Some endocrine characteristics of early menarche, a risk factor for breast cancer, are preserved into adulthood

Abstract

Early menarche is a risk factor for breast cancer. In a longitudinal manner, we have investigated the endocrine features of girls with early menarche. This study extends our investigations to the third decade of life in a cohort of girls followed up for 13 years. The group studied comprised 44 women, 20-31 years of age. Eleven women had had their menarche before 12.0 years, 14 women at 12.0-12.9 years and 19 women at 13.0 years or more. The women who had had early menarche had higher serum oestradiol concentrations during the follicular phase of the menstrual cycle than the women who had had their menarche later. The serum oestradiol concentrations increased rapidly at the beginning of cycle in these "early menarche" women. If there is a threshold which serum oestradiol concentrations must exceed to increase the risk of breast cancer, then these women have more days at risk than other women. In addition, the serum SHBG (sex-hormone-binding globulin) concentration was about 30% lower in the follicular-phase specimens of the women who had had their menarche before 12.0 years compared with those who had had their menarche at 13.0 years. Our data therefore indicate that women with early menarche are subject to a high degree of oestrogen stimulation at least until approximately 30 years of age. Our findings may have important consequences for the design of intervention programs for breast cancer prevention.

Reproductive factors and family history of breast cancer in relation to plasma prolactin levels in premenopausal and postmenopausal women

“…[9][10][11]13,15,34,35 To our knowledge, this is the second largest study of prolactin levels and reproductive and family history correlates, after the Guernsey studies. 12,14 The large number of both premenopausal and postmenopausal women allowed us to examine associations by menopausal status.…”

“…Other birthrelated factors, such as age at first birth, time since last birth and history of lactation, have been assessed in only a few studies, with no clear associations. [11][12][13][14][15] Few studies have examined these associations in postmenopausal women. 9,14 A prior analysis of the correlations between breast cancer risk factors and prolactin levels was conducted among 217 postmenopausal women within the Nurses' Health Study (NHS).…”

Genetic and environmental correlations between obesity phenotypes and age at menarche

“…The onset of menstruation is regulated by hypothalamic-pituitary-gonadal axis and initiated by increased exposure of tissues to estrogen. 23 The women who have earlier menarche may have lower serum concentrations of sex-hormone-binding globulin (SHBG) [24][25][26] and higher serum estrodiol during the follicular phase of the menstrual cycle, as compared to the women who have later menarche. 26 On the other hand, low SHBG and high estrogen levels are associated with increased total and central adiposity in women.…”

“…23 The women who have earlier menarche may have lower serum concentrations of sex-hormone-binding globulin (SHBG) [24][25][26] and higher serum estrodiol during the follicular phase of the menstrual cycle, as compared to the women who have later menarche. 26 On the other hand, low SHBG and high estrogen levels are associated with increased total and central adiposity in women. 20,[27][28][29] SHBG is a protein that binds primarily to steroids such as estrogen.…”

Detrimental psychological outcomes associated with early pubertal timing in adolescent girls

“…They also have higher levels of serum estradiol. Such hormonal differences persist well into adulthood, until girls reach their late 20s and early 30s (Apter & Vihko, 1983;Vihko & Apter, 1984;Apter, Reinila, & Vihko, 1989). …”