Oskar Ragnarsson

Dr. Oskar Ragnarsson

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Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2012 in The Journal of Clinical Endocrinology & Metabolism
Verified
Journal Article
Open access
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GJG. Johannsson
G. Johannsson
ANA. G. Nilsson
A. G. Nilsson
RBR. Bergthorsdottir
R. Bergthorsdottir
PBP. Burman
P. Burman
PDP. Dahlqvist
P. Dahlqvist
SSS. Skrtic
S. Skrtic
Context: Patients with treated adrenal insufficiency (AI) have increased morbidity and mortality rate. Our goal was to improve outcome by developing a once-daily (OD) oral hydrocortisone dual-release tablet with a more physiological exposure-time cortisol profile. Objective: The aim was to compare pharmacokinetics and metabolic outcome between OD and the same daily dose of thrice-daily (TID) dose of conventional hydrocortisone tablets. Design and Setting: We conducted an open, randomized, two-period, 12-wk crossover multicenter trial with a 24-wk extension at five university hospital centers. Patients: The trial enrolled 64 adults with primary AI; 11 had concomitant diabetes mellitus (DM). Intervention: The same daily dose of hydrocortisone was administered as OD dual-release or TID. Main Outcome Measure: We evaluated cortisol pharmacokinetics. Results: Compared with conventional TID, OD provided a sustained serum cortisol profile 0–4 h after the morning intake and reduced the late afternoon and the 24-h cortisol exposure. The mean weight (difference = −0.7 kg, P = 0.005), systolic blood pressure (difference = −5.5 mm Hg, P = 0.0001) and diastolic blood pressure (difference: −2.3 mm Hg; P = 0.03), and glycated hemoglobin (absolute difference = −0.1%, P = 0.0006) were all reduced after OD compared with TID at 12 wk. Compared with TID, a reduction in glycated hemoglobin by 0.6% was observed in patients with concomitant DM during OD (P = 0.004). Conclusion: The OD dual-release tablet provided a more circadian-based serum cortisol profile. Reduced body weight, reduced blood pressure, and improved glucose metabolism were observed during OD treatment. In particular, glucose metabolism improved in patients with concomitant DM.

1 October 2014 in European Journal of Endocrinology
Verified
Journal Article
Closed access
ATAxel Tjörnstrand
Axel Tjörnstrand
KGKerstin Gunnarsson
Kerstin Gunnarsson
MEMax Evert
Max Evert
EHErik Holmberg
Erik Holmberg
OROskar Ragnarsson
Oskar Ragnarsson
HNHelena Filipsson Nyström
Helena Filipsson Nyström
Objective: The number of studies on the incidence of pituitary adenomas (PAs) is limited. The aim of this study was to evaluate the standardised incidence rate (SIR) of PAs in western Sweden.Design, subjects and methods: Data from adult patients diagnosed with PAs in 2001–2011, living in the Västra Götaland County, were collected from the Swedish Pituitary Registry (SPR). In addition, medical records on all patients diagnosed with PAs at the six hospitals in the region were reviewed. In total, 592 patients were included in the study.Age-SIR, given as rate/100 000 inhabitants (95% CI), was calculated using the WHO 2000 standard population as a reference.Results: The total SIR for PAs was 3.9/100 000 (3.6–4.3); 3.3/100 000 (2.9–3.7) for men and 4.7/100 000 (4.1–5.3) for women. In men, SIR increased with age, while in women SIR peaked at 25–34 years, mainly due to prolactinomas. Non-functioning PA (NFPA) was the most common PA (54%, 1.8/100 000 (1.6–2.0)) followed by prolactinomas (32%, 1.6/100 000 (1.3–1.9)), acromegaly (9%, 0.35/100 000 (0.25–0.45)), Cushing's disease (4%, 0.18/100 000 (0.11–0.25)) and TSH-producing PA (0.7%, 0.03/100 000 (0.00–0.05)). The proportion of macroadenomas for NFPA was 82%, prolactinomas 37%, GH-producing PA 77%, ACTH-producing PA 28% and TSH-producing PA 100%. The lifetime risk for PAs was 0.27% (0.24–0.31) in men and 0.29% (0.26–0.33) in women.Conclusion: This study provides a reliable estimate on the overall incidence of PAs and confirms an increased incidence of PAs compared with studies conducted in the pre-magnetic resonance imaging era. The lower proportion of prolactinomas compared with previous studies is probably explained by the different criteria used.

1 April 2015 in The Journal of Clinical Endocrinology & Metabolism
Verified
Journal Article
Closed access
DBDaniel Bengtsson
Daniel Bengtsson
HSHenrik Daa Schrøder
Henrik Daa Schrøder
MAMarianne Skovsager Andersen
Marianne Skovsager Andersen
DMDominique Maiter
Dominique Maiter
KBKatarina Berinder
Katarina Berinder
PBPia Burman
Pia Burman
Locally aggressive pituitary tumors (LAPT) and pituitary carcinomas respond poorly to conventional therapy and cytotoxic drugs. Temozolomide (TMZ) is an oral alkylating drug with good tolerability, approved for treatment of malignant gliomas. The experience of its use in pituitary tumors is limited. We report on 24 patients with aggressive pituitary tumors (16 LAPTs, 8 carcinomas) treated with TMZ for a median of 6 months (range 1-23). Follow-up ranged from 4 to 91 months with a median of 32.5 months. 19/24 tumors were hormone secreting (PRL 9, ACTH 4, GH 4, GH/PRL 2). Ki-67 was 2-50% in LAPTs, and 5-80% in carcinomas. Response to TMZ and the association with tumor expression of O6-methylguanine DNA methyltransferase (MGMT), MLH1, MSH2, and MSH6, examined by immunohistochemistry. Complete tumor regression occurred in two carcinomas and persisted at follow-up after 48 and 91 months, respectively. Partial regress of tumor mass ranging from 35% to 80% occurred in 5 LAPTs and 2 carcinomas. Another patient with LAPT had a 71% decrease in prolactin levels without change in tumor volume. Three LAPTs could not be evaluated. Median MGMT staining was 9% (5-20%) in responders vs 93% (50-100%) in nonresponders. Loss of MSH2 and MSH 6 was observed in a single patient who had a rapid development of resistance to TMZ. This study shows that TMZ is a valuable treatment option for patients with uncontrolled pituitary tumors. The data suggest that tumoral MGMT staining below 50% is associated with a high likelihood of treatment response.

1 July 2015 in European Journal of Endocrinology
Verified
Journal Article
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CACornelie D. Andela
Cornelie D. Andela
FHFemke M van Haalen
Femke M van Haalen
OROskar Ragnarsson
Oskar Ragnarsson
EPEleni Papakokkinou
Eleni Papakokkinou
GJGudmundur Johannsson
Gudmundur Johannsson
APA.M. Pereira
A.M. Pereira
Background: Cushing's syndrome (CS) is characterized by excessive exposure to cortisol, and is associated with both metabolic and behavioral abnormalities. Symptoms improve substantially after biochemical cure, but may persist during long-term remission. The causes for persistent morbidity are probably multi-factorial, including a profound effect of cortisol excess on the brain, a major target area for glucocorticoids.Objective: To review publications evaluating brain characteristics in patients with CS using magnetic resonance imaging (MRI).Methods: Systematic review of literature published in PubMed, Embase, Web of Knowledge, and Cochrane databases.Results: Nineteen studies using MRI in patients with CS were selected, including studies in patients with active disease, patients in long-term remission, and longitudinal studies, covering a total of 339 unique patients. Patients with active disease showed smaller hippocampal volumes, enlarged ventricles, and cerebral atrophy as well as alterations in neurochemical concentrations and functional activity. After abrogation of cortisol excess, the reversibility of structural and neurochemical alterations was incomplete after long-term remission. MRI findings were related to clinical characteristics (i.e., cortisol levels, duration of exposure to hypercortisolism, current age, age at diagnosis, and triglyceride levels) and behavioral outcome (i.e., cognitive and emotional functioning, mood, and quality of life).Conclusion: Patients with active CS demonstrate brain abnormalities, which only partly recover after biochemical cure, because these still occur even after long-term remission. CS might be considered as a human model of nature that provides a keyhole perspective of the neurotoxic effects of exogenous glucocorticoids on the brain.

1 February 2019 in The Journal of Clinical Endocrinology & Metabolism
Verified
Journal Article
Closed access
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OROskar Ragnarsson
Oskar Ragnarsson
DODaniel S Olsson
Daniel S Olsson
EPEleni Papakokkinou
Eleni Papakokkinou
DCDimitrios Chantzichristos
Dimitrios Chantzichristos
PDPer Dahlqvist
Per Dahlqvist
GJGudmundur Johannsson
Gudmundur Johannsson
Context It is still a matter of debate whether patients with Cushing's disease (CD) in remission have increased mortality. Objective To study overall and disease-specific mortality, and predictive factors, in an unselected nationwide cohort of patients with CD. Design, patients and methods A retrospective study on patients diagnosed with CD, identified in the Swedish National Patient Registry between 1987 and 2013. Medical records were systematically reviewed to verify the diagnosis. Standardised mortality ratios (SMRs) with 95% confidence intervals (CI) were calculated and Cox regression models were used to identify predictors of mortality. Results Five-hundred-and-two patients [387 women (77%)] with CD were identified, of whom 419 (83%) were confirmed to be in remission. Mean age at diagnosis was 43 years (SD 16) and median follow-up time was 13 years (IQR 6–23). The observed number of deaths was 133 versus 54 expected, resulting in an overall SMR of 2.5 (95% CI 2.1–2.9). The commonest cause of death was cardiovascular diseases [SMR 3.3 (95% CI 2.6 –4.3)]. Excess mortality was also found due to infections and suicides. SMR in patients in remission was 1.9 (95% CI 1.5–2.3), where bilateral adrenalectomy and glucocorticoid replacement therapy were independently associated with increased mortality whereas growth hormone replacement was associated with improved outcome. Conclusion This large nationwide study shows that patients with CD have an excess mortality. The findings illustrate the importance of obtaining remission and continued active surveillance, along with adequate hormone replacement, and evaluation of cardiovascular risk and mental health.

20 January 2015 in British Journal of Surgery
Verified
Journal Article
Closed access
PDF file
AMA. Muth
A. Muth
OROskar Ragnarsson
Oskar Ragnarsson
GJG. Johannsson
G. Johannsson
BWB. Wängberg
B. Wängberg