Magnus Strømmen

Norwegian version of this page Faculty of Health Sciences and Social Care Norwegian version of this page

Position

Associate Professor

Contact

magnus.strommen@himolde.no

Study place

Molde

Areas of Work

Clinical studies of alcohol-related problems following bariatric surgery, focusing on risk factors (epidemiological studies), mechanisms (pharmacological studies), early detection of alcohol-related problems (biomarkers), and patients’ experiences of such problems (interview studies).
Observational and interview studies of oral health following bariatric surgery.
Patient education – see www.pasientundervisning.no.
Teaching of students.
Supervision of master’s and PhD students.

Background

I am a registered nurse by training and work as a clinical researcher at the Centre for Obesity Research at St. Olavs Hospital and at Kompetansesenteret Tannhelse Midt. I also hold a part-time position as Associate Professor at Molde University College, where I am affiliated with the master’s programme for nurses in mental health, substance use and addiction.

Of particular relevance to my work at Molde University College is my general interest in the systemic effects of bariatric surgery, especially complications related to substance use and oral health. People who have undergone bariatric surgery constitute a larger population than many healthcare professionals realise, and the associated complications are therefore also more prevalent than is commonly recognised. This population is also particularly interesting from a research perspective, as studying it may improve our understanding of alcohol metabolism.

A further research interest is the role of the research nurse and the contribution nurses make to quality in clinical research.

Projects

Patient education material on oral health

Strømmen, Magnus; Dale, Ola; Klöckner, Christian Andreas Nikolaus & Tylleskär, Ida (2026). Ethanol pharmacokinetics before and after sleeve gastrectomy and Roux-en-Y gastric bypass: a 3 year prospective study (the BAR-TRIAL). International Journal of Obesity. ISSN 0307-0565. 50, p. 1573–1580. doi: 10.1038/s41366-026-02113-3. Full text in Research Archive Show summary
Abstract Objectives To compare ethanol pharmacokinetics before and after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) over a three-year period. Methods This was a prospective, longitudinal, non-randomized controlled study at St. Olavs Hospital, Trondheim, including 33 adults without histories of alcohol use disorder (RYGB: n = 14; SG: n = 19). Participants underwent oral and intravenous ethanol challenge tests preoperatively and at 3, 12, and 36 months postoperatively. Primary outcomes included maximum plasma concentration (C max ), time to reach maximum concentration (T max ), and area under the curve to the last measurable concentration (AUC last ). Results The ethanol uptake after both surgical procedures was bioequivalent for AUC last , but not for C max and T max . At 12 months, RYGB gave a 27% higher C max and 31% shorter T max than SG, while no significant differences were observed for AUC last . Both procedures induced profound and persistent alterations in ethanol pharmacokinetics over the three-year period: C max and AUC last approximately doubled, and T max was reduced to about half the preoperative value. C max occurred within 9–15 min compared to 25–29 min before surgery. Patients also had concomitant reductions in total body water, averaging 3.2 kg after SG and 4.8 kg after RYGB at 12 months. Conclusion Both RYGB and SG permanently altered ethanol pharmacokinetics, resulting in faster absorption, higher peak concentrations, and higher systemic exposure of alcohol. These changes, which were more pronounced after RYGB, may increase the risk of alcohol use disorders post-surgery. Awareness of the pharmacokinetic effects on RYGB and SG may be relevant for patient education, surgical decision-making, and postoperative monitoring. Clinical trial registration This study was registered in ClinicalTrials.gov on May 15 2013. Identifier: NCT01840020.
Strømmen, Magnus; Bakken, Inger Johanne Landsjøåsen; Sandvik, Jorunn; Bramness, Jørgen Gustav & Klöckner, Christian Andreas Nikolaus (2026). Alcohol use disorders and related morbidity and mortality after sleeve gastrectomy and Roux-en-Y gastric bypass: a nation-wide registry study (the BAR-REGISTER). International Journal of Obesity. ISSN 0307-0565. 50, p. 1581–1587. doi: 10.1038/s41366-026-02123-1. Full text in Research Archive Show summary
Abstract Background Bariatric surgery provides notable weight loss and metabolic benefits but may also increase the risk of alcohol use disorder (AUD). We investigated whether Roux-en-Y gastric bypass (RYGB) confers higher rates of AUD and related disorders than sleeve gastrectomy (SG) and examined associated morbidity and mortality. Methods We conducted a retrospective, population-based cohort study using data from the Norwegian Patient Registry and the Norwegian Prescription Database. A total of 17,800 patients underwent RYGB ( n = 12,244) or SG ( n = 5556) between 2008 and 2018. Patients with prior diagnoses related to alcohol or use of medications for AUD were excluded. Incidence rates (IR) for alcohol-related diagnoses were calculated per 1000 person-years; hazard ratios (HR) were derived comparing RYGB to SG. Morbidity was measured as number of specialized healthcare contacts, but also as number of prescriptions/defined daily doses in an exploratory model. Results Mean postoperative follow-up was 5.7 years (RYGB) and 3.8 years (SG). By 31 December 2018, 576 patients (3.2%) had developed a new alcohol-related diagnosis – an incidence rate of 6.34 per 1000 person-years. The adjusted HR for such diagnoses was 1.69 (95% CI 1.33–2.13, p < 0.001) for patients undergoing RYGB compared to SG. Because mortality did not differ significantly between RYGB and SG, mortality was assessed for the cohort as a whole: patients with alcohol-related diagnoses had an adjusted HR for death of 2.08 (95% CI 1.40–3.08) relative to those without. They also recorded, on average, 5.5 additional contacts in specialist care. Conclusions Compared with SG, RYGB was associated with a 69% higher risk of alcohol-related diagnoses. Further, given the elevated morbidity and mortality linked to these disorders, enhanced preoperative screening and long-term postoperative monitoring are warranted in modern bariatric practice.
Andersen, John Roger; Kolotkin, Ronette Loganzo; Følling, Ingrid Sørdal; McAleavey, Andrew A.; Hyldmo, Åsne Ask & Bjøru, Hege Tevik [Show all 7 contributors for this article] (2026). Linking overall satisfaction after bariatric surgery with health-related quality of life: a cross-sectional study across varied postoperative time points. Surgery for Obesity and Related Diseases. ISSN 1550-7289. 22(6), p. 636–643. doi: 10.1016/j.soard.2026.02.018. Full text in Research Archive Show summary
Background Initial satisfaction with bariatric surgery is generally high but tends to diminish over time. Impairments in health-related quality of life (HRQoL) likely contribute to this decline. Still, the extent to which HRQoL domains influence overall satisfaction after surgery remains unclear. Objectives We examined the associations between a comprehensive HRQoL model and overall satisfaction after bariatric surgery and whether a smaller set of obesity-specific HRQoL measures could sufficiently account for this outcome. Setting General hospitals, Norway. Methods We conducted a cross-sectional analysis of 373 patients, with time since bariatric surgery ranging from 3 months to 10 years. Partial least squares (PLS) regression models were employed, with overall satisfaction as the dependent variable and 30 distinct HRQoL outcomes as independent variables. We also evaluated whether a smaller model of obesity-specific HRQoL measures could adequately explain variations in overall satisfaction while maintaining robust explanatory power. Results The full HRQoL PLS regression model explained 39.3% of the variance in overall satisfaction. A simplified model with four obesity-specific measures explained 35.6%, which increased to 43.1% when BMI was added. The logistic regression analysis indicated that poorer obesity-specific HRQoL and a higher body mass index were independently associated with lower overall satisfaction, with an area under the curve of 0.90, indicating excellent model performance. Conclusion A simplified obesity-specific HRQoL model, along with body mass index, was strongly associated with overall satisfaction after bariatric surgery, suggesting that a few HRQoL outcomes may effectively capture its key determinants.
Spigset, Olav; Krabseth, Hege-Merete; Strømmen, Magnus & Helland, Arne (2025). Effect of Bariatric Surgery on the Pharmacokinetics of Codeine, Oxycodone and Tramadol—A Case Series. Basic & Clinical Pharmacology & Toxicology. ISSN 1742-7835. 137(6). doi: 10.1111/bcpt.70149. Full text in Research Archive
Schoretsanitis, Georgios; Krabseth, Hege-Merete; Strømmen, Magnus; Helland, Arne & Spigset, Olav (2025). Effects of sleeve gastrectomy and Roux-en-Y gastric bypass on the pharmacokinetics of gabapentin and pregabalin: A cohort study. PLOS ONE. 20(3). doi: 10.1371/journal.pone.0319912. Full text in Research Archive
Bramness, Jørgen Gustav; Lien, Lars; Moe, Jenny Skumsnes; Toft, Helge; Pandey, Susmita & Lid, Torgeir Gilje [Show all 9 contributors for this article] (2024). Bariatric surgery patients in AUD treatment in Norway—an exploratory cross-sectional study. Alcohol and Alcoholism. ISSN 0735-0414. 59(2). doi: 10.1093/alcalc/agae007. Full text in Research Archive Show summary
Aims Patients who have undergone some forms of bariatric surgery have increased risk of developing alcohol use disorder (AUD). In the present observational study, we compared patients with AUD who themselves reported to having undergone bariatric surgery with other patients in treatment for AUD. Materials One-hundred-and-six consecutively enrolled patients in residential treatment for AUD were asked if they had undergone bariatric surgery. Sociodemographics, mental health-related, and alcohol use-related parameters were compared between those who had and those who had not undergone bariatric surgery. Results Of the 106 patients with AUD, seven (6.6%; 95% confidence interval, 2.7%–13.1%) had undergone bariatric surgery. Six of seven patients had undergone such surgery were women (P < .001). The patients with AUD who had undergone bariatric surgery were similar to other patients with AUD on most other parameters, the exception being a larger number of alcohol units ingested to feel an effect of alcohol (adjusted odds ratio 7.1; 95% confidence interval 2.0–12.2; P = .007). Conclusion The high number of patients with AUD that reported having undergone bariatric surgery emphasizes the risks following such a procedure. The overrepresentation of women may reflect than more women undergo such procedures. The unexpected finding that patients with AUD having undergone bariatric surgery seemed to need more alcohol to feel intoxicated warrants further research.
Line, Ida Louise & Strømmen, Magnus (2024). Tannbehandling etter fedmeoperasjon hos pasient med odontofobi - en kasuistikk. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 134, p. 38–43. doi: 10.56373/2024-1-7. Full text in Research Archive
Schoretsanitis, Georgios; Strømmen, Magnus; Krabseth, Hege-Merete; Spigset, Olav & Helland, Arne (2024). Effects of sleeve gastrectomy and Roux-en-Y gastric bypass on pharmacokinetics of lamotrigine and valproate: A cohort study. Epilepsy Research. ISSN 0920-1211. 208. doi: 10.1016/j.eplepsyres.2024.107469. Full text in Research Archive
Krabseth, Hege-Merete; Strømmen, Magnus; Helland, Arne & Spigset, Olav (2024). Effect of bariatric surgery on the pharmacokinetics of drugs used for attention-deficit hyperactivity disorder—A case series. Basic & Clinical Pharmacology & Toxicology. ISSN 1742-7835. doi: 10.1111/bcpt.14099. Full text in Research Archive
Schoretsanitis, Georgios; Strømmen, Magnus; Krabseth, Hege-Merete; Helland, Arne & Spigset, Olav (2023). Effects of Sleeve Gastrectomy and Roux-en-Y Gastric Bypass on Escitalopram Pharmacokinetics: A Cohort Study. Therapeutic Drug Monitoring. ISSN 0163-4356. 45(6), p. 805–812. doi: 10.1097/FTD.0000000000001114. Full text in Research Archive
Debik, Julia; Isaksen, Sylvia Hetlelid; Strømmen, Magnus; Spraul, Manfred; Schäfer, Hartmut & Bathen, Tone Frost [Show all 7 contributors for this article] (2022). Effect of Delayed Centrifugation on the Levels of NMR-Measured Lipoproteins and Metabolites in Plasma and Serum Samples. Analytical Chemistry. ISSN 0003-2700. doi: 10.1021/acs.analchem.2c02167. Full text in Research Archive Show summary
Metabolic profiling is widely used for large-scale association studies, based on biobank material. The main obstacle to the translation of metabolomic findings into clinical application is the lack of standardization, making validation in independent cohorts challenging. One reason for this is sensitivity of metabolites to preanalytical conditions. We present a systematic investigation of the effect of delayed centrifugation on the levels of NMR-measured metabolites and lipoproteins in serum and plasma samples. Blood was collected from 20 anonymous donors, of which 10 were recruited from an obesity clinic. Samples were stored at room temperature until centrifugation after 30 min, 1, 2, 4, or 8 h, which is within a realistic time scenario in clinical practice. The effect of delaying centrifugation on plasma and serum metabolic concentrations, and on concentrations of lipoprotein subfractions, was investigated. Our results show that lipoproteins are only minimally affected by a delay in centrifugation while metabolite levels are more sensitive to a delay. Metabolites significantly increased or decreased in concentration depending on delay duration. Further, we describe differences in the stability of serum and plasma, showing that plasma is more stable for metabolites, while lipoprotein subfractions are equally stable for both types of matrices.
Natvik, Eli; Lavik, Kristina Osland; Ogden, Jane; Strømmen, Magnus Nordvik & Moltu, Christian (2022). The Patient-Practitioner interaction in post bariatric surgery consultations: an interpersonal process recall study. Disability and Rehabilitation. ISSN 0963-8288. 45(26). doi: 10.1080/09638288.2022.2152876. Full text in Research Archive Show summary
Purpose: The patient-practitioner relationship is fundamental to rehabilitation practice and patients’ health and wellbeing. Dissonance between patients who have had bariatric surgery and health care practitioners about what supportive care and good outcomes are can undermine care. To address the mechanisms of this process, we conducted an Interpersonal Process Recall study. Materials and Methods: We interviewed patients (11), video recorded consultations (10), conducted video-assisted individual interviews with patients (10) and practitioners (11) and a dyadic data analysis. Results: We identified relational states and shifts in the clinical encounter 2-3 years post-surgery, described in themes: a) Playing by the Book – Making it Easier for Each Other, b) Down the Blind Alley – Giving up on Each Other, and c) Opposite Poles – Towards and Away from Each Other. Conclusions: The post-surgery consultations facilitated responsibility for health and self-care but did not invite dialogues about the psychosocial burdens of living with obesity and undergoing bariatric surgery. Patients and practitioners tried to avoid creating conflict, which in turn seemed to foster distance, rather than human connection. This limits the encounter’s benefit to both parties, leaving them frustrated and less willing to either meet again or take any gains into their future lives.
Strømmen, Magnus; Kløckner, Christian; Bjerkan, Kirsti Kverndokk; Græslie, Hallvard; Hoff, Dag Arne Lihaug & Johnsen, Gjermund [Show all 10 contributors for this article] (2021). Characteristics of Patients Reporting Presumed Problematic Drinking Behavior After Gastric Bypass: Exploring Long-Term Data From the BAROBS Study. Frontiers in Endocrinology. 12:679006, p. 1–9. doi: 10.3389/fendo.2021.679006. Full text in Research Archive Show summary
Objective: To explore patients’ long-term experiences with drinking alcohol after Roux-n-Y gastric bypass (RYGB) for conceptualizing what may indicate problematic drinking behavior after bariatric surgery. Study Design: Three-center, observational study. Patients: 546 adult patients undergoing RYGB in the period 2003-2009 in Norway. Main Outcome Measures: Self-reported data on drinking behavior and experiences related to alcohol collected 10-15 years after surgery. Results: Out of the 959 patients undergoing RYGB in the period, 29 were diseased and 546 participated in this follow-up study (58.7%). Focusing on suspicious changes in drinking behavior, 8.8% reported drinking more, 11.5% consumed alcohol at least twice a week, and 10.6% consumed at a minimum of 6 units of alcohol at a frequency of at least once monthly. The nature of hangovers had changed for about a third of the patients, with 21.6% reporting these to feel weaker or absent. Repeated alcoholic blackouts were reported by 11.9%. A subgroup of the patients were categorized as displaying presumed problematic drinking behavior(PPDB). Among the PPDB-men there was a significant association to having had a fall last year (6 (100.0%) PPDB-patients vs. 30 (29.7%) non-PPDB, p<.001). Among the PPDB-women, there was a significant association to having had alcohol problems prior to surgery (7 (70.0%) PPDB-patients vs. 67 (17.7%) non-PPDB, p<.001). Less significant associations to PPDB reported for explorative purposes were lack of patient education (men) (16 (26.2%) PPDB-patients vs. 8 (61.5%) non-PPDB, p=.014); more than 3 months persistent musculoskeletal pain (women) (45 (15.3%) PPDB-patients vs. 29 (24.6%) non-PPDB, p=.026); subjective problems with memory (women) (58 (20.7%) PPDB-patients vs. 10 (9.1%) non-PPDB, p=.006); and, receiving professional help for mental problems last 12 months (women) (29 (22.7%) PPDB-patients vs. 45 (14.7%) non-PPDB, p=.043). Conclusion: A subset of patients display drinking behaviors that may be consistent with postsurgical alcohol problems. Screening instruments like AUDIT may not be sufficiently specific to capture several risk behaviors occurring after bariatric surgery.
Rognstad, Stine; Søraas, Camilla Lund; Bergland, Ola Undrum; Høieggen, Aud; Strømmen, Magnus & Helland, Arne [Show all 7 contributors for this article] (2020). Establishing Serum Reference Ranges for Antihypertensive Drugs. Therapeutic Drug Monitoring. ISSN 0163-4356. 43(1), p. 116–125. doi: 10.1097/FTD.0000000000000806. Full text in Research Archive Show summary
Background: Therapeutic drug monitoring (TDM) involves the measurement of serum drug concentrations to optimize pharmacotherapy. Traditionally, blood pressure measurements alone, and not TDM, have been used to evaluate the antihypertensive drug response. However, approximately 50% of hypertensive patients treated with lifestyle changes and antihypertensive drugs fail to achieve blood pressure control. Serum drug concentration measurements could be useful to select the optimal drugs in adjusted doses and to identify nonadherence. Implementation of TDM in clinical routine for antihypertensive drugs depends on established serum reference ranges. Methods: Commonly used antihypertensive drugs were identified based on prescription data. The authors performed a review of authoritative literature on reported serum drug concentrations and calculated expected concentrations from previously reported pharmacokinetic parameters with commonly prescribed daily doses. Finally, serum drug concentrations in samples from patients undergoing antihypertensive treatment were measured. Results: Serum reference ranges for 24 frequently used antihypertensive drugs were established based on results from 3 approaches. Conclusions: Serum drug concentration measurements, interpreted in light of the established reference ranges, together with blood pressure measurements and other clinical data, may help identify nonadherent patients and tailor individual antihypertensive treatment when deviant drug responses appear in line with the concept of personalized medicine.
Krabseth, Hege-Merete; Strømmen, Magnus; Spigset, Olav & Helland, Arne (2020). Effect of sleeve gastrectomy on buprenorphine pharmacokinetics: A planned case observation. Clinical Therapeutics. ISSN 0149-2918. 42(11), p. 2232–2237. doi: 10.1016/j.clinthera.2020.08.016. Full text in Research Archive
Strømmen, Magnus; Bakken, Inger Johanne Landsjøåsen; Kløckner, Christian; Sandvik, Jorunn; Kulseng, Bård Eirik & Holen, Are (2019). Diagnoses related to abuse of alcohol and addictive substances after gastric bypass and sleeve gastrectomy: a nation-wide registry study from Norway. Surgery for Obesity and Related Diseases. ISSN 1550-7289. 16(4), p. 464–470. doi: 10.1016/j.soard.2019.12.011. Full text in Research Archive Show summary
Background After Roux-n-Y gastric bypass (RYGB) patients are at higher risk of alcohol problems. In recent years, sleeve gastrectomy (SG) has become a common procedure, but the incidence rates of alcohol abuse following SG are unexplored. Objectives To compare incidence rates of diagnoses indicating problems with alcohol or other substances between patients having undergone SG or RYGB with a minimum of 6 months follow-up. Setting All government funded hospitals in Norway providing bariatric surgery. Methods A retrospective population-based cohort study based on data from the Norwegian Patient Registry. The outcomes were ICD-10 diagnoses relating to alcohol (F10) and other substances (F11-F19). Results The registry provided data on 10,208 patients who underwent either RYGB or SG during the years 2008-2014 with a total post-operative observation time of 33,352 person-years. This corresponds to 8,196 patients with RYGB (27,846 person-years, average 3.4 years) and 2,012 patients with SG (5,506 person-years; average 2.7 years). The incidence rate (IR) for the diagnoses related to alcohol problems after RYGB was 6.36 (95% CI: 5.45-7.36) per 1,000 person-years and 4.54 (2.94-6.70) after SG. When controlling for age and sex, adjusted hazard ratio (HR) was 0.75 (0.49-1.14) for SG compared to RYGB. When combining both bariatric procedures, women under 26 years were more likely to have alcohol-related diagnoses (3.2%, 2.1-4.4) than women of 26-40 years (1.6%, 1.1-2.1) or women older than 40 (1.3%, 0.9-1.7). The IR after RYGB for the diagnoses related to problems with substances other than alcohol was 3.48 (95% CI: 2.82-4.25) compared to 3.27 (1.94-5.17) per 1,000 person-years after SG. Controlling for age and sex, the HR was 0.99 (0.60-1.64) for SG compared to RYGB. Conclusions In our study, procedure-specific differences were not found in the risks (RYGB vs. SG) for post-operative diagnoses related to problems with alcohol and other substances within the available observation time. A longer observation period seems required to explore these findings further.
Amundsen, Tina; Strømmen, Magnus & Martins, Catia (2017). Suboptimal Weight Loss and Weight Regain after Gastric Bypass Surgery?Postoperative Status of Energy Intake, Eating Behavior, Physical Activity, and Psychometrics. Obesity Surgery. ISSN 0960-8923. 27(5), p. 1316–1323. doi: 10.1007/s11695-016-2475-7. Full text in Research Archive Show summary
BACKGROUND: Suboptimal weight loss (SWL) and weight regain (WR) after gastric bypass surgery (GB) remains poorly understood. OBJECTIVES: This study aims to compare GB patients experiencing SWL or significant WR (SigWR) with successful controls, regarding postoperative food intake, eating behavior, physical activity (PA), and psychometrics. METHODS: Forty-nine patients with >1 year post-surgery were classified as either experiencing SWL (excess body weight loss, EWL, <50%, n = 22) or SigWR (total weight regain ≥15%, n = 38), with respective control groups. Energy intake (EI) was measured with a Food Frequency Questionnaire, eating behavior using the Dutch Eating Behavior Questionnaire and the Three-Factor Eating Questionnaire, and PA using both SenseWear Armbands and the International Physical Activity Questionnaire. Eating disorders, depression, and quality of life (QoL) were measured using the Eating Disorder Examination Questionnaire, Beck Depression Inventory II, and Impact of Weight on Quality of Life, respectively. RESULTS: EI, macronutrient distribution, and meal frequency were similar among groups. However, disinhibited eating behavior score was higher, while most subcategories from IWQOL were significantly lower in both SWL and SigWR groups compared with their respective controls. PA was significantly lower in the SWL and SigWR groups compared with the respective controls. There were no differences between groups regarding depression. CONCLUSIONS: Lower PA levels, disordered eating behavior and lower QoL are associated with unsuccessful weigh loss outcome after GB surgery. Longitudinal studies are needed to clarify the potential causal relationship between the previously described variables and SWL/SigWR after GB.
Øvrebø, Bente; Strømmen, Magnus; Kulseng, Bård Eirik & Martins, Catia (2017). Bariatric surgery versus lifestyle interventions for severe obesity: 5-year changes in body weight, risk factors and comorbidities. Clinical Obesity. ISSN 1758-8103. 7(3), p. 183–190. doi: 10.1111/cob.12190. Full text in Research Archive Show summary
Changes in body weight (BW), risk factors and comorbidities 5 years after Roux-en-Y gastric bypass (RYGB) or different lifestyle interventions are compared. A total of 209 (75% women) severe obese adults were non-randomly allocated to: (A) RYGB (n = 58), (B) weight loss (WL) camp (n = 30), (C) residential intermittent programme (n = 64) or (D) hospital outpatient programme (n = 57). Body weight, risk factors and comorbidities were assessed at baseline, 1 and 5 years. A total of 89 and 54% completed the 1- and 5-year follow-up. The RYGB group experienced more WL at 5 years (−23.9%, 95% CI [−27.7, −20.0]) compared with lifestyle groups: (B) (−9.2%, 95% CI [−16.9, −1.5]), (C) (−4.1%, 95% CI [−8.0, −0.1]) and (D) (−4.1 kg, 95% CI [−10.0, 1.8]) (all P < 0.001). No differences were observed between lifestyle groups, although groups B and C had significant WL after 5 years (all P < 0.05). Plasma glucose and high-density lipoprotein cholesterol were improved in the RYGB group at 5 years compared with lifestyle groups (all P < 0.05). More patients in the RYGB group experienced remission of hypertension (P < 0.05). RYGB was associated with a lower BW, improved blood parameters and hypertension remission compared with lifestyle interventions at 5 years. However, significant WL was also achieved with lifestyle interventions.
Strømmen, Magnus; Helland, Arne; Kulseng, Bård Eirik & Spigset, Olav (2016). Increased bioavailability of methadone following sleeve gastrectomy - a planned case observation. Clinical Therapeutics. ISSN 0149-2918. 38(6), p. 1532–1536. doi: 10.1016/j.clinthera.2016.04.033. Full text in Research Archive
Strømmen, Magnus; Bakken, Inger Johanne; Andenæs, Ellen; Kløckner, Christian; Mårvik, Ronald & Kulseng, Bård Eirik [Show all 7 contributors for this article] (2015). Fet, feit eller bare overvektig = Fat, obese or just overweight. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 135(19), p. 1732–1736. doi: 10.4045/tidsskr.14.0828. Full text in Research Archive
Røkenes, Jessica Ann; Strømmen, Magnus; Kulseng, Bård Eirik & Martins, Catia (2015). The impact of feet callosities, arm posture, and usage of electrolyte wipes on body composition by bioelectrical impedance analysis in morbidly obese adults. Obesity Facts. ISSN 1662-4025. 8(6), p. 364–372. doi: 10.1159/000442033. Full text in Research Archive Show summary
Objective: This study evaluated the impact of feet callosities, arm posture, and use of electrolyte wipes on body composition measurements by bioelectrical impedance analysis (BIA) in morbidly obese adults. Methods: 36 morbidly obese patients (13 males, aged 28-70 years, BMI 41.6 ± 4.3 kg/m2) with moderate/severe feet callosities participated in this study. Body composition (percent body fat (%BF)) was measured while fasting using multi-frequency BIA (InBody 720®), before and after removal of callosities, with and without InBody® electrolyte wipes and custom-built auxiliary pads (to assess arm posture impact). Results from BIA were compared to air displacement plethysmography (ADP, BodPod®). Results: Median %BF was significantly higher with auxiliary pads than without (50.1 (interquartile range 8.2) vs. 49.3 (interquartile range 9.1); p < 0.001), while no differences were found with callosity removal (49.3 (interquartile range 9.1) vs. 50.0 (interquartile range 7.9); NS) or use of wipes (49.6 (interquartile range 8.5) vs. 49.3 (interquartile range 9.1); NS). No differences in %BF were found between BIA and ADP (49.1 (IQR: 8.9) vs. 49.3 (IQR: 9.1); NS). Conclusion: Arm posture has a significant impact on %BF assessed by BIA, contrary to the presence of feet callosities and use of electrolyte wipes. Arm posture standardization during BIA for body composition assessment is, therefore, recommended.

View all works in NVA

Strømmen, Magnus (2026). Munnhelse og fedmebehandling. Full text in Research Archive
Strømmen, Magnus (2026). Studiesykepleierrollen og det frie, informerte samtykke. Full text in Research Archive
Strømmen, Magnus (2026). Vil kartlegge usynlig sykepleiergruppe. [Internet]. Tidsskriftet Sykepleien. doi: https:/sykepleien.no/2026/08/vil-kartlegge-usynlig-sykepleiergruppe. Full text in Research Archive Show summary
Ingen vet hvor mange studiesykepleiere vi har her i landet. Heller ikke hvilken utdanning, erfaring eller hvilke oppgaver de har. Det vil Magnus Strømmen gjøre noe med.
Strømmen, Magnus (2026). Patient Warning: Bariatric Surgery Can Get Them Drunk Faster. [Internet]. Medscape.com. Full text in Research Archive Show summary
‘The same amount of alcohol may produce at least twice the effect,’ experts say. Patients need early education on the situation.
Strømmen, Magnus (2026). Alkoholopptaket dobles etter fedmekirurgi – forsker mener kartleggingen ikke er god nok. [Journal]. www.dagensmedisin.no. Full text in Research Archive Show summary
To nye norske studier viser at pasienter tar opp omtrent dobbelt så mye alkohol etter fedmeoperasjon. Magnus Strømmen mener spørreskjemaene dermed måler feil størrelse – og at de mest utsatte pasientene er dem klinikerne leter minst etter.
Strømmen, Magnus (2026). Kveldsnytt - NRK TV. [TV]. NRK. Full text in Research Archive Show summary
Kveldens siste nyheter
Strømmen, Magnus (2026). Fedmeoperasjon gir økt risiko for alkoholproblemer. [Internet]. Gemini.no. Full text in Research Archive Show summary
Alkoholopptaket i kroppen stiger kraftig etter en fedmeoperasjon. Det gir en økt risiko for alkoholproblemer.
Strømmen, Magnus (2026). Fedmeoperasjonar aukar risiko for alkoholproblem, viser ny studium frå Noreg – NRK Trøndelag. [Internet]. NRK.no. Full text in Research Archive Show summary
Etter ein sånn operasjon blir ein fortare full, meir full og rusen varer lenger.
Strømmen, Magnus (2025). En kvalitativ studie av personer som utviklet munnhelseproblemer etter fedmekirurgi og deres erfaringer med tannhelsetjenesten. Full text in Research Archive
Strømmen, Magnus (2025). Gap opp! Om usynlige komplikasjoner etter fedmekirurgi. Full text in Research Archive
Strømmen, Magnus (2025). Kirurgiske komplikasjoner som går under radaren? Full text in Research Archive
Strømmen, Magnus (2025). Fedmekirurgi og munnhelse. Full text in Research Archive
Strømmen, Magnus (2025). Hva innebærer en fedmeoperasjon for munn- og tannhelsen? Full text in Research Archive
Strømmen, Magnus (2025). Oral helse etter fedmekirurgi: En mulig arena for forebygging? doi: https:/www.tannlegeforeningen.no/kurs-og-etterutdanning/kursoversikt-og--pamelding/kurs/2025-05-07-ntfs-digitale-fagdag-2025.html. Full text in Research Archive
Strømmen, Magnus (2025). Oral helse og fedmekirurgi - noe systemisk vi systematisk overser? Full text in Research Archive
Lee, Irina & Strømmen, Magnus (2025). Fedmekirurgi og munnhelse. [Internet]. Podcasten Spis deg fri. Full text in Research Archive
Strømmen, Magnus (2025). Oral helse og fedmekirurgi: Et svar på bestillingen Oral helse i lys av annen sykdom og behandling. Full text in Research Archive
Strømmen, Magnus (2025). Hva innebærer en fedmeoperasjon for munnhelsen? Full text in Research Archive
Strømmen, Magnus (2024). Fedmekirurgi og rus. Full text in Research Archive
Strømmen, Magnus (2024). Fedmekirurgi og rus. Full text in Research Archive
Strømmen, Magnus (2024). BAR-ORAL - En 10-årig prospektiv kohortstudie av oral helse og alkoholvaner hos pasienter som gjennomgår fedmebehandling. Full text in Research Archive
Strømmen, Magnus (2023). Oral helse hos fedmeopererte. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 133(4), p. 320–321. doi: 10.56373/2023-4-6. Full text in Research Archive
Kalvø, Lily & Strømmen, Magnus (2023). - En sammensatt problemstilling. [Journal]. Tannstikka, medlemsblad Norsk tannpleierforbund. Full text in Research Archive
Strømmen, Magnus (2023). Fedmekirurgi og oral helse. Full text in Research Archive
Strømmen, Magnus (2023). Toril ble alkoholiker etter fedmeoperasjon. [Internet]. NRK.no. Full text in Research Archive
Strømmen, Magnus (2023). NRK Nyhetsmorgen. [Radio]. NRK P2. Full text in Research Archive
Strømmen, Magnus (2023). NRK Dagsnytt. [Radio]. NRK Dagsnytt P1. Full text in Research Archive
Strømmen, Magnus (2023). Fedmekirurgi og oral helse. Full text in Research Archive
Strømmen, Magnus Nordvik & Eftedal, Randi Krog (2023). Et vinnende smil? Oral helse i toppidretten. Norsk tannlegeforening Tidende. doi: 10.56373/2023-11-5. Full text in Research Archive
Strømmen, Magnus Nordvik (2023). Et vinnende smil? Oral helse i toppidretten. Norsk tannlegeforening Tidende. doi: 10.56373/2023-11-5. Full text in Research Archive
Strømmen, Magnus (2023). Alkohol og fedme - Hva vet vi og hvordan kan vi best forene innsatsene våre fremover? Full text in Research Archive
Strømmen, Magnus (2022). Fedmekirurgi og munnhelse. Full text in Research Archive
Strømmen, Magnus (2022). Fedmekirurgi og oral helse. Full text in Research Archive
Strømmen, Magnus (2022). Alkoholproblemer etter fedmekirurgi: Antatte virkningsmekanismer. Full text in Research Archive
Strømmen, Magnus (2022). 1 av 5 kan utvikle alkoholproblem. [Internet]. NRK.no. Full text in Research Archive
Strømmen, Magnus (2022). Gryende forskerspire - et intervju om en spennende karrierevei. [Journal]. Kontaktpunktet. Medlemsblad for Sør-Trøndelag tannlegeforeni. Full text in Research Archive
Debik, Julia; Isaksen, Sylvia Hetlelid; Strømmen, Magnus; Spraul, Manfred; Schäfer, Hartmut & Bathen, Tone Frost [Show all 7 contributors for this article] (2022). Effect of delayed centrifugation on the levels of NMR-measured lipoproteins and metabolites in plasma and serum samples. Full text in Research Archive
Strømmen, Magnus (2022). Fra one-size-fits-nobody til persontilpasset behandling. Full text in Research Archive
Strømmen, Magnus; Bakken, Inger Johanne Landsjøåsen; Kløckner, Christian; Sandvik, Jorunn; Kulseng, Bård Eirik & Holen, Are (2021). Corrigendum to ‘Diagnoses Related to Abuse of Alcohol and Addictive Substances after Gastric Bypass and Sleeve Gastrectomy – A Nation-Wide Registry Study from Norway’. Surgery for Obesity and Related Diseases. ISSN 1550-7289. 17(3), p. 646–647. doi: 10.1016/j.soard.2020.11.029. Full text in Research Archive
Strømmen, Magnus (2021). Veien fra fedme til rus: Hvor gikk det galt? Forbedringsarbeid i klinikken med støtte i biokjemiske analyser. Full text in Research Archive
Strømmen, Magnus (2020). Fedme og sammenhengen psyke-soma. Full text in Research Archive
Strømmen, Magnus & Kløckner, Christian (2020). Letter to the Editor Regarding the Impact of ADHD on Outcomes Following Bariatric Surgery: a Systematic Review and Meta-Analysis. Obesity Surgery. ISSN 0960-8923. doi: 10.1007/s11695-020-05127-6. Full text in Research Archive
Strømmen, Magnus (2019). Fedmekirurgi og opptak av alkohol og legemidler. Full text in Research Archive
Strømmen, Magnus (2019). Fedmekirurgi: Hva med alkohol og medikamenter? Full text in Research Archive
Strømmen, Magnus (2019). Fedmekirurgi og alkoholproblemer. Full text in Research Archive
Strømmen, Magnus (2018). Stigmatisering av mennesker med fedme. Full text in Research Archive
Strømmen, Magnus (2018). Fedmekirurgiens bakside. Full text in Research Archive
Strømmen, Magnus (2018). Alkoholproblemer hos fedmeopererte pasienter. Full text in Research Archive
Strømmen, Magnus (2018). We need Forskningsposten for early phase trials. Full text in Research Archive
Strømmen, Magnus (2017). Alkoholproblemer - Komplikasjon til fedmekirurgi? Full text in Research Archive
Strømmen, Magnus (2017). Fedmekirurgi og alkoholmisbruk. Full text in Research Archive
Strømmen, Magnus (2017). Fedmekirurgi og alkoholmisbruk. Full text in Research Archive
Strømmen, Magnus (2017). Alkoholproblemer - langtidskomplikasjon til fedmekirurgi? Full text in Research Archive
Fremstad, Mads & Strømmen, Magnus (2016). Fastlege slår alarm: -Feige leger dreper pasienter. [Internet]. ABC Nyheter. Full text in Research Archive
Strømmen, Magnus (2016). Elefanten i rommet. Hvorfor er det så vanskelig å snakke om fedme? Full text in Research Archive
Strømmen, Magnus (2016). Fedmekirurgi og alkohol. Full text in Research Archive
Walker, Anne Siri Nørstebø & Strømmen, Magnus (2016). Nyhetsinnslag: "Da Trygve nærmet seg 137 kg, sa legen noe viktig". [Radio]. P4. Full text in Research Archive
Strømmen, Magnus; Helland, Arne; Kulseng, Bård Eirik & Spigset, Olav (2016). Bioavailability of methadone after sleeve gastrectomy: A planned case observation. Full text in Research Archive
Walker, Anne Siri Nørstebø & Strømmen, Magnus (2016). Fedmeopererte blir rusavhengige. [Radio]. P4. Full text in Research Archive
heldal, synne & Strømmen, Magnus (2016). "Feit og stolt!" Intervju med Jørgen Foss og Magnus Strømmen. [Journal]. Psykologisk tidsskrift. Full text in Research Archive
Strømmen, Magnus (2016). Skaper fedmekirurgi alkoholikere? Fra anekdote til klinisk forskning. Full text in Research Archive
Strømmen, Magnus (2016). Fedmekirurgi og alkohol. Full text in Research Archive
Chen, Duan; Olsen, Magnus Kringstad; Strømmen, Magnus; Johannessen, Helene; Bjøru, Hege Tevik & Salater, Sissel [Show all 10 contributors for this article] (2016). Intragastric Injection of Botulinum Toxin a to Treat Obesity: Mechanism of Action and a Randomized, Double-Blind, Placebo-Controlled Phase II Trial With Open-Label Extension Study. Gastroenterology. ISSN 0016-5085. 150(4), p. 823–823. doi: 10.1016/S0016-5085(16)32787-1. Full text in Research Archive
Aas, Elisabeth & Strømmen, Magnus (2015). Bekymret for antall fedmeoperasjoner i Norge. [TV]. NRK Midtnytt, NRK1. Full text in Research Archive
Ukesluttredaksjonen, NRK & Strømmen, Magnus (2015). NRK Ukeslutt. [Radio]. NRK P1. Full text in Research Archive
Strømmen, Magnus (2015). "Fra ord til handling - Fremtidsutsikter fra en utprøverenhet". Full text in Research Archive
walker, Anne Siri Nørstebø & Strømmen, Magnus (2015). Vanskelig for leger å snakke om overvekt. [Radio]. P4. Full text in Research Archive
Strømmen, Magnus & Dommerud, Tine (2015). Overvektige personer vil ikke karakteriseres som feit av fastlegen. [Journal]. Stavanger Aftenblad. Full text in Research Archive
Børstad, Johannes & Strømmen, Magnus (2015). Ikke kall pasienten feit. [Radio]. God ettermiddag Trøndelag, NRK P1. Full text in Research Archive
Gjerstad, Linn & Strømmen, Magnus (2015). Fet, feit eller bare overvektig? [Journal]. Bergens Tidende. Full text in Research Archive
Rugsveen, Henning & Strømmen, Magnus (2015). Overvektig, ja, men ikke kall meg feit. [Journal]. Nordlys. Full text in Research Archive
Dommerud, Tine & Strømmen, Magnus (2015). Overvektige personer vil ikke karakteriseres som "feit" av legen. [Journal]. Aftenposten, s 14. Full text in Research Archive
Rugsveen, Henning & Strømmen, Magnus (2015). Overvektig, ja, men ikke kall meg feit. [Journal]. Telemarksavisa. Full text in Research Archive
Rugsveen, Henning & Strømmen, Magnus (2015). Ingen liker at legen sier at du er feit. [Journal]. Moss Avis. Full text in Research Archive
Brustad, Line & Strømmen, Magnus (2015). Feit er ikke greit. [Journal]. Dagbladet. Full text in Research Archive
Rugsveen, Henning & Strømmen, Magnus (2015). Ikke kall meg feit! [Journal]. Drammens Tidende. Full text in Research Archive
Strømmen, Magnus (2015). Hva gjør legen når pasienten veier for mye? p. 10–11. Full text in Research Archive
Strømmen, Magnus; Kulseng, Bård Eirik & Dale, Ola (2015). Increased bioavailability of alcohol following sleeve gastrectomy. Preliminary results 3 months afters surgery. Full text in Research Archive
Strømmen, Magnus (2014). Gastric surgery increases risk of alcoholism. [Journal]. The Independent. Full text in Research Archive

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Published June 19, 2026 1:58 PM - Last modified Oct. 13, 2026 12:24 PM