Congenital hypogonadotropic hypogonadism (CHH) is characterized by lack of puberty and infertility. Traditionally, it has been considered a life-long condition yet cases of reversibility have been described wherein patients spontaneously recover function of the reproductive axis following treatment. Reversibility occurs in both male and female CHH cases and appears to be more common (~10–15%) than previously thought. These reversal patients span a range of GnRH deficiency from mild to severe and many reversal patients harbor mutations in genes underlying CHH. However, to date there are no clear factors for predicting reversible CHH. Importantly, recovery of reproductive axis function may not be permanent. Thus, CHH is not always life-long and the incidence of reversal warrants periodic treatment withdrawal with close monitoring and follow-up. Reversible CHH highlights the importance of environmental (epigenetic) factors such as sex steroid treatment on the reproductive axis in modifying the phenotype. This review provides an overview and an update on what is known about this phenomenon.
Andrew A Dwyer, Taneli Raivio, and Nelly Pitteloud
Taneli Raivio, Anne M Wikström, and Leo Dunkel
Background: Boys with prepubertal onset of hypogonadotropic hypogonadism (HH) are at a risk of poor testis growth and impaired spermatogenesis. One potential cause for this is deficient proliferation of immature Sertoli cells before and during puberty due to the absence of FSH.
Objective: To evaluate the effects of recombinant human FSH (r-hFSH) and human chorionicgonadotropin (hCG) on testicular function and pubertal development in boys with prepubertal onset of HH.
Design: Retrospective clinical study.
Setting: Two university central hospitals, pediatric referral endocrinology outpatient clinics.
Patients: Fourteen boys (aged, 9.9–17.7 years) with prepubertal (testicular volume (TV) <3 ml) onset of HH (idiopathic HH, n=2; Kallman syndrome, n=2; idiopathic panhypopituitarism, n=4; organic panhypopituitarism, n=6).
Intervention: Treatment with r-hFSH alone (2 mo–2.8 years) prior to induction of puberty with the combination of FSH and hCG.
Main outcome measures: Progression of puberty, change in serum inhibin B, spermatogenesis.
Results: r-hFSH alone increased testicular volume twofold, from 0.9±0.6 ml (mean±s.d.) to 1.8 ± 1.1 ml (P<0.005), and serum inhibin B threefold, from 27±14 to 80±57 pg/ml (P<0.01). Three boys with an apparent absence of postnatal hypothalamic–pituitary–testicular axis activation displayed attenuated inhibin B responses to long-term (≥1 year) r-hFSH (P<0.01). Further significant increase in both TVand inhibin B occurred with induction of puberty with FSH and hCG (P<0.001). Seven boys provided semen samples: one had azoospermia, and others displayed a maximal sperm count range from 2.9 to 92 million/ml (median 8.5 million/ml).
Conclusions: (i) r-hFSH induces prepubertal testis growth and increases circulating inhibin B levels, findings suggesting proliferation of immature Sertoli cells. (ii) Puberty was successfully induced with hCG and r-hFSH following r-hFSH priming. (iii) Inhibin B appears useful for monitoring spermatogenetic activity in boys treated with hCG. (iv) Despite the extremely small initial testis volume, six out of seven patients (86%) primed with r-hFSH displayed sperm in the ejaculate suggesting beneficial effect of r-hFSH priming on testicular function later in life.
Niina Matikainen, Marja-Riitta Taskinen, Sanna Stennabb, Nina Lundbom, Antti Hakkarainen, Kirsi Vaaralahti, and Taneli Raivio
Elevated levels of circulating fibroblast growth factor 21 (FGF21) are commonly encountered in type 2 diabetes, dyslipidemia, and non-alcoholic fatty liver disease, all of which share exaggerated postprandial lipemia as a common proatherogenic feature. How FGF21 responds to an oral fat load in man is unknown.
We measured liver fat contents and subcutaneous and visceral fat volumes in 47 healthy subjects, who also underwent an oral fat load with measurements of plasma FGF21 and free fatty acid (FFA). Triglyceride (TG), apolipoprotein B-48 (apoB-48), and apoB-100 concentrations were measured in triglyceride-rich lipoprotein (TRL) fractions.
When compared with fasting levels, the concentration of FGF21 decreased significantly at 4 h (P<0.05) and tended to return to fasting levels at 8 h after an oral fat load. Fasting and postprandial FGF21 correlated significantly with liver fat as well as with TRLs in the chylomicron and especially in very low-density lipoprotein 1 (VLDL1) and VLDL2 fractions representing remnant particles, but not with FFA. Subjects with increased liver fat (>5%, n=12) showed impaired suppression of FGF21 at 4 h (P<0.05) and at 8 h (P=0.01) and demonstrated higher postprandial TG area under the curve in plasma and TRL fractions (P≤0.032) compared with those with normal liver fat (≤5%, n=35).
We observed a significant decrease of FGF21 concentration after an oral fat load. Fasting and postprandial FGF21 levels were closely related to large VLDL and remnants, but not to plasma FFA. Our pilot findings suggest that the postprandial accumulation of TRL remnants and liver fat may modulate postprandial FGF21 levels.
Marianne K Vihinen, Kaija-Leena Kolho, Merja Ashorn, Matti Verkasalo, and Taneli Raivio
We investigated circulating markers of bone turnover before and during systemic glucocorticoid treatment in paediatric patients with inflammatory bowel disease (IBD).
Twenty-two children (mean age, 12.3 years) with IBD necessitating peroral steroid therapy were studied, with special reference to bone formation and resorption markers amino-terminal type I collagen propeptide (PINP) and carboxyterminal telopeptide of type I collagen (ICTP) respectively. In addition, GH-related IGF-I and sex hormone-binding protein (SHBG) were measured. Bone markers were analyzed at the initiation of the glucocorticoid treatment, at 2 and 5 weeks thereafter and at 1 month following the withdrawal of the steroid. Control group comprised 22 IBD patients in remission.
PINP and IGF-I were already lower before glucocorticoid treatment serum in children with active IBD as compared with control children with IBD in remission (median PINP 271 vs 535 μg/l, P<0.05; IGF-I 23 vs 29 nmol/l, P<0.05). After 2 weeks of glucocorticoid treatment serum PINP levels had declined further, from 271 to 163 μg/l (P<0.001), serum ICTP from 14.2 to 9.6 μg/l (P<0.001), and SHBG from 54 to 35 nmol/l (P<0.001) respectively. By contrast, serum IGF-I increased from 23 to 37 nmol/l (P<0.001). One month after the withdrawal of the glucocorticoid, all bone markers restored to levels similar to the controls.
Bone formation in children with active IBD appears compromised and systemic glucocorticoid treatment further suppresses bone turnover. After the cessation of the glucocorticoid the bone markers show immediate improvement.
Tero Varimo, Leo Dunkel, Kirsi Vaaralahti, Päivi J Miettinen, Matti Hero, and Taneli Raivio
Makorin ring finger protein 3 (MKRN3) gene restrains the hypothalamic–pituitary–gonadal axis. In girls, peripheral levels of MKRN3 decline prior to the onset of puberty. We described longitudinal changes in serum MKRN3 levels in boys before and during puberty and assessed the effect of inhibition of estrogen biosynthesis on MKRN3 levels.
Longitudinal serum samples from a double-blind, randomized controlled study in 30 boys (age range: 9.1–14.2years) with idiopathic short stature who received placebo (Pl; n=14) or aromatase inhibitor letrozole (Lz; 2.5mg/day; n=16) for 2years.
We analyzed the relationships between serum MKRN3 and clinical and biochemical markers of puberty by using summary measures.
Serum MKRN3 declined by 669±713 pg/mL per year (P<0.001). This change was biphasic, as the levels decreased during Tanner genital stage G1 (–2931±2750 pg/mL per year) and plateaued thereafter (–560±1510 pg/mL per year) (P<0.05). During G1, MKRN3 levels in Lz-treated subjects decreased slower than in Pl-treated boys (–782±3190 vs –2030±821 pg/mL per year, P<0.05). The decrease in serum MKRN3 levels in G1 was associated with increases in LH (r=–0.5, P<0.01), testosterone (r=–0.6, P<0.01), and inhibin B (r=–0.44, P<0.05) (n=26).
Peripheral MKRN3 levels in boys appear to serve as a readout of the diminishing central inhibition that controls the onset of puberty.
Juho Kärkinen, Päivi J Miettinen, Taneli Raivio, and Matti Hero
To describe the etiology of severe short stature in the Helsinki University Hospital district covering a population of 1.2 million that is subject to frequent growth monitoring and screening rules during childhood.
Retrospective cohort study.
We identified all subjects born 1990 or later with a height SD score <−3, after the age of 3 years, from the Helsinki University Hospital district growth database. A total of 785 subjects (376 females and 409 males) fulfilled our inclusion criteria; we reviewed their medical records and growth data and report their underlying diagnoses.
A pathological cause for short stature was diagnosed in 76% of the girls and 71% of the boys (P = NS). Syndromes were the most numerous pathological cause (n = 160; 20%), followed by organ disorders (n = 127; 16%), growth hormone deficiency (GHD, n = 94; 12%), SGA without catch-up growth (n = 73; 9%), and skeletal dysplasias (n = 57; 7%). Idiopathic short stature (ISS) was diagnosed in 210 (27%) subjects. The probability of growth-related pathology, particularly of a syndrome or skeletal dysplasia, increased with the shorter height SD score and the greater deviation from the target height. Sitting height to height SDS was increased in subjects with ISS, GHD, and SGA (all P < 0.01).
Height <−3 SDS after 3 years of age usually results from a pathological cause and should be thoroughly investigated in specialized health care. The chance of finding a specific etiology increased with the severity of short stature, and the mismatch with target height.
Päivi Nykänen, Taneli Raivio, Kirsti Heinonen, Olli A Jänne, and Raimo Voutilainen
Objective: Glucocorticoids are widely used before preterm delivery and in preterm infants may bear serious adverse effects. Better knowledge about the circulating glucocorticoid milieu after glucocorticoid treatment could improve treatment modalities. Therefore, we investigated the influence of exogenous glucocorticoids and clinical factors on serum cortisol (F) levels and circulating glucocorticoid bioactivity (GBA) in preterm infants.
Design: Eighty-nine infants (gestational age (GA) 23.6–33.1 weeks at birth) were enrolled in a prospective cohort study in two tertiary neonatal centres.
Methods: Cord, day of birth (D0), fourth day (D4) and 36 weeks postmenstrual age serum F and GBA levels were measured.
Results: The cord GBA was 5.8-fold and D0 GBA 2.3-fold higher in the infants exposed to antenatal steroids within 12 h before birth when compared with those unexposed or exposed >7 days before birth (95% CI 3.8–8.6; P<0.0001, and 1.8–3.0; P<0.0001 respectively). In the infants treated with early postnatal dexamethasone, D4 GBA was 1.7-fold (1.3–2.2; P<0.0005) higher when compared with levels in the infants without this treatment. Clinical factors indicating perinatal distress, such as Apgar scores <7 and low GA, were associated with higher cord, D0 and D4 serum F levels.
Conclusions: Both ante- and postnatally administered glucocorticoids increase circulating GBA not attributable to endogenous F. Perinatal distress and preceding glucocorticoid treatment need to be taken into account when circulating glucocorticoid milieu is evaluated in preterm infants. The GBA assay may prove to be a useful instrument in the development of new glucocorticoid treatment strategies.
Riikka Leminen, Taneli Raivio, Sirpa Ranta, Joachim Oehler, Helena von Hertzen, Olli A Jänne, and Oskari Heikinheimo
Objective: Low dose mifepristone (RU486) is highly effective in emergency post-coital contraception (EC), although the mechanism(s) of action remains unclear. We studied the endocrine actions of 10 mg mifepristone administered orally as a single dose to eight healthy volunteers (aged 20–45 years) during the late follicular phase.
Methods: Serum levels of LH, FSH, oestradiol, progesterone, leptin, mifepristone, cortisol, and gluco-corticoid bioactivity (GBA) were measured before and 1, 2, 4 and 8 h after ingestion of mifepristone on cycle day 10 or 11 (study day 1), and follow-up was continued for 10 days. Ovarian ultrasonography was performed on study days 1 and 7. Similar measurements were carried out during a control cycle.
Results: Mifepristone postponed ovulation, as evidenced by a 3.4±1.1 day (means±s.d.) delay (P < 0.005) in the LH surge and 3.6±4.0 day prolongation of the treatment cycle (P = 0.08). During the mifepristone cycle, an LH surge was displayed by five subjects when serum mifepristone levels had declined to 9.5±7.1 nmol/l. During the day of mifepristone administration, circulating GBA (P < 0.001) and leptin (P < 0.001) levels declined. On the day after mifepristone administration, mean serum FSH and leptin levels were lower than pretreatment values (3.8±1.8 IU/l vs 5.2±1.1 IU/l, n = 7, P < 0.05; 28.9±6.7 μg/l vs 33.2±9.0 μg/l, n = 7, P < 0.05 respectively), and the corresponding difference in the mean serum oestradiol concentration was borderline (452±252 pmol/l vs 647±406 pmol/l, n = 7, P = 0.056). In contrast to the control cycle, individual leptin levels declined during the follow-up after ingestion of mifepristone (n = 8, P < 0.01).
Conclusions: These data showed that the commonly employed dose of mifepristone for EC delays ovulation and prolongs the menstrual cycle, when given during the late follicular phase. The mechanism of action of mifepristone may include a reduction of FSH secretion via a decrease in circulating leptin.