Biomedical subjects

C Longcope

Publications and source records attributed to C Longcope.

At least 73 records · Page 4Linked to original sources

PubMed1993

Effects of alcohol consumption on plasma and urinary hormone concentrations in premenopausal women.

BACKGROUND: Most epidemiologic studies of the relationship between alcohol consumption and breast cancer risk over the past decade have shown that persons who consume a moderate amount of alcohol are at 40%-100% greater risk of breast cancer than those who do not consume alcohol. Dose-response effects have been observed, but no causal relationship has been established. PURPOSE: This study examines the hypothesis that alcohol consumption affects levels of reproductive hormones. METHODS: A controlled-diet study lasting for six consecutive menstrual cycles was conducted. Participants were randomly assigned to two groups, and a crossover design was used. During the last three menstrual cycles, alcohol consumption of the two groups was reversed. Thirty-four premenopausal women, aged 21-40 years, with a history of regular menstrual cycles, consumed 30 g of ethanol (equivalent to approximately two average drinks) per day for three menstrual cycles and no alcohol for the other three. All food and alcohol consumed were provided by the study. Caloric intake was monitored to ensure that each woman would maintain body weight at approximately the baseline level. Hormone assays were performed on pooled plasma or 24-hour urine specimens collected during the follicular (days 5-7), peri-ovulatory (days 12-15), and mid-luteal (days 21-23) phases of the third menstrual cycle for subjects on each diet. RESULTS: Alcohol consumption was associated with statistically significant increases in levels of several hormones. Plasma dehydroepiandrosterone sulfate levels were 7.0% higher in the follicular phase (P = .05). In the peri-ovulatory phase, there were increases of 21.2% (P = .01) in plasma estrone levels, 27.5% (P = .01) in plasma estradiol levels, and 31.9% (P = .009) in urinary estradiol levels. In the luteal phase, urinary estrone levels rose 15.2% (P = .05), estradiol levels increased 21.6% (P = .02), and estriol levels rose 29.1% (P = .03). No changes were found in the percent of bioavailable estradiol, defined by the sum of percent free estradiol and percent albumin-bound estradiol. However, increased total estradiol levels in the peri-ovulatory phase suggest elevated absolute amounts of bioavailable estradiol. CONCLUSION: This study has shown increases in total estrogen levels and amount of bioavailable estrogens in association with alcohol consumption in premenopausal women. IMPLICATION: This possible explanatory mechanism for a positive association between alcohol consumption and breast cancer risk merits further investigation.

Adult↗

PubMed1993

Hormonal regulation of endometrial prostaglandin F2 alpha production during the luteal phase of the rhesus monkey.

To study the hormonal regulation of prostaglandin (PG) production by the endometrium during the luteal phase of the primate menstrual cycle, the standard artificial menstrual cycle (SAMC) of the rhesus monkey was manipulated (MAMC) such that in one group of monkeys, there was an absence of the mid-cycle peak of estradiol-17 beta (E), but normal luteal phase progesterone (P). In the second group, there was a mid-cycle peak of E, but no luteal phase P. The accumulation of PGF2 alpha in tissue culture medium from explants of endometrium obtained on cycle Day 14 or 23 of the MAMC was compared to the accumulation of PGF2 alpha from explants on cycle Day 14 or 23 of the SAMC (expressed as mean ng +/- SEM/mg/24 h). Omission of the mid-cycle E peak in the MAMC did not alter endometrial PGF2 alpha production in vitro on cycle Day 14, compared to the SAMC; whereas, on cycle Day 23 PGF2 alpha, production was reduced (35.1 +/- 6.4 ng/mg/24 h), compared to that in the SAMC (53.8 +/- 10.3 ng/mg/24 h; p = 0.06). Omission of P during the MAMC resulted in higher PGF2 alpha production in vitro on cycle Day 14 (p < 0.01) and lower PGF2 alpha production on cycle Day 23 (p = 0.05), compared to that in the SAMC on these days.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Caffeine and other predictors of bone density among pre- and perimenopausal women.

We evaluated the influence of dietary, anthropomorphic, and hormonal factors on bone density in a cross-sectional sample of 281 pre- and perimenopausal women age 50-60 years living in Massachusetts. The sample included only women who had intact ovaries and were not currently using estrogen. Information on diet was obtained through a semiquantitative food frequency questionnaire. We measured bone density using single-photon absorptiometry in the non-dominant arm in two sites: the midshaft and the ultradistal radius. We observed no important associations between midshaft bone density and dietary variables but found linear relations between ultradistal radius bone density and body mass index [b = 1.10 gm/cm2 per kg/m2, standard error (SE) = 0.56], follicle-stimulating hormone (FSH) (b = -0.36 gm/cm2 per IU/liter, SE = 0.15), and several nutrients: calcium (b = 0.012 gm/cm2 per mg/day, SE = 0.007), retinol (b = 0.002 gm/cm2 per IU/day, SE = 0.0008), vitamin C (b = 0.025 gm/cm2 per mg/day, SE = 0.013), and vitamin D (b = 0.040 gm/cm2 per IU/day, SE = 0.018). We could not clearly distinguish the independent contribution of these micronutrients, however, because many were commonly ingested together in the form of supplements. Caffeine was inversely associated with bone density (b = -0.035, SE = 0.017) independent of dietary, anthropometric, and hormonal factors. Analyses of individual caffeinated beverages revealed consistent inverse associations for coffee (b = -3.42 gm/cm2 per cups/day, SE = 1.49), tea (b = -2.85 gm/cm2 per cups/day, SE = 1.56), and caffeinated cola (b = -14.0 gm/cm2 per cans/day, SE = 5.1), but not for decaffeinated coffee or decaffeinated cola [corrected]. [ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometry↗

PubMed1993

Androgen and estrogen dynamics: relationships with age, weight, and menopausal status.

Previous studies have shown a relationship between age and weight and the MCR and conversions ([rho]) of androgens and estrogens. To assess the relative importance of these relationships in the metabolism and conversion of the androgens and estrogens, we used a series of statistical analyses, including t test, Pearson's correlation, and a step-wise regression analysis of the data obtained from the constant infusion of radiolabeled androgens and estrogens to normal women, 18-90 yr old. The MCRs of testosterone (T), androstenedione (A), and estrone (E1) were strongly correlated with weight, but not age or menopausal status. The MCR of estradiol (E2) was strongly correlated with weight and less strongly correlated with age, but was not correlated with menopausal status. The interconversions of the androgens ([rho]T,ABB and [rho]A,TBB, i.e. percentage of precursor infused measured as product in blood) and estrogens ([rho]E1,E2BB and [rho]E2,E1BB) were not correlated with age or weight, but there was a weak correlation between [rho]T,ABB and menopausal status. The aromatization of androgens to estrogens ([rho] A,E1BM and [rho]T,E2BM, i.e. percentage of androgens infused measured as estrogen glucuronide in the urine) was highly correlated with age, less strongly correlated with weight, and not correlated with menopausal status. The correlation with weight and MCR is a reflection of the extrasplanchnic metabolism of steroids. The lack of correlation with weight for the interconversions of androgens and estrogens indicates that the enzyme(s) responsible is affected differently in extrasplanchnic tissue than is the aromatase complex. The relationship between age and aromatization, while strong, remains unexplained.

Adolescent↗

PubMed1993

Plasma dehydroepiandrosterone sulfate serves as a prehormone for 48% of follicular fluid testosterone during treatment with menotropins.

Evidence has suggested that dehydroepiandrosterone sulfate (DS) is a prehormone for ovarian steroidogenesis. To study this hypothesis, combined 6-h infusions of [3H]dehydroepiandrosterone sulfate and [14C]testosterone ([14C]T) were performed in four normal women treated with menotropins who were undergoing medically indicated surgery, and the data were compared to those from nine normal women. The concentrations of tracer and nonisotopic DS, androst-5-ene-3 beta,17 beta-diol sulfate (delta 5diolS), androst-5-ene-3 beta,17 beta-diol (delta 5diol), dehydroepiandrosterone (D), androstenedione (delta 4A), and T were determined in arterial and venous blood and in follicular fluid. From these data, the concentrations and fractions of steroids in the follicular fluid that were derived from DS were calculated from the specific activity of intravascular DS and the concentrations of follicular fluid tracer steroids and their specific activities. The fractions of T (0.48), delta 5diol (0.31), delta 5diolS (0.42), and D (0.25) in follicular fluid arising from circulating DS were similar and were not significantly different from that of follicular DS arising from circulating DS (0.32). However, the fraction of follicular fluid delta 4A (0.041) was significantly less (P < 0.01), and the fractions of intrafollicular estrone and estradiol arising from DS were both less than 0.04. The mean MCR of DS in the women treated with menotropins of 22.0 +/- 3.5 L/day (mean +/- SE) was significantly higher than the normal control value. These findings elucidate an important mechanism of adrenal/ovarian interaction at the level of steroidogenesis; circulating DS serves as a prehormone for the production of intrafollicular delta 5diolS, delta 5 diol, D, and T.

Adult↗

PubMed1993

Differential changes in serum concentrations of androgens and estrogens (in relation with cortisol) in postmenopausal women with acute illness.

Previous studies of adrenal androgens and estrogens in critical illness were limited by measuring only selected sex steroids and by including men (who have confounding simultaneous changes in gonadal steroids). We evaluated relationships between changes in serum levels of cortisol (F), androgens, estrogens, and gonadotropins in 20 postmenopausal women with acute critical illness to determine if changes in adrenal androgens and estrogens paralleled gonadal axis suppression or adrenal stimulation. Two patterns of changes in sex steroids were observed. Admission serum levels of androstenedione (delta 4-A), estradiol, and estrone, like F, were increased compared to healthy controls (P < 0.0001). delta 4-A and estrone then decreased toward normal by day 5 in parallel with cortisol (r = 0.56 and 0.60). In contrast, admission serum dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEA-S) were not elevated and testosterone (T) was decreased in our patients compared to controls (P < 0.0005) in parallel with serum gonadotropin levels. Serum levels of DHEA and T continued to decrease by day 5 in parallel with gonadotropins. We conclude that in agonadal patients with acute critical illness, serum levels of DHEA-S and T are selectively decreased in relation to F, delta 4-A, and estrogens. The decreased serum T levels suggest inhibition of 17 beta-OH-dehydrogenase and/or increased aromatization to estradiol. The marked increase in serum estrogen levels also suggests increased aromatization. The absence of increases in DHEA and DHEA-S suggest enhanced activity of 3 beta-hydroxysteroid dehydrogenase and/or inhibition of C17,20-lyase activity of P-450c17. The clinical significance of this marked increase in the ratio of estrogens to androgens in acute illness requires further investigation.

Acute Disease↗

PubMed1993

Testosterone, a follicular regulator: key to anovulation.

To study the interrelationships of steroids within the follicle, combined 6-h infusions of [3H]dehydroepiandrosterone sulfate and [14C] testosterone ([14C]T) were performed in four normal women treated with menotropins who were undergoing medically indicated surgery. The concentrations of tracer and/or nonisotopic dehydroepiandrosterone sulfate, androst-5-ene-3 beta,17 beta-diol sulfate, androst-5-ene-3 beta,17 beta-diol, dehydroepiandrosterone, androstenedione, T, dihydrotestosterone, estrone (E1), and estradiol (E2) were determined in arterial and venous blood and follicular fluid. The log-transformed product/precursor ratio of [3H]dihydrotestosterone/[3H]T in follicular fluid was negatively correlated with the log-transformed follicular concentrations of E1 (P = 0.01) and E2 (P = 0.02), suggesting a reciprocal relationship between 5 alpha-reductase and follicular E1 and E2. E2 and T were positively correlated in follicular fluid (r = 0.84; P = 0.0003), suggesting a stimulatory action of follicular T on aromatase. These findings along with extensive published data suggest that follicular T functions as a follicular regulator, enhancing follicular aromatase activity when adequate amounts of FSH are available. These conclusions have important implications with regard to mechanisms for selecting the dominant follicle and producing atresia in the remaining cohort of follicles, and they describe a final common path in the pathophysiology of anovulation.

Anovulation↗

PubMed1993

Estradiol, progesterone, and sex hormone-binding globulin in female rhesus monkeys (Macaca mulatta).

We measured the concentrations of estradiol, progesterone, and the sex hormone-binding globulin capacity (rhSHBG) in serum of female rhesus monkeys (Macaca mulatta). Although the serum rhSHBG capacity was altered by the removal of ovarian hormones, presumably estradiol, acute changes in serum estradiol and progesterone did not influence SHBG capacity. There appears to be a relatively low threshold for the effect of estradiol on rhSHBG capacity. The threshold must be present for a finite length of time to have that effect.

Animals↗

PubMed1992

Recombinant human thyrotropin stimulates thyroid function and radioactive iodine uptake in the rhesus monkey.

The administration of bovine TSH to stimulate thyroid radioactive iodine uptake to detect functioning thyroid tissue in man after surgery for thyroid cancer is rarely, if ever, used, due to allergic reactions and/or the development of TSH antibodies. Human (h) TSH would be far less likely to induce allergic reactions or TSH antibodies. Recombinant hTSH (rec-hTSH) was produced by a line of Chinese hamster ovary cells that had been transfected with cDNA for the two subunit proteins that comprise hTSH. The present study was carried out to determine the half-life of rec-hTSH in the monkey and its ability to stimulate thyroid function. The half-life of rec-hTSH after iv administration was approximately 63 min for the rapid phase and 326 min for the slow phase. After three daily im injections of 2 U rec-hTSH to two monkeys, serum T4 concentrations increased several-fold, and serum T3 increased 2-3 times above basal values. The 6 and 20 h thyroid 123I uptakes doubled after rec-hTSH administration. These results demonstrate the biological efficacy of rec-hTSH administered to the monkey and strongly suggest that rec-hTSH will be effective in stimulating thyroid function in man.

Animals↗

PubMed1992

Both hyper- and hypogonadotropic hypogonadism occur transiently in acute illness: bio- and immunoactive gonadotropins.

Previous reports of hypogonadotropic hypogonadism in critically ill men may not reflect the complexity of changes in the hypothalamic-pituitary-gonadal (HPG) axis during acute illness. We sampled blood throughout hospitalization in 55 men admitted to acute care units to delineate the spectrum of changes in circulating gonadotropin and sex steroid levels at the onset and during recovery from acute illness. Bioactive LH and FSH were measured in a subset of patients. Percent free testosterone was measured to assess changes in binding to sex hormone binding globulin. Medications and serum estrogen and prolactin levels were monitored as potential causes of hypogonadotropism. Sustained suppression of serum testosterone levels below the normal range occurred in 62% of men with varying diagnoses and disease severity. Percent free testosterone remained constant. Hypogonadotropism was observed in most men (60%) and occurred independently from head injury, surgery, medications, or hyperprolactinemia. In a subset of men (n = 16), LH and/or FSH rose transiently above the normal range. Bioactivity of both LH and FSH remained constant while serum testosterone levels decreased. In contrast to serum testosterone levels, mean serum levels of E1, E2 and androstenedione were not less than control values. We conclude that both primary and secondary hypogonadism occur transiently in acutely ill men and cannot be explained solely by medications, hyperprolactinemia, or hyperestrogenemia. Neither biopotency of gonadotropins nor binding of testosterone to SHBG change across the course of acute illness. The hypogonadism, often severe and prolonged, may contribute to the persistent catabolic state observed in many critically ill patients.

Acute Disease↗

PubMed1992

The metabolism of human sex hormone-binding globulin in the rhesus monkey.

The metabolism of human sex hormone-binding globulin (hSHBG) was studied in eight female rhesus monkeys (Macaca mulatta) after the pulse injection of [125I]-hSHBG. hSHBG was iodinated with 125I using a chloramine T technique, and the [125I]-hSHBG was separated from other constituents by molecular sieve chromatography with a Sephadex G-25 column. The [125I]-hSHBG was administered intravenously as a pulse in 2 ml of phosphate buffer, pH 7.4, to each of eight rhesus monkeys. Blood samples (2.0 ml) were obtained at 2, 4, 6, 8, 24, 30, 45, and 54 hr after the injection. The glycoproteins were precipitated with concanavalin A-Sepharose, and the radioactivity was measured. The concentration of radioactivity as fraction of dose/ml of serum was plotted on a semilog scale against time. The disappearance of radioactivity could be expressed best as the sum of two exponentials, with a mean +/- SE t1/2 of 2.5 +/- 0.4 and 33.1 +/- 3.7 hr, respectively. The initial volume of distribution was 461 +/- 78 ml and the metabolic clearance rate was 559 +/- 66 ml/day. The very low clearance rate and prolonged t1/2 are compatible with a relative stability in the circulating mass of SHBG. Rapid changes in concentration of SHBG could be due to changes in serum volume, reversible changes in tissue distribution of SHBG, or the secretion of variable forms of desialylated SHBG.

Animals↗

PubMed1991

An examination of research design effects on the association of testosterone and male aging: results of a meta-analysis.

The study of testosterone is likely to be prominent in future epidemiological work on endocrine function and the clinical treatment of age-related diseases. Thus, understanding the hormonal changes involved in the normal male aging process will be critical. Using techniques of meta-analysis, the authors examined 88 published studies of the age-testosterone relation in men. These studies reported conflicting results: age-testosterone correlations ranged from -0.68 to +0.68. In cross-study comparisons, certain research design characteristics (e.g. time of day of blood sampling) and various sample characteristics (e.g. volunteers vs patients as subjects) were related to both mean testosterone level and the slope of the age-testosterone relation. For example, for subgroups of subjects that did not exclude ill men, the mean testosterone levels were low, and did not decline with age. Subgroups that included only healthy subjects, in contrast, had higher overall testosterone levels and showed a decline of testosterone with age. Implications of these results for design, analysis and reporting of future epidemiologic studies will be discussed. These results also illustrate the utility of meta-analysis for research with the aged.

Adult↗

PubMed1991

Aromatase activity in human adipose tissue stromal cells; the effect of fetal bovine serum fractions on dexamethasone-stimulated aromatization.

Aromatization in human adipose stromal cells is stimulated by dexamethasone, but only in the presence of fetal bovine serum (FBS). To determine whether there was a specific fraction of FBS responsible for this stimulation, FBS was fractionated either by a pressure-driven ultrafiltration membrane or by Sephadex gel filtration techniques. The stimulating factor(s) appeared to be in the FBS fraction of 150,000-300,000 Mw by Sephadex filtration. Conversely, FBS fractions with less than 30,000 Mw as separated by the former method inhibited the dexamethasone-stimulated aromatization of cultured adipose stromal cells. Bovine serum albumin, which constituted the major portion of FBS, had no discernible effect on the dexamethasone action on the aromatization of these cells.

Adipose Tissue↗

PubMed1991

Alcohol and other dietary factors in relation to serum hormone concentrations in women at climacteric.

The relationships between concentrations of endogenous hormones in serum and dietary intakes of alcohol, fats, fiber, and caffeine were examined in 325 healthy Massachusetts women aged 50-60 y who reported having a normal menstrual period within the previous 12 mo. Diet was assessed by a semiquantitative food frequency questionnaire. Hormones assayed were estrone, estradiol, percent free estradiol, sex-hormone-binding globulin (SHBG), cortisol, and gonadotropins. Alcohol intake was not associated with concentrations of estrogens or gonadotropins. Neither total fat intake nor the fat composition of the diet influenced hormone concentrations. Fiber intake was positively correlated with SHBG; no associations with estrogens were seen. Caffeine intake was inversely correlated with free estradiol and positively correlated with SHBG. These data suggest that fat, fiber, and alcohol intakes of US women at climacteric are not determinants of variations in estrone and either total or percent free estradiol.

Alcohol Drinking↗

PubMed1991

Metabolic clearance rate of dehydroepiandrosterone sulfate, its metabolism to testosterone, and its intrafollicular metabolism to dehydroepiandrosterone, androstenedione, testosterone, and dihydrotestosterone in vivo.

At the time of surgery, women were infused with [3H]dehydroepiandrosterone sulfate ([3H]DS)/[14C]testosterone ([14C]T) for 6 h; blood samples were obtained from an artery the ovarian veins, and a peripheral vein; and fluid was obtained from ovarian follicles. Both blood and follicular fluid samples were analyzed for radioactivity as DS, dehydroepiandrosterone (D), androstenedione (delta 4A). T, and dihydrotestosterone (DHT), and the blood was also analyzed for the concentration of nonisotopic DS by RIA. In other subjects the concentrations of D and DS were measured in paired samples of blood and follicular fluid. From these data, values of 13.6 +/- 0.69 L/day four (mean +/- SE; n = 4) for MCRDS, 607 +/- 90 L/day (n = 3) for MCRT, and 0.0190 +/- 0.0089 (n = 3) for [p]DS-T (fraction of plasma DS metabolized to plasma T) were obtained. The ratio of the concentration of the tracer-labeled steroid in the follicular fluid to the concentration in the arterial plasma sample was elevated significantly above 1 for three 3H-labeled and three [14C-labeled metabolites: [3H]D (21-fold; P less than 0.001), [3H]T (81-fold; P less than 0.001), [3H]DHT (19-fold; P less than 0.001), [14C]T (4-fold; P less than 0.025), [14C]DHT (21-fold; P less than 0.01), and [14C]delta 4A (50-fold; P less than 0.001). The estimated concentrations of steroids in follicular fluid derived from DS based on specific activity calculations were as follows: [geometric mean (95% confidence limits; n)]: DS, 5600 (4800-6500 nmol/L; 12); D, 370 (88-1500 nmol/L; 10); delta 4 A, 120 (67-220 nmol/L; 12); T, 130 (39-450 nmol/L; 10); and DHT, 64 (35-120 nmol/L; 8). Comparison of these data to known follicular fluid steroid concentrations shows that DS from the intravascular pool can be used as an ovarian prehormone.

Adult↗

PubMed1991

Sex steroid control of gonadotropin secretion in the human male. I. Effects of testosterone administration in normal and gonadotropin-releasing hormone-deficient men.

The precise sites of action of the negative feed-back effects of gonadal steroids in men remain unclear. To determine whether testosterone (T) administration can suppress gonadotropin secretion directly at the level of the pituitary, the pituitary responses to physiological doses of GnRH were assessed in six men with complete GnRH deficiency, whose pituitary-gonadal function had been normalized with long term pulsatile GnRH delivery, before and during a 4-day continuous T infusion (15 mg/day). Their responses were compared with the effects of identical T infusions on spontaneous gonadotropin secretion and the response to a 100-micrograms GnRH bolus in six normal men. Both groups were monitored with 15 h of frequent blood sampling before and during the last day of the T infusion. In the GnRH-deficient men, the first three GnRH doses were identical and were chosen to produce LH pulses with amplitudes in the midphysiological range of our normal men (i.e. a physiological dose), while the last four doses spanned 1.5 log orders (7.5, 25, 75, and 250 ng/kg). The 250 ng/kg dose was always administered last because it is known to be pharmacological. In the GnRH-deficient men, mean LH (P less than 0.02) and FSH (P less than 0.01) levels as well as LH pulse amplitude (P less than 0.05) decreased significantly during T infusion, demonstrating a direct pituitary-suppressive effect of T and/or its metabolites. Mean LH levels were suppressed to a greater extent in the normal than in the GnRH-deficient men (58 +/- 15% vs. 28 +/- 7%; P less than 0.05). In addition, LH frequency decreased significantly (P less than 0.01) during T administration in the normal men. These latter two findings suggest that T administration also suppresses hypothalamic GnRH release. T was unable to suppress gonadotropin secretion in one GnRH-deficient and one normal man. In both groups, the suppressive effect of T administration was present only in response to physiological doses of GnRH. Because the pituitary- and hypothalamus-suppressive effects of T could be mediated by its aromatization to estrogens, five GnRH-deficient and five normal men underwent identical T infusions with concomitant administration of the aromatase inhibitor testolactone (TL; 500 mg, orally, every 6 h). As an additional control, four GnRH-deficient and four normal men received TL alone. TL administration completely prevented the effect of T administration to suppress gonadotropin secretion in both the normal and GnRH-deficient men, and mean LH levels increased significantly in both the GnRH-deficient (P less than 0.01) and the normal (P less than 0.001) men who received TL alone. The increase in mean LH levels was greater (P less than 0.01) in the normal men who received TL alone than in the normal men who received T plus TL, thus revealing a direct effect of androgens in normal men. Measurements of T and estradiol production rates in three men demonstrated that TL effectively blocked aromatization.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗

PubMed1991

Age, disease, and changing sex hormone levels in middle-aged men: results of the Massachusetts Male Aging Study.

To evaluate the hypothesis that endocrine profiles change with aging independently of specific disease states, we examined the age trends of 17 major sex hormones, metabolites, and related serum proteins in 2 large groups of adult males drawn from the Massachusetts Male Aging Study, a population-based cross-sectional survey of men aged 39-70 yr conducted in 1986-89. Group 1 consisted of 415 men who were free of obesity, alcoholism, all prescription medication, prostate problems, and chronic illness (cancer, coronary heart disease, hypertension, diabetes, and ulcer). Group 2 consisted of 1294 men who reported 1 or more of the above conditions. Each age trend was satisfactorily described by a constant percent change per yr between ages 39-70 yr. Free testosterone declined by 1.2%/yr, and albumin-bound testosterone by 1.0%/yr. Sex hormone-binding globulin (SHBG), the major serum carrier of testosterone, increased by 1.2%/yr, with the net effect that total serum testosterone declined more slowly (0.4%/yr) than the free or albumin-bound pools alone. Among the major androgens and metabolites, androstane-3 alpha,17 beta-diol (androstanediol; 0.8%/yr) and androstanediol glucuronide (0.6%/yr) declined less rapidly than free testosterone, while 5 alpha-dihydrotestosterone remained essentially constant between ages 39-70 yr. Androstenedione declined at 1.3%/yr, a rate comparable to that of free testosterone, while the adrenal androgen dehydroepiandrosterone (3.1%/yr) and its sulfate (2.2%/yr) declined 2-3 times more rapidly. The levels of testosterone, SHBG, and several androgen metabolites followed a parallel course in groups 1 and 2, remaining consistently 10-15% lower in group 2 across the age range of the study. Subgroup analyses suggested that obese subjects might be responsible for much of the group difference in androgen level. Serum concentrations of estrogens and cortisol did not change significantly with age or differ between groups. Of the pituitary gonadotropins, FSH increased at 1.9%/yr, LH increased at 1.3%/yr, and PRL declined at 0.4%/yr, with no significant difference between groups 1 and 2.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1991

Metabolism of dehydroepiandrosterone sulfate (DS) in normal women and women with high DS concentrations.

In order to determine the contribution of serum dehydroepiandrosterone sulfate (DS) to estrone (E1) production in normal women and the effect of chronic elevation of the serum DS concentration on DS metabolism, four normal women and four women with high endogenous serum DS were infused with [3H]DS and [14C]E1 or [14C]testosterone for 6 h. Blood samples were analyzed for radioactivity as DS, dehydroepiandrosterone (D), androstenedione, testosterone, and dihydrotestosterone. Urine was collected for analysis of creatinine, 17-ketosteroids (17-KS), and radioactivity as estrone (E1). The serum DS of 12.4 +/- 1.44 mumol/L (mean +/- SE) in the group with high DS was higher than that of 3.96 +/- 1.0 mumol/L (1.46 +/- 0.37 micrograms/mL) in the normals (P less than 0.005). Those with high DS also had increased 17-KS (13.2 +/- 2.0 vs. 5.68 +/- 0.68 mg/day, P less than 0.025) and a higher blood production rate of DS (PBDS) (126 +/- 21 (n = 3) vs. 54.3 +/- 13.8 mmol/day, P less than 0.05) but a lower MCRDS (10.94 +/- 0.61 (n = 3) vs. 13.8 +/- 0.27 L/day, P less than 0.01) than that in normals. In the four normal women the fraction of infused DS converted to estrone ( [rho]BMDS E1) was 0.00078 +/- 0.00018, the amount of E1 produced from serum DS was 41.3 +/- 15 nmol/day, the basal plasma E1 was 102 +/- 18 pmol/L, the MCRE1 was 1340 +/- 181 L/day, the value for blood production of E1 (PBE1) was 129 +/- 12 nmol/day, and the portion of E1 derived from DS was 30.4 +/- 9.4%. Correlation analysis of the data from these eight subjects showed that 17-KS, PBDS, and the serum DS were all correlated with body surface area, body weight, and ponderal index and that 17-KS excretion, PBDS, and serum DS were all correlated with one another. The most important predictors of 17-KS excretion were serum DS (P less than 0.001) and the ponderal index (P less than 0.05).

17-Ketosteroids↗