The use of tourniquet in primary total knee arthroplasty does not increase the risk of venous thromboembolism within 90 days of surgery: a Danish nationwide cohort study of 19,804 patients

PURPOSE

Existing evidence estimates a twofold risk of venous thromboembolisms (VTEs) if tourniquet is applied during total knee arthroplasties (TKAs). However, this estimate relies on multiple trials with a low number of patients analyzing VTEs as a secondary outcome. We hypothesized that tourniquet-use increases the risk of symptomatic VTE within 90 days of contemporary primary TKA and aimed to use the extensive Danish healthcare registries to quantify this risk.

METHODS

Prospectively collected registry data from Danish patients receiving primary TKAs between 2014 and 2018 were included in the study. Patients were divided by tourniquet-use during surgery. By merging information from four nationwide registries, the study included 44 baseline characteristics with the potential to confound the association between tourniquet-use and VTE. Incidence rate and odds ratios were used to compare the risk of VTE within 90 days of surgery.

RESULTS

19,804 patients of whom 10,111 (51%) were operated with tourniquet and 9693 (49%) without were included. The mean age (SD) was 70 (9) in both groups and 62% were females in the tourniquet group compared with 61% in the no tourniquet group. The groups were similarly comparable across all other baseline characteristics except type of post-operative thromboprophylaxis, type of anaesthesia, implant fixation, and year of surgery. The 90-days incidence of VTE was 0.77% (95% CI 0.60-0.94) in the tourniquet group compared with 1.10% (95% CI 0.90-1.31) in the no tourniquet group. Following adjustment for the unbalanced confounders, the odds ratio for VTE was 0.77 (95% CI 0.54-1.10) associated with tourniquet-use.

CONCLUSION

In contemporary TKAs the rate of VTE within 90 days is low and not significant altered by tourniquet-use. Thus, tourniquet can safely be applied during primary TKA-surgery without jeopardizing the risk of postoperative VTE.

LEVEL OF EVIDENCE

II-prospective cohort study.

Cancer risk in persons with new-onset anaemia: a population-based cohort study in Denmark

Background

The time interval from first symptom and sign until a cancer diagnosis significantly affects the prognosis. Therefore, recognising and acting on signs of cancer, such as anaemia, is essential. Evidence is sparse on the overall risk of cancer and the risk of specific cancer types in persons with new-onset anaemia detected in an unselected general practice population. We aimed to assess the risk of cancer in persons with new-onset anaemia detected in general practice, both overall and for selected cancer types.

Methods

This observational population-based cohort study used individually linked electronic data from laboratory information systems and nationwide healthcare registries in Denmark. We included persons aged 40–90 years without a prior history of cancer and with new-onset anaemia (no anaemia during the previous 15 months) detected in general practice in 2014–2018. We measured the incidence proportion and standardised incidence ratios of a new cancer diagnosis (all cancers except for non-melanoma skin cancers) during 12 months follow-up.

Results

A total of 48,925 persons (median [interquartile interval] age, 69 [55–78] years; 55.5% men) were included in the study. In total, 7.9% (95% confidence interval (CI): 7.6 to 8.2) of men and 5.2% (CI: 4.9 to 5.5) of women were diagnosed with cancer during 12 months. Across selected anaemia types, the highest cancer incidence proportion was seen in women with ‘anaemia of inflammation’ (15.3%, CI: 13.1 to 17.5) (ferritin > 100 ng/mL and increased C-reactive protein (CRP)) and in men with ‘combined inflammatory iron deficiency anaemia’ (19.3%, CI: 14.5 to 24.1) (ferritin < 100 ng/mL and increased CRP). For these two anaemia types, the cancer incidence across cancer types was 10- to 30-fold higher compared to the general population.

Conclusions

Persons with new-onset anaemia detected in general practice have a high cancer risk; and markedly high for ‘combined inflammatory iron deficiency anaemia’ and ‘anaemia of inflammation’. Anaemia is a sign of cancer that calls for increased awareness and action. There is a need for research on how to improve the initial pathway for new-onset anaemia in general practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09912-7.

A low level of naturally occurring antibodies associates with functional antibody deficiency

Functional antibody deficiency is clinically assessed from antibody responses to vaccination. However, diagnostic vaccination is complex and may fail in practice. We hypothesized that the levels of naturally occurring antibodies against galactose-α-1,3-galactose (αGal) may represent alternative markers of functional antibody capacity. We included data from 229 patients with suspected primary immunodeficiency in a retrospective study. Antibody levels against αGal and twelve pneumococcal serotypes were determined with solid-phase immunoassays. Pneumococcal vaccinations and treatment with normal human immunoglobulin were assessed from medical records. Anti-αGal antibody levels correlated positively with anti-pneumococcal antibody levels measured before and after pneumococcal vaccination. Contrary to the anti-pneumococcal antibody levels, the anti-αGal antibody level showed potential for predicting subsequent immunoglobulin treatment - a marker of disease severity. Naturally occurring antibodies may reflect the functional capacity tested by diagnostic vaccination but add more useful clinical data. The clinical utility of this easy test should be evaluated in prospective studies.

Diagnostic workup of cancer in patients with new-onset anaemia: a Danish cohort study in general practice

BACKGROUND

Anaemia is associated with adverse outcomes, including increased morbidity and all-cause mortality. Diagnostic workup of patients with anaemia is essential to detect underlying disease, especially undiagnosed malignancy.

OBJECTIVE

To describe the cancer-relevant diagnostic workup in patients with new-onset anaemia detected in general practice. An additional aim was to analyse associations between patient characteristics and the diagnostic workup.

DESIGN

Observational population-based cohort study using electronic laboratory and register data.

SETTING

Danish general practice.

SUBJECTS

Patients aged 40-90 years with new-onset anaemia (no anaemia in the preceding 15 months) detected in general practice. Patients were identified in Danish laboratory information systems and nationwide registries in 2014-2018.

MAIN OUTCOME MEASURES

We measured the proportion of patients receiving predefined diagnostic investigations, that is, cancer patient pathway, colonoscopy, gastroscopy, computerised tomography (CT) scan, faecal test for haemoglobin, and bone marrow examination within three months of the anaemia index date.

RESULTS

We included 59,993 patients, and around half of the patients with 'iron deficiency anaemia', 'anaemia of inflammation', or 'combined inflammatory iron deficiency anaemia' had no cancer-relevant diagnostic investigations performed. Patients aged 60-79 years and patients with severe anaemia were more likely to have investigations performed, while patients with comorbidity were less likely to have investigations performed.

CONCLUSION

Around half of the patients with anaemia subtypes that may indicate underlying cancer had no cancer-relevant diagnostic investigations performed. This may represent missed diagnostic opportunities. Future interventions are needed to improve the diagnostic workup of cancer in patients with anaemia, for example, laboratory alert systems and clinical decision support.KEY POINTSThe general practitioners are often the first to detect anaemia and its underlying disease (e.g. undiagnosed malignancy).Large-scale studies are needed on the diagnostic workup of patients with anaemia in general practice in relation to an underlying malignancy.This study shows that the majority of patients with anaemia had no cancer-relevant diagnostic investigations performed, which may cause diagnostic delay.Interventions seems needed to improve the diagnostic workup of cancer in these patients to ensure timely diagnosis.

Diagnostic Vaccination in Clinical Practice

Testing the antibody response to vaccination (diagnostic vaccination) is crucial in the clinical evaluation of primary immunodeficiency diseases. Guidelines from the American Academy of Allergy, Asthma & Immunology (AAAAI) provide detailed recommendations for diagnostic vaccination with pure pneumococcal polysaccharide vaccines (PPV). However, the degree of compliance with these guidelines and the utility of the guidelines in actual practice are undescribed. To address this, we systematically evaluated diagnostic vaccination in adult patients with suspected primary immunodeficiency diseases in a single tertiary center from 2011 to 2016 (n = 229). We found that full compliance with the AAAAI guidelines was achieved for only 39 patients (17%), suggesting that the guidelines are not easy to follow. Worse, interpretation according to the guidelines was heavily influenced by which serotype-specific antibodies that were used for the evaluation. We found that the arbitrary choices of serotype-specific antibodies could change the fraction of patients deemed to have ‘adequate immunity’ by a factor of four, exposing an inherent flaw in the guidelines. The flaw relates to dichotomous principles for data interpretation under the AAAAI guidelines. We therefore propose a revised protocol for diagnostic vaccination limited to PPV vaccination, subsequent antibody measurements, and data interpretation using Z-scores. The Z-score compiles multiple individual antibody levels, adjusted for different weighting, into one single continuous variable for each patient. In contrast to interpretation according to the AAAAI guidelines, the Z-scores were robust to variations in the choice of serotype-specific antibodies used for interpretation. Moreover, Z-scores revealed reduced immunity after vaccination in the patients with recurrent pneumonia (a typical symptom of antibody deficiency) compared with control patients. Assessment according to the AAAAI guidelines failed to detect this difference. We conclude that our simplified protocol and interpretation with Z-scores provides more robust clinical results and may enhance the value of diagnostic vaccination.

Insufficient classification of anaemia in general practice: a Danish register-based observational study

BACKGROUND

Anaemia can be a pointer of underlying severe disease, including undiagnosed malignancy. Subsequent blood tests are essential to classify the anaemia into subtypes and to facilitate targeted diagnostic investigation to ensure timely diagnosis of underlying disease.

OBJECTIVE

We aimed to describe and classify anaemia based on laboratory tests from patients with new-onset anaemia detected in general practice. An additional aim was to analyse associations between patient characteristics and unclassified anaemia (not classifiable according to an algorithm).

DESIGN

Population-based cross-sectional study.

SETTING

Danish general practice.

SUBJECTS

A total of 62,731 patients (age: 40-90 years) with new-onset anaemia were identified in Danish laboratory information systems and nationwide registries, and data were obtained for 2014-2018.

MAIN OUTCOME MEASURES

We measured the proportion of patients classified into subtypes of anaemia based on blood tests requested by general practitioners within 31 days of the anaemia index date.

RESULTS

Of the 62,731 patients with new-onset anaemia, we identified unclassified anaemia in 78.9% (95% confidence interval (CI): 77.3-80.5) of men and 65.1% (CI: 63.4-66.9) of women. The likelihood of unclassified anaemia increased with age, increasing comorbidity and decreasing severity of anaemia.

CONCLUSION

The majority of patients with new-onset anaemia could not be classified through a simple algorithm due to missing blood tests, which highlights a potential missed opportunity for diagnosis. Standardised laboratory testing of patients with anaemia is warranted to ensure adequate follow-up and early detection of underlying severe disease.KEY POINTSAnaemia can be a sign of malignancy, and anaemia classification is an important step in the diagnosis of underlying disorders.The majority of patients with anaemia could not be classified according to a simple algorithm due to missing blood tests.Some patient characteristics were associated with a high risk of unclassified anaemia: high age, high comorbidity, and severe anaemia.Standardised laboratory testing in patients with anaemia is needed to inform targeted diagnostic investigation to ensure timely diagnosis.

Comparison of Patients with Hospital-Recorded Nephrotic Syndrome and Patients with Nephrotic Proteinuria and Hypoalbuminemia: A Nationwide Study in Denmark

Background

Registry-based studies of nephrotic syndrome (NS) may only include a subset of patients with biochemical features of NS. To address this, we compared patients with laboratory-recorded nephrotic proteinuria and hypoalbuminemia to patients with hospital-recorded NS.

Methods

We identified adult patients with first-time hospital-recorded NS (inpatients, outpatients, or emergency-room visitors) in the Danish National Patient Registry and compared them with adults with first-time recorded nephrotic proteinuria and hypoalbuminemia in Danish laboratory databases during 2004-2018, defining the date of admission or laboratory findings as the index date. We characterized these cohorts by demographics, comorbidity, medication use, and laboratory and histopathologic findings.

Results

We identified 1139 patients with hospital-recorded NS and 5268 patients with nephrotic proteinuria and hypoalbuminemia; of these, 760 patients were identified in both cohorts. Within 1 year of the first record of nephrotic proteinuria and hypoalbuminemia, 18% had recorded hospital diagnoses indicating the presence of NS, and 87% had diagnoses reflecting any kind of nephropathy. Among patients identified with nephrotic proteinuria and hypoalbuminemia, their most recent eGFR was substantially lower (median of 35 versus 61 ml/min per 1.73 m²), fewer underwent kidney biopsies around the index date (34% versus 61%), and the prevalence of thromboembolic disease (25% versus 17%) and diabetes (39% versus 18%) was higher when compared with patients with hospital-recorded NS.

Conclusions

Patients with nephrotic proteinuria and hypoalbuminemia are five-fold more common than patients with hospital-recorded NS, and they have a lower eGFR and more comorbidities. Selective and incomplete recording of NS may be an important issue when designing and interpreting studies of risks and prognosis of NS.

[Venous thromboembolism in patients with COVID-19]

The importance of venous thromboembolism (VTE) as a major complication in patients with severe corona virus disease 2019 (COVID-19) is becoming increasingly evident. In this review, we describe the proposed pathophysiology of the prothrombotic coagulation changes observed in patients with COVID-19. Further, based on a review of the currently available evidence on VTE prevalence in patients with COVID-19, we present and discuss the recommendations from the Danish Society of Thrombosis and Haemostasis on the use of thromboprophylaxis in patients with COVID-19.

Existing Data Sources in Clinical Epidemiology: Laboratory Information System Databases in Denmark

Routine biomarker results from hospital laboratory information systems, covering hospitals and general practitioners, in Denmark are available to researchers through access to the regional Clinical Laboratory Information System Research Database at Aarhus University and the nationwide Register of Laboratory Results for Research. This review describes these two data sources. The laboratory databases have different geographical and temporal coverage. They both include individual-level biomarker results that are electronically transferred from laboratory information systems. The biomarker results can be linked to all other Danish registries at the individual level, using the unique identifier, the CPR number. The databases include variables such as the CPR number, date and time (hour and minute) of sampling, NPU code, and name of the biomarker, identification code for the laboratory and the requisitioner, the test result with the corresponding unit, and the lower and upper reference limits. Access to the two databases differs since they are hosted by two different institutions. Data cannot be transferred outside Denmark, and direct access is provided only to Danish institutions. It is concluded that access to data on routine biomarkers expands the detailed biological and clinical information available on patients in the Danish healthcare system. The full potential is enabled through linkage to other Danish healthcare registries.

Lectin pathway proteins of the complement system in normotensive pregnancy and pre-eclampsia

PROBLEM

The lectin pathway of the complement system may be involved in the pathogenesis of pre-eclampsia. We aimed to investigate changes in serum concentrations of a broad range of lectin pathway proteins during normal pregnancy and their association with pre-eclampsia, placental infarctions and intrauterine growth restriction (IUGR).

METHOD OF STUDY

We included 51 women with normotensive pregnancies and 54 women with pregnancies complicated by pre-eclampsia. Blood samples were obtained at gestational weeks 16, 33, 37, and after delivery for the normotensive pregnant women and before and after delivery for women with pre-eclampsia. Mannose-binding lectin (MBL), H- and M-ficolin, collectin liver-1 (CL-L1), MBL-associated serine protease (MASP)-1, MASP-2 and MASP-3 and MBL-associated proteins of 19 (MAp19) and 44 (MAp44) kDa were analysed. Clinical information was obtained from medical records. The placentae were examined by two experienced perinatal pathologists.

RESULTS

Lectin pathway protein concentrations generally increased during normal pregnancy and decreased after delivery in both normotensive pregnant women and women with pre-eclampsia. Exceptions were MASP-3 which increased after delivery in both groups (P < 0.0001) and H-ficolin which increased after delivery in pre-eclampsia (P < 0.0001). H-ficolin (P < 0.0001), M-ficolin (P = 0.005) and MASP-3 (P = 0.03) concentrations were lower in women with pre-eclampsia than in normotensive pregnant women. Low MASP-3 concentrations were associated with placental infarction (P = 0.03) and IUGR (P = 0.04). Low H-ficolin concentrations were associated with IUGR (P < 0.01).

CONCLUSION

In general, lectin pathway protein serum concentrations increased during normal pregnancy. H-ficolin and MASP-3 may be involved in the pathophysiology of pre-eclampsia and IUGR and could be potential future pre-eclampsia biomarkers.

Retinal vein thrombosis and risk of occult cancer: A nationwide cohort study

Background

Retinal vein thrombosis has in case reports been reported a clinical sign of cancer, especially hematological cancer. However, it is unclear whether retinal vein thrombosis is a marker of underlying cancer, as is the case for deep venous thrombosis and pulmonary embolism. We investigated the risk of occult cancer in patients with retinal vein thrombosis.

Methods

A nationwide population‐based cohort study in Denmark on all patients diagnosed with a retinal vein thrombosis during 1994 and 2013. The main outcome measures were any cancer and site‐specific cancers <6 months, 6‐12 months, and 5 years following a retinal vein thrombosis diagnosis, as registered in the Danish Cancer Registry and the National Pathology Registry. We calculated the absolute cancer risk and computed standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) for cancer within <6 months, 6‐12 months, and 5 years following a retinal vein thrombosis diagnosis.

Results

Among 9589 patients with retinal vein thrombosis, we observed 1514 cancer cases. The risk of any cancer was 1.2% <6 months and 28.8% after 5 years. The <6 months SIR was 1.20 (95% CI 0.99‐1.44), 6‐12 months SIR was 1.15 (95% CI 0.94‐1.39), and the 5 years’ SIR was 1.08 (95% CI 1.03‐1.14). Stratification by age, gender, calendar year, and Charlson Comorbidity Index score did not change overall cancer risk estimates.

Conclusion

Retinal vein thrombosis was not an important clinical marker for occult cancer. An extensive diagnostic cancer workup does not appear warranted for retinal vein thrombosis patients.

Tinzaparin for the treatment of foetal growth retardation: An open-labelled randomized clinical trial

OBJECTIVE

Foetal growth retardation (FGR) is a leading cause of perinatal death and long-term harms at survivors. Placental infarction plays a role in FGR, yet, no trials have evaluated whether low molecular weight heparins increase birth weight in ongoing FGR pregnancies.

METHODS

An open-labelled randomized trial in Denmark during 2011-2016, including singleton pregnant women with FGR (estimated foetal weight < 2.3 percentile) diagnosed before gestational weeks 32. Participants were randomly assigned using sealed, blinded envelopes 1:1 to tinzaparin (4500 IU daily until 37 gestational weeks) or no tinzaparin. The primary outcomes were the observed birthweight relative to the expected for gestational age and gender, and foetal growth rates in the two trial groups evaluated by an intention to treat analysis.

RESULTS

We enrolled 53 women. The mean gestational age was 261 days in the tinzaparin group and 246 days in the no treatment group. The mean birth weight was 2229 g in the tinzaparin group compared to 1968 g in the no treatment group. However, the birth weight relative to the expected from gestational age and gender was only 2.5 percentage points higher in the tinzaparin group [-5.1 to 10.0] (p = 0.51). The foetal growth rate during follow-up was 124 g/week in the tinzaparin group and 119 g/week in the no treatment group, a difference of 5 g/week [-19 to 29] (p = 0.67). Two perinatal deaths both occurred in the no treatment group.

CONCLUSION

We found no evidence of a tinzaparin effect on the foetal growth rate or the birth weight after adjustment for gestational age.

Blood Chimerism in Dizygotic Monochorionic Twins During 5 Years Observation

Dizygotic monochorionic twin pregnancies can result in blood chimerism due to in utero twin-to-twin exchange of stem cells. In this case, we examined the proportion of allogeneic red blood cells by flow cytometry and the proportion of allogeneic nucleated cells by digital polymerase chain reaction at 7 months and again at 5 years. We found an increase in the proportion of allogeneic cells from 63% to 89% in one twin, and a similar increase in autologous cells in the other twin from 57% to 84%. A paradigm for stem cell therapy could be modeled on this case: induction of tolerance and chimerism by antenatal transfusion of donor stem cells. The procedure would hold the promise of transplantation and tolerance induction without myeloablative conditioning for inheritable benign hematological diseases such as sickle cell disease and thalassemia.

Inflammatory bowel disease and venous thromboembolism during pregnancy and the postpartum period

Essentials Risk of pregnancy-related venous thromboembolism may be increased in inflammatory bowel disease. We performed a study on inflammatory bowel disease and pregnancy-related venous thromboembolism. Inflammatory bowel disease is a risk factor for pregnancy-related venous thromboembolism. Proper disease control before conception is pivotal to avoid venous thromboembolism.

SUMMARY

Background The incidence of inflammatory bowel disease (IBD) increases, and thus is more common, in pregnant women. IBD is a risk factor for venous thromboembolism (VTE) but it is not clear whether IBD predisposes women to an excess risk of VTE during pregnancy and the postpartum period. Methods This was a nationwide population-based cohort study of all deliveries during 1980-2013 in Denmark, using data from two nationwide health registries: the Danish National Patient Registry and the Medical Birth Registry. We computed incidence rates (IRs) per 1000 person-years, and crude and adjusted relative risks (RRs) with 95% confidence intervals (CIs) for VTE during pregnancy and the first 12 postpartum weeks in women with and without IBD. Results We included 1 046 754 women with 1 978 701 deliveries. We identified 3465 VTE events during pregnancy and 1302 VTE events postpartum. The IR for VTE during pregnancy was 4.20 (95% CI, 2.83-5.58) in IBD patients and 2.41 (95% CI, 2.33-2.50) in women without IBD, corresponding to an RR of 1.72 (95% CI, 1.22-2.43). Adjustment for maternal age and smoking (pregnancies during 1991-2013) yielded an adjusted RR of 1.67 (95% CI, 1.15-2.41). IBD flare was associated with an RR of 2.64 (95% CI, 1.69-4.14) for VTE during pregnancy. The IR for postpartum VTE was 7.03 (95% CI, 3.87-10.20) among IBD patients and 2.88 (95% CI, 2.72-3.04) in women without IBD, corresponding to an adjusted RR of 2.10 (95% CI, 1.33-3.30). Conclusions IBD is a risk factor for VTE during pregnancy and postpartum.

Preconception venous thromboembolism and placenta-mediated pregnancy complications

BACKGROUND

Placenta-mediated complications are leading causes of maternal and fetal morbidity and mortality. We hypothesized that a preconception history of venous thromboembolism (VTE) is associated with increased risk of placenta-mediated pregnancy complications.

METHODS

A nationwide population-based cohort study of all singleton pregnancies leading to delivery from 1997 to 2012 (n = 964 967). We obtained data on placenta-mediated pregnancy complications from the Danish Medical Birth Registry and data on VTE before pregnancy from the Danish National Patient Registry. We computed absolute risks, crude and adjusted risk differences (RDs) using a binomial regression model, and crude and adjusted risk ratios (RRs) from a modified Poisson regression model.

RESULTS

Overall, 1419 women had a preconception history of VTE, while 578 112 did not. Preeclampsia occurred in 4.2% of pregnancies in the VTE group and in 2.7% of pregnancies in a comparison cohort (adjusted RD = 1.3%, 95% confidence interval (CI) 0.6-2.0%; adjusted RR = 1.5, 95% CI 1.3-1.8). Stillbirth occurred in 0.7% of pregnancies in the VTE group and in 0.4% of pregnancies in the comparison cohort (adjusted RD = 0.3%, 95% CI 0.02-0.6%; adjusted RR = 1.8, 95% CI 1.1-3.0). Placental abruption occurred in 0.8% of pregnancies in the VTE group and in 0.5% of pregnancies in the comparison cohort (adjusted RD = 0.3%, 95% CI - 0.05-0.6%; adjusted RR = 1.6, 95% CI 1.1-2.4). Small-for-gestational-age infants accounted for 10.9% of live births in the VTE group and 9.8% of live births in the comparison cohort (adjusted RD = 0.6%, 95% CI - 0.5-1.7%; adjusted RR = 1.1, 95% CI 0.9-1.3).

CONCLUSION

Women with a history of VTE were at increased risk of placenta-mediated complications.

No evidence that assisted reproduction increases the risk of thrombosis: a Danish national cohort study

BACKGROUND

Case reports have reported venous and arterial thromboses in women undergoing assisted reproduction. No large systematic studies on the risk of thrombosis have been published. The objective of our study was to investigate whether the risk of thrombosis is increased in women undergoing assisted reproduction.

METHODS

A national register-based cohort study was conducted on all women undergoing IVF or ICSI treatment in Denmark from 1994 to 2005. Data were obtained from the National Patient Registry and the IVF Registry. Women with prior malignant or cardiovascular disease were excluded. Thrombosis occurring within the first 6 and 12 months after assisted reproduction was considered potentially related to the treatment. Thromboses during pregnancy as well as the pregnancy-related diagnoses were excluded from the statistical analysis. The incidence rates of venous and arterial thromboses were compared with previously published estimates of the risk of thrombosis among young Danish women.

RESULTS

We analyzed 30 884 Danish women undergoing 75 141 treatments from 1994 to 2005. The mean age of the women at first treatment was 32.3 years. The delivery rate per cycle was 22%. The incidence rate ratio, with 95% confidence interval (CI), of venous thrombosis within 6 months was 0.95 (CI: 0.38-1.95). The incidence rate ratio of arterial thrombosis within 6 months was 0.36 (CI: 0.04-1.30).

CONCLUSIONS

Our study showed no evidence that assisted reproduction increases the risk of thrombosis.

A blood pressure information campaign including mass screening for hypertension in Copenhagen Supermarkets

During its "Heart-week" in Feb. 1975, the Danish Heart Foundation drew the attention of the public to the importance of blood pressure measurements as a vital part of health control and prevention. In all, 24 thousand men and women attending supermarkets in Copenhagen took advantage of an offer to have their BP checked. 23% of the screened, who had systolic BP greater than or equal to age+110 (and this sum exceeded 145) and/or diastolic BP greater than or equal to 100 mmHg for all ages, were advised to contact a general practitioner for further evaluation. The campaign showed that it is possible to measure BP and obtain reliable results in an easy, quick, inexpensive and unorthodox way accepted by a public accustomed to free medical care.

Concomitant, specific determination of growth hormone and pegvisomant in human serum

Growth hormone (GH) and the GH receptor blocker, pegvisomant are usually circulating in high concentration in pegvisomant treated acromegalic patients. This and the close similarity between the peptides make determination of either difficult. In the present methodological study, endogenous GH in serum is initially isolated and determined in a slightly modified commercial immunometric assay, whereafter the now GH free medium allows measurement of pegvisomant. Inter-individual steady state levels of serum pegvisomant vary remarkably in both acromegalic patients and healthy controls, while the intra-individual variations are negligible.

Coarse media filtration--an alternative to settling in wastewater treatment

In this paper coarse media filtration has been analysed as an alternative to the traditional settling in primary, secondary and tertiary treatment of wastewater. Various filter media configurations were evaluated for enhanced primary filtration. It was found that a dual media configuration based on Kaldnes biofilm media (1 and K2modified) were most suitable when taking both separation efficiency as well as filter run time into consideration. SS removal efficiencies of around 75% were achieved in the dual Kaldnes primary filter at around 20 m/h without any chemical addition and around 85% at low dosage (1-2 mg/l) of a high MW cationic polymer FO4440SH. In the latter case COD was removed by around 70%. Further experiments were carried out on a multi-media Kaldnes-Filtralite-Sand (KFS) filter for enhanced primary treatment as well as for secondary filtration directly downstream of a high-rate moving bed biofilm reactor, resulting in an extremely compact secondary treatment process. The secondary KFS-filter gave SS-removal efficiencies around 90% (effluent SS < 15 mg/l) and filter run times of around 24 hrs at filtration rates of 10 m/h (sludge loading rates of around 1 kg/m2h) when a small dose (2 mg/l) of polymer was used. It is also demonstrated that the primary filter may also be utilised as a pre-denitrification reactor. A denitrification rate of 1.5 kg NO3-N(equiv.)/m3d was achieved when the filter was operated at a filtration rate of 5 m/h.

[Carriers of cystic fibrosis are more susceptible to asthma. The Osterbro study]

We tested the hypothesis that individuals heterozygous for the common cystic fibrosis delta F508 mutation are at risk of obstructive pulmonary disease. We studied a cross-sectional sample from the general population of Copenhagen, aged 20 years and older. We performed spirometry to measure FEV1 and FVC, and genotyped blood samples from 9141 individuals. We identified 250 carriers of the delta F508 mutation (2.7%; 95% CI: 2.5%-3.1%). Nine precent of carriers reported having asthma compared with 6% of non-carriers (chi 2: p = 0.04). Furthermore, among individuals with airway obstruction, the percentage of predicted FEV1 and FVC were significantly lower in participants heterozygous for delta F508 than in non-carriers (49% vs. 58%, p = 0.004 and 70% vs. 82%, p < 0.001, respectively). Cystic fibrosis delta F508 heterozygosity may be over-represented among people with asthma and seems to be associated with decreased pulmonary function in people with airway obstruction who also have asthma.

Pasteurella multocida septicaemia in fallow deer (Dama dama)

Thirteen of 100 fallow deer, aged between 6 months and 10 years, died over a 5 week period. The deaths occurred in 2 outbreaks 3 weeks apart. Both outbreaks were preceded by at least 3 days of cold wet and windy weather, and were associated with water-logged pastures. Affected animals were usually found dead, with a frothy blood-stained nasal discharge. In the 8 deer necropsied, gross lesions included widespread subserosal petechial haemorrhages, severe pulmonary congestion and oedema with froth-filled airways, and fibrinous pneumonia and pleurisy in 4 deer. Two deer, also, had extensive subcutaneous petechial and ecchymotic haemorrhages and oedema of skeletal musculature. Histologically, the most significant lesions were present in the lungs. Moderate to severe pulmonary congestion and oedema, with fibrinous exudation into alveoli and septal oedema, were present in all deer. In some deer these changes were accompanied by a diffuse infiltration with polymorphonuclear leucocytes. Pasteurella multocida was isolated from a range of tissues from 7 of 8 deer examined. The remaining animal had been treated with antibiotics 8 hours before death. The isolates had identical polyacrylamide gel electrophoresis patterns and were of the same antigenic type-Carter group A, Heddleston type 3,4.

[Decrease in cardiac mortality and changes of risk factor levels. The Osterbro study]

From 1974 to 1984, decreases in the mortality of ischaemic heart disease of 11% for men 30 to 69 years of age and 16% for women in the same age-group were observed. From the Copenhagen City Heart Study, a population study of 20,000 men and women, a significant decrease in per cent of smokers, a significant decrease in P-cholesterol, a significant increase in per cent of joggers, but no change in systolic blood pressure were demonstrated, between 1976-1978 and 1981-1983. The decrease in mortality of ischaemic heart disease, may be due to reduction in risk-factor levels, and to advanced medical and surgical treatment.

Linkage analysis of the human insulin receptor gene and maturity onset diabetes of the young

The cloning of the insulin receptor cDNA has permitted the definition of restriction fragment length polymorphisms at that locus. These polymorphisms were used to study the role of the insulin receptor in four pedigrees with maturity onset diabetes of the young through linkage analyses. When each pedigree was individually analysed, no linkage was demonstrated in the two larger pedigrees, implying that an insulin receptor defect was not responsible for the predisposition to diabetes in these pedigrees. One of these pedigrees was known to be hypoinsulinaemic, while insulin levels were unavailable in the second pedigree. In the two smaller pedigrees, however, a single haplotype cosegregated with diabetes. One of these pedigrees is known to be hyperinsulinaemic. The small size of the pedigrees which demonstrated cosegregation precluded statistical proof of linkage. Nonetheless, the presence of an uncommon insertional polymorphism which cosegregated with diabetes in both pedigrees was improbable and suggested that this insertion could be responsible for diabetes in these families. This study thus may be additional evidence for heterogeneity in maturity onset diabetes of the young. For the two larger pedigrees, the insulin gene and HLA region have already been eliminated as genetic markers. This study provides data which eliminate a third candidate gene in these two pedigrees.

Insulin-gene flanking sequences, diabetes mellitus and atherosclerosis: a review

A highly polymorphic locus flanking the human insulin gene contains two major size classes of DNA restriction fragments, which segregate in families as stable genetic elements. The L-allele, i.e. fragments with an average size of about 600 base-pairs seems to be a weak genetic marker for Type 1 (insulin-dependent) diabetes mellitus, whereas the U-allele, i.e. fragments of an average size of about 2500 base-pairs hitherto has been associated with Type 2 (non-insulin-dependent) diabetes mellitus and diabetic hypertriglyceridaemia. The most recent reports on this subject do not confirm an association between the U-allele and Type 2 diabetes. Our own studies indicate that the U-allele is a fairly strong marker for the development of atherosclerosis (relative risk for U-carriers 3.36). The putative functions of the polymorphic region in atherogenesis and the relation of this region to other genetic markers for atherosclerosis are not known.

Mass screening for hypertension in Copenhagen supermarkets

During its "heart week" in February, 1975, the Danish Heart Foundation drew the attention of the public to the problem of heart-disease with special reference to high blood-pressure; and 24 377 people attending supermarkets in Copenhagen took advantage of an offer to have their blood-pressure checked. There was a small charge for measurement, but the supermarket owners usually paid the fee on behalf of their customers. This unconventional approach to blood-pressure screening proved to be cheap, straightforward, and acceptable to the public. 23% of people measured were referred to their general practitioners for further evaluation.