Association of serum cortisol and cortisone levels and risk of recurrence after endocrine treatment in breast cancer.

Metabolic reprogramming in breast cancer involves changes in steroid hormone synthesis and metabolism. Alterations in estrogen levels in both breast tissue and blood may influence carcinogenesis, breast cancer growth, and response to therapy. Our aim was to examine whether serum steroid hormone concentrations could predict the risk of recurrence and treatment-related fatigue in patients with breast cancer. This study included 66 postmenopausal patients with estrogen receptor-positive breast cancer who underwent surgery, radiotherapy, and adjuvant endocrine treatment. Serum samples were collected at six different time points [before the start of radiotherapy (as baseline), immediately after radiotherapy, and then 3, 6, 12 months, and 7-12 years after radiotherapy]. Serum concentrations of eight steroid hormones (cortisol, cortisone, 17α-hydroxyprogesterone, 17ß-estradiol, estrone, androstenedione, testosterone, and progesterone) were measured using a liquid chromatography-tandem mass spectrometry-based method. Breast cancer recurrence was defined as clinically proven relapse/metastatic breast cancer or breast cancer-related death. Fatigue was assessed with the QLQ-C30 questionnaire. Serum steroid hormone concentrations measured before and immediately after radiotherapy differed between relapse and relapse-free patients [(accuracy 68.1%, p = 0.02, and 63.2%, p = 0.03, respectively, partial least squares discriminant analysis (PLS-DA)]. Baseline cortisol levels were lower in patients who relapsed than in those who did not (p < 0.05). The Kaplan-Meier analysis showed that patients with high baseline concentrations of cortisol (≥ median) had a significantly lower risk of breast cancer recurrence than patients with low cortisol levels (

Adipose tissue estrogen production and metabolism in premenopausal women.

OBJECTIVE: Although the ovaries produce the majority of estrogens in women before menopause, estrogen is also synthesized in peripheral tissues such as adipose tissue (AT). The typical female AT distribution, concentrated in subcutaneous and femoro-gluteal regions, is estrogen-mediated, but the significance of estrogen synthesis in AT of premenopausal women is poorly understood. DESIGN AND METHODS: Serum and subcutaneous and visceral AT homogenates from 28 premenopausal women undergoing non-malignant surgery were analyzed for estrone, estradiol, and serum estrone sulfate (E1S) concentrations with liquid chromatography-tandem mass spectrometry. Isotopic precursors were used to measure enzyme activities of estrone-producing steroid sulfatase and estradiol-producing 17ß-hydroxysteroid dehydrogenases (17ß-HSD). Messenger RNA (mRNA) expression levels of genes for estrogen-metabolizing enzymes were analyzed using real-time reverse transcription quantitative polymerase chain reaction. RESULTS: While estradiol was the predominant circulating active estrogen, estrone dominated in AT, with a higher concentration in visceral than subcutaneous AT (median, 2657 vs 1459 pmol/kg; P = 0.002). Both AT depots converted circulating E1S to estrone, and estrone to estradiol. Median levels of estrone were five to ten times higher in subcutaneous and visceral AT than in serum (P < 0.001) and the estradiol level in visceral AT was 1.3 times higher than in serum (P < 0.005). The local estrone concentration in visceral AT correlated positively with mRNA expression of estrone-producing enzyme aromatase (r = 0.65, P = 0.003). Waist circumference correlated positively with increased estradiol production in subcutaneous AT (r = 0.60, P = 0.039). CONCLUSIONS: Premenopausal AT demonstrated high estrogenic enzyme activity and considerable local estrogen concentrations. This may be a factor promoting female-typical AT distribution in premenopausal women.

Estrogen biosynthesis in breast adipose tissue during menstrual cycle in women with and without breast cancer.

Circulating estrogens fluctuate during the menstrual cycle but it is not known whether this fluctuation is related to local hormone levels in adipose tissue. We analyzed estrogen concentrations and gene expression of estrogen-regulating enzymes in breast subcutaneous adipose tissue in premenopausal women with (n = 11) and without (n = 17) estrogen receptor-positive breast cancer. Estrone (E1) was the predominant estrogen in premenopausal breast adipose tissue, and E1 and mRNA expression of CYP19A1 in adipose tissue correlated positively with BMI. Adipose tissue estradiol (E2) concentrations fluctuated during the menstrual cycle, similarly to the serum concentrations. In women with breast cancer median adipose tissue E1 (1519 vs. 3244, p < .05) and E2 (404 vs. 889 pmol/kg, p < .05) levels were lower in the follicular than in the luteal phase whereas in control women no significant differences were observed. In the follicular phase, mRNA expressions of HSD17B1 (median 0.06; interquartile range 0.05-0.07 vs. 0.17; 0.03-0.2, p = .010) and CYP19A1 (0.08; 0.07-0.14 vs. 0.22; 0.09-0.54, p = .025) were lower in women with breast cancer than in controls. In conclusion, the changes in adipose tissue E1 and E2 concentrations and the estrogen-regulating CYP19A1 and HSD17B1 during the menstrual cycle may be related to dysfunctional local estrogen metabolism in women with breast cancer.

Plasma enterolactone and risk of prostate cancer in middle-aged Swedish men.

PURPOSE: Enterolactone (ENL) is formed in the human gut after consumption of lignans, has estrogenic properties, and has been associated with risk of prostate cancer. We examined the association between plasma ENL levels and prostate cancer in a nested case-control study within the population-based Malmö Diet and Cancer cohort. We also examined the association between plasma ENL and dietary and lifestyle factors. METHODS: The study population consisted of 1010 cases occurring during a mean follow-up of 14.6 years, and 1817 controls matched on age and study entry date. We used national registers (95%) and hospital records (5%) to ascertain cases. Diet was estimated by a modified diet history method. Plasma ENL concentrations were determined by a time-resolved fluoroimmunoassay. Odds ratios were calculated by unconditional logistic regression. RESULTS: There were no significant associations between plasma ENL and incidence of all prostate cancer (odds ratio 0.99 [95% confidence interval 0.77-1.280] for the highest ENL quintile versus lowest, p for trend 0.66). However, in certain subgroups of men, including men with abdominal obesity (p for interaction = 0.012), we observed associations between high ENL levels and lower odds of high-risk prostate cancer. Plasma ENL was positively associated with consumption of high-fibre bread, fruit, tea, and coffee; with age, and with height, while it was negatively associated with smoking and waist circumference; however, although significant, all associations were rather weak (r ≤ |0.14|). CONCLUSION: ENL concentration was not consistently associated with lower prostate cancer risk, although it was weakly associated with a healthy lifestyle.

Estrogen Metabolism in Abdominal Subcutaneous and Visceral Adipose Tissue in Postmenopausal Women.

Context: In postmenopausal women, adipose tissue (AT) levels of estrogens exceed circulating concentrations. Although increased visceral AT after menopause is related to metabolic diseases, little is known about differences in estrogen metabolism between different AT depots. Objective: We compared concentrations of and metabolic pathways producing estrone and estradiol in abdominal subcutaneous and visceral AT in postmenopausal women. Design, Setting, Patients, and Interventions: AT and serum samples were obtained from 37 postmenopausal women undergoing surgery for nonmalignant gynecological reasons. Serum and AT estrone, estradiol, and serum estrone sulfate (E1S) concentrations were quantitated using liquid chromatography-tandem mass spectrometry. Activity of steroid sulfatase and reductive 17ß-hydroxysteroid dehydrogenase enzymes was measured using radiolabeled precursors. Messenger RNA (mRNA) expression of estrogen-converting enzymes was analyzed by real-time reverse transcription quantitative polymerase chain reaction. Results: Estrone concentration was higher in visceral than subcutaneous AT (median, 928 vs 706 pmol/kg; P = 0.002) and correlated positively with body mass index (r = 0.46; P = 0.011). Both AT depots hydrolyzed E1S to estrone, and visceral AT estrone and estradiol concentrations correlated positively with serum E1S. Compared with visceral AT, subcutaneous AT produced more estradiol from estrone (median rate of estradiol production, 1.02 vs 0.57 nmol/kg AT/h; P = 0.004). In visceral AT, the conversion of estrone to estradiol increased with waist circumference (r = 0.65; P = 0.022), and estradiol concentration correlated positively with mRNA expression of HSD17B7 (r = 0.76; P = 0.005). Conclusions: Both estrone and estradiol production in visceral AT increased with adiposity, but estradiol was produced more effectively in subcutaneous fat. Both AT depots produced estrone from E1S. Increasing visceral adiposity could increase overall estrogen exposure in postmenopausal women.

Metabolism of sex steroids is influenced by acquired adiposity-A study of young adult male monozygotic twin pairs.

Obesity and ageing are associated with lower serum testosterone levels in men. How fat distribution or adipose tissue metabolism, independent of genetic factors and age, are related to sex steroid metabolism is less clear. We studied the associations between adiposity and serum sex hormone concentrations, and mRNA expression of genes regulating sex hormone metabolism in adipose tissue in young adult male monozygotic (MZ) twin pairs. The subjects [n=18 pairs; mean age, 32 years; individual body mass indexes (BMIs) 22-36kg/m2] included 9 male MZ twin pairs discordant for BMI [intra-pair difference (Δ) in BMI ≥3kg/m2]. Sex steroid concentrations were determined by liquid chromatography-tandem mass spectrometry, body composition by dual-energy X-ray absorptiometry and magnetic resonance imaging, and mRNA expressions from subcutaneous adipose tissue by Affymetrix. In BMI-discordant pairs (mean ΔBMI=5.9kg/m2), serum dihydrotestosterone (DHT) was lower [mean 1.9 (SD 0.7) vs. 2.4 (1.0) nmol/l, P=0.040] and mRNA expressions of DHT-inactivating AKR1C2 (P=0.021) and cortisol-producing HSD11B1 (P=0.008) higher in the heavier compared to the leaner co-twins. Serum free 17ß-estradiol (E2) was higher [2.3 (0.5) vs. 1.9 (0.5) pmol/l, P=0.028], and in all twin pairs, serum E2 and estrone concentrations were higher in the heavier than in the leaner co-twins [107 (28) vs. 90 (22) pmol/l, P=0.006; and 123 (43) vs. 105 (27) pmol/l, P=0.025]. Within all twin pairs, i.e. independent of genetic effects and age, 1) the amount of subcutaneous fat inversely correlated with serum total and free testosterone, DHT, and sex hormone-binding globulin (SHBG) concentrations (P<0.01 for all), 2) intra-abdominal fat with total testosterone and SHBG (P<0.05), and 3) liver fat with SHBG (P=0.006). Also, 4) general and intra-abdominal adiposity correlated positively with mRNA expressions of AKR1C2, HSD11B1, and aromatase in adipose tissue (P<0.05). In conclusion, acquired adiposity was associated with decreased serum DHT and increased estrogen concentrations, independent of genetic factors and age. The reduction of DHT could be linked to its increased degradation (by AKR1C2 and HSD11B1) and increased estrogen levels to increased adiposity-related expression of aromatase in adipose tissue.

Quantitative determination of estrone by liquid chromatography-tandem mass spectrometry in subcutaneous adipose tissue from the breast in postmenopausal women.

Estrone is the most abundant estrogen after the menopause. We developed a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for determination of estrone in adipose tissue. Subcutaneous adipose tissue from the breast was collected during elective surgery in postmenopausal women undergoing mastectomy for treatment of breast cancer (n=13) or reduction mammoplasty (controls, n=11). Homogenized adipose tissue was extracted with organic solvents and the estrone fraction was purified by LH-20 column chromatography from the excess of lipids. The concentration of estrone was analyzed by LC-MS/MS. The method was accurate with an intra-assay variation of 8% and an interassay variation of 10%. The median concentration of estrone in subcutaneous adipose tissue from the breast did not differ between breast cancer and control women, 920 pmol/kg and 890 pmol/kg, respectively. In breast cancer patients but not in the controls, breast adipose tissue estrone levels correlated positively with the serum estrone concentration. In conclusion, the new method provides a reliable means to measure estrone concentrations in adipose tissue in postmenopausal women.

Steroid sulfatase activity in subcutaneous and visceral adipose tissue: a comparison between pre- and postmenopausal women.

OBJECTIVE: Adipose tissue is an important extragonadal site for steroid hormone biosynthesis. After menopause, estrogens are synthesized exclusively in peripheral tissues from circulating steroid precursors, of which the most abundant is dehydroepiandrosterone sulfate (DHEAS). Our aim was to study activity of steroid sulfatase, an enzyme hydrolyzing DHEAS, and expression of steroid-converting enzyme genes in subcutaneous and visceral adipose tissue derived from pre- and postmenopausal women. DESIGN: Serum and paired abdominal subcutaneous and visceral adipose tissue samples were obtained from 18 premenopausal and seven postmenopausal women undergoing elective surgery for non-malignant reasons in Helsinki University Central Hospital. METHODS: To assess steroid sulfatase activity, radiolabeled DHEAS was incubated in the presence of adipose tissue homogenate and the liberated dehydroepiandrosterone (DHEA) was measured. Gene mRNA expressions were analyzed by quantitative RT-PCR. Serum DHEAS, DHEA, and estrogen concentrations were determined by liquid chromatography-tandem mass spectrometry. RESULTS: Steroid sulfatase activity was higher in postmenopausal compared to premenopausal women in subcutaneous (median 379 vs 257 pmol/kg tissue per hour; P=0.006) and visceral (545 vs 360 pmol/kg per hour; P=0.004) adipose tissue. Visceral fat showed higher sulfatase activity than subcutaneous fat in premenopausal (P=0.035) and all (P=0.010) women. The mRNA expression levels of two estradiol-producing enzymes, aromatase and 17ß-hydroxysteroid dehydrogenase type 12, were higher in postmenopausal than in premenopausal subcutaneous adipose tissue. CONCLUSIONS: Steroid sulfatase activity in adipose tissue was higher in postmenopausal than in premenopausal women suggesting that DHEAS, derived from the circulation, could be more efficiently utilized in postmenopausal adipose tissue for the formation of biologically active sex hormones.

Novel structural features increase the antioxidant effect of estrogen analogues on low density lipoprotein.

Many known estrogens, both natural and synthetic, may act as antioxidants. We designed and synthesized 22 novel estrogen analogues with different ring junctions or substitutions, such as fluorine. We studied the antioxidant capacity in vitro of 35 synthetic estrogen analogues in aqueous lipoprotein solution by monitoring the formation of conjugated dienes. In addition to a free C-3 hydroxyl group, the two most active antioxidants had either a methyl group at C-4 and a six-carbon D-ring, or a fluorine atom at C-2 and an unsaturated B-ring. Extension of the D-ring increased the antioxidant capacity of 6-oxa estrogens. Compounds with a fluorine atom at C-2 were similar or more potent antioxidants compared with the principal endogenous estrogen, 17ß-estradiol. In compounds with a substituted C-3 hydroxyl group, the antioxidant capacity could be significantly increased by additional double bonds in the C- or D-rings. In conclusion, we show that the antioxidant capacity of estrogen analogues could be increased by structural changes.

Breast adipose tissue estrogen metabolism in postmenopausal women with or without breast cancer.

CONTEXT: It has been shown that breast tumor actively produces and metabolizes steroid hormones. However, little is known about the possible mechanisms through which the nonmalignant adipose tissue contributes to steroid hormone metabolism. OBJECTIVE: We compared the metabolic pathways producing active estradiol in breast sc adipose tissue of postmenopausal women with or without breast cancer. DESIGN AND SETTING: Serum and adipose tissue samples were obtained during elective surgery. PATIENTS: We studied postmenopausal women undergoing mastectomy due to an estrogen receptor-positive breast tumor (n = 14) and women undergoing breast reduction mammoplasty (n = 14). INTERVENTIONS: Estrone, estradiol, and estradiol fatty acyl ester concentrations were determined by liquid chromatography-tandem mass spectrometry. mRNA expression levels of estrogen-converting enzymes were analyzed by quantitative RT-PCR. RESULTS: Estradiol concentration in breast sc adipose tissue was lower in women with cancer than in controls (median 33 vs 62 pmol/kg; P = .002), whereas the serum concentrations did not differ. Also, the mRNA expression for 17ß-hydroxysteroid dehydrogenase type 12 was lower in the adipose tissue of women with cancer compared with controls (0.19 ± 0.10 vs 0.37 ± 0.21, P = .018). CONCLUSIONS: Estrogen metabolism is differentially regulated in the adipose tissue of women with or without cancer. In the sc adipose tissue proximal to breast tumor 17ß-hydroxysteroid dehydrogenase type 12 expression is lower than in controls, which could indicate that the conversion of estrone to estradiol is decreased. Further studies are needed to establish the clinical significance of our findings in the development and growth of breast cancer in postmenopausal women.

The orientation and dynamics of estradiol and estradiol oleate in lipid membranes and HDL disc models.

Estradiol (E2) and E2 oleate associate with high-density lipoproteins (HDLs). Their orientation in HDLs is unknown. We studied the orientation of E2 and E2 oleate in membranes and reconstituted HDLs, finding that E2 and E2 oleate are membrane-associated and highly mobile. Our combination of NMR measurements, molecular dynamics simulation, and analytic theory identifies three major conformations where the long axis of E2 assumes a parallel, perpendicular, or antiparallel orientation relative to the membrane's z-direction. The perpendicular orientation is preferred, and furthermore, in this orientation, E2 strongly favors a particular roll angle, facing the membrane with carbons 6, 7, 15, and 16, whereas carbons 1, 2, 11, and 12 point toward the aqueous phase. In contrast, the long axis of E2 oleate is almost exclusively oriented at an angle of ∼60° to the z-direction. In such an orientation, the oleoyl chain is firmly inserted into the membrane. Thus, both E2 and E2 oleate have a preference for interface localization in the membrane. These orientations were also found in HDL discs, suggesting that only lipid-E2 interactions determine the localization of the molecule. The structural mapping of E2 and E2 oleate may provide a design platform for specific E2-HDL-targeted pharmacological therapies.

Inhibition of hepatic microsomal triglyceride transfer protein - a novel therapeutic option for treatment of homozygous familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the low-density lipoprotein (LDL)-receptor gene (LDLR). Patients with homozygous FH (hoFH) have inherited a mutated LDLR gene from both parents, and therefore all their LDL-receptors are incapable of functioning normally. In hoFH, serum LDL levels often exceed 13 mmol/L and tendon and cutaneous xanthomata appear early (under 10 years of age). If untreated, this extremely severe form of hypercholesterolemia may cause death in childhood or in early adulthood. Based on recent data, it can be estimated that the prevalence of hoFH is about 1:500,000 or even 1:400,000. Until now, the treatment of hoFH has been based on high-dose statin treatment combined with LDL apheresis. Since the LDL cholesterol-lowering effect of statins is weak in this disease, and apheresis is a cumbersome treatment and not available at all centers, alternative novel pharmaceutical therapies are needed. Lomitapide is a newly introduced drug, capable of effectively decreasing serum LDL cholesterol concentration in hoFH. It inhibits the microsomal triglyceride transfer protein (MTTP). By inhibiting in hepatocytes the transfer of triglycerides into very low density lipoprotein particles, the drug blocks their assembly and secretion into the circulating blood. Since the very low density lipoprotein particles are precursors of LDL particles in the circulation, the reduced secretion of the former results in lower plasma concentration of the latter. The greatest concern in lomitapide treatment has been the increase in liver fat, which can be, however, counteracted by strictly adhering to a low-fat diet. Lomitapide is a welcome addition to the meager selection of drugs currently available for the treatment of refractory hypercholesterolemia in hoFH patients.

Plasma alkylresorcinol metabolites as biomarkers for whole-grain intake and their association with prostate cancer: a Swedish nested case-control study.

BACKGROUND: Observational studies have mostly found no association between self-reported whole-grain intake and prostate cancer. Plasma alkylresorcinol metabolites have been suggested as biomarkers for whole-grain intake in free-living populations. METHODS: We investigated the major dietary and lifestyle determinants of plasma alkylresorcinol metabolites in a nested case-control study (1,016 cases and 1,817 controls) in the Malmö Diet and Cancer Study. Multivariate adjusted ORs and 95% confidence intervals (95% CI) were estimated to assess the association between plasma alkylresorcinol metabolites and prostate cancer using logistic regression. RESULTS: Whole-grain intake, waist circumference, educational level, and smoking status were the main determinants of alkylresorcinol metabolites. We observed significant correlations between alkylresorcinol metabolites and whole-grain (r = 0.31) and fiber (r = 0.27) intake. Metabolite concentration was positively associated with prostate cancer risk (Poverall effect = 0.0004) but the association was not linear (P = 0.04). The lowest risk was seen among men with moderate plasma concentrations. The OR for high compared with moderate plasma alkylresorcinol metabolites was 1.41 (95% CI, 1.10-1.80) for prostate cancer. CONCLUSIONS: Results suggest that plasma alkylresorcinol metabolites are mainly determined by whole-grain intake in this nested case-control study of Swedish men. The increased risk of prostate cancer seen among men with high plasma alkylresorcinol metabolites requires further study, but residual confounding, detection bias, or competing risks of nonprostate cancer-related deaths are plausible explanations that could not be ruled out. IMPACT: We found no evidence of a protective effect of whole grains on incident prostate cancer. Further validation of alkylresorcinol metabolites as a biomarker for whole-grain intake is needed.

17ß-Estradiol and estradiol fatty acyl esters and estrogen-converting enzyme expression in adipose tissue in obese men and women.

CONTEXT: Obesity is associated with increased circulating 17ß-estradiol (E2), but less is known about E2 concentrations in adipose tissue. In addition to E2, adipose tissue synthesizes E2 fatty acyl esters (E2-FAE). OBJECTIVE: The aim was to compare estrogen concentrations and expression of estrogen-converting enzymes in adipose tissue between severely obese men and women. DESIGN AND SETTING: Tissue samples were obtained during elective surgery in University Central Hospital in the years 2008 through 2011. PATIENTS: We studied 14 men and 22 premenopausal women undergoing bariatric surgery and 10 control women operated for nonmalignant reasons. INTERVENTIONS: Paired samples were taken from abdominal sc and visceral adipose tissue and serum and analyzed for E2 and E2-FAE by fluoroimmunoassay and liquid chromatography-tandem mass spectrometry. mRNA expression of genes was analyzed by quantitative PCR. RESULTS: Compared with men, E2 levels in sc adipose tissue in obese women were higher, along with higher relative mRNA expression of steroid sulfatase and 17ß-hydroxysteroid dehydrogenases 1, 7, and 12. In men, E2-FAE concentrations in adipose tissue were similar to E2 but in women significantly lower compared with E2. Adipose tissue E2-FAE and serum E2-FAE levels correlated positively in obese subjects. Serum E2 did not significantly correlate with E2 concentration or mRNA expression of genes in adipose tissue in obese men or women. CONCLUSIONS: The production of E2 by the large adipose mass was not reflected by increased circulating E2 concentrations in severely obese men or women. However, adipose tissue may contribute to concentrations of serum E2-FAE.

The impact of gender and serum estradiol levels on HDL-mediated reverse cholesterol transport.

OBJECTIVE: Premenopausal women have a lower incidence of cardiovascular disease compared to men of the same age. Endogenous oestrogens, especially estradiol, presumably protect against atherosclerosis by a variety of mechanisms. Reverse cholesterol transport (RCT) mechanisms also provide protection against this disease. RCT is defined as the removal of cholesterol from peripheral macrophage foam cells, via high-density lipoproteins (HDL), and cholesterol transportation to the liver for excretion. We have previously shown in a preliminary study that HDL, isolated from premenopausal women, enhanced macrophage cholesterol efflux compared to HDL derived from age-matched male subjects. MATERIALS AND METHODS: Here, we expanded this study by analysing a larger population of healthy volunteers and evaluated the capacity of HDL derived from women with high or low serum E2 concentrations, mainly representing premenopausal and postmenopausal women, respectively, or men (each group consisting of 30 subjects) to facilitate cholesterol removal from human THP-1 macrophages. HDL isolated from serum samples was incubated with [(3)H] cholesterol oleate-loaded macrophages for 16 h, after which cholesterol efflux to HDL was determined. RESULTS: No significant differences in the efflux-promoting ability of HDL existed among the three groups. Relevant plasma factors involved in further steps of RCT, such as cholesterol ester transfer protein (CETP), phospholipid transfer protein (PLTP) and lecithin:cholesterol acyltransferase (LCAT) activities were also analysed, but no differences were observed among the study groups. CONCLUSION: The results do not support a role for estradiol status or gender in modifying the initial step of RCT as a protective mechanism against cardiovascular disease.

Fatty acyl esterification and deesterification of 17ß-estradiol in human breast subcutaneous adipose tissue.

CONTEXT: Adipose tissue has an important role in peripheral estrogen synthesis. One of the metabolic pathways of estradiol (E(2)) is its conversion to lipophilic fatty acyl esters. OBJECTIVE: The aim was to study the metabolism of E(2) fatty acyl esters in adipose tissue and, specifically, the role of hormone-sensitive lipase (HSL) in steroid ester hydrolysis. DESIGN AND SETTING: Tissue samples were obtained during elective surgery in University Central Hospital in the years 2008-2011. PATIENTS: Women undergoing reduction mammoplasty (n = 27) or surgery for breast cancer (n = 16) participated in the study. INTERVENTIONS: Two sc adipose tissue samples were taken from different quadrants of the breast. Radiolabeled steroids were incubated with tissue homogenate (esterase assay) or microsomal fraction (acyl transferase assay). E(2) and E(2) fatty acyl ester concentrations were determined by fluoroimmunoassay or liquid chromatography-tandem mass spectrometry. MAIN OUTCOME MEASURES: We evaluated the hydrolysis rate of E(2) fatty acyl esters as well as the esterification rate of E(2); we also related tissue concentrations of E(2) and E(2) esters to serum estrogen concentrations. RESULTS: Compared to esters of dehydroepiandrosterone and cholesterol, the hydrolysis of E(2) esters was much slower, whereas the esterification rate of E(2) was higher. The hydrolysis of E(2) esters in adipose tissue was reduced by 33-51% by inhibition of HSL. Estrogen concentration in sc adipose tissue was higher than in serum in both pre- and postmenopausal women. CONCLUSIONS: E(2) fatty acyl esters in adipose tissue surrounding the mammary gland may act as a reservoir for conversion back to biologically active E(2). This is partly dependent on HSL activity.

Fatty acid esters of steroids: synthesis and metabolism in lipoproteins and adipose tissue.

At the end of the last century ideas concerning the physiological role of the steroid fatty acid ester family were emerging. Estrogens, fatty acylated at C-17 hydroxyl group and incorporated in lipoproteins were proposed to provide antioxidative protection to these particles. A large number of studies involving non-estrogenic adrenal steroids, and their fatty acylated forms, demonstrated their lipoprotein-mediated transport into cells and subsequent intracellular activation, suggesting a novel transport mechanism for lipophilic steroid derivatives. After these important advances the main focus of interest has shifted away from C-19 and C-21 steroids to fatty acylated estrogens. However, interest in their lipoprotein-mediated transport has decreased because only minute amounts of these derivatives were detected in circulating lipoproteins, and their antioxidative activity remained unconfirmed under physiological circumstances. It now appears that the overwhelming majority of estradiol in postmenopausal women resides in adipose tissue, most of it in esterified form. This is poorly reflected in plasma levels which are very low. Recent data suggest that estrogen fatty acid esters probably represent a storage form. The future focus of investigation is likely to be on firstly, the enzymatic mechanisms regulating the esterification and de-esterification of estradiol and other steroids residing in adipose tissue and secondly, on the role of insulin and other hormones in the regulation of these enzymatic mechanisms. Thirdly, as a large proportion of fatty acid esterified C-19 and C-21 non-estrogenic steroids is transported in lipoproteins and as they are important precursors of androgens and estrogens, this field should be investigated further.

Dehydroepiandrosterone fatty acyl esters in high density lipoprotein: interaction with human vascular endothelial cells and vascular responses ex vivo.

Dehydroepiandrosterone (DHEA) fatty acyl esters once incorporated in high density lipoprotein (HDL) induce a stronger vasodilatory response in rat mesenteric arteries ex vivo compared to native HDL. We studied the role of HDL receptor, scavenger receptor class B, type 1 (SR-B1), as well as estrogen and androgen receptors in the vasodilatory response of HDL-associated DHEA fatty acyl esters. Using cultured human vascular endothelial cells (HUVEC), we investigated the possible internalization and cellular response of HDL-associated DHEA esters. We prepared DHEA ester-enriched HDL by incubating human plasma in the presence of DHEA. After isolation and purification, HDL was added in cumulative doses to arterial rings precontracted with noradrenaline. Inhibition of the function of SR-B1 almost completely abolished maximal vasorelaxation by DHEA-enriched HDL while estrogen or androgen receptor blockage had no significant effect. When HUVECs were incubated in the presence of [³H]DHEA ester-enriched HDL, the amount of intracellular [³H]-radioactivity increased steadily during 24 h. Blocking of SR-B1 reduced this uptake by a mean of 30%. The proportion of unesterified [³H]DHEA, as analyzed by thin-layer chromatography, increased intracellularly and in the cell culture media after several hours of incubation of the cells in the presence of [³H]DHEA ester-enriched HDL. This indicated slow hydrolysis of DHEA fatty acyl esters and subsequent excretion of unesterified DHEA by the cells. In conclusion, DHEA-enriched HDL induced vasorelaxation via the SR-B1-facilitated pathway. However, this vasodilation is not likely to be attributed to rapid hydrolysis of HDL-associated DHEA esters by the vascular endothelium.

Hormonal and metabolic characteristics of premenopausal women with a history of preeclamptic pregnancy.

OBJECTIVE: To investigate whether women with a history of preeclampsia have more signs of hyperandrogenism and insulin resistance in the premenopausal period than women with history of normotensive pregnancies. DESIGN: Case-control study. SETTING: University Hospital. SAMPLE: Eighteen women with a history of preeclamptic first pregnancy and 19 women with prior normotensive first pregnancy studied 23-24 years after delivery. METHODS: Diagnosis of metabolic syndrome was based on the International Diabetes Federation (IDF) criteria. Matsuda's whole-body insulin sensitivity index, serum concentrations of follicle-stimulating hormone (FSH), sex hormone-binding globulin, and total and free calculated testosterone were assessed. Polycystic ovary syndrome (PCOS) phenotype was defined using Rotterdam criteria. MAIN OUTCOME MEASURES: Insulin sensitivity, metabolic syndrome and signs of hyperandrogenism. RESULTS: Insulin sensitivity and total and free testosterone were similar in the two groups. However, in women with prior preeclampsia and FSH below the median, calculated free testosterone levels were higher than in women with prior preeclampsia and FSH above the median (median 13.4 range (8.0-22.5) vs. 7.1 (5.1-20.5), p = 0.03). Of the women with previous preeclampsia, 17% (3/18) had metabolic syndrome and 11% (2/18) PCOS, versus 11% (2/19) and 0% of the controls, respectively. CONCLUSIONS: In women with prior preeclampsia, premenopause was not associated with insulin resistance, but signs of hyperandrogenism were present if FSH was within a premenopausal level.

Biochemical markers for cardiovascular disease in recently postmenopausal women with or without hot flashes.

OBJECTIVE: Menopausal hot flashes may affect vascular function and perhaps explain conflicting data on cardiovascular disease (CVD) between observational and randomized hormone therapy (HT) studies. We prospectively assessed hot flash status in recently postmenopausal women and related it to a number of biochemical vascular surrogate markers for CVD. METHODS: Healthy, nonsmoking women (n = 150) exhibiting a broad range (no, mild, moderate, severe) of hot flashes and an onset of menopause within the previous 0.5 to 3 years were studied with laboratory tests for lipids, lipoproteins, apolipoproteins, high-sensitivity C-reactive protein, and sex hormone-binding globulin. RESULTS: Apart from marked differences in hot flashes, the groups showed comparable levels of estrone, estradiol, or free estradiol index. The levels of total cholesterol (3.7-9.1 mmol/L) were similar between the groups (P = 0.744), and hypercholesterolemia (>6.5 mmol/L) was encountered equally often (P = 0.699). No difference was seen in high-, low-, or very low-density lipoproteins, triglycerides, apolipoprotein A-1, apolipoprotein B (or their ratio), or lipoprotein(a) between the groups. The levels of sex hormone-binding globulin and high-sensitivity C-reactive protein correlated negatively with each other (r = -0.204; P = 0.013) but showed no dependence on hot flashes (P = 0.531 and P = 0.215, respectively). CONCLUSIONS: No baseline difference in lipid or nonlipid CVD risk factors was observed between women with hot flashes (potential HT users) and women with no or mild hot flashes (potential HT nonusers). This may imply that hot flash status per se cannot explain the difference between observational and randomized trials.