Pubertal timing and adult fracture risk in men: A population-based cohort study

Birth weight and birth length affect future fracture risk differently in men and women

We wanted to determine if there are any associations between birth factors and adult fracture risk. For women only, shorter birth length was associated with lower relative fracture risk. For women and men, individuals who were long at birth as well as tall in adulthood had a substantially higher relative fracture risk.

PURPOSE

We aimed to examine associations between birth anthropometry and adult fracture risk and to investigate if developmental mismatch is associated with fracture risk.

METHODS

We included 4635 participants (476 women and 4159 men; born 1921-1950) with hospital and national registry-based data on birth anthropometry and adult fractures (≥ 50 years). We tested associations by Cox proportional hazards regressions and present hazard ratios (HR) with 95% confidence intervals.

RESULTS

In total, 1215 (26%) suffered ≥ 1 fracture during a mean observation period of 26 years. In women, unadjusted analyses indicated that both higher birth weight (HR 1.42 per kg (1.10-1.84)) and birth length (1.10 per cm (1.05-1.17)) were associated to higher adult fracture risk. After adjustment (year of birth and gestational age), statistical significance remained only for birth length, HR 1.10 per cm (1.04-1.17). For men, no associations were apparent. We found no associations between developmental mismatch (lower birth weight followed by higher adult weight) and adult fracture risk. However, for both sexes, being born tall and staying tall into adulthood was associated with a markedly higher (55-105%) relative fracture risk (HR women 2.09 (1.18-3.68), men 1.55 (1.19-2.03)) compared to being born short and remaining short in adulthood.

CONCLUSION

In this study, being born shorter and lighter was associated with a lower risk for fractures ≥ 50 years in women. However, analyses indicated that tall adults who were also long at birth may be at markedly higher risk of fractures; this warrants further examinations.

Joint models reveal genetic architecture of pubertal stage transitions and their association with BMI in admixed Chilean population

Early or late pubertal onset can lead to disease in adulthood, including cancer, obesity, type 2 diabetes, metabolic disorders, bone fractures, and psychopathologies. Thus, knowing the age at which puberty is attained is crucial as it can serve as a risk factor for future diseases. Pubertal development is divided into five stages of sexual maturation in boys and girls according to the standardized Tanner scale. We performed genome-wide association studies (GWAS) on the "Growth and Obesity Chilean Cohort Study" cohort composed of admixed children with mainly European and Native American ancestry. Using joint models that integrate time-to-event data with longitudinal trajectories of body mass index (BMI), we identified genetic variants associated with phenotypic transitions between pairs of Tanner stages. We identified $42$ novel significant associations, most of them in boys. The GWAS on Tanner $3\rightarrow 4$ transition in boys captured an association peak around the growth-related genes LARS2 and LIMD1 genes, the former of which causes ovarian dysfunction when mutated. The associated variants are expression and splicing Quantitative Trait Loci regulating gene expression and alternative splicing in multiple tissues. Further, higher individual Native American genetic ancestry proportions predicted a significantly earlier puberty onset in boys but not in girls. Finally, the joint models identified a longitudinal BMI parameter significantly associated with several Tanner stages' transitions, confirming the association of BMI with pubertal timing.

Long-term health consequences of central precocious/early puberty (CPP) and treatment with Gn-RH analogue: a short update

BACKGROUND

The relationship between precocious or early puberty and its treatment has received significant research attention, yielding diverse outcomes. This short review aims to comprehensively analyze and summarize research articles to elucidate the potential link between precocious or early pubertal onset (CPP) and crucial health factors.

METHODS

We conducted a systematic review of studies published from -January 2000 to March 2023, sourced from databases of Medline, PubMed, Google Scholar and Web of Science. We assessed the relationship between CPP and final adult height (FHt), bone health, reproductive function, body mass index, metabolic and cardiovascular abnormalities, and increased cancer risk.

RESULTS

Upon reviewing and analyzing selected studies, the following key findings emerged: (a) treating CPP in girls before age 6-7 and in boys before age 9 improves FHt; (b) bone mineral density (BMD) decreases during GnRHa treatment but normalizes afterward, with no lasting effects on peak bone mass during puberty; (c) GnRH treatment does not negatively affect menstrual cycles; however, untreated CPP increases the risk of premature or early-onset menopause; (d) the incidence of PCOS/hyperandrogenemia may be slightly elevated in women with a history of CPP, but overall reproductive function remains largely unaffected; (e) earlier thelarche and menarche may enhance susceptibility to breast carcinogenesis; (f) CPP contributes to an increased risk of obesity and type 2 diabetes in both genders; (g) early menarche may slightly increase the risk of coronary heart disease and ischemic strokes and (h) early pubertal timing increases the risk of depression and anxiety disorders.

CONCLUSION

Monitoring and early diagnosis of these conditions are of paramount importance for successful management.

Exposure to famine in every stage of life and the risk of osteoporosis and fractures later in life: A cross-sectional study

BACKGROUND AND OBJECTIVE

Data on the association between early-life famine exposure and osteoporosis and fractures remain limited and inconclusive. The aim of this study was to investigate the correlation between famine exposure and osteoporosis and fractures.

METHODS

We performed a cross-sectional analysis using the first follow-up survey data from the China Cardiometabolic Disease and Cancer Cohort Study from 2014 to 2016. We classified 4807 Lanzhou participants into seven groups based on their birthday (non-exposed or exposed in the fetal stage, early childhood, mid-childhood, late childhood, adolescence, or early adulthood). And we combined the non-exposed and early-adulthood exposed groups as a control group, which was called "age balanced group". This age-balanced group was used as the control group to further evaluate the risk of osteoporosis and fracture. We used multiple logistic regression to estimate the association between famine exposure and the risk of osteoporosis (T-score ≤ -1.8 by QUS) and self-reported fracture.

RESULTS

In women, compared to the age-balanced group, the odds ratios (95 % CI) for the risk of osteoporosis were 1.400(1.034, 1.897), 1.630(1.268, 2.095), 1.707(1.314, 2.218), 2.150(1.732.2.668) and 2.885(2.286,3.641) in the fetal stage, early childhood, mid-childhood, late childhood and adolescence famine-exposed cohorts. In men, no association between famine and osteoporosis was noted with exposed cohort compared with the age-balanced control cohort (p > 0.05). Interestingly, the association between famine exposure and fractures was slightly different from the above results: in women, the odds ratios (95 % CI) for fractures in mid-childhood famine exposure was 1.461(1.082,1.973), in late childhood famine exposure was 1.333(1.035,1.718) and in adolescence famine exposure was 1.607(1.239,2.085). However, compared to the age-balanced control cohort, men exposed to famine in early childhood (OR: 1.801, 95 % CI: 1.010,3.211) had a higher risk of fracture.

CONCLUSION

Famine exposure in different life stage has adverse effects on bone health. Famine exposure in not only the period from gestation to infancy, but also childhood and adolescence was associated with an increased risk of osteoporosis, especially in women. Exposure to famine in childhood- (mid and late) and adolescence- life period is associated with fracture in women. But, in men early-childhood famine exposure was only associated with fracture.

Family environmental antecedents of pubertal timing in girls and boys: A review and open questions

Across nonhuman species, pubertal timing is affected by the social environment, with consequences for reproductive success and behavior. In human beings, variations in pubertal timing have not been systematically examined in relation to social environmental antecedents, although their psychological consequences are well documented. This paper focuses on links in human beings between pubertal timing and the childhood social environment, with several sections: A review of studies relating pubertal timing to the family context, a key aspect of the social environment; challenges in studying the issue; and opportunities for future work that takes advantage of and creates links with evidence in other species. The review shows that pubertal timing in girls is accelerated by adversity in aspects of the early family social context, with effects small in size; data in boys are not sufficient to enable conclusions. Inferences from existing studies are limited by variations in conceptualizations and measurement of relevant aspects of puberty and of the family social environment, and by methodological issues (e.g., reliance on existing data, use of retrospective reports, nonrandom missing data). Open questions remain about the nature, mechanisms, and specificity of the links between early family social environment and pubertal timing (e.g., form of associations, consideration of absence of positive experiences, role of timing of exposure). Animal studies provide a useful guide for addressing these questions, by delineating potential hormonal mechanisms that underlie links among social context, pubertal timing, and behavior, and encouraging attention to aspects of the social environment outside the family, especially peers.

Family Experiences and Parent Personality as Antecedents of Pubertal Timing in Girls and Boys

Pubertal timing may be influenced by typical variations in early family environmental events, but questions remain concerning the roles of specific parenting factors, developmental age of exposure to events, moderation by child temperament, and comparability of effects for girls and boys. This study focused on these questions utilizing longitudinal data from 733 same-sex twins (45% girls) in the U.S.; family context was measured at ages 1-3, 4-5, and 6-7 years and pubertal status was assessed annually via self-report at ages 9-15, enabling estimates of pubertal timing. Home environment at ages 4-5 years predicted pubertal timing better than home environment at other ages for both girls and boys, but parent personality was more predictive than home experiences (e.g., divorce, parental harshness, family conflict). Thus, effects of family environment must be considered within the context of parent characteristics, encouraging caution in implicating early environmental experiences as direct influences on early pubertal timing.

Critical Role of Estrogens on Bone Homeostasis in Both Male and Female: From Physiology to Medical Implications

Bone is a multi-skilled tissue, protecting major organs, regulating calcium phosphate balance and producing hormones. Its development during childhood determines height and stature as well as resistance against fracture in advanced age. Estrogens are key regulators of bone turnover in both females and males. These hormones play a major role in longitudinal and width growth throughout puberty as well as in the regulation of bone turnover. In women, estrogen deficiency is one of the major causes of postmenopausal osteoporosis. In this review, we will summarize the main clinical and experimental studies reporting the effects of estrogens not only in females but also in males, during different life stages. Effects of estrogens on bone involve either Estrogen Receptor (ER)α or ERβ depending on the type of bone (femur, vertebrae, tibia, mandible), the compartment (trabecular or cortical), cell types involved (osteoclasts, osteoblasts and osteocytes) and sex. Finally, we will discuss new ongoing strategies to increase the benefit/risk ratio of the hormonal treatment of menopause.

Revisiting the critical weight hypothesis for regulation of pubertal timing in boys

BACKGROUND

Recent findings indicate that there is a body weight-sensing homeostatic regulation of body weight in postpubertal rodents and humans. It is possible that body weight sensing also might be involved in the regulation of pubertal timing. Although an early small study suggested that there is a critical body weight for pubertal timing in girls, most studies have focused on BMI and reported an inverse association between BMI and pubertal timing.

OBJECTIVES

In the present longitudinal well-powered cohort study, we revisited the critical weight hypothesis and tested if prepubertal body weight is a more robust inverse predictor of pubertal timing than prepubertal BMI in boys.

METHOD

We included men born during 1945-1961 (old cohort; n = 31,971) and men born during 1981-1996 (recent cohort; n = 1465) in the large BMI Epidemiology Study (BEST) Gothenburg (combined BEST cohort n = 33,436). Men with information on prepubertal body weight and BMI at 8 y of age and age at peak height velocity (PHV; an objective measure of pubertal timing) were included.

RESULTS

Body weight explained more of the variance in age at PHV than BMI in both the old cohort and the recent cohort (combined cohort, body weight 6.3%, BMI 3.6%). Both body weight (β: -0.24 SD/SD increase in weight; 95% CI: -0.25, -0.23) and BMI (β: -0.18 SD/SD increase in BMI, 95% CI: -0.19, -0.17) were inversely associated with age at PHV but the association for body weight was significantly more pronounced than the association for BMI (P < 0.001).

CONCLUSIONS

In conclusion, prepubertal body weight is a more robust inverse predictor of pubertal timing than prepubertal BMI in boys. We propose that body weight sensing constitutes a feedback mechanism to regulate pubertal timing.

Association of Early-Life Adversity With Measures of Accelerated Biological Aging Among Children in China

IMPORTANCE

A growing body of literature suggests that exposure to early-life adversity (ELA) is associated with accelerated biological aging, offering 1 mechanism through which ELA may be associated with an increased risk for age-related disease. These investigations, however, have been predominantly cross-sectional and focused on adults and females.

OBJECTIVE

To evaluate associations of threat-related (ie, physical abuse) and deprivation-related (ie, emotional neglect) ELA exposure with cellular and reproductive strategy metrics of biological aging among boys and girls with specific genetic backgrounds around the period of pubertal onset.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, 997 boys and girls in grade 1 to grade 3 from 3 large elementary schools were recruited from Bengbu, Anhui Province, China, and were followed up from March 21, 2016 (baseline; wave 1), for 4 consecutive years, through March 25, 2019.

MAIN OUTCOMES AND MEASURES

The outcome was accelerated biological aging in both cellular and reproductive strategy metrics: telomere attrition and age at thelarche (for girls) and testicular maturation (for boys). Multi-informant assessment of exposure to threat-related and deprivation-related ELA was done at baseline (wave 1) and 1-year follow-up (wave 2). The polygenic risk score (PRS) was computed based on 17 single-nucleotide variations for early pubertal timing.

RESULTS

Of the 997 participants (579 girls [58.1%]; mean [SD] age at baseline, 8.0 [0.8] years), 550 (55.2%) reported exposure to threat-related ELA and 443 (44.4%) reported exposure to deprivation-related ELA. Threat-related ELA was associated with onset of thelarche 2.6 months earlier and deprivation-related ELA with onset of thelarche 3.3 months earlier in exposed girls than in unexposed peers; these associations were observed only among girls with a low PRS. Among boys, a similar pattern was found. Threat-related ELA was associated with testicular volume of 4 mL or more 1.4 months earlier and deprivation-related ELA was associated with testicular volume of 4 mL or more 2.3 months earlier than in unexposed peers but only among those with a low PRS. Boys and girls with greater exposure to threats showed a significantly higher percentage of telomere length change during 1-year follow-up, but only among those with low PRS (boys: β = 1.50; 95% CI, 0.80-2.21; P < .001; girls: β = 2.40; 95% CI, 1.78-3.05; P < .001) and moderate PRS (boys: β = 1.09; 95% CI, 0.43-1.75; P = .001; and girls: β = 1.27; 95% CI, 0.77-1.77; P < .001). No associations of deprivation-related ELA with percentage of telomere length change were found.

CONCLUSIONS AND RELEVANCE

This study suggests that the accelerating association of ELA with biological aging might occur at an earlier age and in a genetic background-dependent and dimension-specific manner.