Mutations in kelch-like 3 and cullin 3 cause hypertension and electrolyte abnormalities.

Hypertension affects one billion people and is a principal reversible risk factor for cardiovascular disease. Pseudohypoaldosteronism type II (PHAII), a rare Mendelian syndrome featuring hypertension, hyperkalaemia and metabolic acidosis, has revealed previously unrecognized physiology orchestrating the balance between renal salt reabsorption and K(+) and H(+) excretion. Here we used exome sequencing to identify mutations in kelch-like 3 (KLHL3) or cullin 3 (CUL3) in PHAII patients from 41 unrelated families. KLHL3 mutations are either recessive or dominant, whereas CUL3 mutations are dominant and predominantly de novo. CUL3 and BTB-domain-containing kelch proteins such as KLHL3 are components of cullin-RING E3 ligase complexes that ubiquitinate substrates bound to kelch propeller domains. Dominant KLHL3 mutations are clustered in short segments within the kelch propeller and BTB domains implicated in substrate and cullin binding, respectively. Diverse CUL3 mutations all result in skipping of exon 9, producing an in-frame deletion. Because dominant KLHL3 and CUL3 mutations both phenocopy recessive loss-of-function KLHL3 mutations, they may abrogate ubiquitination of KLHL3 substrates. Disease features are reversed by thiazide diuretics, which inhibit the Na-Cl cotransporter in the distal nephron of the kidney; KLHL3 and CUL3 are expressed in this location, suggesting a mechanistic link between KLHL3 and CUL3 mutations, increased Na-Cl reabsorption, and disease pathogenesis. These findings demonstrate the utility of exome sequencing in disease gene identification despite the combined complexities of locus heterogeneity, mixed models of transmission and frequent de novo mutation, and establish a fundamental role for KLHL3 and CUL3 in blood pressure, K(+) and pH homeostasis.

A nationwide study on parathyroid carcinoma.

BACKGROUND: Parathyroid carcinoma (PC) is rare and diagnostically challenging. Reported outcomes are rather poor and the incidence might be increasing. MATERIAL AND METHODS: We performed a nationwide study on all cases (n= 32) diagnosed in 2000-2011 in Finland, and compared clinical and histopathological characteristics and outcome to atypical parathyroid (APA; n= 28) and parathyroid adenomas (PA; n= 72). The incidence in years 1955-1999 was compared to that in 2000-2013. RESULTS: Preoperatively, calcium and parathyroid hormone concentrations were higher in PC compared to APA and PA (1.76, 1.56 and 1.44 mmol/l, p < .001; and 989, 355 and 160 µmol/l, p < .001, respectively). Calcium was ≤1.77 mmol/l for all PAs. Hospitalization (44% vs. 22% and 3%, respectively, p = .01), renal (50% vs. 48% vs. 22%, respectively, p = .01) and bone (47% vs. 15% vs. 38%, respectively p = .002) manifestations were more common. PC and APA tumors were larger than PA (p < .001). Histopathological characteristics of PC compared to PA are increased mitotic activity (p= .001), chief cells (p = .003), diffuse growth pattern (p < .001), higher Ki67 (p< .001) and negative parafibromin (p < .001). One PC (1/18) and one APA (1/16) patient had a CDC73 mutation. After 6.7 (2-13.9) years of follow-up, 9.4% of PC had residual, 21% recurrent disease and 12.5% died of disease. Overall mortality did not differ between subgroups (p = .094). Recurrent PC was characterized by vascular invasion, lymph node metastases, high mitotic activity, necrosis and negative parafibromin. Incidence increased from 1.42 (range 0.52-2.14) to 7.14 (range 3.42-10.38)/10.000.000/years; (p < .001). CONCLUSIONS: PC associates with severe primary hyperparathyroidism and must be suspected if calcium ≥1.77 mmol/l. The prevalence of CDC73 germline mutations in PC and APA in Finland is 6%. PC has distinct histopathological characteristics and its incidence has increased over the past decades.

Osteosclerosis associated with hepatitis C.

We describe the first Finnish case of hepatitis C associated osteosclerosis. In which the patient's bone symptoms and bone density were resolved with hepatitis C treatment. Suspecting the possibility of osteosclerosis underlying bone pains in a hepatitis C patient is well-founded, although osteoporotic fractures are a more common problem.

How well are the optimal serum 25OHD concentrations reached in high-dose intermittent vitamin D therapy? a placebo-controlled study on comparison between 100 000 IU and 200 000 IU of oral D3 every 3 months in elderly women.

OBJECTIVE: Intermittent dosing may improve adherence to vitamin D therapy. Dosing regimen should maintain optimal serum 25-hydroxyvitamin D (25OHD) levels over all the year. We compared two dosing regimens, the primary outcome being the percentage of 25OHD measurements reaching the targets of 75 nmol/l or 50 nmol/l after baseline. DESIGN: Randomized, placebo-controlled parallel group comparison. PATIENTS: Sixty women aged 75·0 ± 2·9 years. INTERVENTIONS: 100 000 IU (group 1D) or 200 000 IU (2D) of vitamin D3 or placebo orally every 3 months plus calcium 1 g daily for 1 year. MEASUREMENTS: Serum 25OHD, 1,25-dihydroxyvitamin D, PTH, sclerostin, ionized calcium, urinary calcium, renal function, bone turnover markers. RESULTS: Serum 25OHD increased, but the difference between two doses was of borderline significance (P = 0·0554; area under curve analysis). Immediate postadministrative increases were higher in the 2D vs 1D group (P < 0·05) after 3 and 6 months' dosing. In the 1D and 2D groups, 51·2% and 57·7% of all on-treatment measurements reached the target of 75 nmol/l. PTH levels differed marginally (P = 0·0759) due to tendency to lowering immediately after vitamin D boluses. Urinary calcium differed between the groups (P = 0·0193) due to increases 1 week after vitamin D dosing. CONCLUSIONS: The doses of 100 000 or 200 000 IU of oral cholecalciferol every 3 months were not capable of stabilizing 25OHD levels over the target of 75 nmol/l over the year. To improve the efficacy of high-dose vitamin D therapy, the interval between boluses has to be shortened instead of increasing their size.

[Licorice as the cause of elevated blood pressure and headache?]. / Lakritsiko kohonneen verenpaineen ja päänsäryn syynä?

Physicians are familiar with the effect on potassium metabolism of glycyrrhizine acid contained in licorice and salmiac. Even so, glycyrrhizine acid as the cause of even severe symptoms may escape attention, especially in an emergency situation. We describe a patient, who sought medical advice from an endocrinologist for recurrent, severe and symptomatic hypertension. After the patient had stopped eating salmiac and licorice, the headache that had persisted for years disappeared, fluctuations in weight stabilized and occasional edemas of the lower limbs vanished. Since the cessation of using licorice products normalized the blood pressure, it is likely that the patient had licorice-induced hypertension.

[Hemolysis and metastatic cancer in an elderly man]. / Iäkkään miehen hemolyysi ja levinnyt syöpä.

Sometimes correct diagnoses is reached after many years and even after decades. Our patient had for decades suffered from a hemolytic disease, life-threatening, metastatic cancer at the age of almost 90 years was also suspected. The patient was finally diagnosed as having mild hereditary spherocytosis and the associated paraspinal extramedullar hematopoiesis as well as an osteoporotic vertebral fracture caused by osteoporosis.

The novel WHO 2010 classification for gastrointestinal neuroendocrine tumours correlates well with the metastatic potential of rectal neuroendocrine tumours.

BACKGROUND: Approximately 10-15% of gastroenteropancreatic neuroendocrine tumours (NETs, carcinoids) occur in the rectum, some of which are potentially able to metastasize. The new WHO 2010 classification of NETs applies to all gastroenteropancreatic NETs, but no reports have studied its correlation with the prognosis of rectal NETs. PATIENTS AND METHODS: We retrospectively classified 73 rectal NETs according to the novel WHO 2010 and the previous WHO 2000 classifications. The aim was to assess the validity of the classifications in distinguishing indolent rectal NETs from metastasising tumours. RESULTS: Using the WHO 2010 criteria, we identified 61 G1 tumours, none of which had metastasised during follow-up. Of 11 G2 tumours, 9 had shown distant metastases. The only G3 neuroendocrine carcinoma that occurred had been disseminated at initial presentation. CONCLUSION: Our results show that rectal NETs classified as G1 according to the WHO 2010 classification have an indolent clinical course, whereas G2 NETs often metastasise. The WHO 2010 classification of NETs predicts the metastatic potential of rectal NETs better than the WHO 2000 classification.

Serum TSH reference interval in healthy Finnish adults using the Abbott Architect 2000i Analyzer.

BACKGROUND: Current serum TSH reference intervals have been criticized as they were established from unselected background populations. A special concern is that the upper limit, which defines subclinical hypothyroidism, is too high. The objective was to redefine the TSH reference interval in the adult Finnish population. The current reference interval for the widely used Abbott Architect method in Finland is 0.4-4.0 mU/L. METHODS: Serum TSH and free T4 concentrations were derived from 606 healthy, non-pregnant, 18-91-year-old Finns from the Nordic Reference Interval Project (NORIP) and the possible effects of age, sex and thyroid peroxidase antibody (TPOAb) status were evaluated. RESULTS: After excluding TPOAb-positive subjects and outliers, a reference population of 511 subjects was obtained. In the reference population, no statistically significant gender- or age-specific differences in mean TSH (1.55 ± 3.30 mU/L) or TSH reference intervals were observed. The new reference interval was 0.5-3.6 mU/L (2.5th-97.5th percentiles). CONCLUSIONS: The current upper TSH reference limit is 10% too high. A TSH > 3.6 mU/L, confirmed with a repeat TSH sampling, may indicate subclinical hypothyroidism. Differences in ethnicity, regional iodine-intake and analytical methods underline the need for redefining the TSH reference interval in central laboratories in different countries.

[Neuroendocrine tumors of the digestive tract and the pancreas]. / Ruoansulatuskanavan ja haiman neuroendokriiniset kasvaimet.

Neuroendocrine tumors (NET) originate from hormone-producing cells and may appear in any organ. Approximately 230 NET tumors are detected in Finland annually. NET tumors of the digestive tract and the pancreas can be detected accidentally in emergency surgery, after years of abdominal symptoms, or based on symptoms caused by the hormones produced. Basic investigations include determination of 5-hydroxyindoleacetic acid in 24-hour urine sample and plasma chromogranin, as well as gamma-imaging of somatostatin receptors. A treatment plan is devised on the basis of the pathologic-anatomic classification of the tumor. Surgery and drug therapy are first-line treatments. Targeted radiation therapy has also appeared promising.

Bone material properties and response to teriparatide in osteoporosis due to WNT1 and PLS3 mutations.

CONTEXT: Patients with osteoporosis-associated WNT1 or PLS3 mutations have unique bone histomorphometric features and osteocyte-specific hormone expression patterns. OBJECTIVE: To investigate the effects of WNT1 and PLS3 mutations on bone material properties. DESIGN: Transiliac bone biopsies were evaluated by quantitative backscattered electron imaging, immunohistochemistry, and bone histomorphometry. SETTING: Ambulatory patients. PATIENTS: Three pediatric and eight adult patients with WNT1 or PLS3 mutations. INTERVENTION: Bone mineralization density distribution and osteocyte protein expression was evaluated in 11 patients and repeated in six patients who underwent repeat biopsy after 24 months of teriparatide treatment. MAIN OUTCOME MEASURE: Bone mineralization density distribution and protein expression. RESULTS: Children with WNT1 or PLS3 mutations had heterogeneous bone matrix mineralization, consistent with bone modeling during growth. Bone matrix mineralization was homogenous in adults and increased throughout the age spectrum. Teriparatide had very little effect on matrix mineralization or bone formation in patients with WNT1 or PLS3 mutations. However, teriparatide decreased trabecular osteocyte lacunae size and increased trabecular bone FGF23 expression. CONCLUSION: The contrast between preserved bone formation with heterogeneous mineralization in children and low bone turnover with homogenous bone mineral content in adults suggests that WNT1 and PLS3 have differential effects on bone modeling and remodeling. The lack of change in matrix mineralization in response to teriparatide, despite clear changes in osteocyte lacunae size and protein expression, suggests that altered WNT1 and PLS3 expression may interfere with coupling of osteocyte, osteoblast, and osteoclast function. Further studies are warranted to determine the mechanism of these changes.

The same annual dose of 292000 IU of vitamin D (cholecalciferol) on either daily or four monthly basis for elderly women: 1-year comparative study of the effects on serum 25(OH)D concentrations and renal function.

OBJECTIVE: Daily dosing of vitamin D supplements may be difficult among older people. Infrequent administration of 'megadoses' controlled by health care personnel may overcome adherence problem. We compared the efficacy and safety of two oral dosages (800 IU daily or 97333 IU four monthly) of vitamin D(3) resulting in the equal annual dose of 292000 IU. DESIGN: Randomized, double-blind, double-dummy parallel group comparison. Patients Forty women aged 69.3-78.8 years. INTERVENTIONS: Vitamin D(3) 400 IU twice daily (D group) or vitamin D(3) oil 97333 IU every 4 months (4 M group) for 1 year. All received 1 g of calcium daily. MEASUREMENTS: Serum 25-hydroxyvitamin D(3) [25(OH)D(3)] in relation to the target levels of 50-75 nmol/l, PTH, serum type I procollagen aminoterminal propeptide (PINP), serum and urine calcium, renal function. RESULTS: A quantity of 25OHD(3) increased more in D group than in 4 M group (P < 0.0001). All participants in D group and 67% in 4 M group had 25(OH)D(3) above 50 nmol/l at 12 months; the target level of 75 nmol/l was reached by 47% and 28% respectively. PTH did not show any seasonal perturbation in either group. PINP declined and urinary calcium rose similarly in the study groups over time (P < 0.0001). Renal function did not worsen in either group. CONCLUSIONS: In terms of serum 25(OH)D(3) concentrations, 800 IU daily was more efficient than a 97333 IU every 4 months. However, to increase adherence, the latter is still worth developing. Both treatments increased urinary excretion of calcium, but did not worsen renal function.

Nordic Guidelines 2010 for diagnosis and treatment of gastroenteropancreatic neuroendocrine tumours.

The diagnostic work-up and treatment of patients with neuroendocrine tumours has undergone a major change during the last decade. New diagnostic possibilities and treatment options have been developed. These Nordic guidelines, written by a group with a major interest in the subject, summarises our current view on how to diagnose and treat these patients. The guidelines are meant to be useful in the daily practice for clinicians handling patients with neuroendocrine tumours.

[Follow-up of papillary and follicular thyroid cancer--when and where?]. / Papillaarisen ja follikulaarisen kilpirauhas- syövän seuranta--mitä ja missä?

While papillary and follicular thyroid cancer usually has an excellent prognosis, recurrent and aggressive forms of the disease do occur. The success of surgical excision and radioiodine therapy is evaluated by ultrasonography of the neck, and TSH-stimulated serum thyreoglobulin. Based on investigational results, the patients are divided into three groups: the cancer does not exist, may exist or remains. This classification determines the thyroxine dose and follow-up arrangements. In cancer-free patients, thyroxine therapy will be implemented as in ordinary hypothyreoidism. For others a thyroxine dose will be used that lowers the serum TSH below reference values.

Health-related quality of life in long-term follow-up of patients with cured TNM Stage I or II differentiated thyroid carcinoma.

OBJECTIVE: The purpose of this study was to assess the impact of cured low-risk differentiated thyroid carcinoma (DTC) on health-related quality of life (HRQoL) after long-term follow-up. DESIGN: A cross-sectional study including an age- and gender-standardized sample of the general population. PATIENTS AND METHODS: HRQoL was assessed by the 15D in 341 DTC patients, whose initial treatment for stage I or II DTC was performed 12.4 years (range 5-20) earlier. The results were compared to those of an age- and gender-standardized sample of the general population (n= 6001). Determinants of HRQoL in DTC patients were assessed by the Tobit model. RESULTS: Mean total 15D scores did not differ between patients and control subjects. In single dimensions, DTC patients were significantly worse off with regards to sleeping, speech and distress (P= 0.001, 0.002 and 0.012, respectively), but better off with regards to discomfort and symptoms (P < 0.001). Within the patient group, the only significant independent predictor of HRQoL was age at the time of the initial treatment (P < 0.001). CONCLUSIONS: After long-term follow-up, overall HRQoL in DTC patients is comparable to that of the general population. DTC patients demonstrate an age-related decline in HRQoL, similar to that seen in the population in general.

Long-term outcome of 495 TNM stage I or II patients with differentiated thyroid carcinoma followed up with neck ultrasonography and thyroglobulin measurements on T4 treatment.

OBJECTIVE: Recent guidelines for surveillance of patients with differentiated thyroid carcinoma emphasize TSH-stimulated serum thyroglobulin (Tg) measurements and neck ultrasonographies (US) over Tg measurements on T(4) and diagnostic whole body scans (DxWBS). We evaluated the safety and efficacy of a surveillance paradigm comprising yearly T(4)-suppressed Tg measurements and neck US every second year, with an increase in Tg to a detectable level being a prompt indication for DxWBS. DESIGN: A retrospective study with a median follow-up of 11.6 years. PATIENTS AND MEASUREMENTS: Recurrences, cancer-specific deaths and number of neck US, fine needle aspiration biopsies (FNABs) and operations performed were evaluated in 495 low-risk (TNM stage I and II) patients, the majority of whom had total thyroidectomy and radioactive iodine remnant ablation as initial treatment. RESULTS: Forty-four patients (8.9%) experienced a recurrence in the neck and one patient died. Recurrences were established histopathologically in 26 and by a new uptake in DxWBS in 16 cases. A combination of neck US and high Tg revealed 42 of 44 recurrences. Of 993 ultrasonographies, 149 led to FNAB and 28 FNABs to surgery. Serum Tg was elevated 173 times, indicating a recurrence in 23 patients. CONCLUSIONS: Although longer follow-up is still needed, monitoring low-risk differentiated thyroid carcinoma patients with neck US and T(4)-suppressed Tg appears to be safe, provided radioactive iodine remnant ablation has been given and a low-alarm threshold for Tg indicating further evaluation, is used. The number of additional studies caused by this surveillance paradigm was reasonable. DxWBS was helpful in selected cases. Comparative studies are warranted to show how much rhTSH-stimulation tests add to this surveillance scheme.

The A1330V polymorphism of the low-density lipoprotein receptor-related protein 5 gene (LRP5) associates with low peak bone mass in young healthy men.

INTRODUCTION: Polymorphisms in the gene coding for low-density lipoprotein receptor-related protein 5 (LRP5) contribute to variation in bone mass in the general population. Whether this is due to influence on bone mass acquisition or on bone loss thereafter has not been established. METHODS: We studied the association of LRP5 polymorphisms with peak bone mass in young men. The study included 235 Finnish men, aged 18.3 to 20.6 years. Lifestyle factors and fracture history were recorded. Bone mineral content (BMC), density (BMD) and scan area were measured for the lumbar spine and proximal femur by dual energy X-ray absorptiometry (DXA). Blood and urine were collected for determination of bone turnover markers, serum 25-OHD and PTH. Genomic DNA was extracted from peripheral blood for genetic analysis of LRP5. Ten single nucleotide polymorphisms in LRP5 were analyzed and correlated with bone parameters. RESULTS: Only the A1330V polymorphism of LRP5 significantly associated with bone parameters. In comparison with subjects with the AlaAla genotype (n=215), those with AlaVal genotype (n=20) had lower femoral neck BMC (P=0.029) and BMD (P=0.012), trochanter BMC (P=0.0067) and BMD (P=0.015), and total hip BMC (P=0.0044) and BMD (P=0.0089). Fracture history was similar for the genotypes. CONCLUSION: The polymorphic valine variant at position 1330 of LRP5 was significantly associated with reduced BMC and BMD values in healthy young Finnish men. The results provide evidence for the crucial role of LRP5 in peak bone mass acquisition.

Effects of risedronate 5 mg/d on bone mineral density and bone turnover markers in late-postmenopausal women with osteopenia: a multinational, 24-month, randomized, double-blind, placebo-controlled, parallel-group, phase III trial.

BACKGROUND: Randomized clinical trials have shown that risedronate reduces the risk for both ver- tebral and nonvertebral fractures in postmenopausal women with osteoporosis (bone mineral density [BMD] T-score, <-2.5). If left untreated, osteopenia (T-score, between -1 and -2.5) may progress to osteo- porosis. Risedronate sodium, a pyridinyl bisphospho- nate, is an antiresorptive drug approved by the US Food and Drug Administration for the prevention and treatment of osteoporosis in postmenopausal women. Although the effects of risedronate in preventing frac- tures has been established, its effects in maintaining or increasing BMD in osteopenia have not. OBJECTIVE: In this clinical trial, the efficacy and tol- erability of risedronate in improving and maintaining BMD levels in late-postmenopausal women with os- teopenia were assessed. METHODS: This 24-month, randomized, double- blind, placebo-controlled, parallel-group, Phase III trial was conducted at 14 study centers across Finland, The Netherlands, Norway, Spain, and Sweden. Late- postmenopausal (> or =5 years from menopause) women with lumbar spine (LS) BMD T-score between -1 and -2.5 and the presence of > or =1 additional risk factor for osteo- porosis or proximal femur (Fern) BMD T-score < or = -1 were randomized to receive risedronate 5 mg (n = 114) or placebo (n = 57) PO QD for 24 months. The primary efficacy end point was the percentage change from baseline in LS BMD at study end point (24 months or last observation carried forward). Secondary efficacy end points were the percentage changes from base- line in total proximal Fern BMD and 2 bone turnover markers-urinary type I collagen cross-linked N-telopeptide (uNTx) and serum bone-specific alkaline phosphatase (sBAP)-at 12 months and study end point. Tolerability was assessed using reported adverse events (AEs), laboratory analysis, and physical exami- nation including vital-sign measurements. RESULTS: A total of 171 women were included (mean [SD] age, 65.9 [6.8] years; mean [SD] LS BMD T-score,-1.82 [0.42]; risedronate group, 114 patients; placebo group, 57). At study end point, LS BMD had significantly increased from baseline in the risedronate group (P < 0.05) but remained unchanged in the placebo group (mean [SE] %Delta, +4.49% [0.38%] and +0.05% [0.54%], respectively; P < 0.001). Between- treatment differences in mean (SE) percentage changes from baseline in LS BMD and Fem BMD were signif- icant at 12 months and study end point (LS BMD, both P < 0.001; Fem BMD, P = 0.002 and P < 0.001, respectively). At 12 months and study end point, ris- edronate use was associated with significantly reduced concentrations of uNTx and sBAP compared with placebo (both, P < 0.001). Risedronate treatment was well tolerated with regard to gastrointestinal AEs; the most frequent AEs in the risedronate group were hy- pertension (n = 13), constipation (n = 8), and hyper- cholesterolemia (n = 8). CONCLUSIONS: In these late-postmenopausal women with LS osteopenia and > or=1 additional risk factor or hip osteopenia, 24-month treatment with risedronate 5 mg/d was associated with the prevention of bone loss at the spine and hip (based on significant increases in BMD in the LS and total proximal Fem) and reduced bone resorption (based on significantly reduced concen- trations of uNTx and sBAP) and was well tolerated.

The effect of hormone therapy on the health-related quality of life in elderly women.

OBJECTIVES: The purpose of this study was to compare the health-related quality of life (HRQoL) of elderly users and non-users of hormone therapy (HT). SUBJECTS AND METHODS: Subjects were participants in an ongoing intervention study, which is aimed at elucidating the effectiveness of an educational program in the prevention of osteoporosis. A random sample (n=4200) of the female population in Southern Finland within the age group of 60-70 years was drawn from the population register and invited to take part in the trial; 2181 (52%) accepted the invitation and were randomized either to the educational program or to a control group. In 2002 all 2181 participants were asked by a postal survey about HRQoL (generic15D), education, profession, climacteric symptoms, use of HT, chronic diseases and medication. Of the 1663 respondents (76% of the participants; 40% of the original cohort) 585 (mean age 67.5 years) were HT users and 1078 (mean age 68.9 years) non-users. RESULTS: After standardizing for age, education, number of continuous medication and ongoing diseases HRQoL of HT users was significantly better on the dimensions of usual activities, vitality and sexual activity. The effect of HT on overall HRQoL on a 0-1 scale was positive, but neither statistically significant nor clinically important. The number of medication and diseases had a statistically significant negative effect, but higher education a positive, but statistically non-significant effect on HRQoL overall. CONCLUSIONS: Among elderly women HT use has a statistically significant positive effect on some dimensions of HRQoL, but not on HRQoL overall. To improve HRQoL is not an indication for elderly postmenopausal women to use HT.

Gender has to be taken into account in diagnosing adult growth hormone deficiency by the GHRH plus arginine test.

OBJECTIVE: Data on the effect of gender on the interpretation of the GHRH plus arginine stimulation test (GHRH+ARG test) is controversial. We validated the GHRH+ARG stimulation test in control subjects and patients with organic or idiopathic pituitary disease and a suspicion of adult growth hormone deficiency (AGHD) using the Immulite 2000 XPi GH assay. DESIGN: We studied 126 apparently healthy adults (median age 38.8years) and 34 patients with a suspicion of AGHD (median age 42.2years). Identification of AGHD with the GHRH+ARG test was investigated with commonly accepted BMI-related consensus cut-off limits for peak GH concentrations. Serum samples collected during the GHRH+ARG test were analysed for GH in 2014-2015. Serum IGF-1 concentrations were studied as a reference. RESULTS: In 14 of 65 (22%) control males the GH peak value was below the BMI-related cut-off limits for GH sufficiency indicating a false diagnosis of AGHD. All control females had a normal GHRH+ARG response. Median peak GH response was significantly (p<0.001) higher in female (39.3µg/L) than in male controls (21µg/L). According to consensus cut-offs all but one young female patient had a deficient response compatible with a diagnosis of AGHD. CONCLUSIONS: The GH response to stimulation by GHRH+ARG is gender-dependent, being lower in healthy males than in females. Gender should be considered when defining cut-off limits for peak GH concentrations in the GHRH+ARG test. The presently used BMI-related cut-off levels will lead to a significant misclassification of males as GH deficient.

Osteocyte Protein Expression Is Altered in Low-Turnover Osteoporosis Caused by Mutations in WNT1 and PLS3.

Context: Osteocytes express proteins that regulate bone remodeling and mineralization. Objective: To evaluate the relationship between osteocyte-specific protein expression and bone histology in patients with monogenic osteoporosis due to wingless integration site 1 (WNT1) or plastin 3 (PLS3) mutations. Design and Setting: Cross-sectional cohort study at a university hospital. Participants: Six patients (four males; ages: 14 to 72 years) with a heterozygous WNT1 mutation and five patients (four males; ages: 9 to 70 years) with a heterozygous/hemizygous PLS3 mutation. Methods and Main Outcome Measures: Immunohistochemistry was performed for fibroblast growth factor 23 (FGF23), dentin matrix protein 1 (DMP1), sclerostin, and phosphorylated (phospho-)ß-catenin in iliac crest samples and compared with bone histomorphometry. Results: FGF23 expression in WNT1 patients was 243% that observed in PLS3 patients (P < 0.01). DMP1, sclerostin, and phospho-ß-catenin expression did not differ between groups. Serum phosphate correlated inversely with FGF23 expression (r = -0.79, P = 0.01) and serum ionized calcium correlated inversely with sclerostin expression (r = -0.60, P = 0.05). Phospho-ß-catenin expression correlated inversely with DMP1 expression (r = -0.88, P < 0.001), osteoid volume/bone volume (r = -0.68, P = 0.02), and bone formation rate (r = -0.78, P < 0.01). FGF23 expression did not correlate with DMP1 expression, sclerostin expression, or bone histomorphometry. Marrow adiposity was higher in WNT1 than in PLS3 patients (P = 0.04). Conclusions: Mutations that disrupt WNT signaling and osteocytic mechanosensing affect osteocyte protein expression. Abnormal osteocyte function may play a role in the pathogenesis of monogenetic forms of osteoporosis.