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Dive into the research topics where J. A. M. J. L. Janssen is active.

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Featured researches published by J. A. M. J. L. Janssen.


European Journal of Endocrinology | 2009

Combined treatment for acromegaly with long-acting somatostatin analogs and pegvisomant: long-term safety for up to 4.5 years (median 2.2 years) of follow-up in 86 patients

Sebastian Neggers; W. W. de Herder; J. A. M. J. L. Janssen; R. A. Feelders; A. J. van der Lely

BACKGROUNDnWe previously reported on the efficacy, safety, and quality of life (QoL) of long-acting somatostatin analogs (SSA) and (twice) weekly pegvisomant (PEG-V) in acromegaly and improvement after the addition of PEG-V to long-acting SSA.nnnOBJECTIVEnTo assess the long-term safety in a larger group of acromegalic patients over a larger period of time: 29.2 (1.2-57.4) months (mean (range)).nnnDESIGNnPegvisomant was added to SSA monotherapy in 86 subjects (37 females), to normalize serum IGF1 concentrations (n=63) or to increase the QoL. The median dosage was 60.0 (20-200) mg weekly.nnnRESULTSnAfter a mean treatment period of 29.2 months, 23 patients showed dose-independent PEG-V related transient liver enzyme elevations (TLEE). TLEE occurred only once during the continuation of combination therapy, but discontinuation and re-challenge induced a second episode of TLEE. Ten of these patients with TLEE also suffered from diabetes mellitus (DM). In our present series, DM had a 2.28 odds ratio (CI 1.16-9.22; p=0.03) higher risk for developing TLEE. During the combined therapy, a clinical significant decrease in tumor size by more than 20% was observed in 14 patients. Two of these patients were previously treated by pituitary surgery, 1 with additional radiotherapy and all other patients received primary medical treatment.nnnCONCLUSIONnLong-term combined treatment with SSA and twice weekly PEG-V up to more than 4 years seems to be safe. Patients with both acromegaly and DM have a 2.28 higher risk of developing TLEE. Clinical significant tumor shrinkage was observed in 14 patients during combined treatment.


The Journal of Clinical Endocrinology and Metabolism | 2009

Quality of Life in Acromegalic Patients during Long-Term Somatostatin Analog Treatment with and without Pegvisomant

Sebastian Neggers; M. O. van Aken; W. W. de Herder; R. A. Feelders; J. A. M. J. L. Janssen; Xavier Badia; Susan M. Webb; A. J. van der Lely

OBJECTIVEnThe objective of the study was to assess whether weekly administration of 40 mg pegvisomant (PEG-V) improves quality of life (QoL) and metabolic parameters in acromegalic patients with normal age-adjusted IGF-I concentrations during long-acting somatostatin analog (SSA) treatment.nnnDESIGNnThis was a prospective, investigator-initiated, double blind, placebo-controlled, crossover study. Twenty acromegalic subjects received either PEG-V or placebo for two consecutive treatment periods of 16 wk, separated by a washout period of 4 wk. Efficacy was assessed as change between baseline and end of each treatment period. QoL was assessed by the Acromegaly Quality of Life Questionnaire (AcroQoL) and the Patient-Assessed Acromegaly Symptom Questionnaire (PASQ).nnnRESULTSnThe AcroQoL (P = 0.008) and AcroQoL physical (P = 0.002) improved significantly after PEG-V was added. The addition of PEG-V also significantly improved the PASQ (P = 0.038) and the single PASQ questions, perspiration (P = 0.024), soft tissue swelling (P = 0.036), and overall health status (P = 0.035). No significant change in Z-score of IGF-I (P = 0.34) was observed during addition of PEG-V. Transient liver enzyme elevations were observed in five subjects (25%).nnnCONCLUSIONnImprovement in quality of life was observed without significant change in IGF-I after the addition of 40 mg pegvisomant weekly to monthly SSA therapy in acromegalic patients who had normalized IGF-I on SSA monotherapy. These data question the current recommendations in how to assess disease activity in acromegaly. Moreover, the findings question the validity of the current approach of medical treatment in which pegvisomant is used only when SSA therapy has failed to normalize IGF-I.


The Journal of Clinical Endocrinology and Metabolism | 2014

Long-Term Efficacy and Safety of Pegvisomant in Combination With Long-Acting Somatostatin Analogs in Acromegaly

S. Neggers; S. E. Franck; F. W. M. de Rooij; Alof H G Dallenga; R.M.L. Poublon; R. A. Feelders; J. A. M. J. L. Janssen; Michael Buchfelder; L. J. Hofland; Jens Otto Lunde Jørgensen; A. J. van der Lely

BACKGROUNDnTreatment for acromegaly patients with long-acting somatotropin release-inhibiting factor (LA-SRIF) often does not result in complete normalization of IGF-1. Addition of pegvisomant (PEGV), a GH receptor antagonist, could improve this; however, the literature has not described long-term follow-up.nnnOBJECTIVEnTo assess long-term efficacy and safety of this combined treatment in the largest current single-center cohort of patients, from 2004-2013.nnnDESIGNnAcromegaly patients were treated for at least 6 months with a high-dose LA-SRIF. To patients with persistently elevated IGF-1 levels (>1.2 × upper limit of normal) or poor quality of life, PEGV was added as one weekly injection.nnnRESULTSnThe patients (n = 141) were treated with PEGV and LA-SRIFs for a median period of 4.9 years (range, 0.5-9.2). Efficacy, defined as the lowest measured IGF-1 level during treatment, was 97.0%. The median PEGV dose to achieve this efficacy was 80 mg weekly (interquartile range, 60-120 mg). Combination treatment-related adverse events were recorded in 26 subjects (18.4%). Pituitary tumor size increase was observed in one patient. Injection-site reactions were observed in four subjects. In 19 patients (13.5%), transiently elevated liver transaminases of more than three times the upper limit of normal were observed, of which 83% occurred within the first year of combination treatment. Eight patients died, at a mean age of 71 years; none of them were considered treatment-related.nnnCONCLUSIONSnThe combination treatment with LA-SRIFs and PEGV was effective in 97% of the patients, it appears to be a safe medical treatment and it reduces the required dose of PEGV.


Journal of Endocrinological Investigation | 2004

There are no acute cardiac effects of a single iv dose of human ghrelin in severe growth hormone deficient patients

J. A. M. J. L. Janssen; D. Poldermans; L. J. Hofland; E. C. Vourvouri; Alex F. Muller; J. J. Bax; Romano Deghenghi; Fabio Broglio; Ezio Ghigo; A. J. van der Lely

ABSTRACT. It has previously been suggested that ghrelin mediates GH-independent biologic activities on the heart. We investigated the acute effects on cardiac contraction of a single iv administration of human ghrelin (in a dose of 1 gMg/kg) in severe untreated GH deficient subjects. Prior to the ghrelin infusion, an echocardiographic examination was performed at rest (baseline), after physiologic saline and during dobutamine stress echocardiography (DSE) to exclude a preexisting (subclinical) myocardial dysfunction. To evaluate the acute cardiac effect of infusion and during DSE the velocity of left ventricular (LV) wall contraction was measured continuously by echocardiography. Despite severe GH deficiency we observed in all subjects a normal cardiac function at rest after physiologic saline and during DSE. No acute changes in cardiac performance or cardiac parameters could be observed after a single iv dose of ghrelin. Also, no important increase in GH secretion was detected after ghrelin administration. Our study suggests that, in contrast to hexarelin, a single iv administration of ghrelin in a physiological dose has no acute effects on cardiac function in severe GH deficiency. This suggests that GH-independent effects of ghrelin play no important role in the acute regulation of cardiac function in man.


International Journal of Obesity | 2017

Efficacy and safety of bariatric surgery for craniopharyngioma-related hypothalamic obesity: a matched case–control study with 2 years of follow-up

Mark Wijnen; Daniel S Olsson; M.M. van den Heuvel-Eibrink; Ville Wallenius; J. A. M. J. L. Janssen; Patric J. D. Delhanty; A. J. van der Lely; Gudmundur Johannsson; S. Neggers

Background:Hypothalamic obesity is a devastating consequence of craniopharyngioma. Bariatric surgery could be a promising therapeutic option. However, its efficacy and safety in patients with craniopharyngioma-related hypothalamic obesity remain largely unknown.Objectives:We investigated the efficacy of bariatric surgery for inducing weight loss in patients with craniopharyngioma-related hypothalamic obesity. In addition, we studied the safety of bariatric surgery regarding its effects on hormone replacement therapy for pituitary insufficiency.Methods:In this retrospective matched case–control study, we compared weight loss after bariatric surgery (that is, Roux-en-Y gastric bypass and sleeve gastrectomy) between eight patients with craniopharyngioma-related hypothalamic obesity and 75 controls with ‘common’ obesity during 2 years of follow-up. We validated our results at 1 year of follow-up in a meta-analysis. In addition, we studied alterations in hormone replacement therapy after bariatric surgery in patients with craniopharyngioma.Results:Mean weight loss after bariatric surgery was 19% vs 25% (difference −6%, 95% confidence of interval (CI) −14.1 to 4.6; P=0.091) at 2 years of follow-up in patients with craniopharyngioma-related hypothalamic obesity compared with control subjects with ‘common’ obesity. Mean weight loss was 25% vs 29% (difference −4%, 95% CI −11.6 to 8.1; P=0.419) after Roux-en-Y gastric bypass and 10% vs 20% (difference −10%, 95% CI −14.1 to −6.2; P=0.003) after sleeve gastrectomy at 2 years of follow-up in patients with craniopharyngioma-related hypothalamic obesity vs control subjects with ‘common’ obesity. Our meta-analysis demonstrated significant weight loss 1 year after Roux-en-Y gastric bypass, but not after sleeve gastrectomy. Seven patients with craniopharyngioma suffered from pituitary insufficiency; three of them required minor adjustments in hormone replacement therapy after bariatric surgery.Conclusions:Weight loss after Roux-en-Y gastric bypass, but not sleeve gastrectomy, was comparable between patients with craniopharyngioma-related hypothalamic obesity and control subjects with ‘common’ obesity at 2 years of follow-up. Bariatric surgery seems safe regarding its effects on hormone replacement therapy.


The Journal of Clinical Endocrinology and Metabolism | 2017

Efficacy and Safety of Switching to Pasireotide in Patients With Acromegaly Controlled With Pegvisomant and First-Generation Somatostatin Analogues (PAPE Study)

Ammar Muhammad; Aart Jan van der Lely; Patric J. D. Delhanty; Alof H G Dallenga; Iain Haitsma; J. A. M. J. L. Janssen; Sebastian Neggers

AimnTo assess the efficacy and safety of pasireotide long-acting release (PAS-LAR) alone or in combination with pegvisomant by switching patients with acromegaly who were well controlled with long-acting somatostatin analogues (LA-SSAs) and pegvisomant to PAS-LAR with or without pegvisomant.nnnMethodsnSixty-one patients with acromegaly were enrolled in a prospective open-label study. We included patients with an insulin-like growth factor I (IGF-I) ≤1.2 × upper limit of normal (ULN) during treatment with LA-SSAs and pegvisomant. At baseline, the pegvisomant dose was reduced by 50% up to 12 weeks. When IGF-I remained ≤1.2 × ULN after 12 weeks, patients were switched to PAS-LAR 60 mg monotherapy. When IGF-I was >1.2 × ULN, patients were switched to PAS-LAR 60 mg, and they continued with the 50% reduced pegvisomant dose.nnnResultsnAt baseline, mean IGF-I was 0.97 × ULN, and the median pegvisomant dose was 80 mg/wk. At 12 weeks, mean IGF-I increased to 1.59 × ULN, and IGF-I levels ≤1.2 ULN were observed in 24.6% of participants. At 24 weeks, IGF-I levels were reduced into the reference range in 73.8% of patients. Between baseline and 24 weeks, the pegvisomant dose was reduced by 66.1%. PAS-LAR was well tolerated, but hyperglycemia was the most frequent adverse event. The frequency of diabetes increased from 32.8% at baseline to 68.9% at 24 weeks.nnnConclusionsnSwitching to PAS-LAR, either as monotherapy or combination with pegvisomant, can control IGF-I levels in most patients. PAS-LAR demonstrated a pegvisomant-sparing effect of 66% compared with the combination with LA-SSAs. Hyperglycemia was the most important safety issue.


European Journal of Endocrinology | 2016

What is the efficacy of switching to weekly pegvisomant in acromegaly patients well controlled on combination therapy

Ammar Muhammad; A. J. van der Lely; R D O’Connor; Patric J. D. Delhanty; J Dal; Alof H G Dallenga; R. A. Feelders; J. A. M. J. L. Janssen; Jens Otto Lunde Jørgensen; Sebastian Neggers

CONTEXTnAlthough combination therapy of acromegaly with long-acting somatostatin analogs (LA-SSAs) and pegvisomant (PEGV) normalizes insulin-like growth factor-1 (IGF1) levels in the majority of patients, it requires long-term adherence. Switching from combination therapy to monotherapy with weekly PEGV could improve patients comfort, but the efficacy is unknown.nnnOBJECTIVEnTo assess the efficacy of switching to PEGV monotherapy in patients well controlled on combination therapy of LA-SSAs and PEGV.nnnDESIGNnSingle-center, open-label observational pilot study. LA-SSA therapy was discontinued at baseline and all patients were switched to PEGV monotherapy for 12 months. If IGF1 levels exceeded 1.0 times upper limit of normal (ULN), PEGV dose was increased by 20 mg weekly.nnnSUBJECTS AND METHODSnThe study included 15 subjects (eight males), with a median age of 58 years (range 35-80) on combination therapy of high-dose LA-SSAs and weekly PEGV for >6 months, and IGF1 levels within the normal range. Treatment efficacy was assessed by measuring serum IGF1 levels.nnnRESULTSnAfter 12 months of weekly PEGV monotherapy, serum IGF1 levels of 73% of the subjects remained controlled. In one patient, LA-SSA had to be restarted due to recurrence of headache. IGF1 levels increased from a baseline level of 0.62 × ULN (range 0.30-0.84) to 0.83 × ULN (0.30-1.75) after 12 months, while the median weekly PEGV dose increased from 60 (30-80) mg to 80 (50-120) mg.nnnCONCLUSIONnOur results suggest that switching from combination therapy of LA-SSAs and PEGV to PEGV monotherapy can be a viable treatment option for acromegaly patients without compromising efficacy.


Endocrine connections | 2014

In active acromegaly, IGF1 bioactivity is related to soluble Klotho levels and quality of life

Aimee J. Varewijck; A J van der Lely; S. Neggers; S. W. J. Lamberts; L. J. Hofland; J. A. M. J. L. Janssen

The value of measuring IGF1 bioactivity in active acromegaly is unknown. Soluble Klotho (S-Klotho) level is elevated in active acromegaly and it has been suggested that S-Klotho can inhibit activation of the IGF1 receptor (IGF1R). A cross-sectional study was carried out in 15 patients with active acromegaly based on clinical presentation, unsuppressed GH during an oral glucose tolerance test, and elevated total IGF1 levels (>+2 s.d.). Total IGF1 was measured by immunoassay, IGF1 bioactivity by the IGF1R kinase receptor activation assay and S-Klotho by an ELISA. Quality of Life (QoL) was assessed by Acromegaly QoL (AcroQoL) Questionnaire and Short-Form-36 Health Survey Questionnaire (SF-36). Out of 15 patients, nine had IGF1 bioactivity values within the reference range. S-Klotho was higher in active acromegaly compared with controls. Age-adjusted S-Klotho was significantly related to IGF1 bioactivity (r=0.75, P=0.002) and to total IGF1 (r=0.62, P=0.02). IGF1 bioactivity and total IGF1 were inversely related to the physical component summary of the SF-36 (r=−0.78, P=0.002 vs r=−0.60, P=0.03). Moreover, IGF1 bioactivity, but not total IGF1, was significantly inversely related to the physical dimension of the AcroQoL Questionnaire (r=−0.60, P=0.02 vs r=−0.37, P=0.19). In contrast to total IGF1, IGF1 bioactivity was within the reference range in a considerable number of subjects with active acromegaly. Elevated S-Klotho levels may have reduced IGF1 bioactivity. Moreover, IGF1 bioactivity was more strongly related to physical measures of QoL than total IGF1, suggesting that IGF1 bioactivity may better reflect physical limitations perceived in active acromegaly.


Journal of Surgical Oncology | 2015

Absence or low IGF‐1R‐expression in esophageal adenocarcinoma is associated with tumor invasiveness and radicality of surgical resection

Kirstin De Bruijn; Katharina Biermann; Joel Shapiro; Fadime Dogan; Manon Spaander; J. A. M. J. L. Janssen; Bas P. L. Wijnhoven; Gerard J. J. M. Borsboom; L. J. Hofland; Casper H.J. van Eijck

Esophageal adenocarcinoma (EAC) incidence increases, maybe due to increasing prevalences of obesity and diabetes. Concurrent hyperinsulinemia might promote carcinogenesis via the insulin‐like growth factor‐I receptor (IGF‐1R). Expression of the IGF‐1R was studied in correlation with diabetes and prognostic parameters.


Clinical Endocrinology | 2018

Disagreement in normative IGF-I levels may lead to different clinical interpretations and GH dose adjustments in GH deficiency

Aimee J. Varewijck; A. J. van der Lely; S. Neggers; L. J. Hofland; J. A. M. J. L. Janssen

Normative data for the iSYS IGF‐I assay have been published both in the VARIETE cohort and by Bidlingmaier et al.

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Dive into the J. A. M. J. L. Janssen's collaboration.

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A. J. van der Lely

Erasmus University Rotterdam

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L. J. Hofland

Erasmus University Medical Center

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R. A. Feelders

Erasmus University Medical Center

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S. Neggers

Federal University of Rio de Janeiro

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Alof H G Dallenga

Erasmus University Medical Center

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Sebastian Neggers

Erasmus University Rotterdam

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S. W. J. Lamberts

Erasmus University Rotterdam

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Aimee J. Varewijck

Erasmus University Rotterdam

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Alex F. Muller

Erasmus University Rotterdam

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