events, particularly stroke.

TWEETABLE ABSTRACT

A systematic review and meta-analysis found that women with a shorter reproductive lifespan have a higher risk of stroke events.

High estrogen exposure may not be detrimental on endometrial receptivity in women with PCOS

The study aimed to assess the effect of high estrogen exposure and coasting on cycle outcome in women at risk for developing ovarian hyperstimulation syndrome (OHSS). Retrospective case-control study was conducted to figure out the outcomes of GnRH antagonist cycles in which women were at risk to develop OHSS. Women who underwent coasting (n = 100) were compared with a control group of women who did not undergo coasting (n = 287). Effect of endometrial estrogen exposure was determined by calculating area under curve of temporal estrogen measurements (AUCEM) through the cycle. Among 387 women with PCOS, 100 cases were required to undergo coasting to avoid OHSS. All participants reached to embryo transfer stage and clinical pregnancy rate was 44% in group with coasting whereas 39% in group without coasting (p > .05). AUCEM was a significant predictor for the cases who required coasting to avoid OHSS (AUC = 0.754, p < .001). Optimal cut off value was calculated to be 6762 with 71% sensitivity and 67% specificity. ROC analysis showed no predictive value of AUCEM for clinical pregnancy in subgroup of women with coasting (AUC = 0.496, p > .05). Consistently, ROC analysis showed no predictive value of AUCEM for clinical pregnancy in subgroup of women without coasting (AUC = 0.494, p > .05). In conclusion, neither coasting nor the high endometrial estrogen exposure was found to have detrimental effect on endometrial receptivity and cycle outcome in PCOS.

Greater endogenous estrogen exposure is associated with longer telomeres in postmenopausal women at risk for cognitive decline

Longer duration of reproductive years of life and thus greater exposure to endogenous estrogen may be associated with a lower risk of age-related diseases in women. The present study examined the relationship between estimated endogenous estrogen exposure and telomere length (TL) and telomerase activity, two biomarkers of cellular aging, in a sample of postmenopausal women at risk for cognitive decline. Telomere length was measured using a quantitative PCR method and telomerase activity by TRAP (Telomere-Repeats Amplification Protocol) assay in peripheral blood mononuclear cells (PBMCs). Study subjects were 53 postmenopausal women (35 with natural and 18 with surgical menopause) receiving hormone therapy (HT) for at least one year or longer. Length of reproductive years of life, computed as the difference between age at menopause and age at menarche, was used as a proxy of duration of exposure to endogenous estrogen. Length of time on HT was the measure used for duration of exogenous estrogen exposure. We found that longer endogenous estrogen exposure was associated with greater TL (standardized β=0.06, Wald χ(2)=3.7, p=0.04) and with lower telomerase activity (standardized β=-0.09, Wald χ(2)=5.0, p=0.03). Length of reproductive years was also inversely associated with the combination of short TL and high telomerase (OR=0.78, 95% CI: 0.63, 0.97, p=0.02). Length of HT use was not associated with TL or telomerase activity in this study. The results suggest that the endogenous estrogens may be associated with deceleration of cellular aging. This is the first study to examine associations between endogenous estrogens, telomere length and telomerase activity.