RESUMO
BACKGROUND: Early onset of menarche is considered an important risk factor for a number of diseases in adulthood. Iron intake may be related to pubertal timing because of its role in childhood growth and reproductive function. OBJECTIVE: We investigated the relation between dietary iron intake and age at menarche in a prospective cohort of Chilean girls. METHODS: Overall, 602 Chilean girls were included in the Growth and Obesity Cohort Study, a longitudinal study that began in 2006 when the girls were 3-4 y old. Starting in 2013, diet was assessed every 6 mo through 24-h recall. The date of menarche was reported every 6 mo. Our analysis included 435 girls with prospective data on diet and age at menarche. We used a multivariable Cox proportional hazards regression model with restricted cubic splines to estimate HRs and 95% CIs for the association between cumulative mean iron intake and age at menarche. RESULTS: Most girls (99.5%) attained menarche with a mean (standard deviation) age at menarche of 12.2 (0.9) y. The mean dietary iron intake was 13.5 (range: 4.0-30.6) mg/d. Only 3.7% of girls consumed below 8 mg/d, the RDA. After multivariable adjustment, cumulative mean iron intake had a nonlinear association with menarche (P-for-nonlinearity: 0.02). Iron intakes above the RDA, between 8 and 15 mg/d, were associated with progressively lower probability of earlier menarche. Above 15 mg/d, the HRs were imprecise but tended to approach the null as iron intake increased. This association was attenuated after adjusting for girls' BMI and height before menarche (P-for-nonlinearity: 0.11). CONCLUSION: In Chilean girls, iron intake during late childhood, independent of body weight, was not an important determinant of menarche timing.
Assuntos
Ferro da Dieta , Menarca , Feminino , Criança , Humanos , Estudos de Coortes , Estudos Prospectivos , Estudos Longitudinais , Ferro , Chile , Dieta , PuberdadeRESUMO
Background: Frequent dairy consumption in childhood has been related to higher growth-hormone concentrations that may affect mammary gland and pubertal development.Objective: We evaluated the relation of dairy intake to breast composition at Tanner stage 4 and age at menarche.Design: A total of 515 Chilean girls are included in the Growth and Obesity Cohort Study. The subjects have been followed longitudinally since they were 3-4 y old (from 2006 to the present). Starting in 2013, diet was assessed every 6 mo via a 24-h recall. The breast fibroglandular volume (FGV) was measured with the use of dual-energy X-ray absorptiometry at Tanner stage 4. The date of menarche was reported every 6 mo. Our analysis included 290 girls with data on prospective diet and breast composition and 324 girls with data on prospective diet and age at menarche.Results: The mean ± SD breast FGV and percentage of fibroglandular volume (%FGV) (i.e., FGV divided by total breast volume times 100) at Tanner stage 4 was 81.7 ± 32.2 cm3 and 42.0% ± 16.7%, respectively. Only sweetened, artificially flavored milk-based drinks were associated with the %FGV with girls who consumed >125 g/d having a %FGV that was 4.5% (95% CI: 0.9%, 8.1%) higher than that of girls who consumed none (P-trend = 0.007). Yogurt intake was associated with a lower FGV. Specifically, girls who consumed >125 g yogurt/d had -10.2 cm3 (95% CI: -20.2, -0.3 cm3) less FGV than did girls who consumed no yogurt (P-trend = 0.03). The majority (90.7%) of girls in our cohort attained menarche before the data analyses with a mean ± SD age at menarche of 11.9 ± 0.7 y. In multivariable models, low-fat dairy, low-fat milk, and yogurt intakes were associated with a later age at menarche. In particular, girls who consumed >125 g yogurt/d had menarche, on average, 4.6 mo (95% CI: 1.9, 7.4 mo) later than girls who consumed no yogurt (P-trend = 0.01).Conclusion: More-frequent consumption of sweetened, artificially-flavored milk-based drinks is associated with a higher %FGV, whereas higher yogurt intake is associated with a lower FGV and delayed age at menarche in Chilean girls.
Assuntos
Mama/crescimento & desenvolvimento , Dieta , Comportamento Alimentar , Menarca , Leite , Maturidade Sexual , Iogurte , Absorciometria de Fóton , Fatores Etários , Animais , Criança , Chile , Laticínios , Registros de Dieta , Sacarose Alimentar/efeitos adversos , Ingestão de Energia , Feminino , Humanos , Estudos Longitudinais , Glândulas Mamárias Humanas , Rememoração Mental , Estudos Prospectivos , Puberdade Precoce/etiologiaRESUMO
OBJECTIVE: To assess the association between coenzyme Q10 (CoQ10) intake from food sources and semen quality. We assessed this association in a prospective cohort of men attending a fertility clinic. CoQ10 supplementation has been associated with improvements in semen parameters. However, the impact of CoQ10 intake from food sources on semen quality has not been investigated. MATERIALS AND METHODS: Subfertile couples seeking fertility evaluation at the Massachusetts General Hospital Fertility Center were invited to participate in an ongoing study of environmental factors and fertility. In total, 211 male participants completed a validated food frequency questionnaire and provided 476 semen samples. Multivariable linear mixed models were used to examine the relation between CoQ10 intake from food and semen parameters while adjusting for potential confounders and accounting for within-person correlations. RESULTS: Mean dietary CoQ10 intake was 19.2 mg/day (2.4-247.2 mg/day). No subjects were taking CoQ10 supplements. There were no associations between dietary CoQ10 intake from food and conventional semen parameters. The adjusted mean difference (95% confidence interval) comparing men in the top and bottom quartiles of CoQ10 intake from food were -3.1 mil/mL (95% confidence interval -29.5, 38.8 mil/mL) for sperm concentration, -4.5% (-15.1%, 6.0%) for total motility, -1.3% for progressive motility (-8.4%, 5.7%), and 0.3% (-1.4%, 2.0%) for sperm morphology. CONCLUSION: CoQ10 intake from food was not related to semen parameters among subfertile men. Mean dietary intake of CoQ10 in this study was 10-fold lower than the supplemental dose used in clinical trials showing improved sperm motility. CoQ10 intake from food alone may be insufficient to optimize semen parameters.
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Suplementos Nutricionais , Alimentos , Infertilidade Masculina/dietoterapia , Análise do Sêmen , Ubiquinona/análogos & derivados , Vitaminas/uso terapêutico , Adulto , Humanos , Masculino , Estudos Prospectivos , Ubiquinona/uso terapêuticoRESUMO
OBJECTIVE: To study the relation of dietary phytoestrogens intake and clinical outcomes of women undergoing infertility treatment with the use of assisted reproductive technology (ART). DESIGN: Prospective cohort study. SETTING: Fertility center. PATIENT(S): A total of 315 women who collectively underwent 520 ART cycles from 2007 to 2013. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Implantation, clinical pregnancy, and live birth rates per initiated cycle. RESULT(S): Soy isoflavones intake was positively related to live birth rates in ART. Compared with women who did not consume soy isoflavones, the multivariable-adjusted odds ratios of live birth (95% confidence interval) for women in increasing categories of soy isoflavones intake were 1.32 (0.76-2.27) for women consuming 0.54-2.63 mg/d, 1.87 (1.12-3.14) for women consuming 2.64-7.55 mg/d, and 1.77 (1.03-3.03) for women consuming 7.56-27.89 mg/d. CONCLUSION(S): Dietary soy intake was positively related to the probability of having a live birth during infertility treatment with ART.