Maternal serum vitamin D level in early pregnancy and risk for preeclampsia: A case-control study in Southern Sweden.

BACKGROUND: Preeclampsia is considered a major cause of maternal and fetal morbidity and mortality. The aim of the present case-control study in Sweden was to assess the hypothesized association between low serum vitamin D concentrations in early pregnancy and the risk of developing preeclampsia since vitamin D may play a role in early placental development. METHODS: The study included 296 women diagnosed with preeclampsia (cases) and 580 healthy pregnant women (controls). Serum samples were obtained from a biobank of samples collected in early pregnancy including almost all pregnancies in Southern Sweden. Concentrations of 25-hydroxyvitamin D3 (vitamin D) were analyzed using liquid chromatography-tandem-mass-spectrometry (LC/MS/MS). The cases were divided into two categories: i) infants were born before gestational week 34 (early onset) and/or born small-for-gestational age (SGA)(n = 51), ii) and others defined as late onset (n = 245). Vitamin D concentrations were analyzed both as a continuous and a categorized variable. RESULTS: When all preeclampsia cases were included in the analyses no consistent patterns were observed. However, the median serum concentrations of vitamin D were significantly lower among the cases who were early onset and/or were born SGA (median 39.2 nmol/L, range 1.2-93.6) as compared to the controls (49.0 nmol/L, 0.1-219; p = 0.01). In addition, high concentrations were statistically significantly associated with a decreased risk of preeclampsia (>66.9 vs ≤30.1 nmol/L; crude OR 0.39, 95% CI 0.16-0.96). When potential confounders were included in the models the associations were even more pronounced. CONCLUSIONS: Our results support the hypothesis that vitamin D deficiency is a risk factor for preeclampsia, but only in preeclampsia cases who were early-onset and/or were born SGA. Preeclampsia is not a homogenous condition and more studies are needed before vitamin D supplementation during pregnancy can be recommended.

[Treatment of erectile dysfunction - from pill to implant]. / Behandling av erektil dysfunktion ­ från piller till implantat - Region Skåne har kapat kön till implantatkirurgi utan att urologisk cancerkirurgi påverkats.

The article gives an overview of erectile mechanisms and erectile dysfunction (ED). Current treatment of ED is presented. Most of the patients with ED should be treated by their primary care physician. Urologists should be involved only when treatment has failed, and when erectile implants might be an option. In Skåne the waiting list for these patients has been eliminated by using the operating capacity of a smaller hospital.

Seasonal fluctuation in the secretion of the antioxidant melatonin is not associated with alterations in sperm DNA damage.

A high sperm DNA fragmentation index (DFI) is associated with reduced fertility. DFI is influenced by the balance between reactive oxygen species and antioxidants. A circannual variation in melatonin, an antioxidant and free radical scavenger, could thus impact semen quality and fertility. The association between the major melatonin metabolite, urine 6-sulfatoxymelatonin (aMT6s), and DFI was analyzed in 110 Oslo men (south of the Arctic Circle) and 86 Tromsoe men (north of the Arctic Circle). Two semen analyses, summer and winter, and four urine samples (early/late summer; early/late winter), were analyzed. The associations between aMT6s in urine and DFI were characterized in a cross-sectional and longitudinal manner using correlation analysis and linear regression. Regardless of season and location, no significant correlations between aMT6s and DFI were observed. The correlation coefficients for associations between changes over time (early winter-early summer) in aMT6s and DFI were for the total cohort: rho = -0.08 (P = 0.322), for the Oslo cohort: rho = -0.07 (P = 0.485), and for the Tromsoe cohort: rho = -0.14 (P = 0.273), respectively. Similar results were seen when comparing late winter and late summer. There was no any statistically significant correlation between changes over time in aMT6s and DFI for men with DFI below and above the median value (10%), respectively. The seasonal variation in melatonin excretion seems not to have any impact on DFI.

Hearing loss in patients with mucopolysaccharidosis II: data from HOS - the Hunter Outcome Survey.

BACKGROUND: Subjectively reported hearing loss is a common feature of mucopolysaccharidosis II (MPS II, Hunter syndrome). This study provides an epidemiological description of hearing loss and other otolaryngological manifestations reported by patients registered in the Hunter Outcome Survey (HOS), an international registry of patients with MPS II. METHODS: Data about ear signs and symptoms were available for 554 of the 605 patients alive at HOS entry. The degree of hearing loss for 162 pure-tone audiograms (PTAs) from 83 patients was classified by independent interpreters using both the age-specific International Institute of Standardization (ISO) 7029 standard and the age-independent World Health Organization (WHO) clinical guidelines. A linear regression analysis using cross-sectional data was conducted to investigate the relationship between hearing loss and age. RESULTS: The most prevalent otolaryngological manifestations and interventions reported were otitis (either acute otitis media or chronic otitis media [72%]), hearing loss (67%), insertion of ventilation tubes (50%), adenoidectomy (47%), and hearing aids (41%). According to the ISO standard, only one patient out of the 83 with audiogram data in HOS had normal hearing in both ears at all time points. According to the WHO classification, 16% had normal hearing; hearing loss was mild in 24%, moderate in 31%, severe in 22%, and profound in 7%. In the linear regression analysis, the hearing threshold in the cohort increased with age at an estimated rate of approximately 1 dB per year. CONCLUSIONS: Hearing impairment is common in MPS II. Early otolaryngological evaluation and intervention is recommended.

Mucopolysaccharidosis type II: European recommendations for the diagnosis and multidisciplinary management of a rare disease.

UNLABELLED: Mucopolysaccharidosis type II (MPS II) is a rare, life-limiting, X-linked recessive disease characterised by deficiency of the lysosomal enzyme iduronate-2-sulfatase. Consequent accumulation of glycosaminoglycans leads to pathological changes in multiple body systems. Age at onset, signs and symptoms, and disease progression are heterogeneous, and patients may present with many different manifestations to a wide range of specialists. Expertise in diagnosing and managing MPS II varies widely between countries, and substantial delays between disease onset and diagnosis can occur. In recent years, disease-specific treatments such as enzyme replacement therapy and stem cell transplantation have helped to address the underlying enzyme deficiency in patients with MPS II. However, the multisystem nature of this disorder and the irreversibility of some manifestations mean that most patients require substantial medical support from many different specialists, even if they are receiving treatment. This article presents an overview of how to recognise, diagnose, and care for patients with MPS II. Particular focus is given to the multidisciplinary nature of patient management, which requires input from paediatricians, specialist nurses, otorhinolaryngologists, orthopaedic surgeons, ophthalmologists, cardiologists, pneumologists, anaesthesiologists, neurologists, physiotherapists, occupational therapists, speech therapists, psychologists, social workers, homecare companies and patient societies. TAKE-HOME MESSAGE: Expertise in recognising and treating patients with MPS II varies widely between countries. This article presents pan-European recommendations for the diagnosis and management of this life-limiting disease.

Differences in serum levels of CB-153 and p,p'-DDE, and reproductive parameters between men living south and north in Norway.

Arctic is contaminated with persistent organochlorine pollutants (POPs), and exposure to these compounds may differ between south and north in Norway. POPs may have negative impact on male reproductive characteristics. We compared serum levels of the CB-153 and p,p'-DDE in men who were born and had lived most of their lifetime south and north (close to or above the Arctic Circle) in Norway. We found no geographical differences in levels of CB-153 (south: 50 ng/g lipid (mean), north: 59 ng/g lipid; p=0.27) or sperm parameters. However, the levels of p,p'-DDE were higher in south than in north (81 ng/g lipid (mean) vs. 66 ng/g lipid; p=0.02), as were the levels of total and free testosterone. The FSH levels were lowest in south. A strong relationship between the CB-153 and the SHBG levels was observed. The regional differences observed for p,p'-DDE, testosterone and FSH were not reflected in the semen quality.

Importance of surgical history in diagnosing mucopolysaccharidosis type II (Hunter syndrome): data from the Hunter Outcome Survey.

PURPOSE: To characterize surgical histories typical of patients with mucopolysaccharidosis type II, thereby broadening understanding of the natural history of these patients and helping physicians recognize the disease. METHODS: Data on surgical interventions from the Hunter Outcome Survey--a multinational, observational database of patients with mucopolysaccharidosis type II-were analyzed. The study population comprised 527 patients for whom surgical data were reported on/before July 23, 2009. RESULTS: Surgical interventions were performed in 83.7% of the study population. Patients underwent their first operation at a median age of 2.6 years. Tympanostomies, repairs of inguinal hernias, and operations for carpal tunnel syndrome were performed in a greater proportion of the study population than the general population. A median of 3.0 operations was performed per patient; repeat operations for hernia or carpal tunnel syndrome were common. The majority of patients (221/389) underwent at least one surgical intervention before diagnosis of mucopolysaccharidosis type II. CONCLUSION: Patients with mucopolysaccharidosis type II typically undergo surgical intervention at a young age, often before diagnosis. Repeated early surgical interventions, particularly for hernias or carpal tunnel syndrome, are characteristic of patients with mucopolysaccharidosis type II. We recommend that such patients are carefully examined for manifestations of mucopolysaccharidosis disorders and referred for diagnostic testing.

Prenatal treatment for serious neurological sequelae of congenital toxoplasmosis: an observational prospective cohort study.

BACKGROUND: The effectiveness of prenatal treatment to prevent serious neurological sequelae (SNSD) of congenital toxoplasmosis is not known. METHODS AND FINDINGS: Congenital toxoplasmosis was prospectively identified by universal prenatal or neonatal screening in 14 European centres and children were followed for a median of 4 years. We evaluated determinants of postnatal death or SNSD defined by one or more of functional neurological abnormalities, severe bilateral visual impairment, or pregnancy termination for confirmed congenital toxoplasmosis. Two-thirds of the cohort received prenatal treatment (189/293; 65%). 23/293 (8%) fetuses developed SNSD of which nine were pregnancy terminations. Prenatal treatment reduced the risk of SNSD. The odds ratio for prenatal treatment, adjusted for gestational age at maternal seroconversion, was 0.24 (95% Bayesian credible intervals 0.07-0.71). This effect was robust to most sensitivity analyses. The number of infected fetuses needed to be treated to prevent one case of SNSD was three (95% Bayesian credible intervals 2-15) after maternal seroconversion at 10 weeks, and 18 (9-75) at 30 weeks of gestation. Pyrimethamine-sulphonamide treatment did not reduce SNSD compared with spiramycin alone (adjusted odds ratio 0.78, 0.21-2.95). The proportion of live-born infants with intracranial lesions detected postnatally who developed SNSD was 31.0% (17.0%-38.1%). CONCLUSION: The finding that prenatal treatment reduced the risk of SNSD in infected fetuses should be interpreted with caution because of the low number of SNSD cases and uncertainty about the timing of maternal seroconversion. As these are observational data, policy decisions about screening require further evidence from a randomized trial of prenatal screening and from cost-effectiveness analyses that take into account the incidence and prevalence of maternal infection. Please see later in the article for the Editors' Summary.

Single semen analysis as a predictor of semen quality: clinical and epidemiological implications.

It is generally thought that a single ejaculate is a bad predictor of semen quality of a subject, because of significant intra-individual variation. Therefore, we investigated the degree to which the results of a first semen analysis differ from that of a second analysis among men from a general population in Norway. In addition, we analysed how the two different semen results mirrored the overall semen quality assessment. A total of 199 volunteers participated in the study and delivered two semen samples with an interval of 6 months. The semen parameters were determined according to the World Health Organization (WHO) 1999 guidelines, which were also used to determine whether semen quality was normal or abnormal. In addition, the DNA fragmentation index (DFI) was determined using the Sperm Chromatin Structure Assay. The two samples from each individual were very similar with regard to standard semen parameters and DFI (r(s:) 0.67-0.72), and there were no significant systematic differences between the two samples. The result of the first sample (normal/abnormal) was highly predictive of the overall conclusion based on the two samples (sperm concentration: in 93% of the cases (95% confidence interval [CI]: 89%-96%); sperm motility: in 85% of the cases (95% CI: 79%-89%); overall semen quality: in 85% of the cases (95% CI: 80%-90%). In epidemiological studies, one ejaculate is a sufficient indicator of semen quality in a group of subjects. In a clinical situation, when the question is whether the semen quality is normal or not, the first ejaculate will, in at least 85% of cases, give a correct overall conclusion.

Neonatal herpes simplex virus infection.

Herpes simplex virus (HSV) infection in the neonate is a rare event with severe consequences for the child even if adequately treated with antiviral drugs. Mothers with primary genital herpes infections late in pregnancy or at delivery have a high risk of transferring the infection to the child, while the risk of transfer in mothers with recurrent genital infections is only a few percent. Neonatal herpes localized in skin-eye-mouth has no mortality and morbidity after antiviral treatment. In neonatal disseminated and central nervous system disease, early treatment is a predictor for better outcome. The morbidity in survivors is high; after herpes encephalitis, only one-third of children have normal development. While awaiting vaccines or reliable predictors for prevention of neonatal herpes, clinical awareness of primary maternal herpes during pregnancy and recommendations for prophylactic treatment are important tools. For pediatricians the differential diagnosis of a child aged two to four weeks with seizures, neonatal herpes encephalitis must be considered and either excluded or treated. Neurological follow-up and training programs to minimize the consequences of a disability are important clinical aspects.

High prevalence of cardio-metabolic risk factors among adolescents with intellectual disability.

UNLABELLED: Adults with intellectual disabilities (IDs) have poor lifestyle-related health compared with the general population. Our aim was to study whether such differences are present already in adolescents. AIM: To compare the prevalence and severity of cardio-metabolic risk factors and cardio-vascular fitness in adolescents with and without IDs. METHODS: Intellectual disability (ID) students (n = 66) and non-intellectual disability (non-ID) students from practical (non-ID-p) (n = 34) and theoretical (non-ID-t) (n = 56) programmes were recruited from three upper secondary schools. Anthropometric data, blood pressure, body composition, fasting-insulin, fasting-glucose, fasting-lipids and cardio-vascular fitness were measured. RESULTS: Participants with and without ID differed significantly in the prevalence of cardio-metabolic risk factors with participants with ID having a higher percentage of total fat mass, wider waist circumferences (WCs), lower levels of fat-free mass (FFM), lower bone mineral density (BMD) and higher insulin and homeostasis model assessment of insulin resistance (HOMA) levels and poorer cardio-vascular fitness. The healthiest levels were found in the non-ID-t group compared to the group with ID and the group with non-ID-p in between. CONCLUSION: The prevalence of cardio-metabolic risk factors and poor cardio-vascular fitness was found to be high in this young population with intellectual disabilities. Measures should be taken to improve the health messages directed towards children and adolescents with intellectual disabilities.

MtDNA mutations are a common cause of severe disease phenotypes in children with Leigh syndrome.

Leigh syndrome is a common clinical manifestation in children with mitochondrial disease and other types of inborn errors of metabolism. We characterised clinical symptoms, prognosis, respiratory chain function and performed extensive genetic analysis of 25 Swedish children suffering from Leigh syndrome with the aim to obtain insights into the molecular pathophysiology and to provide a rationale for genetic counselling. We reviewed the clinical history of all patients and used muscle biopsies in order to perform molecular, biochemical and genetic investigations, including sequencing the entire mitochondrial DNA (mtDNA), the mitochondrial DNA polymerase (POLGA) gene and the surfeit locus protein 1 (SURF1) gene. Respiratory chain enzyme activity measurements identified five patients with isolated complex I deficiency and five with combined enzyme deficiencies. No patient presented with isolated complex IV deficiency. Seven patients had a decreased ATP production rate. Extensive sequence analysis identified eight patients with pathogenic mtDNA mutations and one patient with mutations in POLGA. Mutations of mtDNA are a common cause of LS and mtDNA analysis should always be included in the diagnosis of LS patients, whereas SURF1 mutations are not a common cause of LS in Sweden. Unexpectedly, age of onset, clinical symptoms and prognosis did not reveal any clear differences in LS patients with mtDNA or nuclear DNA mutations.

Congenital CMV infection: prevalence in newborns and the impact on hearing deficit.

Congenital cytomegalovirus (CMV) infection is asymptomatic in 90% of infected newborns but approximately 10-20% of these infants are at risk of developing sequelae later, mostly hearing deficit. The aims of the study were to investigate the prevalence of congenital CMV infection in a Swedish population of newborns and investigate the relative risk of hearing deficit in newborns with congenital CMV infection. The dried blood spot (DBS) samples of 6060 newborns in southern Stockholm during 12 months (October 2003-June 2004; August 2004-October 2004) were analysed for CMV DNA by TaqMan based real-time PCR. Hearing deficit was assessed by otoacoustic emission (OAE) within a newborn screening programme. 12 infants out of 6060 or 0.2% (95% CI 0.1-0.3%) had congenital CMV infection. One boy among the 12 infected infants had unilateral hearing loss, indicating that the risk of hearing loss is greatly increased (about 20 times) in CMV infected infants. No child developed ocular complications such as chorioretinopathy during 3 y of follow-up. Congenital CMV has an impact on child health but can easily be overlooked due to lack of signs in the neonatal period. Surveillance for congenital CMV is important in addition to programmes for prevention and treatment.

Mucopolysaccharidoses in the Scandinavian countries: incidence and prevalence.

AIM: The aim of this study was to estimate the incidence and prevalence of mucopolysaccharidoses (MPS disorders) in Scandinavia. METHODS: The retrospective period used for the incidence study covered the period from 1975 to 2004 in Sweden and Denmark and from 1979 to 2004 in Norway. Prevalence was derived from the number of MPS patients alive as of December 31, 2007. RESULTS: The incidence of all MPS disorders was 1.75 cases in Sweden, 3.08 cases in Norway and 1.77 cases in Denmark per 100 000 newborns. The incidence of MPS I was the most common in all three countries, with 0.67, 1.85 and 0.54 cases per 100 000 newborns, respectively; for MPS II, numbers were 0.27, 0.13 and 0.27, respectively. For patients with other MPS disorders the incidence varied widely. The prevalence for all MPS disorders was 4.24, 7.06 and 6.03 per 1 000 000 inhabitants in Sweden, Norway and Denmark, respectively. CONCLUSION: From three Scandinavian countries the incidence of MPS disorders is retrospectively evaluated for 25 years in Norway and 30 years in Sweden and Denmark. Incidence and prevalence studies of lysosomal disorders are prerequisites for cost benefit calculations in the face of newly developed and expensive therapies in the future.

Neuropsychologic outcomes in children with neonatal herpes encephalitis.

Neonatal herpes simplex virus infection with involvement of the central nervous system is a serious disease with high morbidity, even with acyclovir therapy. The disability includes cerebral palsy and different aspects of cognitive dysfunction which are of utmost importance for the child's future habilitation. We conducted a descriptive cohort study to define neuropsychologic outcomes and determine the relationship between neonatal neuroimaging and neuropsychologic outcomes. Among 267,690 children born in the Stockholm area over 12 years (1989-2000), 14 were diagnosed with neonatal herpes including central nervous system involvement. Nine children were neuropsychologically evaluated. Neonatal herpes virus infection had an even greater impact on cognitive function, speech ability, and attention deficit than anticipated. Relapse leading to deterioration was demonstrated in one child. Social skills were influenced to a lesser degree. Neurodevelopmental outcomes of the children were not well-correlated with extent of cerebral damage as visualized by computed tomography at 7-28 days after onset of signs. Neuropsychologic assessment is essential in the habilitation of the child, and a prerequisite for the evaluation of new treatments and for the assessment of deterioration of cerebral function related to relapses.

Outcome in six children with mucopolysaccharidosis type IH, Hurler syndrome, after haematopoietic stem cell transplantation (HSCT).

AIM: To follow-up six children with severe mucopolysaccharidosis type IH, Hurler syndrome, who were treated before 24 months of age with haematopoietic stem cell transplantation. METHODS: In Sweden, during the last 10-year period, six consecutive children born with severe mucopolysaccharidoses type IH have been successfully transplanted using matched unrelated donors between the ages of 11 and 24 months (mean age 18 months). Three children received intravenous enzyme replacement therapy once a week, from diagnosis until engraftment of their bone marrow. RESULT: Two children developed chimerism and a progressive increase in recipient cells and later received a successful re-transplantation. One to two years after transplantation the children demonstrated some developmental delays in cognitive function. Latterly this was followed by normalization. Orthopaedic operations on the spine and hips and carpal tunnel syndrome were still required following transplantation. Cardiac valve involvement remained progressive in the children. CONCLUSION: The outcome of six children in this study confirms that early haematopoietic stem cell transplantation in mucopolysaccharidosis type I, Hurler syndrome, preserves an affected child's mental ability. Consequently, it is essential that clinical recognition and early diagnosis take place, providing an additional challenge to paediatricians treating this condition.

Predictors of retinochoroiditis in children with congenital toxoplasmosis: European, prospective cohort study.

OBJECTIVE: By school age, 20% of children infected with congenital toxoplasmosis will have > or = 1 retinochoroidal lesion. We determined which children are most at risk and whether prenatal treatment reduces the risk of retinochoroiditis to help clinicians decide about treatment and follow-up. PATIENTS AND METHODS: We prospectively studied a cohort of children with congenital toxoplasmosis identified by prenatal or neonatal screening in 6 European countries. We determined the effects of prenatal treatment and prognostic markers soon after birth on the age at first detection of retinochoroiditis. RESULTS: Of 281 children with congenital toxoplasmosis, 50 developed ocular disease, and 17 had recurrent retinochoroiditis during a median follow-up of 4.1 years. Prenatal treatment had no significant effect on the age at first or subsequent lesions. Delayed start of postnatal treatment did not increase retinochoroiditis, but the analysis lacked power. Older gestational age at maternal seroconversion was weakly associated with a reduced risk of retinochoroiditis. The presence of nonocular clinical manifestations of congenital toxoplasmosis at birth strongly predicted retinochoroiditis. For 92% (230 of 249) of children with no retinochoroiditis detected before 4 months of age, the probability of retinochoroiditis by 4 years was low, whether clinical manifestations were present or not 8.0%. CONCLUSIONS: Prenatal treatment did not significantly reduce the risk of retinochoroiditis in this European cohort. If children have no retinochoroiditis in early infancy, the low risk of subsequent ocular disease may not justify postnatal treatment and repeated ophthalmic assessments during childhood. Controlled trials are needed to address the lack of evidence for the effectiveness of postnatal treatment.

Mucopolysaccharidosis type II (Hunter syndrome): a clinical review and recommendations for treatment in the era of enzyme replacement therapy.

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is a rare X-linked recessive disease caused by deficiency of the lysosomal enzyme iduronate-2-sulphatase, leading to progressive accumulation of glycosaminoglycans in nearly all cell types, tissues and organs. Clinical manifestations include severe airway obstruction, skeletal deformities, cardiomyopathy and, in most patients, neurological decline. Death usually occurs in the second decade of life, although some patients with less severe disease have survived into their fifth or sixth decade. Until recently, there has been no effective therapy for MPS II, and care has been palliative. Enzyme replacement therapy (ERT) with recombinant human iduronate-2-sulphatase (idursulfase), however, has now been introduced. Weekly intravenous infusions of idursulfase have been shown to improve many of the signs and symptoms and overall wellbeing in patients with MPS II. This paper provides an overview of the clinical manifestations, diagnosis and symptomatic management of patients with MPS II and provides recommendations for the use of ERT. The issue of treating very young patients and those with CNS involvement is also discussed. ERT with idursulfase has the potential to benefit many patients with MPS II, especially if started early in the course of the disease.

Seasonal variation in serum concentrations of reproductive hormones and urinary excretion of 6-sulfatoxymelatonin in men living north and south of the Arctic Circle: a longitudinal study.

OBJECTIVE: Seasonal variation in photoperiod or temperature may influence human reproductive biology. The present study evaluated whether seasonal changes occurred in the levels of reproductive hormones and the major melatonin metabolite, 6-sulfatoxymelatonin (aMT6s), in populations exposed to extreme variation in photoperiod and temperature. DESIGN: Two separate cohorts of Norwegian men were recruited from the general population in either of two locations: Tromsø (69.5 degrees N, n = 92) or Oslo (60 degrees N, n = 112), located north and south of the Arctic Circle (66.5 degrees N), respectively. MEASUREMENTS: Four blood and 12-h overnight urine samples were obtained on separate occasions over a 12-month period, including during the photoperiod maximum and minimum. Serum concentrations of FSH, LH, testosterone (T), oestradiol (E(2)), SHBG and the urinary excretion of aMT6s were assessed. RESULTS: Statistical analysis using generalized estimating equations indicated that LH levels were lowest during early winter in both locations (both P = 0.01). In Tromsø, free T and E(2) concentrations peaked during early winter (P = 0.02 and 0.003, respectively). In Oslo, free T levels were lowest during early winter (P = 0.06) whereas E(2) levels were lowest during late summer (P < 0.001). Urinary aMT6s concentrations were lowest during early summer in Tromsø and Oslo. Concentrations peaked during early winter in Tromsø (P < 0.001) and during late winter in Oslo (P < 0.001). CONCLUSIONS: LH levels exhibited similar changes in both locations, whereas the patterns of changes of the sex steroid concentrations differed, possibly indicating different underlying mechanisms. Excretion of aMT6s was lowest during early summer in both locations, indicating that the long natural photoperiod was sufficient to cause suppression of melatonin secretion. Whether these changes have any biological significance remains uncertain.