Klinefelter syndrome, 47,XXY (KS), is the most frequent sex chromosome aberration in males, affecting 1 in 660 newborn boys. The syndrome is characterized by testicular destruction with extensive fibrosis and hyalinization of the seminiferous tubules resulting in small testes, hypergonadotropic hypogonadism, and azoospermia in the majority of cases. Until recently, infertility was considered an untreatable condition in KS. However, with the development of new advanced assisted reproductive techniques such as testicular sperm extraction (TESE) combined with ICSI it seems that KS patients should no longer be labelled as infertile. Especially, microdissection (micro)-TESE has proved to be an advantageous procedure for the identification of testicular spermatozoa in KS. The aim of this review was to describe current knowledge on the testicular changes occurring in KS, the associated changes in reproductive hormones and spermatogenesis, and the existing possibilities of biological fatherhood in 47,XXY patients.
M Andreassen, R B Jensen, N Jørgensen and A Juul
GH activity may be involved in male reproductive function. A common genetic polymorphism in the gene encoding the GH receptor (GHR) results in deletion of the entire exon 3 sequence (GHRd3 isoform). The short GHRd3/d3 isoform seems more sensitive compared with full-length receptors (GHRfl/fl).
To investigate the associations between GH activity, evaluated by exon 3 GHR polymorphism, and serum IGF1 vs reproductive hormones, semen quality, and pre- and postnatal growth in healthy young males (n=838, mean age: 19.4 years).
Compared with GHRfl/fl homozygous individuals (n=467) GHRd3/d3 homozygous individuals (n=69) tended to have larger semen volume (3.2 (2.4–4.3) vs 3.6 (2.6–4.7) ml, P=0.053) and higher serum inhibin-B levels (208 pg/ml (158–257) vs 227 pg/ml (185–264), P=0.050). Semen quality, levels of gonadotropins, testosterone, estradiol, sex hormone-binding globulin, and IGF1 were not associated with GHRd3 genotype.
A twofold increase in serum IGF1 was associated with a 13% (4–23) increase in calculated free testosterone (P=0.004). By contrast IGF1 was inversely associated with serum inhibin-B (P=0.027), but showed no associations to semen quality. GHR genotype and serum IGF1 were not associated with size at birth or final height.
GHRd3 polymorphism seemed only to have a weak influence on male reproductive function of borderline significance. The sensitive GHRd3/d3 genotype may slightly increase testicular function, as evaluated by semen volume and levels of inhibin-B, but does not seem to influence Leydig cell steroidogenesis. GHR genotype did not influence pre- and postnatal growth.
P Christiansen, AM Andersson, NE Skakkebaek and A Juul
BACKGROUND: Several studies have indicated that cryptorchidism is associated with degenerative changes in both Sertoli cells and germ cells. The gonadal peptide hormone inhibin B reflects Sertoli cell function. Low inhibin B levels are found in a large portion of formerly cryptorchid men who show compromised seminiferous tubule function. It is not known if inhibin B can be used to demonstrate early damage of seminiferous tubules in prepubertal boys with cryptorchidism. METHODS: We investigated the relationship between serum levels of inhibin B, testosterone, FSH and LH in 62 prepubertal boys with uni- and bilateral cryptorchidism. Furthermore, we investigated the changes in serum levels of inhibin B and the corresponding changes in serum levels of FSH, LH and testosterone during a short course (3 weeks) of human chorionic gonadotropin (hCG) injections in 18 of these cryptorchid boys. RESULTS: In the 62 prepubertal boys with uni- or bilateral cryptorchidism there were no significant differences in baseline levels (median and range) of inhibin B (88 (20-195) pg/ml vs 78 (35-182) pg/ml; not significant), LH (0.08 (<0.05-0.99) IU/l vs 0.06 (<0.05-1.61) IU/l; not significant) and FSH (0.60 (0.08-3.73) IU/l vs 0.85 (0.25-2.55); not significant) compared with 156 healthy prepubertal boys, and there were no differences in hormonal levels between boys with uni- or bilateral cryptorchidism. There was no correlation between baseline levels of inhibin B and FSH. In boys younger than 9 years, we found no correlation between baseline levels of inhibin B and LH whereas, in boys older than 9 years, baseline levels of inhibin B were positively correlated to baseline LH (Spearman rank correlation coefficient ((R(s))=0.58, P=0.03). Treatment with hCG (1500 IU intramuscularly twice weekly for 3 weeks) resulted in descensus of testes in 9 out of 18 patients. In all boys but one, irrespective of age, hCG induced a marked increase in testosterone into the adult range (from undetectable to 21.8 (7.0-35.4) nmol/l; P<0.001) and completely suppressed FSH and LH levels. Serum levels of inhibin B increased significantly from 116 (50-195) pg/ml to 147 (94-248) pg/ml (P<0.05), but not uniformly. The increase in serum levels of inhibin B was inversely correlated to baseline inhibin B (Rs=-0.52, P=0.03) and baseline FSH (R(s)=-0.59, P<0.01). CONCLUSIONS: We therefore suggest that, in the prepubertal testes, inhibin B is secreted from the prepubertal Sertoli cells following hCG, whereas early pubertal testes with more differentiated Sertoli cells are not able to secrete inhibin B in response to hCG stimulation, perhaps due to lack of germ cell-derived betaB-subunits. We found (a) normal inhibin B levels in prepubertal boys with uni- or bilateral cryptorchidism, (b) that hCG stimulated testosterone markedly and suppressed FSH and LH levels and (c) that hCG treatment stimulated inhibin B levels in the youngest cryptorchid boys. In the oldest prepubertal boys no hCG-induced changes in inhibin B were shown.
A Klamer, K Skogstrand, D M Hougaard, B Nørgaard-Petersen, A Juul and G Greisen
Objective: Adiponectin levels measured in neonatal dried blood spot samples (DBSS) might be affected by both prematurity and being born small for gestational age (SGA). The aim of the study was to measure adiponectin levels in routinely collected neonatal DBSS taken on day 5 (range 3–12) postnatal from infants.
Design: A retrospective case–control study.
Subjects and methods: One hundred and twenty-two infants: 62 very premature (34 SGA) and 60 mature infants (27 SGA). Adiponectin concentrations were determined in stored neonatal DBSS using a sandwich immunoassay based on flow metric Luminex xMap technology.
Results: Adiponectin was measurable in all samples, and repeated measurements correlated significantly (r = 0.94). Adiponectin concentrations were negatively associated with both SGA (B = −0.283, P = 0.04) and prematurity (B = −2.194, P < 0.001), independently of each other. In the premature but not the mature group, adiponectin levels increased with increasing postnatal age at blood sampling (B = 0.175, P < 0.001).
Conclusions: Reliable quantification of adiponectin in stored DBSS is feasible and may be used to study large populations of routinely collected samples. Low levels of adiponectin in neonatal DBSS are associated with SGA as well as prematurity. Blood adiponectin levels increase with postnatal age in premature infants, suggesting a rapid yet unexplained metabolic adaptation to premature extrauterine life.
W Kiess, M Anil, WF Blum, P Englaro, A Juul, A Attanasio, J Dotsch and W Rascher
The ob protein, termed leptin, is produced by adipocytes and is thought to act as an afferent satiety signal regulating weight through suppressing appetite and stimulating energy expenditure in humans and/or rodents. Insulin has been found to be a potent stimulator of leptin expression in rodents. It is unclear at present whether this insulin action is a direct or an indirect effect. To investigate whether leptin concentrations in children and adolescents with type 1 diabetes (IDDM) were related to metabolic status, body weight, body mass index and insulin treatment, we have measured leptin concentrations in serum from 13 newly diagnosed IDDM patients before the beginning of insulin treatment (8 girls, 5 boys, aged 4.7-17.5 years) and in 134 patients with IDDM during treatment (64 girls, 70 boys, aged 2.6-20.1 years) using a specific radioimmunoassay. The data from patients with diabetes were compared with normative data that were derived from a large cohort of healthy children and adolescents. Serum from children with newly diagnosed diabetes had significantly lower levels of leptin (mean 1.28+/-1.60 ng/ml, range 0.14-6.13 ng/ml) compared with healthy children (n=710) (mean 2.2 ng/ml, range 0.26-14.4ng/ml) and compared with insulin-treated children and adolescents (mean 5.18+/-5.48 ng/ml, range 0.26-29.77 ng/ml) (P<0.0001) even after adjustment for gender and body mass index (BMI). Serum leptin levels in patients with IDDM were significantly correlated with BMI (r=0.42, P<0.0001). Multiple regression analysis showed that age and BMI were significantly correlated with leptin levels, while duration of diabetes, mean HbA1c levels, insulin dose and plasma glucose, triglyceride and cholesterol levels were not. Females had higher serum leptin concentrations than males even when adjusted for BMI (P<0.0001). Surprisingly and most importantly, leptin levels in insulin-treated young adult (Tanner stage 5) patients were significantly higher than values found in the healthy nondiabetic reference population when adjusted for sex, Tanner stage and BMI. These findings suggest that leptin levels in IDDM patients show a similar dependency on adipose tissue and age as in healthy, normal children. The data provide evidence that insulin may be of importance as a regulator of serum leptin levels in vivo not only in rodents but also in humans. It is hypothesized that the elevated BMI-adjusted leptin levels in adolescents with IDDM could indicate either that these patients may be oversubstituted by the intensified insulin therapy that they are receiving or that their body composition and body fat content may differ from that of healthy adolescents in the sense that they have a relative increase in fat mass.
Lars J Vatten, Tom I L Nilsen, Anders Juul, Stig Jeansson, Pål A Jenum and Anne Eskild
To assess whether circulating IGF-I and IGF-binding protein-1 (IGFBP-1) in the first and second trimester are associated with subsequent risk of preterm and term preeclampsia.
Nested case–control study within a cohort of 29 948 pregnant women. Cases were women, who later developed preeclampsia, and controls were randomly selected women, who did not develop preeclampsia. IGF-I and IGFBP-1 were measured with ELISA in maternal blood samples that were collected in the first and second trimesters. We assessed associations of IGF-I and IGFBP-1 concentrations with later development of preterm (before the 37th week of gestation) and term preeclampsia.
An increase in IGF-I from the first to second trimester was associated with higher risk of preterm preeclampsia; the odds ratio (OR) for the highest compared with lowest quartile of increase was 4.9 (95% confidence interval, 1.1–21.8). Low concentrations of IGFBP-1, both in the first and in the second trimesters, were related to higher risk of term preeclampsia (OR 4.0, 95% confidence interval, 1.9–8.4) and moderately increased risk of preterm preeclampsia (OR 2.3, 95% confidence interval, 1.2–4.4).
The higher risk of preterm preeclampsia related to IGF-I increase may reflect placental disease, whereas low concentrations of IGFBP-1 associated with term preeclampsia may reflect maternal metabolic aberrations, indicating different etiologies in preeclampsia.
P E Clayton, R C Cuneo, A Juul, J P Monson, S M Shalet and M Tauber
The European Society for Paediatric Endocrinology held a consensus workshop in Manchester, UK in December 2003 to discuss issues relating to the care of GH-treated patients in the transition from paediatric to adult life. Clinicians experienced in the care of paediatric and adult patients on GH treatment, from a wide range of countries, as well as medical representatives from the pharmaceutical manufacturers of GH participated.
M Lange, OL Svendsen, NE Skakkebaek, J Muller, A Juul, M Schmiegelow and U Feldt-Rasmussen
OBJECTIVE: The insulin-tolerance test (ITT) is currently considered to be the gold standard for evaluating adults suspected of GH deficiency (GHD). The aim of this study was to determine factors that may influence nadir blood glucose (BG) when using a mean insulin dose of 0.1 IU/kg body weight. Furthermore, we wanted to evaluate the safety and GH-related aspects of the ITT. DESIGN: ITT was performed in 277 patients, of whom 255 (129 females) were eligible for evaluation. RESULTS: Multiple regression analysis, including the whole population, showed that the major determining factors for nadir BG were basal BG and body mass index (BMI) (P<0.02). No serious adverse event was recorded. Sixty-three percent of all patients tested had severe GHD with peak GH response to hypoglycaemia below 7.8 mIU/l. The positive predictive value for IGF-I was 0.82 and the negative predictive value was 0.47, using a cut-off value corresponding to -2 s.d. GH peak response to hypoglycaemia decreased with increasing numbers of other pituitary hormone deficiencies. CONCLUSIONS: When determining the dose of insulin based on weight, factors like pre-test BG and BMI should also be considered. We propose an algorithm stating that the dose of insulin should be 0.1 IU insulin/kg body weight minus 2 IU if pre-test BG is <4.0 mmol/l and minus 2 IU if BMI is <20 kg/m(2) in order to take these factors into account. Our findings furthermore support the concept that the low-dose ITT is a safe test in adults, when performed in experienced hands. It was confirmed that IGF-I is not sufficient when diagnosing GHD in adults, and reliable stimulation tests like ITT are required in the diagnosis.
Anders Juul, Søren A Pedersen, Steen Sørensen, Kjeld Winkler, Jens OL Jørgensen, Jens S Christiansen and Niels E Skakkebæk
Juul A, Pedersen SA, Sørensen S, Winkler K, Jørgensen JOL, Christiansen JS, Skakkebæk NE. Growth hormone (GH) treatment increases serum insulin-like growth factor binding protein- bone isoenzyme alkaline phosphatase and forearm bone mineral content in young adults with GH deficiency of childhood onset. Eur J Endocrinol 1994;131:41–9. ISSN 0804–4643
Recent studies have demonstrated that growth hormone (GH)-deficient adults have a markedly decreased bone mineral content compared to healthy adults. However, there are conflicting results regarding the effects of GH treatment on bone mineral content in GH-deficient adults. Therefore, we evaluated the effect of GH treatment on a marker of bone formation (bone alkaline phosphatase), hepatic excretory function and distal forearm bone mineral content in GH-deficient adults. Growth hormone was administered subcutaneously in 21 adults (13 males and 8 females) with GH deficiency of childhood onset for 4 months in a double-blind, placebo-controlled GH trial, while 13 of the patients then received further GH for an additional 14 months. Serum insulin-like growth factor I (IGF-I) increased significantly from 100 to 279 μg/l and IGF binding protein-3 (IGFBP-3) from 1930 to 3355 μg/l after 4 months of GH treatment (p < 0.0001). In addition, the molar ratio between IGF-I and IGFBP-3 increased significantly from 0.22 to 0.33 after GH treatment (p < 0.0001), Bone alkaline phosphatase increased significantly from 38.6 to 92.9 U/l during GH therapy in male patients (p < 0.0001), whereas liver-derived alkaline phosphatase was unaltered by GH. In the females, the increase in bone alkaline phosphatase did not reach statistical significance (19.1 vs 40.0 U/l, p = 0.06). The GH-induced increase in bone alkaline phosphatase correlated significantly with the increase in serum IGFBP-3 (r = 0.46, p = 0.04) but not with the increase in serum IGF-I (p = 0.16). Liver function as assessed by the galactose elimination capacity was within the normal range for healthy adults and did not change after GH treatment. Bone mineral content increased significantly between 7 and 14 months of GH treatment (mean increase in bone mineral content Z score = 0.24 sd/ 7 months), but remained low even after 14 months of GH treatment (Z score = –2.2 ± 0.24 (mean ± sem)). We conclude that GH administration increases serum levels of bone-derived alkaline phosphatase in male patients and has a potentially beneficial impact on bone mineral content in young adults with GH deficiency of childhood onset.
Anders Juul, Department of Growth and Reproduction, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark
Mikkel G Mieritz, Peter Christiansen, Martin Blomberg Jensen, Ulla N Joensen, Loa Nordkap, Inge A Olesen, A Kirstine Bang, Anders Juul and Niels Jørgensen
Gynaecomastia is a benign proliferation of glandular tissue of the breast; however, it is an important clinical observation because it can be the first symptom of an underlying disease. Some controversy exists concerning the clinical importance of an in-depth investigation of men who develop gynaecomastia. We hypothesise that a thorough work-up is required in adult men with gynaecomastia.
All adult men (n = 818) referred to a secondary level andrological department at Rigshospitalet in Copenhagen, Denmark during a four-year period (2008–2011) under the diagnosis of gynaecomastia (ICD-10: N62) were included.
Thirty-two men who did not have gynaecomastia when examined were excluded; leaving 786 men for final analyses. They underwent an andrological examination, ultrasound of the testicles and analysis of endogenous serum hormones levels.
In 43% of men with adult onset of gynaecomastia (≥18 years) an underlying, and often treatable, cause could be detected. In men younger at onset an underlying cause for gynaecomastia could be detected in merely 7.7%. The study is limited by the fact that we did not have access to investigate men who were referred directly by their GP to private clinics for plastic surgery or who sought cosmetic correction without consulting their GP first.
Our study demonstrates the importance of a thorough examination and provides a comprehensible examination strategy to disclose the underlying pathology leading to the development of gynaecomastia in adulthood.