A. Wayne Meikle

Male obesity and alteration in sperm parameters

OBJECTIVE To study the effect of male obesity on sperm parameters and erectile dysfunction. DESIGN Retrospective analysis. SETTING Referral fertility center. PATIENT(S) Couples presenting for infertility treatment. INTERVENTION(S) On presentation, all men reported their weight and height and filled out an intake form that includes questions regarding factors that affect male infertility, including presence of erectile dysfunction. Body mass index (BMI) was divided into three groups: normal (BMI <25 kg/m(2)), overweight (25 kg/m(2) <or= BMI < 30 kg/m(2)), and obese (BMI >or=30 kg/m(2)). Sperm parameters reviewed included sperm concentration and progressively motile sperm count. MAIN OUTCOME MEASURE(S) Oligozoospermia, low progressively motile sperm count, and self-reported erectile dysfunction. RESULT(S) The mean age of the study population was 32.8 +/- 0.3 years. Among the 526 patients, 10.2% (54 of 526) were excluded because of the presence of a male factor known to affect fertility. The incidence of oligozoospermia increased with increasing BMI: normal weight = 5.32%, overweight = 9.52%, and obese = 15.62%. The prevalence of a low progressively motile sperm count was also greater with increasing BMI: normal weight = 4.52%, overweight = 8.93%, and obese = 13.28%. The incidence of erectile dysfunction did not vary across BMI categories when corrected for potential contributing factors. CONCLUSION(S) Male obesity is associated with increased incidence of low sperm concentration and low progressively motile sperm count.

Impact of male obesity on infertility: a critical review of the current literature

OBJECTIVE To evaluate the current understanding of the effects and potential mechanisms of obesity on male fertility. DESIGN Literature review of articles pertaining to obesity and male infertility. RESULT(S) Recent population-based studies suggest an elevated risk for subfertility among couples in which the male partner is obese and an increased likelihood of abnormal semen parameters among heavier men. Male factor infertility is associated with a higher incidence of obesity in the male partner. Obese men exhibit reduced androgen and SHBG levels accompanied by elevated estrogen levels. Reduced inhibin B levels correlate with degree of obesity and are not accompanied by compensatory increases in FSH. This complexly altered reproductive hormonal profile suggests that endocrine dysregulation in obese men may explain the increased risk of altered semen parameters and infertility. Additional features of male obesity that may contribute to an increased risk for infertility are altered retention and metabolism of environmental toxins, altered lifestyle factors, and increased risks for sexual dysfunction. Neither reversibility of obesity-associated male infertility with weight loss nor effective therapeutic interventions have been studied yet. CONCLUSION(S) The increasing prevalence of obesity calls for greater clinician awareness of its effects on fertility, better understanding of underlying mechanisms, and eventually avenues for mitigation or treatment.

The presence of a dehydroepiandrosterone-specific receptor binding complex in murine T cells

We have investigated the ability of dehydroepiandrosterone (DHEA) to alter the production of interleukin-2 (IL-2) and to bind to a specific binding complex in antiCD3 epsilon activated T cells. Binding activity correlated with the presence of a specific DHEA binding complex in the cytosol and nuclei of DHEA-responsive T-cell hybridomas, as well as in CD4+ and CD8+ cells isolated from peripheral lymph nodes of normal mice. Scatchard analysis determined that intact lymphocytes and cytosolic fractions contained high affinity binding for [3H]DHEA (approx. 2.6 nM) with 1000-7000 binding sites existing per cell. Five of the T-cell hybridomas tested both responded to DHEA treatment with increased production of IL-2 and also contained specific high affinity [3H]DHEA binding. Four additional T-cell hybridomas were found to contain no specific [3H]DHEA binding and were also unresponsive to DHEA influences on IL-2 production. Sucrose density gradients demonstrated a 3-4s [3H]DHEA binding complex in high salt and a 7-8s binding complex in low salt. Specific binding was inhibited by preincubation of the cytosol fractions with either trypsin or chymotrypsin, or by heating to 60 degrees C for 1 h (less than 15% of control). [3H]DHEA binding was unaffected by preincubation of the cytosol fractions with ribonuclease, deoxyribonuclease, or phospholipase A. The DHEA-protein complexes bound to DNA-cellulose with the amount of binding being slightly increased by preincubation at 25 degrees C as compared to 4 degrees C. As expected, [3H]DHEA binding was inhibited by the addition of unlabeled DHEA, but was also modestly inhibited by dihydrotestosterone and cortisol. Binding of DHEA was unaffected by progesterone, dexamethasone, estradiol, androsterone, DHEAS, and beta-etiocholanolone at all concentrations tested. DHEA was incapable of inhibiting the binding of [3H]DHT to the androgen receptor or [3H]dexamethasone to the glucocorticoid receptor. Collectively, these findings suggest that murine T cells contain a specific DHEA receptor. We believe that DHEA is a steroid hormone that is directly involved in the regulation of IL-2 production by both normal and some T-cell hybridomas.

Potency and duration of action of glucocorticoids: Effects of hydrocortisone, prednisone and dexamethasone on human pituitary-adrenal function

Abstract This study was designed to quantitate the relative potencies of orally administered glucocorticoids and to investigate some of the factors affecting their relative potency in normal subjects. Corticosterone was measured in plasma samples obtained at 8 A.M. from eight normal adult subjects, three women and five men, following oral doses of dexamethasone, prednisone and hydrocortisone on the preceding midnight, at 6 P.M. and at 8 A.M. The half-time of disappearance of prednisolone and dexamethasone from plasma and their free concentrations in plasma were also determined. Concentrations of plasma corticosterone and cortisol showed a significant correlation (r = 0.68 to 0.99, p Our data indicate that relative intrinsic biologic potency and relative rates of disappearance from plasma are two of the most important factors in determining the relative glucocorticoid potency of orally administered glucocorticoids.

Liquid Chromatography–Tandem Mass Spectrometry Assay for Androstenedione, Dehydroepiandrosterone, and Testosterone with Pediatric and Adult Reference Intervals

BACKGROUND Measurement of serum androgens is important in adult, geriatric, pediatric endocrinology, and oncology patients. We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous measurement of androstenedione, dehydroepiandrosterone (DHEA), and testosterone in these patients. METHODS We spiked 200 muL of serum or plasma with isotope-labeled internal standards and performed extraction with methyl t-butyl ether. We then derivatized the extracts with hydroxylamine and analyzed them by LC-MS/MS using a 2-dimensional chromatographic separation with a 3.5-min analysis time. RESULTS Total imprecision for each analyte was <11.2%. Limits of quantification were 10, 50, and 10 ng/L for androstenedione, DHEA, and testosterone, respectively. Reference intervals were established for children (age 6 months to 17 years), men, and women. Androstenedione and DHEA concentrations were lowest in 2- to 3-year-old children. Adult concentrations were achieved in girls at Tanner stage 3 and in boys at Tanner stage 4-5. In premenopausal and (postmenopausal) women the median concentrations of androstenedione, DHEA, and testosterone were 810 (360), 3000 (1670), 270 (180) ng/L, respectively. In postmenopausal women, concentrations of testosterone were age independent, whereas androstenedione and DHEA concentrations decreased with age. In men the median concentrations of androstenedione, DHEA, and testosterone were 440, 2000, and 3700 ng/L, respectively. In men older than 40 years, median concentrations decreased at rates of 5%, 10%, and 20% per decade for androstenedione, DHEA, and testosterone, respectively. CONCLUSIONS This LC-MS/MS method has the required lower limit of quantification and specificity for analysis of endogenous concentrations of androgens in all groups studied. Reference intervals were established for healthy children and adults.

Natural history of thyroid abnormalities: Prevalence, incidence, and regression of thyroid diseases in adolescents and young adults

PURPOSE This study reports the prevalence, incidence, and regression of thyroid abnormalities in a population observed from adolescence to adulthood. PATIENTS AND METHODS Examinations for thyroid abnormalities were performed in 4,819 school-age children, ages 11 to 18, in 1965 to 1968; two thirds of this original cohort (3,121) were re-examined 20 years later (1985 to 1986). Each subject with a thyroid abnormality detected by physical examination was studied by means of a series of re-examinations, and tests of thyroid function, imaging, and biopsy to determine the exact nature of the thyroid abnormality. RESULTS In the initial examinations (1965 to 1968), 185 thyroid abnormalities were found (3.7%). Diffuse hypertrophy with normal function (adolescent goiter) was the most common abnormality (19.3/1,000); 12.7/1,000 had chronic lymphocytic thyroiditis, and 4.6/1,000 had thyroid nodules, including two papillary carcinomas. Hyperthyroidism or hypothyroidism was found in 1.9/1,000. In the follow-up examinations in 1985 to 1986, 298 subjects had thyroid abnormalities (10.5%), of whom 81 (28.7/1,000) had simple goiters, 145 (51.3/1,000) had chronic thyroiditis, 45 (15.9/1,000) had hypothyroidism, 11 (3.9/1,000) had hyperthyroidism, and 66 (23.2/1,000) had nodules, which included 10 carcinomas. Of the 92 subjects with simple or adolescent goiter in 1965 to 1968, 60% were normal by 1985 to 1986, 20% were unchanged, and a few had developed thyroiditis (10%) or colloid goiters (3.0%). Of 61 subjects with thyroiditis, 27% had become normal, 33% remained unchanged, and 33% had become hypothyroid. Of the 22 subjects with thyroid nodules, two had complete disappearance of the nodules, and three had nodules considered to be variants of normal. The others exhibited a variety of nodular pathologic conditions. CONCLUSIONS The natural history of thyroid disorders, including simple goiter, chronic thyroiditis, hyperthyroidism, hypothyroidism, and nodular diseases of the thyroid, indicates they are dynamic and changeable in form, function, appearance, and disappearance.

Effect of Roux-en-Y Gastric Bypass Surgery on the Sex Steroids and Quality of Life in Obese Men

CONTEXT The effect of bariatric surgery on the reproductive function of obese men is not entirely elucidated. OBJECTIVE The aim of the study was to define the effect of Roux-En-Y gastric bypass surgery on the reproductive hormones and sexual function in obese men. DESIGN AND SETTING The cohort was followed for 2 yr at a clinical research center. PATIENTS Sixty-four severely obese men (22 who had gastric bypass surgery and 42 controls) participated in the study. INTERVENTION(S) Anthropometrics [weight, body mass index (BMI), and percentage body fat] and reproductive hormones were measured. The sexual quality of life was assessed using the Impact of Weight on the Quality Of Life-Lite questionnaire. MAIN OUTCOME MEASURE(S) Reproductive hormones and sexual quality of life were measured. RESULTS The mean age was 48.9 +/- 1.2 yr. At baseline, mean weight was 333.0 +/- 7.1 lb, BMI was 46.2 +/- 0.9 kg/m(2), and total testosterone was 339.9 +/- 21.32 ng/dl. BMI correlated positively with estradiol and negatively with total and free testosterone. Indices of dissatisfaction with sexual quality of life correlated positively with measures of obesity. Difficult sexual performance and low sexual desire correlated negatively with free and total testosterone (r = -0.273, P = 0.038; and r = -0.267, P = 0.042, respectively). After 2 yr, the gastric bypass surgery group had a significant decrease in BMI (-16.6 +/- 1.2 vs. -0.46 +/- 0.51 kg/m(2)) and estradiol (-8.1 +/- 2.4 vs. 1.6 +/- 1.4 pg/ml) and had an increase in total testosterone (310.8 +/- 47.6 vs. 14.2 +/- 15.3 ng/dl) and free testosterone (45.2 +/- 5.1 vs. -0.4 +/- 3.0 pg/ml). Sexual quality of life was improved after gastric bypass surgery. CONCLUSION Hormonal alterations and diminished sexual quality of life among obese men are related to degree of obesity, and both are improved after gastric bypass surgery.

DEXAMETHASONE SUPPRESSION TESTS: USEFULNESS OF SIMULTANEOUS MEASUREMENT OF PLASMA CORTISOL AND DEXAMETHASONE

The effect of oral dexamethasone on the plasma content of cortisol and dexa‐methasone was investigated in 175 patients suspected of having Cushings syndrome. Plasma concentrations of cortisol and dexamethasone were measured by specific radioimmunoassays at 08.00 h following administration of either a low‐low (0·5 mg), low (1·0 mg), high (4·0 mg) or high‐high (8·0 or more mg) dose of dexamethasone at midnight. All seventeen patients with documented Cushings syndrome exhibited resistance to the action of low‐low and/or low dose dexamethasone on suppression of 08.00 h plasma cortisol content. Nine of twelve patients with pituitary dependent Cushings syndrome had plasma cortisol values of less than 166 nmol/l following high‐high dose testing. In 157 patients with suspected Cushings syndrome, standard dexamethasone testing was considered unsatisfactory in at least 20%. After low‐low or low dose tests 11% had supranormal cortisol values, but plasma cortisol content overlapped with values observed in patients with Cushings syndrome only when plasma dexamethasone content was less than 5·6 nmol/l. Twelve per cent of patients suspected of having Cushings syndrome had sufficient elevation of plasma dexamethasone values after low dose testing so that marked reduction of plasma cortisol might be expected even in patients with pituitary dependent Cushings syndrome. Four patients receiving anticonvulsants had subnormal plasma levels of dexamethasone for the dose administered, but all exhibited normal suppression when plasma levels of dexamethasone and cortisol were correlated simultaneously. In summary, there is considerable variation in the plasma content of dexamethasone following oral doses. Simultaneous measurement of both plasma levels of dexamethasone and cortisol has proved most useful in identifying patients with unsatisfactory dexamethasone suppression tests.

Liquid chromatography tandem mass spectrometry for analysis of steroids in clinical laboratories

Liquid chromatography tandem mass spectrometry is one of the most specific techniques available in clinical laboratories. In the past, immunoassays were the primary methodology for analysis of steroids in biological samples because they are rapid and easy to perform. However, these methods were shown to suffer from the lack of specificity for measuring many of the diagnostically important steroids. LC-MS/MS overcomes many of the limitations of immunoassays, enhances diagnostic utility of the testing, and expands diagnostic capabilities in endocrinology. In addition to the superior quality of the measurements, LC-MS/MS allows high throughput testing using small sample volume with minimal sample preparation, and frees the laboratory from dependence on suppliers of assay specific reagents. LC-MS/MS is being widely employed for routine measurement of steroids, and the methodology plays an important role in the standardization and harmonization of measurements among clinical laboratories.

High-Sensitivity Tandem Mass Spectrometry Assay for Serum Estrone and Estradiol

High-sensitivity measurement of serum estrogens is important in adult and pediatric endocrinology and oncology. We developed a high-sensitivity liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous measurement of estrone (E1) and estradiol (E2). Aliquots of 200 muL of serum were spiked with internal standard, extracted, derivatized with dansyl chloride, and analyzed by LC-MS/MS using 2-dimensional chromatographic separation. Total imprecision for the method was less than 11%; the limit of quantitation was 1 pg/mL. Reference intervals were established with samples from more than 900 healthy postmenopausal women, men, girls, and boys. Concentrations of estrogens in children reached adult levels by Tanner stage 3. In men and postmenopausal women, the median concentrations of total estrogens (E1 + E2) were 39 and 22 pg/mL, and the median E2/E1 ratios were 0.98 and 0.55, respectively. The method requires a small sample volume and has adequate sensitivity and specificity for analyzing estrogens in samples from postmenopausal women, men, and children.