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- Axelsson, Kristian F, et al.
(författare)
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Fracture risk after gastric bypass surgery – a retrospective cohort study
- 2018
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Ingår i: Journal of Bone and Mineral Research. - : Wiley-Blackwell Publishing Inc.. - 0884-0431 .- 1523-4681. ; 33:12, s. 2122-2131
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Tidskriftsartikel (refereegranskat)abstract
- Gastric bypass surgery constitutes the most common and effective bariatric surgery to treat obesity. Gastric bypass leads to bone loss, but fracture risk following surgery has been insufficiently studied. Furthermore, the association between gastric bypass and fracture risk has not been studied in patients with diabetes, which is a risk factor for fracture and affected by surgery. In this retrospective cohort study using Swedish national databases, 38 971 obese patients undergoing gastric bypass were identified, 7758 with diabetes and 31 213 without. An equal amount of well-balanced controls were identified through multivariable 1:1 propensity score matching. The risk of fracture and fall injury was investigated using Cox proportional hazards and flexible parameter models. Fracture risk according to weight loss and degree of calcium and vitamin D supplementation one-year post- surgery was investigated. During a median follow-up time of 3.1 (IQR 1.7-4.6) years, gastric bypass was associated with increased risk of any fracture, in patients with and without diabetes using a multivariable Cox model (HR 1.26, 95% CI 1.05- 1.53 and HR 1.32, 95% CI 1.18-1.47, respectively). Using flexible parameter models, the fracture risk appeared to increase with time. The risk of fall injury without fracture was also increased after gastric bypass. Larger weight loss or poor calcium and vitamin D supplementation after surgery were not associated with increased fracture risk. In conclusion, gastric bypass surgery is associated with an increased fracture risk, which appears to be increasing with time and not associated with degree of weight loss or calcium and vitamin D supplementation following surgery. An increased risk of fall injury was seen after surgery, which could contribute to the increased fracture risk. This article is protected by copyright. All rights reserved.
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| 2. |
- Axelsson, Kristian F, 1973, et al.
(författare)
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Risk of fracture in adults with type 2 diabetes in Sweden: A national cohort study
- 2023
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Ingår i: Plos Medicine. - : Public Library of Science (PLoS). - 1549-1277 .- 1549-1676. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Author summary Why was this study done? Type 2 diabetes mellitus (T2DM) is considered a risk factor for fracture but the evidence regarding the impact of T2DM on fracture risk is conflicting.We sought to determine if patients with T2DM had increased fracture risk and if so, to identify T2DM-related risk factors. What did the researchers do and find? We used a national register covering nearly all adult patients with T2DM in Sweden to compare the risk of fracture between T2DM patients ( = 580,127) and population controls ( = 580,127) without T2DM.In general, the risk of fracture was only marginally increased (by 1% for major osteoporotic fracture (MOF) and by 6% for hip fracture) for patients with T2DM compared to controls, but for patients with presence of risk factors, such as low BMI, long T2DM duration, insulin treatment, and/or low physical activity, the risk increase was more substantial (20% or higher) and potentially clinically relevant. What do these findings mean? Our findings suggest that T2DM per se should not be considered an important risk factor for fracture.Special consideration of the T2DM-related risk factors can be used to identify T2DM patients with a clinically relevant increased fracture risk.Further studies are needed to develop fracture risk calculators for different settings and populations for T2DM patients specifically. BackgroundType 2 diabetes mellitus (T2DM) is considered a risk factor for fracture but the evidence regarding the impact of T2DM on fracture risk is conflicting. The objective of the study was to determine if patients with T2DM have increased fracture risk and if T2DM-related risk factors could be identified. Methods and findingsIn this national cohort study in Sweden, we investigated the risk of fracture in 580,127 T2DM patients, identified through the national diabetes register including from both primary care and hospitals, and an equal number of population-based controls without diabetes matched for age, sex, and county from 2007 to 2017. The mean age at entry was 66.7 years and 43.6% were women. During a median follow-up time of 6.6 (interquartile range (IQR) 3.1 to 9.8) years, patients with T2DM had a marginally but significantly increased risk of major osteoporotic fracture (MOF) (hazard ratio (HR) 1.01 (95% confidence interval [CI] 1.00 to 1.03)) and hip fracture (HR 1.06 (95% CI 1.04 to 1.08)) compared to controls, associations that were only minimally affected (HR 1.05 (95% CI 1.03 to 1.06) and HR 1.11 (95% CI 1.09 to 1.14), respectively) by multivariable adjustment (age, sex, marital status, and an additional 20 variables related to general morbidity, cardiovascular status, risk of falls, and fracture). In a multivariable-adjusted Cox model, the proportion of the risk for all fracture outcomes (Heller's R2) explained by T2DM was below 0.1%. Among the T2DM patients, important risk factors for fracture were a low BMI (<25 kg/m(2)), long diabetes duration (>= 15 years), insulin treatment, and low physical activity. In total, 55% of the T2DM patients had none of these risk factors and a significantly lower fracture risk than their respective controls. The relatively short mean duration of T2DM and lack of bone density data, constitute limitations of the analysis. ConclusionIn this study, we observed only a marginally increased fracture risk in T2DM, a condition that explained less than 0.1% of the fracture risk. Consideration of the herein identified T2DM-related risk factors could be used to stratify T2DM patients according to fracture risk.
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| 6. |
- Brodin, Gert, 1963-, et al.
(författare)
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Quantum-electrodynamical photon splitting in magnetized Nonlinear pair plasmas
- 2007
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 98:12
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Tidskriftsartikel (refereegranskat)abstract
- We present for the first time the nonlinear dynamics of quantum electrodynamic (QED) photon splitting in a strongly magnetized electron-positron (pair) plasma. By using a QED corrected Maxwell equation, we derive a set of equations that exhibit nonlinear couplings between electromagnetic (EM) waves due to nonlinear plasma currents and QED polarization and magnetization effects. Numerical analyses of our coupled nonlinear EM wave equations reveal the possibility of a more efficient decay channel, as well as new features of energy exchange among the three EM modes that are nonlinearly interacting in magnetized pair plasmas. Possible applications of our investigation to astrophysical settings, such as magnetars, are pointed out.
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| 7. |
- Brunström, Mattias, et al.
(författare)
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Blood pressure treatment levels and choice of antihypertensive agent in people with diabetes mellitus : an overview of systematic reviews
- 2017
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Ingår i: Journal of Hypertension. - 0263-6352 .- 1473-5598. ; 35, s. 435-462
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Forskningsöversikt (refereegranskat)abstract
- OBJECTIVE: Multiple systematic reviews address the effect of antihypertensive treatment in people with diabetes. Here, we summarize current systematic reviews concerning antihypertensive treatment effect at different blood pressure (BP) levels, and relative treatment effect of different antihypertensive agents.METHODS: We searched MEDLINE, BIOSIS, DARE and CDSR during years 2005-2016. Eligibility criteria, number of trials and participants, outcomes analysed, statistical methods used for data synthesis, and principal results were extracted for each review. Review quality was assessed using the assessment of multiple systematic reviews tool.RESULTS: We found four reviews concerning BP treatment level. These consistently showed that the effect of antihypertensive treatment on mortality, cardiovascular disease and coronary heart disease was attenuated at lower BP levels. If SBP was more than 140 mmHg, treatment reduced all-cause and cardiovascular mortality, cardiovascular disease, stroke, myocardial infarction and heart failure. If SBP was less than 140 mmHg, treatment increased the risk of cardiovascular death. We found eight reviews concerning choice of agent. We found no difference between angiotensin-converting enzyme inhibitors, angotensin receptor blockers, beta-blockers, calcium channel blockers and diuretics in preventing all-cause or cardiovascular mortality, combined cardiovascular disease, coronary heart disease and end-stage renal disease. Minor differences exist for stroke and heart failure. Data were limited on people with type 1 diabetes and very elderly patients with type 2 diabetes. None of the reviews concerning choice of agent included all relevant trials.CONCLUSION: The available evidence supports treatment in people with type 2 diabetes and SBP more than 140 mmHg, using any of the major antihypertensive drug classes.
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| 8. |
- Brunström, Mattias, 1988-
(författare)
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Effect of antihypertensive treatment at different blood pressure levels
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundHigh blood pressure is associated with an increased risk of cardiovascular disease and premature death. The shape of association between blood pressure and the risk of cardiovascular events is debated. Some researchers suggest that the association is linear or log-linear, whereas others suggest it is J-shaped. Randomized controlled trials of antihypertensive treatment have been successful in hypertension, but ambiguous in the high normal blood pressure range. Previous systematic reviews have not found any interaction between baseline systolic blood pressure and treatment effect, with beneficial effects at systolic blood pressure levels well below what is currently recommended. These reviews, however, use a method to standardize treatment effects and study weights according to within-trial blood pressure differences that may introduce bias.MethodsWe performed two systematic reviews to assess the effect of antihypertensive treatment on cardiovascular disease and mortality at different blood pressure levels. The first review was limited to people with diabetes mellitus. The second review included all patient categories except those with heart failure and acute myocardial infarction. Both reviews were designed with guidance from Cochrane Collaborations Handbook for Systematic Reviews of Interventions, and are reported according to PRISMA guidelines. We included randomized controlled trials assessing any antihypertensive agent against placebo or any blood pressure targets against each other. Results were combined in random-effects meta-analyses, stratified by baseline systolic blood pressure. Non-stratified analyses were performed for coronary heart disease trials and post-stroke trials. Interaction between blood pressure level and treatment effect was assessed with Cochran’s Q in the first review, and multivariable-adjusted metaregression in the second review.The third paper builds on data from the second paper, and assesses the effect of standardization according to within-trial blood pressure differences on the results of meta-analyses. We performed non-standardized analyses, analyses with standardized treatment effects, and analyses with standardized treatment effects and standard errors. We compared treatment effect measures and heterogeneity across different methods of standardization. We also compared treatment effect estimates between fixed-effects and random-effects meta-analyses within each method of standardization. Lastly, we assessed the association between number of events and study weights, using linear regression.ResultsForty-nine trials assessed the effect of antihypertensive treatment in people with diabetes mellitus. Treatment effect on cardiovascular mortality and myocardial infarction decreased with lower baseline systolic blood pressure. Treatment reduced the risk of death and cardiovascular disease if baseline systolic blood pressure was 140 mm Hg or higher. If baseline systolic blood pressure was below 140 mm Hg, however, treatment increased the risk of cardiovascular death by 15 % (0-32 %).Fifty-one trials assessed the effect of antihypertensive treatment in primary prevention. Treatment effect on cardiovascular mortality, major cardiovascular events, and heart failure decreased with lower baseline systolic blood pressure. If baseline systolic blood pressure was 160 mm Hg or higher treatment reduced the risk of major cardiovascular events by 22 % (95 % confidence interval 13-30 %). If systolic blood pressure was 140-159 mm Hg treatment reduced the risk by 12 % (4-20 %), whereas if systolic blood pressure was below 140 mm Hg, treatment effect was neutral (4 % increase to 10 % reduction). All-cause mortality was reduced if systolic blood pressure was 140 mm Hg or higher, with neutral effect at lower levels.Twelve trials compared antihypertensive treatment against placebo in people with coronary heart disease. Mean baseline systolic blood pressure was 138 mm Hg. Treatment reduced the risk of major cardiovascular events by 10 % (3-16 %), whereas the effect on mortality was neutral (7 % increase to 11 % reduction).Standardization of treatment effects resulted in more extreme effect estimates for individual trials. This caused increased between-study heterogeneity, and different results with fixed- and random-effects model. Standardization of standard errors shifted weights from trials with many events to trials with large blood pressure differences. This caused biased overall effect estimates. Standardization of standard errors also resulted in wider confidence intervals, masking the previously increased heterogeneity. This reduced the possibility to find different treatment effects at different blood pressure levels.Conclusion The effect of antihypertensive treatment depends on blood pressure level before treatment. Treatment reduces the risk of death and cardiovascular disease if baseline systolic blood pressure is 140 mm Hg or higher. Below this level, treatment is potentially harmful in people with diabetes, has neutral effect in primary prevention, but might offer additional protection in people with coronary heart disease. Standardization should generally be avoided in meta-analyses of antihypertensive treatment. Previous meta-analyses using standardized methods should be interpreted with caution.
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| 10. |
- Brunström, Mattias, et al.
(författare)
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SCORE2 – ett uppdaterat verktyg för att skatta kardiovaskulär risk : [SCORE2 - an updated model for cardiovascular risk prediction]
- 2021
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 118
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Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular disease is the most important cause of death and life-years lost in Sweden today. Cardiovascular risk prediction is a cornerstone in primary prevention; the use of antihypertensive and lipid-lowering therapy is guided by absolute cardiovascular risk. The Systematic COronary Risk Evaluation (SCORE) model has been the most widely applied model in Sweden for almost two decades. Recently, an updated model called SCORE2 was published. The new risk prediction model is based on contemporary data, predicts the risk of incident cardiovascular disease in addition to cardiovascular mortality, and accounts for competing risks, thus overcoming some major limitations with SCORE. Sweden is classified as a moderate-risk country according to the new model; here we report the risk chart for moderate-risk countries translated into Swedish.
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