Galactose-1-phosphate uridyl transferase activity associated with age at menopause and reproductive history

The Role of Lifestyle and Dietary Factors in the Development of Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition that arises from dysfunction or early depletion of the ovarian follicle pool accompanied by an earlier-than-normal loss of fertility in young women. Oxidative stress has been suggested as an important factor in the decline of fertility in women and POI. In this review, we discuss the mechanisms of oxidative stress implicated in ovarian ageing and dysfunction in relation to POI, in particular mitochondrial dysfunction, apoptosis and inflammation. Genetic defects, autoimmunity and chemotherapy, are some of the reviewed hallmarks of POI that can lead to increased oxidative stress. Additionally, we highlight lifestyle factors, including diet, low energy availability and BMI, that can increase the risk of POI. The final section of this review discusses dietary factors associated with POI, including consumption of oily fish, mitochondria nutrient therapy, melatonin, dairy and vitamins that can be targeted as potential interventions, especially for at-risk women and in combination with personalised nutrition. Understanding the impact of lifestyle and its implications for POI and oxidative stress holds great promise in reducing the burden of this condition.

Dietary lactose and galactose intakes are associated with a later onset of natural menopause among women in a Japanese community

Galactose and its metabolites, primarily derived from lactose, may have toxic effects on the ovary. We aimed to prospectively examine the associations of galactose and lactose intakes with the onset of natural menopause. The data of a population-based cohort study in a Japanese community (the Takayama study) initiated in 1992 were analysed, with follow-up data collected in 2002. Among the participants of the Takayama study, premenopausal women (n 3115) aged 35-56 years at baseline were included in this study. Dietary intake, including lactose and galactose was assessed only at baseline using a FFQ. The menopausal status and age at menopause were determined based on the participants' self-reports, and natural menopause was defined as the absence of menstruation for 12 months or more. Cox proportional hazards models were used to estimate the hazard ratios (HR) and 95 % CI. A total of 1790 women experienced natural menopause within the 10-year follow-up. Lactose and galactose intakes were associated with a later onset of natural menopause after adjusting for potential confounding factors and the HR (95 % CI) for the highest v. lowest quartile were 0·80 (0·69, 0·92) (P-trend = 0·001) in lactose and 0·86 (0·74, 1·00) in galactose (P-trend = 0·036), respectively. High intakes of lactose and galactose were associated with a later onset of natural menopause. Despite the presumed ovotoxicity effects, lactose and galactose intakes at usual levels may not be deleterious to the ovarian aging process among Japanese community-dwelling women.

Do dietary intakes influence the rate of decline in anti-Mullerian hormone among eumenorrheic women? A population-based prospective investigation

BACKGROUND

Dietary intakes are suggested to affect age at menopause but associations between dietary factors and ovarian reserve reduction have not yet been investigated. We aimed to examine dietary intakes in relation to the rate of decline in anti-Mullerian hormone (AMH), an indicator of ovarian reserve, in a generally healthy cohort of women.

METHODS

This prospective investigation was conducted among 227 eumenorrheic women, aged 20-50 years, from the Tehran Lipid and Glucose study, who were followed over a mean of 16 years. AMH was measured twice, at baseline and the 5th follow-up examination cycle, and yearly rate of decline in AMH was calculated. Rapid decline in AMH was defined as the annual percent change AMH > 5.9%/year based on tertile 3 of the variable. Average usual dietary intakes were estimated using the food frequency questionnaires administered at the second, third, and the fourth follow-up examinations. After adjusting for potential covariates, the association between dietary factors and both risk of rapid decline in AMH and also annual percent decline of AMH (as a continuous variable) were examined using logistic regression and the Spearman correlation, respectively.

RESULTS

The baseline age of the participants and the median rate of decline in AMH were 37.2 years and was 5.7% yearly, respectively. The odds of rapid decline in AMH was reduced by 47% for dairy products (95% CIs = 0.36, 0.79; p = 0.002), 38% for milk (95% CIs = 0.41, 0.93; p = 0.020), and 36% for fermented dairy (95% CIs = 0.45, 0.93, p = 0.018) per one standard deviation (SD) increase in their dietary intakes. The odds of rapid decline in AMH was significantly reduced with higher intakes of fat, carbohydrate, protein, and calcium intakes from dairy sources, lactose and galactose. Annual rate of AMH decline was inversely correlated with dairy products, milk, fermented dairy, fruits, dairy carbohydrate, dairy fat, dairy protein, total calcium and dairy calcium, lactose and galactose, and positively correlated with organ meats.

CONCLUSION

Dairy foods consumption may reduce the rate of AMH decline in regularly menstruating women. Life style modification in terms of dietary advice may be considered as a preventive strategy for reduction in the rate of ovarian reserve loss.

Dehydroepiandrosterone supplementation attenuates ovarian ageing in a galactose-induced primary ovarian insufficiency rat model

PURPOSE

Almost every female classic galactosemia patient develops primary ovarian insufficiency (POI). The unique pathophysiology of classic galactosemia, with a severely reduced follicle pool at an early age, requires a new therapeutic approach. This study evaluated the effect of dehydroepiandrosterone (DHEA) on ovarian tissue in a galactose-induced POI rat model.

METHODS

Pregnant rats were fed with either a normal or a 35% galactose-containing diet from day 3 of conception continuing through weaning of the litters. Galactose-exposed female offspring were further divided into 5 groups on PND21. The first group received no application. Treatment groups were fed orally by gavage once daily with sesame oil (group 2), or DHEA at doses of 0.1 mg/kg (group 3), 1 mg/kg (group 4) or 10 mg/kg (group 5) until PND70. Fertility rates of mothers with galactosemia, body weights (BWs), and ovarian weights of the litters from PND21 to PND70 were recorded. Ovarian follicle count, immunohistochemistry for proliferation and apoptosis marker expressions and TUNEL for cell death assessment were performed in offspring ovaries.

RESULTS

Decreased fertility, ovarian/body weights were observed under galactosemic conditions, together with decreased follicle number and increased atresia. Improved postnatal development, primordial follicle recruitment and follicular growth were observed after DHEA treatment. After DHEA treatment, the expression of Ki67 protein was found to be increased; elevated expression of cleaved-caspase-3 under galactosemia was found to be reduced.

CONCLUSIONS

Our data suggests that DHEA treatment may be a potentially useful clinical therapy to improve ovarian ageing in women with POI-induced by galactosemia.

Menopause

Menopause is an inevitable component of ageing and encompasses the loss of ovarian reproductive function, either occurring spontaneously or secondary to other conditions. It is not yet possible to accurately predict the onset of menopause, especially early menopause, to give women improved control of their fertility. The decline in ovarian oestrogen production at menopause can cause physical symptoms that may be debilitating, including hot flushes and night sweats, urogenital atrophy, sexual dysfunction, mood changes, bone loss, and metabolic changes that predispose to cardiovascular disease and diabetes. The individual experience of the menopause transition varies widely. Important influential factors include the age at which menopause occurs, personal health and wellbeing, and each woman's environment and culture. Management options range from lifestyle assessment and intervention through to hormonal and non-hormonal pharmacotherapy, each of which has specific benefits and risks. Decisions about therapy for perimenopausal and postmenopausal women depend on symptomatology, health status, immediate and long-term health risks, personal life expectations, and the availability and cost of therapies. More effective and safe therapies for the management of menopausal symptoms need to be developed, particularly for women who have absolute contraindications to hormone therapy. For an illustrated summary of this Primer, visit: http://go.nature.com/BjvJVX.

Consumption of low-fat dairy products may delay natural menopause

Later menopause is a risk factor for breast and endometrial cancer, yet few studies have investigated dietary predictors of this potentially modifiable event. In particular, dairy contains hormones and growth factors that could potentially affect menopausal timing. We therefore assessed the association between regular consumption of dairy foods and related nutrients and age at natural menopause. We conducted a prospective analysis with up to 20 y of follow-up in 46,059 participants in the Nurses' Health Study who were premenopausal in 1980. We observed 30,816 events of natural menopause over 401,754 person-years. In the total population, the estimated mean age at natural menopause was 51.5 y for women who consumed no low-fat dairy and 51.5, 51.6, 51.7, and 51.8 y for women who consumed 0.1-1.0, 1.1-2.0, 2.1-3.0, and >3 servings of low-fat dairy daily, respectively. Premenopausal women <51 y of age consuming >3 servings of low-fat dairy per day were 14% less likely (HR: 0.86; 95% CI: 0.77, 0.96; P-trend < 0.0001) to report natural menopause in the next month relative to those consuming 0.1-1 servings/d. Similar results were obtained for skim milk (for >6 servings/wk vs. 0-1 servings/mo: HR: 0.93; 95% CI: 0.89, 0.97; P-trend < 0.0001) but not for total high-fat dairy or whole milk. Dairy foods were not associated with age at menopause among women ≥51 y of age. These findings support the growing body of literature on the hormonally active nature of milk and dairy foods.

Ovotoxic effects of galactose involve attenuation of follicle-stimulating hormone bioactivity and up-regulation of granulosa cell p53 expression

Clinical evidence suggests an association between galactosaemia and premature ovarian insufficiency (POI); however, the mechanism still remains unresolved. Experimental galactose toxicity in rats produces an array of ovarian dysfunction including ovarian development with deficient follicular reserve and follicular resistance to gonadotrophins that characterize the basic tenets of human POI. The present investigation explores if galactose toxicity in rats attenuates the bioactivity of gonadotrophins or interferes with their receptor competency, and accelerates the rate of follicular atresia. Pregnant rats were fed isocaloric food-pellets supplemented with or without 35% D-galactose from day-3 of gestation and continuing through weaning of the litters. The 35-day old female litters were autopsied. Serum galactose-binding capacity, galactosyltransferase (GalTase) activity, and bioactivity of FSH and LH together with their receptor competency were assessed. Ovarian follicular atresia was evaluated in situ by TUNEL. The in vitro effects of galactose were studied in isolated whole follicles in respect of generation of reactive oxygen species (ROS) and expression of caspase 3, and in isolated granulosa cells in respect of mitochondrial membrane potential, expression of p53, and apoptosis. The rats prenatally exposed to galactose exhibited significantly decreased serum GalTase activity and greater degree of galactose-incorporation capacity of sera proteins. LH biopotency and LH-FSH receptor competency were comparable between the control and study population, but the latter group showed significantly attenuated FSH bioactivity and increased rate of follicular atresia. In culture, galactose increased follicular generation of ROS and expression of caspase 3. In isolated granulosa cells, galactose disrupted mitochondrial membrane potential, stimulated p53 expression, and induced apoptosis in vitro; however co-treatment with either FSH or estradiol significantly prevented galactose-induced granulosa cell p53 expression. We conclude that the ovotoxic effects of galactose involves attenuation of FSH bioactivity that renders the ovary resistant to gonadotrophins leading to increased granulosa cell expression of p53 and follicular atresia.

Aging of the human ovary and testis

Aging is associated with structural and functional alterations in all organs of the human body. The aging of gonads represents in this respect a special case, because these organs are not functional for the whole lifespan of an individual and their normal function is not indispensable for functions of the rest of the body. Ovarian function lasts for the reproductive life of a woman, i.e., from menarche until menopause. The testicular endocrine function, in contrast, begins already in utero, is interrupted between neonatal life and puberty, and continues thereafter along with spermatogenesis, with only slight decline, until old age. The aging processes of the ovary and testis are therefore very different. We describe in this review the structural and functional alterations in the human ovary and testis upon aging. Special emphasis will be given to clinically significant alterations, which in women concern the causes and consequences of the individual variability of fertility during the latter part of the reproductive age. The clinically important aspect of testicular aging entails the decline of androgen production in aging men.

Association study of the oestrogen signalling pathway genes in relation to age at natural menopause

Genetic factors play a significant role in influencing the variation of age at natural menopause (AANM). Estrogen receptor beta (ESR2), is an important factor in the mechanism of action of estrogen, while the aromatase gene (CYP19) and the 17-alpha-hydroxylase gene (CYP17) are involved in the biosynthesis of estrogen. We tested whether polymorphisms of ESR2, CYP19 and CYP17 genes are associated with AANM in Caucasian females. A total of 52 SNPs (17 for ESR2, 28 for CYP19, and 7 for CYP17) were successfully genotyped for 229 Caucasian women having experienced natural menopause. Comprehensive statistical analyses focusing on the association of these genes with AANM were conducted. The effects of age, height and age at menarche on AANM were adjusted when conducting association analyses. We found that six SNPs (2, 6-7, 9, 13 and 16) within ESR2 were not significantly associated with AANM after Bonferroni correction. However, two blocks of ESR2 were associated with AANM. For CYP19, two SNPs (24 and 27) were nominally associated with AANM. No significant association was observed between CYP17 and AANM. Our results suggest that genetic variation in the ESR2 and CYP19 genes may influence the variation in AANM in Caucasian women.

Primary ovarian insufficiency: a more accurate term for premature ovarian failure

Premature ovarian failure (POF) is a disorder with a complicated clinical presentation and course that is poorly defined by its name. A more scientifically accurate term for the disorder is primary ovarian insufficiency (POI), a term that can be appropriately modified to describe the state of ovarian function. In recent years, the known aetiologies of POI have expanded, although the cause of POI in a majority of clinical cases remains undefined. The most common aetiologies should be ruled out clinically including chromosomal abnormalities, fragile X premutations and autoimmune causes. Management should be directed at symptom resolution and bone protection, but most importantly should include psychosocial support for women facing this devastating diagnosis.

A prospective study of dairy foods intake and anovulatory infertility

BACKGROUND

Dairy foods and lactose may impair fertility by affecting ovulatory function. Yet, few studies have been conducted in humans and their results are inconsistent. We evaluated whether intake of dairy foods was associated with anovulatory infertility and whether this association differed according to fat content.

METHODS

We prospectively followed 18,555 married, premenopausal women without a history of infertility who attempted a pregnancy or became pregnant during an 8-year period. Diet was assessed twice during the study using food-frequency questionnaires.

RESULTS

During follow-up, 438 women reported infertility due to an ovulatory disorder. The multivariate-adjusted relative risks (RR) [95% confidence interval (CI); P, trend] of anovulatory infertility comparing women consuming > or = 2 servings per day to women consuming < or = 1 serving per week was 1.85 (1.24-2.77; 0.002) for low-fat dairy foods. The RR (95% CI; P, trend) comparing women consuming > or = 1 serving per day of high-fat dairy foods to those consuming < or = 1 serving per week was 0.73 (0.52-1.01; 0.01). There was an inverse association between dairy fat intake and anovulatory infertility (P, trend = 0.05). Intakes of lactose, calcium, phosphorus and vitamin D were unrelated to anovulatory infertility.

CONCLUSIONS

High intake of low-fat dairy foods may increase the risk of anovulatory infertility whereas intake of high-fat dairy foods may decrease this risk. Further, lactose (the main carbohydrate in milk and dairy products) may not affect fertility within the usual range of intake levels in humans.

Adolescent Milk Fat and Galactose Consumption and Testicular Germ Cell Cancer

Recent case-control studies suggested that dairy product consumption is an important risk factor for testicular cancer. We examined the association between consumption of dairy products, especially milk, milk fat, and galactose, and testicular cancer in a population-based case-control study including 269 case and 797 controls (response proportions of 76% and 46%, respectively). Dietary history was assessed by food frequency questions for the index persons and through their mothers including diet 1 year before interview and diet at age 17 years. We used conditional logistic regression to calculate odds ratios as estimates of the relative risk (RR), 95% confidence intervals (95% CI), and to control for social status and height. The RR of testicular cancer was 1.37 (95% CI, 1.12-1.68) per additional 20 servings of milk per month (each 200 mL) in adolescence. This elevated overall risk was mainly due to an increased risk for seminoma (RR, 1.66; 95% CI, 1.30-2.12) per additional 20 milk servings per month. The RR for seminoma was 1.30 (95% CI, 1.15-1.48) for each additional 200 g milk fat per month and was 2.01 (95% CI, 1.41-2.86) for each additional 200 g galactose per month during adolescence. Our results suggest that milk fat and/or galactose may explain the association between milk and dairy product consumption and seminomatous testicular cancer.

Polymorphisms of the vitamin D receptor gene predict the onset of surgical menopause in Caucasian females

We tested association of four single nucleotide polymorphisms (SNPs) of the vitamin D receptor gene (VDR) with age at surgical and natural menopause in a sample of Caucasians composed of 153 women with surgical and 260 with natural menopause. A significant association was observed between age at surgical menopause and two SNPs, rs1544410 (BsmI) and rs731236 (TaqI) (p < 0.05). For rs1544410, homozygotes of the minor allele, AA, had about two-fold higher risk of surgical menopause than homozygotes of the major allele, GG (95% confidence ratio (CI) 1.09-3.82). For rs731236, the CC subjects had a greater chance of surgical menopause than the TT subjects (odds ratio = 2.01, 95% CI 1.07-3.78). Since rs1544410 and rs731236 are in strong linkage disequilibrium, the haplotypes based on these two loci were also tested. The haplotype AC was highly significantly associated with age at surgical menopause (p = 0.008). Women with this haplotype had surgical menopause on average 2.8 years earlier than non-carriers. These results reveal the potential effect of the VDR gene on ovaries and uterus, and suggest that its SNPs can be used as predictors of genetic susceptibility for early surgical menopause and respective causal health problems.

Relationship Between Calcium, Lactose, Vitamin D, and Dairy Products and Ovarian Cancer

Few prospective studies of the relationship between intake of dairy foods, calcium, vitamin D, and lactose and ovarian cancer have been conducted, and results have been largely inconsistent. Two recent studies found significant increased risk with frequent dairy consumption and perhaps with high intakes of calcium or lactose. The authors investigated the association between these foods and nutrients and ovarian cancer risk among 31,925 subjects in the Breast Cancer Detection Demonstration Project follow-up cohort. Multivariable (MV) relative risks (RRs) adjusted for age, parity, and other factors were estimated using Cox proportional hazards models. Over an average follow-up of 8.3 yr, 146 incident ovarian cancer cases were confirmed. Higher intakes of total dairy food (comparing four or more servings per day vs. less than one serving per day) were associated with a statistically significant decreased risk of ovarian cancer, although the trend was not significant (MV RR = 0.42; 95% confidence interval (CI) = 0.20-0.89; P for trend = 0.07). Comparing extreme quartiles, we observed a statistically nonsignificant inverse association between high dietary calcium intake and ovarian cancer (RR = 0.67; 95% CI = 0.43, 1.04; P for trend = 0.08). No statistically significant relations were found for consumption of specific dairy foods, lactose, or vitamin D and ovarian cancer risk. The possibility of a decreased risk of ovarian cancer for dietary calcium merits further evaluation.

Pathophysiology of impaired ovarian function in galactosaemia

Classical galactosaemia is an inherited inborn error of the major galactose assimilation pathway, caused by galactose-1-phosphate uridyltransferase (GALT) deficiency. Many GALT mutations have been described, with different clinical consequences. In severe forms, newborns present with a life-threatening, acute toxic syndrome that rapidly regresses under a galactose-restricted diet. However, long-term complications, particularly cognitive and motor abnormalities, as well as hypergonadotrophic hypogonadism in female patients are still unavoidable. The pathogenesis of galactose-induced ovarian toxicity remains unclear but probably involves galactose itself and its metabolites such as galactitol and UDP-galactose. Possible mechanisms of ovarian damage include direct toxicity of galactose and metabolites, deficient galactosylation of glycoproteins and glycolipids, oxidative stress and activation of apoptosis. As there is no aetiological treatment, clinical management of ovarian failure in galactosaemic patients principally relies on hormonal replacement therapy to induce pubertal development and to prevent bone loss and other consequences of estrogen deprivation. Further investigations will be necessary to better understand the metabolic flux of galactose through its biochemical pathways and the mechanisms of these secondary complications. The aim of this article is to present an extensive review on the pathogenesis and clinical management of galactose-induced premature ovarian failure.

Predictive factors for age at menopause in Caucasian females

OBJECTIVE

Early onset of menopause results in the premature exposure to low estrogen levels and is associated with a number of postmenopausal health problems and higher risk of mortality. The aim of this study was to determine genetic and environmental factors associated with age at natural and surgical menopause.

METHODS

Multiple regression analysis using a sample of Caucasians composed of 154 females with surgical and 248 with natural menopause.

RESULTS

Breastfeeding is a significant predictor of earlier natural menopause (P<0.05). Use of oral contraceptives and smoking were not significantly associated with age at menopause. Females who did not have history of pregnancies are at significantly higher risk (P<0.001) of getting early surgical menopause than those who did. We also tested the association of seven single nucleotide polymorphisms (SNPs) of the estrogen receptor alpha (ER-alpha) gene with age at menopause. No association was observed with age at menopause but the PvuII p allele was overrepresented in women with surgical menopause and associated with menopause per se (P=0.029; OR=1.8, 95% CI=1.1-3.0).

CONCLUSIONS

Breastfeeding and alcohol consumption are significantly associated with earlier natural menopause. No significant effects of the ER-alpha genotypes were observed on the age of menopause. Given the important role of the ER-alpha in estrogen signaling, which directly influences the menopausal process, further studies are required to better define the relationship between this gene and age at menopause.

Screening of the galactose-1-phosphate uridyltransferase gene in Indian women with ovarian failure

The present study was aimed at mutational screening of the gene coding for galactose-1-phosphate uridyltransferase in females with premature ovarian failure within an Indian population. A case-control-based study approach was used. It included females with premature ovarian failure (n = 108), primary amenorrhoea (n = 37) and secondary amenorrhoea (n = 9), and a control group of 136 women with a normal ovarian pattern. Gene sequencing analysis for the presence of mutations in the promoter and the coding regions of GALT has shown the absence of any mutation. A hexanucleotide deletion was found in the third intronic region of GALT in both cases and controls. These data support the hypothesis that there is no significant association between GALT mutations and ovarian failure, and hence the present authors conclude that there is no relationship between ovarian failure and GALT polymorphisms in Indian women.

Galactose-1-phosphate uridyl transferase gene mutations in women with premature ovarian failure

We determined the frequency of galactose-1-phosphate uridyl transferase gene mutations: Q188R, K285N, and the Duarte allelle in 86 patients with idiopathic premature ovarian failure (POF) and 95 controls. No association of the mutations with POF was found.

Q188R, K285N, and N314D mutation-associated alleles in the galactose-1-phosphate uridyltransferase gene and female infertility

In a retrospective case-control study, the frequencies of Q188R, K285N, N314D, and IVS5-24G>A mutations were determined with the use of polymerase chain reaction and restriction fragment length polymorphism in the group of infertile women and the controls. No statistically significant differences were observed in the allele frequencies between the infertile women and control groups.

Body mass index but not a polymorphism of the interleukin-1 receptor antagonist (IL-1 RA) gene is associated with age at natural menopause

BACKGROUND

A genetic component of the onset of menopause has been described and several candidate genes have been identified. We hypothesized that carriage of a polymorphism of the interleukin-1 receptor antagonist gene (IL-1 RA) is associated with an early age at menopause.

METHODS

In a prospective cohort study, 90 consecutive postmenopausal Caucasian women were genotyped by PCR for the presence of an 86-base pair tandem repeat polymorphism in intron 2 of IL-1 RA.

RESULTS

We found that 36/90 (40%) women were homozygous for the wild-type allele 1 and 49/90 (54%) women were heterozygous for any of the variant alleles (1/2 [n = 44], 1/3 [n = 3], 2/3 [n = 2]). Two women (2%) were homozygous carriers of the variant allele 2. The wild-type allele 1 was identified on 119 of 180 chromosomes for an allele frequency of 0.66. The polymorphic alleles 2 and 3 were present on 56 and 5 chromosomes, respectively (allele frequencies 0.31 and 0.03, respectively). No correlation between the IL-1 RA genotype and the age at menarche and menopause, the length of the reproductive period, and the number of deliveries and miscarriages was ascertained. As to allele frequencies, homozygous and heterozygous carriers of the variant allele 2 had a median age at menopause of 50 (range 40-48) years, compared to 49.5 (range 39-56) years for women with no allele 2 (p value 0.41). Women with at least one allele 2 had a median age at menarche of 13 (range 10-16) years, compared to 13 (range 10-17) years for women with no allele 2 (p value 0.1). Decreasing body mass index, but not smoking, was correlated with an increasing age at natural menopause (r = -0.23, p = 0.04).

CONCLUSIONS

Our preliminary data suggest that an 86-base pair tandem repeat polymorphism in intron 2 of IL-1 RA does not modulate the onset and cessation of menses in this cohort of Caucasian women.

Applications of polymorphisms and pharmacogenomics in obstetrics and gynecology

The number of reports investigating disease susceptibility based on the carriage of low-penetrance, high-frequency polymorphisms has steadily increased over the last years. Evidence based on meta-analyses of individual case-control studies is accumulating, defining specific individual variations in disease susceptibility. For example, genetic variations of the estradiol metabolism have been described as significant contributors to disease susceptibility with variations depending on ethnic background. In the field of obstetrics and gynecology, the genetic contribution of polymorphic markers to a series of disorders has been characterized. These disorders include recurrent pregnancy loss, pre-eclampsia, endometriosis, breast cancer, and hormone replacement therapy (HRT)-related complications such as thrombosis. Among other genetic markers, thrombophilic genetic variants, such as the Factor V Leiden and prothrombin G20210A polymorphisms, as well as genetic variants of cytochrome P450 (CYP) enzymes, for example, CYP19 and CYP1B1, have been established as genetic risk markers and disease modifiers of recurrent and sporadic pregnancy loss and HRT-independent and -dependent breast cancer, respectively. In addition, meta-analyses of data in the literature established the TGFBR1*6A, GSTP I105V, and TP53 R72P polymorphisms, as well as the GSTM1 gene deletion as low-penetrance genetic risk factors of sporadic breast cancer. With respect to genetic modulation of therapeutic effects, beneficial effects of estrogen replacement therapy and HRT are modulated by the carriage of single nucleotide polymorphisms, for example, osteoprotection and blood lipid changes by the estrogen receptor-alpha (ER-a) PvuII polymorphism. Polymorphisms of the catechol-O-methyltransferase (COMT), ER-alpha, IL-1 receptor antagonist, and Factor V genes have been demonstrated to modulate the timing of natural menopause. Lastly, a strong genetic contribution of polymorphisms to the development and the clinical course of endometriosis has been established with data pointing to polymorphisms of the COMT, GST, NAT-2, and ER-alpha genes as susceptibility markers. In summary, the available evidence points to a number of polymorphisms of a wide variety of genes as strong hereditary determinants of the susceptibility to benign and malignant gynecologic and obstetric conditions.

[Premature ovarian failure in galactosaemia: pathophysiology and clinical management]

Classic galactosaemia is a rare aetiology of premature ovarian failure. It is caused by galactose-1-phosphate uridyltransferase deficiency and leads to a severe disease in the newborn. This acute toxic syndrome will completely regress under a galactose-free diet, but some long-term complications, particularly hypergonadotropic hypogonadism in female patients, are frequently observed. Ovarian toxicity could be due to intracellular accumulation of galactose metabolites or to deficient glycosylation reactions. Moreover, the tremendous follicular decrease in the galactosaemic ovary could also involve programmed cell death (apoptosis). As the exact mechanisms of this ovarian injury are still unknown, there is no prevention of follicular loss, thus clinical management especially includes hormonal replacement therapy in order to prevent bone loss and cardiovascular risks and sometimes to allow patients to become pregnant.

Frequencies of Q188R and N314D mutations and IVS5-24g>A intron variation in the galactose-1-phosphate uridyl transferase (GALT) gene in the Slovenian population

Numerous mutations in the galactose-1-phosphate uridyl transferase (GALT) gene have been found to impair GALT activity to different extent, causing galactosemia. This disorder exhibits considerable allelic heterogeneity in different populations and ethnic groups. The Q188R mutation accounts for 60-70% of classical galactosemia alleles in the Caucasian population. Individuals homoallelic for Q188R have a severe phenotype with complete loss of enzyme activity. Another form of GALT deficiency is Duarte galactosemia with N314D mutation associated alleles (Duarte-2). Although heterozygotes for classical galactosemia are asymptomatic at birth and Duarte galactosemia appears to be quite benign, there are some indications that these disorders can increase the risk of developing certain diseases later in life. The aim of our study was to analyze a healthy Slovenian population for the frequencies of Q188R and N314D mutations, and for the Duarte-2 indicative intronic variation IVS5-24G>A. DNA samples from 174 healthy subjects were analyzed for all three mutations by polymerase chain reaction and digestion with restriction enzymes. Allele frequencies for Q188R and N314D mutations and IVS5-24G>A intron variation were found to be 0.29%, 8.0% and 5.7%, respectively. These results correlate well with those reported for most other healthy Caucasian populations.

Ovarian autoimmune disease and ovarian autoantibodies

Detection of specific autoantibodies remains the most practical clinical and research marker of autoimmune disease. The lack of consensus on ovary specific antibodies as a marker for ovarian autoimmunity has clinical and research consequences. The objective of this review is to summarize the evidence for ovarian autoimmunity and the detection of ovary specific autoantibodies in humans. Evidence favors the presence of an autoimmune disease of the ovary. Ovarian autoantibodies are associated primarily with premature ovarian failure (POF) and unexplained infertility. Variations in detection of ovarian autoantibodies are likely to be due to study design elements such as antibody test format, antigen preparation, and criteria for study and comparison groups. In addition, multiple targets appear to be involved in ovarian autoimmunity including ovarian cellular elements and oocyte related antigens. Many studies only assess one target antigen, leaving individuals with ovarian autoimmunity unidentified. The next most significant advance in characterizing ovarian autoimmunity will be definitive identification of the specific antigens and development of standardized tests based on use of specific antigens.

The genetic basis of endometriosis

Family studies have long suggested a role for genetic factors in the aetiology of endometriosis. The influence of genes on disease development has mainly been researched independently of environmental factors, yet their interaction must play an important role. Greater exposure to retrograde menstruation and oestrogen is likely to increase the risk of endometriosis; toxic compounds such as dioxin may increase the risk, although the only direct evidence has come from primate studies. Previous association studies implicated GALT (a gene involved in galactose metabolism), and GSTM1 and NAT2 (genes encoding for the detoxification enzymes) as possible disease susceptibility genes. Recent findings have added to the evidence for the involvement of GSTM1 and NAT2, but have cast doubt on the role of GALT. However, the design of many genetic and epidemiological studies has been inadequate with respect to sample size, consistency in phenotype definition, and the choice of control populations. These features are likely to influence results, and could partly explain the lack of consistency in the findings. Future studies should use a consistent disease definition and be of appropriate epidemiological design.

Measurement of lactose consumption reliability and comparison of two methods

The objective of this study was to assess the reliability of lactose consumption measured with a food-frequency questionnaire and to compare food-frequency data to prospectively recorded data. A self-administered food-frequency questionnaire (FF1) was completed by 295 women ages 38 to 49. Two months later, 75 received the same food-frequency questionnaire (FF2), and 75 received a 1-week diet diary listing 23 commonly eaten lactose-containing foods. Estimated mean intake of lactose was 16.1 g/d with FF1. Intake was slightly (but not significantly) higher at follow-up: Mean difference (95% confidence interval) was 1.4 (-0.8, 3.7) g/d for FF2 versus FF1, and 0.5 g (1.3, 2.3) g/d for the diet diary versus FF1. A moderate level of correlation was found: r = 0.57 between FF1 and FF2, and r = 0.65 between FF1 and the diet diary. Smaller subsets of items (n = 15 and n = 7) could be used to estimate lactose, with 89% and 82% agreement within tertiles, respectively. Since relatively few foods contain substantial amounts of lactose, a limited food-frequency or structured diary may be useful in research studies on the association between lactose consumption and ovarian cancer or other diseases.

Family history as a predictor of early menopause

OBJECTIVE

To determine the relative importance of family history as a predictor of early menopause.

DESIGN

Case-control study. From a population-based survey of 10,606 women between 45 and 54 years of age, we selected 344 cases with early menopause (average age 42.2 years) and 344 age-matched controls who were still menstruating or who had a menopause after age 46 years. Subjects were interviewed about their medical and family history and blood was drawn for identification of women who were carriers for the classic or Duarte variant of galactosemia, a potential hereditary factor for early menopause. Logistic regression analysis was used to estimate the risk of an early menopause in women with and without a family history of early menopause.

RESULTS

Overall 129 (37.5%) of the early menopause cases reported a family history of menopause before age 46 years in a mother, sister, aunt, or grandmother compared to 31 (9.0%) of controls yielding an odds ratio (OR) of 6.1 (95% confidence interval [CI] of 3.9 to 9.4) after adjustment for smoking history, education, parity, and body mass index. Risk for early menopause associated with family history of same was greatest: for family history in a sister, OR = 9.1 (95% CI 3.1 to 26.5); multiple relatives, OR = 12.4 (95% CI 4.4 to 34.2); and cases menopausal before age 40 years, OR = 8.4 (95% CI 2.5 to 31.2). Cases with a family history of early menopause were not more likely to have errors of galactose metabolism compared with cases without a family history or to all controls, nor did they possess Turner's stigmata such as short stature, but they were less likely to have brothers in their sibships.

CONCLUSIONS

Although preferential recall of family history by women with early menopause could contribute to the association between family history and early menopause observed in this study, a genetic factor is also plausible including partial deletions of the X chromosome compatible with the deficiency of male siblings in cases with family history of early menopause.

Gonadal function in galactosemics and in galactose-intoxicated animals

Gonadal dysfunction, specifically hypergonadotropic hypogonadism, in female galactosemics is an almost universal finding. Minimal transferase activity may modulate ovarian function and the time of menopause. In contrast, male galactosemics have a relatively low risk of gonadal dysfunction. Animal models have variously suggested prenatal and postnatal insults which may play a role in the gonadal pathology. Several candidate toxic states may be involved. Current dietary restrictions are inadequate to prevent ovarian failure. Until such time as the pathophysiology is better understood, therapy will remain palliative and supportive. Exogenous estrogen and progesterone have roles in assisting pubertal changes and in prevention of the sequelae of a post-menopausal state.

Dietary lactose intake, lactose intolerance, and the risk of epithelial ovarian cancer in southern Ontario (Canada)

A case-control study of dietary factors and cancer of the ovary was conducted during 1989-92 in metropolitan Toronto and surrounding areas of southern Ontario, Canada. Four hundred and fifty women aged 35-79 years, with newly diagnosed, histologically verified, primary epithelial ovarian-cancer were interviewed concerning reproduction and diet. Over the same period, 564 randomly-selected population controls, frequency-matched to the cases within three 15-year age groups, also were interviewed. From information obtained by quantitative diet history, average daily macro- and micronutrient intake values were calculated through use of the United States Department of Agriculture Food Composition Databank, which was extended and modified for Canadian items and recipes. Analysis was performed with continuous, unconditional logistic-regression methods, adjusting for age at interview, number of full-term pregnancies, total duration of oral contraceptive use, and total daily caloric intake. Neither reported history of lactose intolerance, nor average daily consumption of lactose or free galactose, were found to be associated with risk of ovarian cancer. Lactose intake or intolerance did not appear to modify the protective effects of parity and oral contraceptive use. Nevertheless, other studies suggest that ovarian galactose metabolism still may have a relationship with risk of ovarian cancer, though more evidence is needed.

Characteristics of women with a family history of ovarian cancer. I. Galactose consumption and metabolism

BACKGROUND

Galactose metabolism may be a risk factor for ovarian cancer based upon evidence that galactose causes ovarian failure and that ovarian cancer arises from premature ovarian failure. This study examines galactose-1-phosphate uridyl transferase (GALT) activity in women with a family history of ovarian cancer (FOC) to determine if low GALT activity occurs in women who are at risk for but in whom ovarian cancer has not yet developed.

METHODS

The authors studied 106 premenopausal women (FOC patients) with one primary or two second-degree relatives with ovarian cancer compared with 116 age matched control subjects without a family history of ovarian cancer (FOC controls). All women completed questionnaires and had blood drawn to measure GALT activity and genotype.

RESULTS

Mean erythrocyte GALT activity, in micromoles of hexose conversion per hour per gram of hemoglobin was 21.5 in FOC patients, significantly lower than the mean of 23.1 observed in FOC control subjects, (P = 0.001). FOC patients more frequently displayed the Duarte variant of galactosemia as detected by electrophoresis. In a subset of 87 patients and 113 control subjects for whom DNA was available, the allelelic frequency of the Duarte variant based upon molecular genetic detection of the N314D mutation that is associated with the Duarte variant was 15.5% among FOC cases compared with 7.5% among control subjects (P < 0.02). Galactose consumption did not differ between FOC patients and control subjects.

CONCLUSION

Galactose metabolism differs between women with and without a family history of ovarian cancer, suggesting that it may be a genetic risk factor for ovarian cancer, possibly mediated through oocyte toxicity from galactose.

Results of a survey of carrier women for the galactosemia gene

A survey of 108 heterozygote women for the classic galactosemia gene, GALT, did not reveal that the carrier state was associated with premature ovarian failure or ovarian cancer. This survey did not support previous epidemiologic studies suggesting an increased risk for ovarian dysfunction in women with deficiency of the GALT enzyme.

Aldose reductase inhibition prevents galactose-induced ovarian dysfunction in the Sprague-Dawley rat

OBJECTIVE

Our objective was to determine whether impaired ovarian function induced by short-term creation of a galactosemic state in the rat might be prevented by the coadministration of an aldose reductase inhibitor.

STUDY DESIGN

Prepubertal Sprague-Dawley rats were fed four different diets including (1) control, (2) 40% galactose, (3) 40% galactose and an aldose reductase inhibitor, and (4) an aldose reductase inhibitor with the control diet. Percentage germinal vesicle breakdown, postovulatory oocyte quantities, hormonal parameters, ovarian histologic evaluation, and ovarian galactitol concentrations were determined.

RESULTS

The galactose-fed animals (group 2) had decreased germinal vesicle breakdown (47%) versus control (69%, p < 0.05). Galactose-exposed animals had significantly decreased quantities of postovulatory eggs (6.4 per animal) after menotropin ovarian stimulation in comparison with controls (14.1, p < 0.01). In rats exposed to high dietary levels of galactose (group 2) ovarian galactitol concentrations were significantly higher (protein 42.12 mumol/gm versus 0.0 for controls, p < 0.005). When galactose-fed animals received the aldose reductase inhibitor, ovarian accumulation of galactitol was significantly reduced and the observed detrimental effects on the oocyte were prevented.

CONCLUSION

Galactitol accumulation or metabolic flux through aldose reductase in galactosemic rodents may be involved in the demonstrated ovarian dysfunction.

Galactose metabolism and reproductive history in women with type 1 neurofibromatosis

To explore a possible relationship between neurofibromatosis and abnormalities of galactose metabolism, we examined the activity and characteristics of red cell galactokinase and galactose-1-phosphate uridyl transferase in 14 white women with type 1 neurofibromatosis and in 28 control women. Women with NF1 had a significantly lower activity of galactokinase and were more likely to have the 3-band pattern on electrophoresis of their transferase enzyme known as the Duarte variant. In addition, we found that women with NF1 were more likely to have reproductive histories suggestive of hypogonadism, including irregular menses, infertility, ovarian cysts, and early menopause. We conclude that abnormalities of galactose metabolism may be linked to abnormalities of both germ cell and neural crest development.

Epidemiologic aspects of early menopause and ovarian cancer

The concept of ovarian cancer as a consequence of hypergonadotropic hypogonadism implies that risk factors for early menopause may also be risk factors for ovarian cancer. Gonadal radiation and the oophoritis of mumps are possible examples of environmental risk factors for early menopause and ovarian cancer. Family history is a strong determinant for both early menopause and ovarian cancer, implicating genetic factors in these disorders. Case-control data suggest that galactose consumption through the ingestion of high-lactose dairy foods may be a dietary risk factor and that galactose metabolism, as measured by galactose-1-phosphate uridyl transferase, may be a genetic risk factor for early menopause and ovarian cancer. Supporting evidence includes animal studies, case reports, and ecologic studies. Avoidance of a high-galactose diet may decrease the risk for early menopause and ovarian cancer. Alternatively, hormonal agents that lower gonadotropins may block ovarian cancer as a consequence of oocyte toxins, even if they do not prevent the early menopause.

Galactose consumption and metabolism in relation to the risk of ovarian cancer

In a case-control study, consumption of dairy foods by 235 white women with epithelial ovarian cancer and by 239 control women, and activity of red blood cell galactose-1-phosphate uridyl transferase (transferase) in a subset of 145 cases and 127 controls were determined. Yogurt was consumed at least monthly by 49% of cases and 36% of controls. The mean transferase activity of cases was significantly lower than that of controls. When a ratio of lactose consumption to transferase (L/T) was calculated, cases had a mean L/T of 1.17 compared with 0.98 for controls; there was a highly significant trend for increasing ovarian cancer risk with increasing L/T ratio. Lactose consumption may be a dietary risk factor and transferase a genetic risk factor for ovarian cancer.