The influence of age at menarche on cross-sectional geometry of bone in young adulthood

Abstract

Elucidating the somatic and maturational influences on the biomechanical properties of bone in children is crucial for a proper understanding of bone strength and quality in childhood and later life, and has significant potential for predicting adult fracture and osteoporosis risks. The ability of a long bone to resist bending and torsion is primarily a function of its cross-sectional geometric properties, and is negatively impacted by smaller external bone diameter. In pubescent girls, elevated levels of estrogen impede subperiosteal bone growth and increase endosteal bone deposition, resulting in bones averaging a smaller external and internal diameter relative to boys. In addition, given a well-documented secular trend for an earlier menarche, the age at which the rate of subperiosteal bone deposition decreases may also be younger in more recent cohorts of girls.In this study we examined the relationship between pubertal timing and subsequent bone strength in girls. Specifically, we investigated the effects of age at menarche on bone strength indicators (polar moment of inertia and section modulus) determined from cross-sectional geometry of the second metacarpal (MC2) using data derived from serial hand-wrist radiographs of female participants (N=223) in the Fels Longitudinal Study, with repeated measures of MC2 between the ages of 7 and 35 years. Using multivariate regression models, we evaluated the effects of age at menarche on associations between measures of bone strength in early adulthood and the same measures at a prepubertal age. Results indicate that later age at menarche is associated with stronger adult bone (in torsion and bending) when controlling for prepubertal bone strength (R 2 ranged between 0.54 and 0.70, p<0.001). Since cross-sectional properties of bone in childhood may have long lasting implications, they should be considered along with pubertal timing in assessing risk for future fracture and in clinical recommendations.

Sex-specific regulation of weight and puberty by the Lin28/let-7 axis

“…The basis for these differences is not fully understood, but understanding the differences is important because they are linked to cardiovascular and other health outcomes (Day et al 2015; Golub et al 2008; Joinson et al 2011; Lakshman et al 2009; Ritte et al 2013; Seselj et al 2012; Weir et al 1998; Widen et al 2012). Certainly sex steroids play a role in this sex specificity and so do sex chromosomes as is evidenced by the height in women with complete androgen insensitivity and Turner syndrome.…”

“…Girls also experience puberty at younger ages than boys and are more likely to exhibit precocious puberty, while boys are more likely to have delayed puberty (Carel and Leger 2008; Palmert and Dunkel 2012; Styne and Grumbach 2012; Walvoord 2010). The factors that contribute to these differences are unknown but important because variations in the timing of puberty have been associated with higher risk for adult metabolic abnormalities, cancer and osteoporosis (Day, et al 2015; Golub, et al 2008; Joinson, et al 2011; Lakshman, et al 2009; Ritte, et al 2013; Seselj, et al 2012; Weir, et al 1998; Widen, et al 2012). …”

Childhood socioeconomic status and adult femoral neck bone strength: Findings from the Midlife in the United States Study

“…It may also be that the childhood SES measure we used does not adequately reflect the social stressors experienced by impoverished girls and young women. A third possibility is that childhood SES effects on femoral neck strength in women are masked by much larger changes in bone strength during the menarche [75] and the menopause transition [76]. …”

Sex-Specific Muscular Mediation of the Relationship Between Physical Activity and Cortical Bone in Young Adults

“…Because the timing of pubertal onset is inversely related with peak bone mass and may also affect bone geometric properties during young adulthood, (47,48) future research should aim to clarify whether interactions exist with regard to PA and the muscle-bone unit, especially in females where menarche-related increases in estrogen may alter patterns of mineralization following PA (ie, endosteal versus periosteal). Primarily, our use of cross-sectional data limit the inference of causality from our hypothesized path model.…”

“…Though our data are tightly controlled with regard to chronological age, we did not measure maturational status or history in our sample. Because the timing of pubertal onset is inversely related with peak bone mass and may also affect bone geometric properties during young adulthood, (47,48) future research should aim to clarify whether interactions exist with regard to PA and the muscle-bone unit, especially in females where menarche-related increases in estrogen may alter patterns of mineralization following PA (ie, endosteal versus periosteal). (18,49) Excess adiposity may also affect the muscle-bone unit in the context of adaptation to habitual PA. (50,51) Results of our sensitivity analyses suggested that further controlling for relative adiposity did not alter the outcomes of our models; however, participants in the current study were healthy and not obese.…”