Context: The effects of COVID-19 on the thyroid axis remain uncertain. Recent evidence has been conflicting, with both thyrotoxicosis and suppression of thyroid function reported. Objective: We aimed to detail the acute effects of COVID-19 on thyroid function and determine if these effects persisted on recovery from COVID-19. Design: A cohort observational study was conducted. Participants and Setting: Adult patients admitted to Imperial College Healthcare National Health Service Trust, London, UK, with suspected COVID-19 between March 9 to April 22, 2020, were included, excluding those with preexisting thyroid disease and those missing either free thyroxine (FT4) or thyrotropin (TSH) measurements. Of 456 patients, 334 had COVID-19 and 122 did not. Main Outcome Measures: TSH and FT4 measurements were recorded at admission, and where available, in 2019 and at COVID-19 follow-up. Results: Most patients (86.6%) presenting with COVID-19 were euthyroid, with none presenting with overt thyrotoxicosis. Patients with COVID-19 had a lower admission TSH and FT4 compared to those without COVID-19. In the COVID-19 patients with matching baseline thyroid function tests from 2019 (n = 185 for TSH and 104 for FT4), TSH and FT4 both were reduced at admission compared to baseline. In a complete case analysis of COVID-19 patients with TSH measurements at follow-up, admission, and baseline (n = 55), TSH was seen to recover to baseline at follow-up. Conclusions: Most patients with COVID-19 present with euthyroidism. We observed mild reductions in TSH and FT4 in keeping with a nonthyroidal illness syndrome. Furthermore, in survivors of COVID-19, thyroid function tests at follow-up returned to baseline.

BACKGROUND. Patients with mutations that inactivate kisspeptin signaling are infertile. Kisspeptin-54, the major circulating isoform of kisspeptin in humans, potently stimulates reproductive hormone secretion in humans. Animal studies suggest that kisspeptin is involved in generation of the luteinizing hormone surge, which is required for ovulation; therefore, we hypothesized that kisspeptin-54 could be used to trigger egg maturation in women undergoing in vitro fertilization therapy. METHODS. Following superovulation with recombinant follicle-stimulating hormone and administration of gonadotropin-releasing hormone antagonist to prevent premature ovulation, 53 women were administered a single subcutaneous injection of kisspeptin-54 (1.6 nmol/kg, n = 2; 3.2 nmol/kg, n = 3; 6.4 nmol/kg, n = 24; 12.8 nmol/kg, n = 24) to induce a luteinizing hormone surge and egg maturation. Eggs were retrieved transvaginally 36 hours after kisspeptin injection, assessed for maturation (primary outcome), and fertilized by intracytoplasmic sperm injection with subsequent transfer of one or two embryos. RESULTS. Egg maturation was observed in response to each tested dose of kisspeptin-54, and the mean number of mature eggs per patient generally increased in a dose-dependent manner. Fertilization of eggs and transfer of embryos to the uterus occurred in 92% (49/53) of kisspeptin-54–treated patients. Biochemical and clinical pregnancy rates were 40% (21/53) and 23% (12/53), respectively. CONCLUSION. This study demonstrates that a single injection of kisspeptin-54 can induce egg maturation in women with subfertility undergoing in vitro fertilization therapy. Subsequent fertilization of eggs matured following kisspeptin-54 administration and transfer of resulting embryos can lead to successful human pregnancy. TRIAL REGISTRATION. ClinicalTrials.gov NCT01667406. FUNDING. Medical Research Council, Wellcome Trust, and National Institute for Health Research.

Context: In vitro fertilization (IVF) treatment is an effective therapy for infertility, but can result in the potentially life-threatening complication, ovarian hyperstimulation syndrome (OHSS). Objective: This study aimed to investigate whether kisspeptin-54 can be used to effectively and safely trigger oocyte maturation in women undergoing IVF treatment at high risk of developing OHSS. Setting and Design: This was a phase 2, multi-dose, open-label, randomized clinical trial of 60 women at high risk of developing OHSS carried out during 2013–2014 at Hammersmith Hospital IVF unit, London, United Kingdom. Intervention: Following a standard recombinant FSH/GnRH antagonist protocol, patients were randomly assigned to receive a single injection of kisspeptin-54 to trigger oocyte maturation using an adaptive design for dose allocation (3.2 nmol/kg, n = 5; 6.4 nmol/kg, n = 20; 9.6 nmol/kg, n = 15; 12.8 nmol/kg, n = 20). Oocytes were retrieved 36 h after kisspeptin-54 administration, assessed for maturation, and fertilized by intracytoplasmic sperm injection with subsequent transfer of one or two embryos. Women were routinely screened for the development of OHSS. Main Outcome Measure: Oocyte maturation was measured by oocyte yield (percentage of mature oocytes retrieved from follicles ≥ 14 mm on ultrasound). Secondary outcomes include rates of OHSS and pregnancy. Results: Oocyte maturation occurred in 95% of women. Highest oocyte yield (121%) was observed following 12.8 nmol/kg kisspeptin-54, which was +69% (confidence interval, −16–153%) greater than following 3.2 nmol/kg. At all doses of kisspeptin-54, biochemical pregnancy, clinical pregnancy, and live birth rates per transfer (n = 51) were 63, 53, and 45%, respectively. Highest pregnancy rates were observed following 9.6 nmol/kg kisspeptin-54 (85, 77, and 62%, respectively). No woman developed moderate, severe, or critical OHSS. Conclusion: Kisspeptin-54 is a promising approach to effectively and safely trigger oocyte maturation in women undergoing IVF treatment at high risk of developing OHSS.

Neurokinin B (NKB) is a hypothalamic neuropeptide binding preferentially to the neurokinin 3 receptor. Expression of the gene encoding NKB is elevated in postmenopausal women. Furthermore, rodent studies suggest that NKB signalling may mediate menopausal hot flushes. However, the effects of NKB administration on hot flushes have not been investigated in humans. To address this, we performed a randomised, double-blinded, placebo-controlled, 2-way cross-over study. Ten healthy women were admitted to a temperature and humidity-controlled research unit. Participants received 30 minute intravenous infusions of NKB and vehicle in random order. Symptoms, heart rate, blood pressure, sweating and skin temperature were compared between NKB and vehicle in a double-blinded manner. Eight of ten participants experienced flushing during NKB infusion with none experiencing flushing during vehicle infusion (P = 0.0007). Significant elevations in heart rate (P = 0.0106 vs. pre-symptoms) and skin temperature measured using skin probe (P = 0.0258 vs. pre-symptoms) and thermal imaging (P = 0.0491 vs. pre-symptoms) characteristic of menopausal flushing were observed during hot flush episodes. Our findings provide evidence that NKB administration can cause hot flushes in women. Further studies are required to determine if pharmacological blockade of NKB signalling could inhibit hot flushes during the menopause and during treatment for sex-steroid dependent cancers.

Background: Hypothalamic amenorrhea (HA) is the one of the most common causes of period loss in women of reproductive age and is associated with deficient LH pulsatility. High-dose kisspeptin-54 acutely stimulates LH secretion in women with HA, but chronic administration causes desensitization. GnRH has paradoxical effects on reproductive activity; we therefore hypothesized that a dose-dependent therapeutic window exists within which kisspeptin treatment restores the GnRH/LH pulsatility in women with HA. Aim: The aim of the study was to determine whether constant iv infusion of kisspeptin-54 temporarily increases pulsatile LH secretion in women with HA. Methods: Five patients with HA each underwent six assessments of LH pulsatility. Single-blinded continuous iv infusion of vehicle or kisspeptin-54 (0.01, 0.03, 0.10, 0.30, or 1.00 nmol/kg/h) was administered. The LH pulses were detected using blinded deconvolution. Results: Kisspeptin increased LH pulsatility in all patients with HA, with peak responses observed at different doses in each patient. The mean peak number of pulses during infusion of kisspeptin-54 was 3-fold higher when compared with vehicle (number of LH pulses per 8 h: 1.6 ± 0.4, vehicle; 5.0 ± 0.5, kisspeptin-54, P < .01 vs vehicle). The mean peak LH pulse secretory mass during kisspeptin-54 was 6-fold higher when compared with vehicle (LH pulse secretory mass in international units per liter: 3.92 ± 2.31, vehicle; 23.44 ± 12.59, kisspeptin-54; P < .05 vs vehicle). Conclusions: Kisspeptin-54 infusion temporarily increases LH pulsatility in women with HA. Furthermore, we have determined the dose range within which kisspeptin-54 treatment increases basal and pulsatile LH secretion in women with HA. This work provides a basis for studying the potential of kisspeptin-based therapies to treat women with HA.