Female sex hormones and body mass in adolescent and postmenopausal Korean women

Estrogen-mediated mitigation of cardiac oxidative stress in ovariectomized rats is associated with upregulated cardiac circadian clock Per2 and heart-specific miRNAs

AIM

Estrogen (E2) confers cardioprotection in premenopausal women and in models of menopause and its effects, mostly studied in female reproductive organs, vary on a circadian rhythm basis in relation to the circadian clock genes. However, it remains unknown if a similar circadian pattern exists in the female heart in a manner that explains, at least partly, the cardioprotective effect of E2. The aim of the present investigation was to determine if upregulation of the circadian clock Per2 and its regulated heart-specific miRNAs, and redox enzymes contribute to the E2-mediated cardioprotection in ovariectomized rats.

MAIN METHODS

Rats were subjected to ovariectomy (OVX) 2-weeks prior to a 2-week E2 treatment. On the last treatment day, hearts were collected every 4 h. for ex-vivo biochemical measurements. In parallel studies, telemetric mean arterial pressure (MAP) was obtained at the tissue collection times.

KEY FINDINGS

OVX + E2 rats exhibited lower body weight during daytime and MAP during day and night times, and their hearts exhibited: (1) higher Per2 protein abundance, cardioprotective miRNAs (miRNA1, miRNA133a, miRNA208a, miRNA499), mALDH2, and catalase; (2) lower reactive oxygen species, cardio-detrimental miRNA652, carbonyl, MDA and HO-1 levels. The reciprocal Per2/HO-1 relationship was more evident during the daytime and correlated with the upregulated cardioprotective miRNAs in OVX + E2 rats. Finally, cardiac Per2, heart-specific miRNAs and reactive oxygen species levels and redox enzymes activities were similar in normal female and OVX + E2 rats.

SIGNIFICANCE

Enhancement of cardiac Per2, redox enzymes and heart-specific miRNAs likely contribute to E2-mediated mitigation of cardiac oxidative stress in OVX rats.

Ethnic differences in the lifestyle behaviors and premature coronary artery disease: a multi-center study

BACKGROUND

Diverse ethnic groups that exist in Iran may differ regarding the risk factors such as hypertension, hyperlipidemia, dyslipidemia, diabetes mellitus, and family history of non-communicable disease. Premature Coronary Artery Disease (PCAD) is more endemic in Iran than before. This study sought to assess the association between ethnicity and lifestyle behaviors in eight major Iranian ethnic groups with PCAD.

METHODS

In this study, 2863 patients aged ≤ 70 for women and ≤ 60 for men who underwent coronary angiography were recruited in a multi-center framework. All the patients' demographic, laboratory, clinical, and risk factor data were retrieved. Eight large ethnicities in Iran, including the Farses, the Kurds, the Turks, the Gilaks, the Arabs, the Lors, the Qashqai, and the Bakhtiari were evaluated for PCAD. Different lifestyle components and having PCAD were compared among the ethnical groups using multivariable modeling.

RESULTS

The mean age of the 2863 patients participated was 55.66 ± 7.70 years. The Fars ethnicity with 1654 people, was the most subject in this study. Family history of more than three chronic diseases (1279 (44.7%) was the most common risk factor. The Turk ethnic group had the highest prevalence of ≥ 3 simultaneous lifestyle-related risk factors (24.3%), and the Bakhtiari ethnic group had the highest prevalence of no lifestyle-related risk factors (20.9%). Adjusted models showed that having all three abnormal lifestyle components increased the risk of PCAD (OR = 2.28, 95% CI: 1.04-1.06). The Arabs had the most chance of getting PCAD among other ethnicities (OR = 2.26, 95%CI: 1.40-3.65). While, the Kurds with a healthy lifestyle showed the lowest chance of getting PCAD (OR = 1.96, 95%CI: 1.05-3.67)).

CONCLUSIONS

This study found there was heterogeneity in having PACD and a diverse distribution in its well-known traditional lifestyle-related risk factors among major Iranian ethnic groups.

A review of menopause nomenclature

Menopause nomenclature varies in the scholarly literature making synthesis and interpretation of research findings difficult. Therefore, the present study aimed to review and discuss critical developments in menopause nomenclature; determine the level of heterogeneity amongst menopause definitions and compare them with the Stages of Reproductive Aging Workshop criteria. Definitions/criteria used to characterise premenopausal and postmenopausal status were extracted from 210 studies and 128 of these studies were included in the final analyses. The main findings were that 39.84% of included studies were consistent with STRAW classification of premenopause, whereas 70.31% were consistent with STRAW classification of postmenopause. Surprisingly, major inconsistencies relating to premenopause definition were due to a total lack of reporting of any definitions/criteria for premenopause (39.84% of studies). In contrast, only 20.31% did not report definitions/criteria for postmenopause. The present findings indicate that there is a significant amount of heterogeneity associated with the definition of premenopause, compared with postmenopause. We propose three key suggestions/recommendations, which can be distilled from these findings. Firstly, premenopause should be transparently operationalised and reported. Secondly, as a minimum requirement, regular menstruation should be defined as the number of menstrual cycles in a period of at least 3 months. Finally, the utility of introducing normative age-ranges as supplementary criterion for defining stages of reproductive ageing should be considered. The use of consistent terminology in research will enhance our capacity to compare results from different studies and more effectively investigate issues related to women's health and ageing.

Fat mass changes during menopause: a metaanalysis

OBJECTIVE

Data: Fat mass has been shown to increase in aging women; however, the extent to which menopausal status mediates these changes remains unclear. The purpose of this review was to determine (1) how fat mass differs in quantity and distribution between premenopausal and postmenopausal women, (2) whether and how age and/or menopausal status moderates any observed differences, and (3) which type of fat mass measure is best suited to the detection of differences in fat mass between groups.

STUDY

This review with metaanalyses is reported according to Metaanalysis of Observational Studies in Epidemiology guidelines.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies (published up to May 2018) were identified via PubMed to provide fat mass measures in premenopausal and postmenopausal women. We included 201 cross-sectional studies in the metaanalysis, which provided a combined sample size of 1,049,919 individuals and consisted of 478,734 premenopausal women and 571,185 postmenopausal women. Eleven longitudinal studies were included in the metaanalyses, which provided a combined sample size of 2472 women who were premenopausal at baseline and postmenopausal at follow up.

RESULTS

The main findings of this review were that fat mass significantly increased between premenopausal and postmenopausal women across most measures, which included body mass index (1.14 kg/m²; 95% confidence interval, 0.95-1.32 kg/m²), bodyweight (1 kg; 95% confidence interval, 0.44-1.57 kg), body fat percentage (2.88%; 95% confidence interval, 2.13-3.63%), waist circumference (4.63 cm; 95% confidence interval, 3.90-5.35 cm), hip circumference (2.01 cm; 95% confidence interval, 1.36-2.65 cm), waist-hip ratio (0.04; 95% confidence interval, 0.03-0.05), visceral fat (26.90 cm²; 95% confidence interval, 13.12-40.68), and trunk fat percentage (5.49%; 95% confidence interval, 3.91-7.06 cm²). The exception was total leg fat percentage, which significantly decreased (-3.19%; 95% confidence interval, -5.98 to -0.41%). No interactive effects were observed between menopausal status and age across all fat mass measures.

CONCLUSION

The change in fat mass quantity between premenopausal and postmenopausal women was attributable predominantly to increasing age; menopause had no significant additional influence. However, the decrease in total leg fat percentage and increase in measures of central fat are indicative of a possible change in fat mass distribution after menopause. These changes are likely to, at least in part, be due to hormonal shifts that occur during midlife when women have a higher androgen (ie, testosterone) to estradiol ratio after menopause, which has been linked to enhanced central adiposity deposition. Evidently, these findings suggest attention should be paid to the accumulation of central fat after menopause, whereas increases in total fat mass should be monitored consistently across the lifespan.

Antiestrogen Resistant Cell Lines Expressing Estrogen Receptor α Mutations Upregulate the Unfolded Protein Response and are Killed by BHPI

Outgrowth of metastases expressing ERα mutations Y537S and D538G is common after endocrine therapy for estrogen receptor α (ERα) positive breast cancer. The effect of replacing wild type ERα in breast cancer cells with these mutations was unclear. We used the CRISPR-Cas9 genome editing system and homology directed repair to isolate and characterize 14 T47D cell lines in which ERαY537S or ERαD538G replace one or both wild-type ERα genes. In 2-dimensional, and in quantitative anchorage-independent 3-dimensional cell culture, ERαY537S and ERαD538G cells exhibited estrogen-independent growth. A progestin further increased their already substantial proliferation in micromolar 4-hydroxytamoxifen and fulvestrant/ICI 182,780 (ICI). Our recently described ERα biomodulator, BHPI, which hyperactivates the unfolded protein response (UPR), completely blocked proliferation. In ERαY537S and ERαD538G cells, estrogen-ERα target genes were constitutively active and partially antiestrogen resistant. The UPR marker sp-XBP1 was constitutively activated in ERαY537S cells and further induced by progesterone in both cell lines. UPR-regulated genes associated with tamoxifen resistance, including the oncogenic chaperone BiP/GRP78, were upregulated. ICI displayed a greater than 2 fold reduction in its ability to induce ERαY537S and ERαD538G degradation. Progestins, UPR activation and perhaps reduced ICI-stimulated ERα degradation likely contribute to antiestrogen resistance seen in ERαY537S and ERαD538G cells.

The effects of ovarian hormones and emotional eating on changes in weight preoccupation across the menstrual cycle

OBJECTIVE

Previous research has shown that fluctuations in ovarian hormones (i.e., estradiol and progesterone) predict the changes in binge eating and emotional eating across the menstrual cycle. However, the extent to which other eating disorder symptoms fluctuate across the menstrual cycle and are influenced by ovarian hormones remains largely unknown. This study sought to examine whether the levels of weight preoccupation vary across the menstrual cycle and whether the changes in ovarian hormones and/or other factors (i.e., emotional eating and negative affect) account for menstrual cycle fluctuations in this eating disorder phenotype.

METHOD

For 45 consecutive days, 352 women (age, 15-25 years) provided daily ratings of weight preoccupation, negative affect, and emotional eating. Saliva samples were also collected on a daily basis and assayed for levels of estradiol and progesterone using enzyme immunoassay techniques.

RESULTS

Weight preoccupation varied significantly across the menstrual cycle, with the highest levels in the premenstrual and menstrual phases. However, ovarian hormones did not account for within-person changes in weight preoccupation across the menstrual cycle. Instead, the most significant predictor of menstrual cycle changes in weight preoccupation was the change in emotional eating.

DISCUSSION

Fluctuations in weight preoccupation across the menstrual cycle appear to be influenced primarily by emotional eating rather than ovarian hormones. Future research should continue to examine the relationships among ovarian hormones, weight preoccupation, emotional eating, and other core eating disorder symptoms (e.g., body dissatisfaction, compensatory behaviors) in an effort to more fully understand the role of these biological and behavioral factors for the full spectrum of eating pathology.

Risk factors and control strategies for the rapidly rising rate of breast cancer in Korea

Due to the aging population and tremendous changes in life style over the past decades, cancer has been the leading cause of death in Korea. The incidence rate of breast cancer is the second highest in Korea, and it has shown an annual increase of 6.8% for the past 6 years. The major risk factors of breast cancer in Korean women are as follows: Early menarche, late menopause, late full-term pregnancy (FTP), and low numbers of FTP. Height and body mass index increased the risk of breast cancer in postmenopausal women only. There are ethnic variations in breast cancer due to the differences in genetic susceptibility or exposure to etiologic agent. With the epidemiological evidences on the possibility of further increase of breast cancer in Korea, the Korean Government began implementing the National Cancer Screening Program against breast cancer in 2002. Five-year survival rates for female breast cancer have improved significantly from 78.0% in early 1993-1995 to 90.0% in 2004-2008. This data indicate that improvement of the survival rate may be partially due to the early diagnosis of breast cancer as well as the increased public awareness about the significance of early detection and organized cancer screening program. The current primary prevention programs are geared towards strengthening national prevention campaigns. In accordance with the improvement in 5-year survival rate, the overall cancer mortality has started to decrease. However, breast cancer death rate and incidence rates are still increasing, which need further organized effort by the Korean Government.

Relation of body mass and sex steroid hormone levels to hot flushes in a sample of mid-life women

OBJECTIVE

Previous studies indicate that obesity is associated with a higher risk of experiencing hot flushes in mid-life women. The reasons for this association are unknown, although altered hormone levels have been associated with both hot flushes and obesity. Thus, this current study tested the hypothesis that obesity is associated with hot flushes in mid-life women through a mechanism involving levels of total and free androgen, free estrogen, progesterone, and sex hormone binding globulin (SHBG).

METHODS

Women aged 45-54 years were recruited from Baltimore and its surrounding counties. Each participant (n=628) was weighed, measured, completed a questionnaire, and provided a blood sample that was used to measure estradiol, estrone, testosterone, androstenedione, dehydroepiandrosterone sulfate, progesterone, and SHBG.

RESULTS

Obese mid-life women (body mass index (BMI)>or=30.0 kg/m2) had significantly higher testosterone, and lower estradiol, estrone, progesterone, and SHBG levels than normal-weight mid-life women (BMI<or=24.9 kg/m2) after adjustment for age, race, smoking, and number of days since last menstrual period. The association between obesity and hot flushes was no longer significant after adjustment for estrogens and progesterone, and/or SHBG.

CONCLUSION

These data suggest that obesity may be associated with hot flushes through a mechanism involving multiple hormones and SHBG.

Prevalence of obesity, central obesity and the associated factors in urban population aged 20-70 years, in the north of Iran: a population-based study and regression approach

Obesity is an undesirable outcome of changing of lifestyle and behaviours. It is also reversible predisposing factor for the development of several debilitating diseases. This study was aimed to determine the prevalence rate of obesity, overweight, central obesity and their associated factors in the north of Iran. We conducted a population-based cross-sectional study with a sample of 1800 women and 1800 men with respective mean ages of 37.5 +/- 13.0 and 38.5 +/- 14.2 years of urban population aged 20-70 years living in the north of Iran. The demographic and lifestyle data, in particular, age, gender, marital status, marriage age, family history of obesity, educational level, occupation, occupational and leisure time physical activity, duration of exercise per week, parity and the number of children were collected with a designed questionnaire. Diagnosis of obesity and central obesity were confirmed by the WHO standard recommended method by determining of body mass index (BMI) and waist circumference (WC). Logistic regression model was used to estimate the adjusted odds ratio (OR) and its 95% confidence interval. Over half of the study subjects were at educational levels of high school or higher; 79.4% of population was married and 35.3% had a family history of parental obesity. The majority of subjects in particular women had none or low levels of physical activity. The overall prevalence rates of obesity and overweight were 18.8% and 34.8% respectively. The overall prevalence rate of central obesity was 28.3%. The rate of obesity in women was higher than men (P < 0.0001). In both genders, particularly in the women, the rate of obesity was raised by increasing age. There was an inverse relation between the risk of obesity and marriage age, the high level of education (OR = 0.19, P < 0.0001), severe occupational activity (OR = 0.44, P < 0.0001), the level of exercise (in subjects with 3-4 h exercise per week, OR = 0.58, P < 0.001) and leisure time activity. Marriage, history of parental obesity and parity > or =5 were associated with increased risk of obesity (OR = 2.2, P < 0.001 and OR = 2.43, P < 0.0001 and OR = 3.73, P < 0.0001 respectively). The results of this study indicate an increased rate of obesity and overweigh in the north population of Iran. With respect to these findings, low level of activity and education, parity, family history of obesity, marriage at earlier age and ageing are responsible for both obesity and central obesity in the north of Iran. Therefore, a community-based multiple strategies are required to combat with increasing rate of obesity and its subsequent complications such as diabetes, coronary artery disease, hypertension and osteoarthritis.

Current researches on breast cancer epidemiology in Korea

As a cause of death in women, breast cancer ranks second to stomach cancer in Korea. Age-standardized mortality rates for breast cancer steadily increased during the 1980s and 1990s. There are big differences in the incidence rates for breast cancer compared with Western countries. Epidemiological features, trends in morbidity and mortality, various age-specific incidence curves, migrant study results, and analysis of the risk factors, however, suggest that the incidence of breast cancer might be further increasing in Korea. The key epidemiological hormonal risk factors for breast cancer are all explicable in terms of the estrogen augmented by progesterone hypothesis. These include older age, family history of breast cancer, early menarche, late menopause, late full-term pregnancy, and never a breast feeding. Both the establishment of high-risk groups and the estimation of lifetime risk are essential to develop a control strategy against breast cancer. Invasive ductal carcinoma is the most common histologic type of breast cancer in Korea, and the five-year survival rate has been estimated as 80-83%. Recent studies on the identification of susceptibility factors such as genetic polymorphisms of GSTM1/T1/P1, COMT, CYP2E1, CYP19, CYP17, ER-alpha, XRCC1, XRCC3, RAD52, TGF-alpha, TNF-alpha, IL-1B, IL-1RN, CDK7 etc. that predispose individuals to breast cancer by gene-environment or gene-gene interactions may possibly give further insight into both the etiology and the prevention of this malignancy.