Impact of chronic inflammation, assessed by hs-CRP, on the association between red cell distribution width and arterial cardiovascular disease: the Tromso Study

Red cell distribution width (RDW), a measure of variability in size of circulating erythrocytes, is associated with arterial cardiovascular disease (CVD), but the underlying mechanism remains unclear. We aimed to investigate the impact of chronic inflammation as measured by high-sensitivity C-reactive protein (hs-CRP) on this relationship, and explore whether RDW could be a mediator in the causal pathway between inflammation and arterial CVD. Baseline characteristics, including RDW and hs-CRP, were obtained from 5,765 individuals attending a population-based cohort study. We followed up participants from inclusion in the fourth survey of the Tromsø Study (1994/1995) until December 31, 2012. Multivariable Cox-regression models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI) for incident myocardial infarction (MI) and ischemic stroke across quintiles of hs-CRP and RDW. Subjects with hs-CRP in the highest quintile had 44% higher risk of MI (HR: 1.44, 95% CI: 1.14–1.80), and 64% higher risk of ischemic stroke (HR: 1.64, 95% CI: 1.20–2.24) compared with subjects in the lowest quintile. RDW mediated 7.2% (95% CI: 4.0–30.8%) of the association between hs-CRP and ischemic stroke. Subjects with RDW in the highest quintile had 22% higher risk of MI (HR: 1.22, 95% CI: 0.98–1.54) and 44% higher risk of ischemic stroke (HR: 1.44, 95% CI: 1.06–1.97) compared with subjects in the lowest quintile. These risk estimates were slightly attenuated after adjustments for hs-CRP. Our findings suggest that chronic inflammation is not a primary mechanism underlying the relationship between RDW and arterial CVD

Magnetic resonance imaging of the knee in Norway 2002–2004 (national survey): rapid increase, older patients, large geographic differences

<p>Abstract</p> <p>Background</p> <p>Magnetic resonance imaging (MRI) of the knee is the second most common MRI examination in Norway after head/brain MRI. Little has been published internationally on trends in the use of knee MRI after 1999. This study aimed to describe levels and trends in ambulant knee MRI utilisation in Norway 2002–2004 in relation to type of radiology service, geographic regions, number of MRI-scanners, patient age and gender, and type of referring health care provider.</p> <p>Methods</p> <p>We analysed administrative data on all claims for reimbursement of ambulant knee MRI performed in Norway in 2002, 2003 and 2004 and noted nominal reimbursement. We also recorded the referring health care provider from clinical requests of ambulant knee MRI done consecutively during two months in 2004 at one private institute and three hospitals. Number of MRI-scanners was given by manufacturers and radiology services.</p> <p>Results</p> <p>In Norway, the rate of knee MRI claims for 2004 was 15.6 per 1000 persons. This rate was 74% higher in East than in North region (18.4 vs. 10.6), slightly higher for men than women (16.4 vs. 14.7) and highest for ages 50–59 years (29.0) and 60–69 years (21.2). Most claims (76% for 2004) came from private radiology services. In 2004, the referring health care provider was a general practitioner in 63% of claims (unspecified in 24%) and in 83.5% (394/472) of clinical requests. From 2002 to 2004, the rate of knee MRI claims increased 64%. In the age group 50 years or above the increase was 86%. Rate of MRI-scanners increased 43% to 21 scanners per million persons in 2004. Reimbursement for knee MRI claims (nominal value) increased 80% to 70 million Norwegian kroner in 2004.</p> <p>Conclusion</p> <p>Ambulant knee MRI utilisation in Norway increases rapidly especially for patients over 50, and shows large geographic differences. Evaluation of clinical outcomes of this activity is needed together with clinical guidelines for use of knee MRI.</p

Impact of red cell distribution width on future risk of cancer and all-cause mortality among cancer patients – the Tromsø Study

Obtained from the Haematologica Journal website http://www.haematologica.org, available at http://dx.doi.org/10.3324/haematol.2015.129601</a

Red cell distribution width is associated with incident venous thromboembolism (VTE) and case-fatality after VTE in a general population

SummaryRecent studies suggest an association between red cell distribution width (RDW) and incident venous thromboembolism (VTE). We aimed to investigate the impact of RDW on risk of incident and recurrent VTE, and case-fatality, in a general population. RDW was measured in 26,223 participants enrolled in the Tromsø Study in 1994–1995. Incident and recurrent VTE events and deaths during follow-up were registered until January 1, 2012. Multivariate Cox proportional hazards regression models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI). There were 647 incident VTE events during a median of 16.8 years of follow-up. Individuals with RDW in the highest quartile (RDW≥13.3%) had 50% higher risk of an incident VTE than those in the lowest quartile (RDW≤12.3%). The association was strongest for unprovoked deep-vein thrombosis (HR highest vs lowest quartile of RDW: 1.8, 95% CI 1.1–3.1). VTE patients with baseline RDW≥13.3% had 30% higher risk of all-cause mortality after the initial VTE event than VTE patients with RDW&lt;13.3%. There were no association between RDW and risk of recurrent VTE. Our findings suggest that high RDW is a risk factor of incident VTE, and that RDW is a predictor of all-cause mortality in VTE patients.</jats:p

Plasma hepcidin is associated with future risk of venous thromboembolism

Red cell distribution width (RDW) is associated with venous thromboembolism (VTE), but the underlying mechanism(s) is unclear. Iron deficiency is associated with high RDW, and studies suggest an association between iron deficiency and VTE. To assess whether iron deficiency is a risk factor for VTE that explains the association between RDW and VTE, we conducted a nested case-control study of 390 patients with VTE and 802 age- and sex-matched controls selected from the population-based cohort of the Tromsø Study. Physical measurements and blood samples were collected from 1994 to 1995. Logistic regression models were used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for VTE by RDW, hepcidin, and ferritin light chain (FtL). RDW was inversely associated with hepcidin, FtL, and hemoglobin. The risk of VTE increased linearly across categories of higher plasma hepcidin levels. Participants with hepcidin in the highest quartile had an OR for VTE of 1.32 (95% CI, 1.00-2.42), and those in the >90% percentile had an OR for VTE of 1.66 (95% CI, 1.14-2.42) compared with the reference group (quartiles 2 and 3). The risk estimates remained similar after adjustment for C-reactive protein. The risk of VTE increased by categories of higher RDW and was strengthened after inclusion of hepcidin and FtL in the multivariable model. Our findings reject the hypothesis that iron deficiency explains the association between RDW and VTE and suggest, in contrast, that high body iron levels might increase the risk of VTE

Adding smoking to the Fardal model of cost‐effectiveness for the lifetime treatment of periodontal diseases

Background Little is known about the financial costs that smoking adds to the lifetime treatment of periodontal disease. Methods The total lifetime cost of periodontal treatment was modeled using data from private periodontal practice. The costs of initial and supportive therapy, re‐treatment and tooth replacements (with bridgework or implants) were identified using average dental charges from the American Dental Association survey. Smoking costs at $6 and$10 for 20 cigarettes were compared to the costs of lifetime periodontal treatment for stable and unstable compliant patients. Results Smoking added 8.8% to the financial cost of the lifetime cost of periodontal therapy in stable maintenance patients, 40.1% in patients who needed one extra maintenance visit, and 71.4% in patients who needed two extra maintenance visits per year in addition to added retreatment. The cost of smoking far exceeded the cost of periodontal treatment; For patients who smoked 10 to 40 cigarettes per day at the cost of $6 or$10 a pack, the cost of smoking exceeded the cost of lifetime periodontal treatment by between 2.7 and 17.9 times. Smoking 40 cigarettes at $10 a packet for 3.4 years would pay for the entire lifetime cost of periodontal treatment. Conclusion Smoking adds considerable extra financial costs to the lifetime treatment of periodontal diseases. The cost of smoking itself exceeds the cost of periodontal therapy

Red cell distribution width is associated with future risk of incident stroke. The Tromsø study

Red cell distribution width (RDW), a measure of the variability in size of the circulating erythrocytes, is associated with cardiovascular morbidity and mortality. We aimed to investigate whether RDW was associated with incident stroke and case fatality in subjects recruited from the general population. Baseline characteristics were obtained from 25,992 subjects participating in the fourth survey of the Tromsø Study, conducted in 1994/95. Incident stroke was registered from inclusion until December 31, 2010. Cox regression models were used to calculate hazard ratios (HR) with 95 % confidence intervals (95 % CI) for stroke, adjusted for age, sex, body mass index, smoking, haemoglobin level, white blood cell count, thrombocyte count, hypertension, total cholesterol, triglycerides, self-reported diabetes, and red blood cell count. During a median follow-up of 15.8 years, 1152 participants experienced a first-ever stroke. A 1 % increment in RDW yielded a 13 % higher risk of stroke (multivariable HR: 1.13, 95 % CI: 1.07–1.20). Subjects with RDW in the highest quintile compared to the lowest had a 37 % higher risk of stroke in multivariable analysis (HR: 1.37, 95 % CI: 1.11–1.69). Subjects with RDW above the 95-percentile had 55 % higher risk of stroke compared to those in the lowest quintile (HR: 1.55, 95 % CI: 1.16–2.06). All risk estimates remained unchanged after exclusion of subjects with anaemia (n=1102). RDW was not associated with increased risk of death within one year or during the entire follow-up after an incident stroke. RDW is associated with incident stroke in a general population, independent of anaemia and traditional atherosclerotic risk factors

Red cell distribution width and carotid atherosclerosis progression: The Tromsø study

Red cell distribution width (RDW), a measure of the size variability of circulating erythrocytes, is associated with cardiovascular morbidity and mortality. We aimed to investigate whether RDW was associated with progression of atherosclerotic plaques in subjects recruited from the general population. Baseline characteristics, including RDW, were collected from 4677 participants in the fourth survey of the Tromsø Study conducted in 1994/95. Prevalence of carotid plaques and total plaque area (TPA) were assessed by ultrasonographic imaging at baseline and after seven years of follow-up. Generalised linear models were used to analyse change in TPA across tertiles of RDW. Change in TPA was significantly higher across tertiles of RDW in crude analysis and in multivariable analysis adjusted for cardiovascular risk factors. The mean change in TPA increased from 5.6 mm² (4.9–6.4) in tertile 1 (RDW ≤ 12.6 %) to 6.7 mm² (5.9–7.6) in tertile 3 (RDW ≥ 13.3) in multivariable analysis adjusted for body mass index, total cholesterol, HDL cholesterol, systolic blood pressure, self-reported diabetes, smoking status, platelet count, white blood cell count, and hs-CRP levels (p for trend 0.003). A 1 % increase in RDW was associated with 0.6 mm² (0.1–1.2) increase in TPA in multivariable analysis (p=0.03). RDW was associated with progression of atherosclerosis after adjustments for traditional atherosclerotic risk factors. Our findings suggest that the link between RDW and cardiovascular morbidity and mortality may be explained by atherosclerosis

Impact of Chronic Inflammation, Assessed by hs-CRP, on the Association between Red Cell Distribution Width and Arterial Cardiovascular Disease: The Tromsø Study

Red cell distribution width (RDW), a measure of variability in size of circulating erythrocytes, is associated with arterial cardiovascular disease (CVD), but the underlying mechanism remains unclear. We aimed to investigate the impact of chronic inflammation as measured by high sensitivity CRP (hs-CRP) on this relationship, and explore whether RDW could be a mediator in the causal pathway between inflammation and arterial CVD. Baseline characteristics, including RDW and hs-CRP were obtained from 5,765 individuals attending a population-based cohort study. We followed participants from inclusion in the fourth survey of the Tromsø Study (1994/95) until December 31st 2012. Multivariable Cox-regression models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI) for incident myocardial infarction (MI) and ischemic stroke across quintiles of hs-CRP and RDW. Subjects with hs-CRP in the highest quintile had 44% higher risk of MI (HR: 1.44, 95% CI 1.14-1.80), and 64% higher risk of ischemic stroke (HR: 1.64, 95% CI 1.20- 2.24) compared to subjects in the lowest quintile. RDW mediated 7.2% (95% CI 4.0- 30.8%) of the association between hs-CRP and ischemic stroke. Subjects with RDW in the highest quintile had 22% higher risk of MI (HR: 1.22, 95% CI 0.98-1.54) and 44% higher risk of ischemic stroke (HR: 1.44, 95% CI 1.06-1.97) compared to subjects in the lowest quintile. These risk estimates were slightly attenuated after adjustments for hs-CRP. Our findings suggest that chronic inflammation is not a primary mechanism underlying the relationship between RDW and arterial CVD