Pubertal Timing, Androgens, and Obesity Phenotypes in Women at Midlife
Context: Individuals with metabolically healthy or benign obesity vs. unhealthy or at risk obesity have been distinguished; however, the predisposing factors for developing these phenotypes are poorly understood. Objective: Our objective was to examine pubertal timing marked by menarcheal age in relation to at-risk obese, benign obese, and healthy normal-weight phenotypes at midlife and to characterize the potential role of androgens, marked by the free androgen index (FAI), in accounting for any associations between menarcheal age and obesity phenotype. Design: The study was cross-sectional. Setting and Participants: Participants included a multiethnic community sample of 989 premenopausal women ages 25-45 yr (mean = 35.2 yr; sd = 5.5 yr). Main Outcome Measure: Membership in at-risk obese, benign obese, and healthy normal-weight groups was defined by body mass index and number of metabolic syndrome components. Results: With each 1-yr increase in menarcheal age, the probability of having the at-risk obese compared with the healthy normal-weight phenotype decreased by 22%. This association attenuated when FAI was covaried, suggesting androgen levels may account for this association. In addition, higher FAI was independently related to having the at-risk obese compared with the healthy normal-weight phenotype as well as having the at-risk compared with the benign obese phenotype (all P < 0.05). Conclusions: Younger menarcheal age is associated with having the metabolically unhealthy obesity phenotype compared with the healthy normal-weight phenotype at midlife. This relation may be driven by levels of bioavailable androgens, which were especially elevated among women with the at-risk obesity phenotype.
Available from: Casper Hagen
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ABSTRACT: To investigate whether genetic polymorphisms in the FSH pathway (FSHB-211 G→T and FSHR 2039 A→G) affect serum levels of FSH, antimüllerian hormone (AMH), and age at pubertal onset. FSH secretion and FSH signal transduction are enhanced in carriers of FSHB GG and FSHR AA, respectively. Furthermore, the combined genotype FSHB GG+FSHR AA is the most favorable for male gonadal function, but the effect of this genotype has never been evaluated in peripubertal females. AMH is a marker of ovarian function and is negatively correlated with FSH in prepubertal girls.
Secondary analyses of a prospective cohort study.
We examined 78 healthy girls twice yearly for 6 years; the median age at baseline was 9.3 years.
Hormone levels were measured by immunoassays, and DNA was isolated from blood and genotyped by restriction fragment length polymorphism of polymerase chain reaction-amplified regions.
Carriers of FSHB GG+FSHR AA had higher FSH before pubertal onset (median 2.2 vs. 1.5 IU/L) and lower AMH (13.8 vs. 19.4 pmol/L) compared with carriers of other genotypes. In crude analysis, girls with FSHB GG+FSHR AA entered puberty earlier, 9.7 vs. 10.6 years. However, the difference was no longer statistically significant after including interval-, right-, and left-censored data in a probit analysis.
The combined effect of FSHB GG+FSHR AA may potentiate the FSH pathway, which increases serum levels of FSH and reduces AMH. Common variations in genes regulating follicle growth may affect AMH levels independently of the number of resting primordial follicles.
Fertility and sterility 07/2013; 100(4). DOI:10.1016/j.fertnstert.2013.06.026 · 4.59 Impact Factor
Available from: onlinelibrary.wiley.com
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ABSTRACT: Obesity in women is associated with serious reproductive sequelae. Given its prevalence among women of reproductive age, much recent attention has focused on the mechanisms by which obesity affects female reproductive function and fertility. This review summarizes the literature investigating the epidemiology and pathophysiology of obesity in women of reproductive age and proposes research strategies that may help inform approaches to improve reproductive function and outcomes among obese women.
Nutrition Reviews 10/2013; 71(S1). DOI:10.1111/nure.12056 · 6.08 Impact Factor
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ABSTRACT: To identify and relate body fat percentage (skin fold measures), body mass index (BMI) and age at menarcheto aerobic capacity using the indirect VO2 maximum value (VO2 max) of girls in the second cycle of primary school.
A total of 197 girls aged 13.0±1.2 years on average, students from two public schools in the city of Atibaia in São Paulo, were evaluated. Anthropometric evaluation of skin folds was performed using the Slaughter protocol for teenage girls, and BMI (kg/m2) was based on "Z score" (graphic of percentile) according to WHO recommendations. The Léger protocol was used to determine VO2 max. Pearson linear regression and the Student t-test were used for statistical analysis.
22.3% of the girls were overweight and 3.5% were obese according to the classification proposed by the WHO; 140 (71.1%) girls reported menarche. The average age at menarche was 12.0±1.0 years and was significantly higher in the group with normal BMI (12.2±0.9 years) than in the overweight or obese groups (11.6±1.0 years). The average indirect VO2 max value was 39.6±3.7 mL/kg/min, ranging from 30.3 to 50.5 mL/kg/min. The advance of chronological age and early age at menarche were positively correlated with lower VO2 max values.
This study showed that 25.8% of the girls had aBMI value above WHO recommendations. Girls with higher BMI and higher body fat percentage had lower VO2 max. The earlier age at menarche and the advance of chronological age were the most important factors for the reduction of aerobic capacity. The ageat menarche was higher in girls with adequate BMI compared tooverweight or obese girls.
Revista brasileira de ginecologia e obstetrićia: revista da Federação Brasileira das Sociedades de Ginecologia e Obstetrícia 02/2014; 36(2):84-9.
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