Regional dGEMRIC analysis in patients at risk of osteoarthritis provides additional information about activity related changes in cartilage structure

BACKGROUND

Previously, a positive effect of exercise on cartilage structure was indicated with delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC). However, in that study only one full-thickness region of interest (ROI) in the medial femoral condyle was analyzed.

PURPOSE

To improve the knowledge about exercise effects on cartilage structure by re-analyzing previous images with regional dGEMRIC analysis.

MATERIAL AND METHODS

Thirty patients (age range, 38-50 years) with a previous medial meniscus resection were divided into three groups according to self-reported change in physical activity (PA) level in a 4-month exercise intervention study: Group I (n = 11), increased PA level; Group II (n = 13), no change in PA level; and Group III (n = 6), reduced PA level. dGEMRIC index was analyzed at inclusion and after 4 months. Anterior (less load) and posterior (more load) ROIs of medial and lateral femoral condyles were analyzed, as well as superficial and deep cartilage regions.

RESULTS

Group I increased the dGEMRIC index in the posterior cartilage (P = 0.004). The increase was larger in the lateral (P = 0.005) than the medial compartment in both superficial and deep cartilage regions. The dGEMRIC index did not change in Group II. In Group III, the dGEMRIC index decreased in the medial posterior cartilage (P = 0.03).

CONCLUSION

In patients with a previous medial meniscectomy, the beneficial effect of exercise varies between different locations within the joint, the largest improvement being observed in lateral posterior cartilage, i.e. the load-bearing cartilage in the compartment without a meniscus lesion. The effects of exercise do not seem to vary with cartilage depth.

Bayesian modelling of the emission spectrum of the Joint European Torus Lithium Beam Emission Spectroscopy system

A Bayesian model of the emission spectrum of the JET lithium beam has been developed to infer the intensity of the Li I (2p-2s) line radiation and associated uncertainties. The detected spectrum for each channel of the lithium beam emission spectroscopy system is here modelled by a single Li line modified by an instrumental function, Bremsstrahlung background, instrumental offset, and interference filter curve. Both the instrumental function and the interference filter curve are modelled with non-parametric Gaussian processes. All free parameters of the model, the intensities of the Li line, Bremsstrahlung background, and instrumental offset, are inferred using Bayesian probability theory with a Gaussian likelihood for photon statistics and electronic background noise. The prior distributions of the free parameters are chosen as Gaussians. Given these assumptions, the intensity of the Li line and corresponding uncertainties are analytically available using a Bayesian linear inversion technique. The proposed approach makes it possible to extract the intensity of Li line without doing a separate background subtraction through modulation of the Li beam.

A novel statistical analysis method to improve the detection of hepatic foci of (111)In-octreotide in SPECT/CT imaging

Background

Low uptake ratios, high noise, poor resolution, and low contrast all combine to make the detection of neuroendocrine liver tumours by ¹¹¹In-octreotide single photon emission tomography (SPECT) imaging a challenge. The aim of this study was to develop a segmentation analysis method that could improve the accuracy of hepatic neuroendocrine tumour detection.

Methods

Our novel segmentation was benchmarked by a retrospective analysis of patients categorized as either ¹¹¹In-octreotide positive (¹¹¹In-octreotide(+)) or ¹¹¹In-octreotide negative (¹¹¹In-octreotide(−)) for liver tumours. Following a 3-year follow-up period, involving multiple imaging modalities, we further segregated ¹¹¹In-octreotide-negative patients into two groups: one with no confirmed liver tumours (¹¹¹In-octreotide(−)/radtech(−)) and the other, now diagnosed with liver tumours (¹¹¹In-octreotide(−)/radtech(+)). We retrospectively applied our segmentation analysis to see if it could have detected these previously missed tumours using ¹¹¹In-octreotide. Our methodology subdivided the liver and determined normalized numbers of uptake foci (nNUF), at various threshold values, using a connected-component labelling algorithm. Plots of nNUF against the threshold index (ThI) were generated. ThI was defined as follows: ThI = (c_max − c_thr)/c_max, where c_max is the maximal threshold value for obtaining at least one, two voxel sized, uptake focus; c_thr is the voxel threshold value. The maximal divergence between the nNUF values for ¹¹¹In-octreotide(−)/radtech(−), and ¹¹¹In-octreotide(+) livers, was used as the optimal nNUF value for tumour detection. We also corrected for any influence of the mean activity concentration on ThI. The nNUF versus ThI method (nNUFTI) was then used to reanalyze the ¹¹¹In-octreotide(−)/radtech(−) and ¹¹¹In-octreotide(−)/radtech(+) groups.

Results

Of a total of 53 ¹¹¹In-octreotide(−) patients, 40 were categorized as ¹¹¹In-octreotide(−)/radtech(−) and 13 as ¹¹¹In-octreotide(−)/radtech(+) group. Optimal separation of the nNUF values for ¹¹¹In-octreotide(−)/radtech(−) and ¹¹¹In-octreotide(+) groups was defined at the nNUF value of 0.25, to the right of the bell shaped nNUFTI curve. ThIs at this nNUF value were dependent on the mean activity concentration and therefore normalized to generate nThI; a significant difference in nThI values was found between the ¹¹¹In-octreotide(−)/radtech(−) and the ¹¹¹In-octreotide(−)/radtech(+) groups (P < 0.01). As a result, four of the 13 ¹¹¹In-octreotide(−)/radtech(+) livers were redesigned as ¹¹¹In-octreotide(+).

Conclusions

The nNUFTI method has the potential to improve the diagnosis of liver tumours using ¹¹¹In-octreotide.

Seasonal variation in month of diagnosis in children with type 1 diabetes registered in 23 European centers during 1989-2008: little short-term influence of sunshine hours or average temperature

BACKGROUND

The month of diagnosis in childhood type 1 diabetes shows seasonal variation.

OBJECTIVE

We describe the pattern and investigate if year-to-year irregularities are associated with meteorological factors using data from 50 000 children diagnosed under the age of 15 yr in 23 population-based European registries during 1989-2008.

METHODS

Tests for seasonal variation in monthly counts aggregated over the 20 yr period were performed. Time series regression was used to investigate if sunshine hour and average temperature data were predictive of the 240 monthly diagnosis counts after taking account of seasonality and long term trends.

RESULTS

Significant sinusoidal pattern was evident in all but two small centers with peaks in November to February and relative amplitudes ranging from ± 11 to ± 38% (median ± 17%). However, most centers showed significant departures from a sinusoidal pattern. Pooling results over centers, there was significant seasonal variation in each age-group at diagnosis, with least seasonal variation in those under 5 yr. Boys showed greater seasonal variation than girls, particularly those aged 10-14 yr. There were no differences in seasonal pattern between four 5-yr sub-periods. Departures from the sinusoidal trend in monthly diagnoses in the period were significantly associated with deviations from the norm in average temperature (0.8% reduction in diagnoses per 1 °C excess) but not with sunshine hours.

CONCLUSIONS

Seasonality was consistently apparent throughout the period in all age-groups and both sexes, but girls and the under 5 s showed less marked variation. Neither sunshine hour nor average temperature data contributed in any substantial way to explaining departures from the sinusoidal pattern.

Prevalence and predictors of severe hypoglycemia in Danish children and adolescents with diabetes

OBJECTIVE

To investigate the prevalence of severe hypoglycemia in Danish children and adolescents with type 1 diabetes and to pinpoint predictors of this acute complication in children on modern treatment modalities.

RESEARCH DESIGN AND METHODS

The study is based on data from DanDiabKids, a national diabetes register for children and adolescents. The register contains data on patients with type 1 diabetes with an ascertainment rate of 99%. Data from 3320 patients aged 0-18 yr was included in the study period from 1998 to 2009 and analyzed using a negative binomial model.

RESULTS

One thousand nine hundred and ninety-nine episodes of severe hypoglycemia in 867 patients were registered conferring an overall incidence of severe hypoglycemia of 15.1 [95% confident interval (CI): 13.8; 16.4] per 100 patient years. This remained unchanged during the study period. Duration of diabetes, age and treatment in centers managing less than 100 patients significantly increased the risk of severe hypoglycemia (p < 0.001). Patients on insulin pump therapy had a 42% reduced risk of severe hypoglycemia compared with pen treated patients (p = 0.01). Patients treated with five or more daily insulin injections had a 31% (95% CI: 17; 49) reduced risk of severe hypoglycemia compared to patients on fewer daily injections (p = 0.015).

CONCLUSIONS

Despite improvements in metabolic control over a decade the prevalence of severe hypoglycemic events remained unchanged. More intensive treatments such as insulin pump therapy and multiple daily injections on a national level seems to be a protective factor for developing severe hypoglycemia up to 2009.

Glycaemic control of Type 1 diabetes in clinical practice early in the 21st century: an international comparison

AIMS

Improving glycaemic control in people with Type 1 diabetes is known to reduce complications. Our aim was to compare glycaemic control among people with Type 1 diabetes using data gathered in regional or national registries.

METHODS

Data were obtained for children and/or adults with Type 1 diabetes from the following countries (or regions): Western Australia, Austria, Denmark, England, Champagne-Ardenne (France), Germany, Epirus, Thessaly and Thessaloniki (Greece), Galway (Ireland), several Italian regions, Latvia, Rotterdam (The Netherlands), Otago (New Zealand), Norway, Northern Ireland, Scotland, Sweden, Volyn (Ukraine), USA and Wales) from population or clinic-based registries. The sample size with available data varied from 355 to 173 880. Proportions with HbA1c < 58 mmol/mol (< 7.5%) and ≥ 75 mmol/mol (≥ 9.0%) were compared by age and sex.

RESULTS

Data were available for 324 501 people. The proportions with HbA1c 58 mmol/mol (< 7.5%) varied from 15.7% to 46.4% among 44 058 people aged < 15 years, from 8.9% to 49.5% among 50 766 people aged 15-24 years and from 20.5% to 53.6% among 229 677 people aged ≥ 25 years. Sex differences in glycaemic control were small. Proportions of people using insulin pumps varied between the 12 sources with data available.

CONCLUSION

These results suggest that there are substantial variations in glycaemic control among people with Type 1 diabetes between the data sources and that there is room for improvement in all populations, especially in young adults.

Characterization of metabolic responders on CSII treatment amongst children and adolescents in Denmark from 2007 to 2013

AIM

This prospective study aimed to identify and estimate the frequency of responders offered Continuous subcutaneous insulin infusion (CSII) from baseline data and during follow-up, and secondly to characterize CSII users with good adherence to pump therapy among 463 children and adolescents with Type 1 diabetes mellitus.

METHODS

A response was defined as lowering HbA1c with 1% or achieving an HbA1c<7.5% (58 mmol/mol). Good adherence was defined as measuring ≥7 self monitored blood glucoses (SMBGs) and taking ≥7 boluses daily. Logistic regression was used to estimate the effect of demographic and clinical variables prior to and during pump treatment.

RESULTS

At 24 months follow-up 32% qualified as responders. Stratifying for age at onset, 45% of the children aged <6 yrs qualified as responders vs. 32% and 28% of the youngsters and adolescents aged 6-12 yrs. and 12-19 yrs., respectively (p=0.02). Responders were characterized by their HbA1c-level at pump onset (p=0.001), taking more daily boluses (7.64 ± 3.33 vs. 6.40 ± 3.18 p=0.003) and measuring more SMBGs per day at follow-up (6.88 ± 2.35 vs. 6.31 ± 2.54 p=0.03). The incidence of severe hypoglycemia decreased from 14.3 to 3.3 events per 100 person years (p<0.0001). Twenty percent did not respond despite a good adherence toward CSII therapy.

CONCLUSION

Age <6 years, high or low HbA1c at pump initiation and number of daily boluses were associated with improved or sustained near-normal metabolic outcome. The incidence of severe hypoglycemia was significantly reduced. Twenty percent of the population had good adherence without any metabolic improvement.

Insulin pump treatment; increasing prevalence, and predictors for better metabolic outcome in Danish children and adolescents with type 1 diabetes

AIMS

Few studies have looked at nationwide data for insulin pump treatment. Since 1996 the Danish Childhood Diabetes Registry (DanDiabKids) has collected data on all Danish diabetic patients aged 0-15 yr. The purpose of this study is to evaluate the prevalence of continuous subcutaneous insulin infusion (CSII) use among Danish children with diabetes and to compare metabolic control in CSII-treated children and adolescents to those treated with MDI.

MATERIALS AND METHODS

The Registry collects on a yearly basis data on insulin regimen, central measured hemoglobin A1c (HbA1c), and demographic data on all patients. In the period 2005-2011, 2983 young patients (1721 males) with diabetes were followed in the Registry. Mean observation period was 5.11 yr [standard error (SE) 0.09]. In the total period 1846 patients were treated with MDI and 1493 changed from MDI to CSII. In 2005, less than 5% of children were treated with CSII whereas the percentage of children on CSII increased to approximately 50% in 2011. The patients were divided into age groups, <5 yr, 5-10 yr, and > 15 yr.

RESULTS

HbA1c was significantly higher in MDI-treated children, +5.29 (CI 95% 4.29; 6.29 mmol/mol). HbA1c in all age groups was significantly lower in CSII-treated patients, and longitudinally HbA1c continued to be lower in all age groups. In multivariate analysis, a low HbA1c at CSII start, centers with more than 100 pump patients, a more recent year of diabetes onset, a higher number of self-monitoring of blood glucose (SMBG) measurements, a higher number of daily boluses, and a higher percentage of bolus insulin were all related to a lower HbA1c.

CONCLUSION

The percentage of children on pumps (CSII) is CSII treatment is associated with a significantly lower Hba1c, achieved just after treatment initiation. In the following years there is a parallel rise in HbA1c in both MDI as well as in MDI treated patients. Patients coming from larger clinics, and patients measuring more blood glucose values and taking more boluses have a better metabolic control.

Nationwide reduction in the frequency of severe hypoglycemia by half

AIMS

To examine contemporary rates of severe hypoglycemia (SH) and identify the effect of predictors of SH in a pediatric type 1 diabetes population.

METHODS

The national diabetes register provided data on children residing in Denmark from 2008 to 2013 in this register-based population study. Robust Poisson regression models were applied.

RESULTS

The study population [n = 2,715 (50.9 % boys), mean (SD) age at onset; 8.1 (4.0) years, diabetes duration; 5.6 (4.9) years] comprised 7,390 person-years of data and 561 events of SH. The overall incidence of SH was 7.6 per 100 person-years. The incidence rate peaked with 16.0 per 100 person-years in 2008 reaching a nadir of 4.9 in 2011. Overall, insulin pump reduced the rate of SH with 27 % compared to any pen treatment (P = 0.003). When stratifying pen treatment, premixed insulin increased the rate of SH by 1.9-fold (P = 0.0015) and NPH increased the rate by 1.6-fold (P = 0.003) versus pump treatment, whereas long-acting insulin analogues were comparable with pump treatment (P = 0.1485). We found no association of SH with glycemic control (P > 0.05).

CONCLUSIONS

A nationwide halving in rates of severe hypoglycemia was observed during the study period independent of the prevailing average HbA1c level. Changes in diabetes care and successful educational programs may have influenced the lower incidence rate of severe hypoglycemia.

Systemic levels of CCL2, CCL3, CCL4 and CXCL8 differ according to age, time period and season among children newly diagnosed with type 1 diabetes and their healthy siblings

The mechanisms by which antigen-specific T cells migrate to the islets of Langerhans in type 1 diabetes (T1D) are largely unknown. Chemokines attract immune cells to sites of inflammation. The aim was to elucidate the role of inflammatory chemokines in T1D at time of diagnosis. From a population-based registry of children diagnosed with T1D from 1997 to 2005, we studied five different inflammatory chemokines (CCL2, CCL3, CCL4, CCL5 and CXCL8). Four hundred and eighty-two cases and 479 sibling frequencies matched on age and sample year distribution were included. Patients showed lower levels of CCL4 compared to siblings, but this result was not significant after correction for multiple testing. CCL2, CCL3, CCL4 and CXCL8 levels were highest in the most recent cohorts (P < 0.01) in both patients and siblings. A significant seasonal variation - for most of the chemokines - was demonstrated with the highest level during the summer period in both patients and siblings. In addition, there was a significant inverse relationship between CCL4 levels and age. When comparing patients and siblings, remarkably few differences were identified, but interestingly chemokine levels varied with age, season and period for the entire study population. Such variations should be taken into account when studying chemokines in paediatric populations.

Costs and quality of life in multiple sclerosis patients with spasticity

BACKGROUND

The resource use and health-related quality of life (HRQoL) of patients with multiple sclerosis (MS) spasticity are not well known. The purpose of this study was to obtain estimates of resource utilization, costs, and HRQoL, for patients with different levels of MS spasticity in southern Sweden.

MATERIAL AND METHODS

Cross-sectional data on spasticity severity (using a Numerical Rating Scale, NRS), resource use and HRQoL (using EQ-5D) were collected using a patient questionnaire and chart review. Patients were recruited through a clinic in southern Sweden. The study reviews direct medical, direct non-medical and indirect costs.

RESULTS

Total costs were estimated to €114,293 per patient and year. Direct medical costs (€7898) accounted for 7% of total costs. Direct non-medical costs (€68,509) accounted for 60% of total costs. Total costs increased with severity of spasticity: for patients with severe spasticity, the total cost was 2.4 times greater than those for patients with mild spasticity. HRQoL decreased as spasticity increases.

CONCLUSION

The results of this study show that MS spasticity is associated with a substantial burden on society in terms of costs and HRQoL.

Bayesian soft X-ray tomography using non-stationary Gaussian Processes

In this study, a Bayesian based non-stationary Gaussian Process (GP) method for the inference of soft X-ray emissivity distribution along with its associated uncertainties has been developed. For the investigation of equilibrium condition and fast magnetohydrodynamic behaviors in nuclear fusion plasmas, it is of importance to infer, especially in the plasma center, spatially resolved soft X-ray profiles from a limited number of noisy line integral measurements. For this ill-posed inversion problem, Bayesian probability theory can provide a posterior probability distribution over all possible solutions under given model assumptions. Specifically, the use of a non-stationary GP to model the emission allows the model to adapt to the varying length scales of the underlying diffusion process. In contrast to other conventional methods, the prior regularization is realized in a probability form which enhances the capability of uncertainty analysis, in consequence, scientists who concern the reliability of their results will benefit from it. Under the assumption of normally distributed noise, the posterior distribution evaluated at a discrete number of points becomes a multivariate normal distribution whose mean and covariance are analytically available, making inversions and calculation of uncertainty fast. Additionally, the hyper-parameters embedded in the model assumption can be optimized through a Bayesian Occam's Razor formalism and thereby automatically adjust the model complexity. This method is shown to produce convincing reconstructions and good agreements with independently calculated results from the Maximum Entropy and Equilibrium-Based Iterative Tomography Algorithm methods.

Diabetic ketoacidosis at the onset of type 1 diabetes is associated with future HbA1c levels

AIMS/HYPOTHESIS

We investigated the long-term impact of diabetic ketoacidosis (DKA) at onset on metabolic regulation and residual beta cell function in a Danish population with type 1 diabetes.

METHODS

The study is based on data from DanDiabKids, a Danish national diabetes register for children. The register provides clinical and biochemical data on patients with type 1 diabetes diagnosed in 1996-2009 and then followed-up until 1 January 2012. Repeated-measurement models were used as statistical methods.

RESULTS

The study population comprised 2,964 children <18 years. The prevalence of DKA at diagnosis was 17.9%. Of the total subjects, 8.3% had mild, 7.9% had moderate and 1.7% had severe DKA. DKA (moderate and severe) was associated with increased HbA1c (%) levels (0.24; 95% CI 0.11, 0.36; p = 0.0003) and increased insulin dose-adjusted HbA1c (IDAA1c, 0.51; 95% CI 0.31, 0.70; p < 0.0001) during follow-up, after adjustment for covariates. Children without a family history of diabetes were more likely to present with DKA (19.2% vs 8.8%, p < 0.0001); however, these children had a lower HbA1c (%) level over time (-0.35; 95% CI -0.46, -0.24; p < 0.0001). Continuous subcutaneous insulin infusion (CSII) was associated with a long-term reduction in HbA1c, changing the effect of DKA, after adjustment for covariates (p < 0.0001).

CONCLUSIONS/INTERPRETATION

DKA at diagnosis was associated with poor long-term metabolic regulation and residual beta cell function as assessed by HbA1c and IDAA1c, respectively; however, CSII treatment was associated with improvement in glycaemic regulation and residual beta cell function, changing the effect of DKA at onset in our population.

Deaths among adult patients with hypopituitarism: hypocortisolism during acute stress, and de novo malignant brain tumors contribute to an increased mortality

CONTEXT

Patients with hypopituitarism have an increased standardized mortality rate. The basis for this has not been fully clarified.

OBJECTIVE

To investigate in detail the cause of death in a large cohort of patients with hypopituitarism subjected to long-term follow-up.

DESIGN AND METHODS

All-cause and cause-specific mortality in 1286 Swedish patients with hypopituitarism prospectively monitored in KIMS (Pfizer International Metabolic Database) 1995-2009 were compared to general population data in the Swedish National Cause of Death Registry. In addition, events reported in KIMS, medical records, and postmortem reports were reviewed.

MAIN OUTCOME MEASURES

Standardized mortality ratios (SMR) were calculated, with stratification for gender, attained age, and calendar year during follow-up.

RESULTS

An excess mortality was found, 120 deaths vs 84.3 expected, SMR 1.42 (95% confidence interval: 1.18-1.70). Infections, brain cancer, and sudden death were associated with significantly increased SMRs (6.32, 9.40, and 4.10, respectively). Fifteen patients, all ACTH-deficient, died from infections. Eight of these patients were considered to be in a state of adrenal crisis in connection with death (medical reports and post-mortem examinations). Another 8 patients died from de novo malignant brain tumors, 6 of which had had a benign pituitary lesion at baseline. Six of these 8 subjects had received prior radiation therapy.

CONCLUSION

Two important causes of excess mortality were identified: first, adrenal crisis in response to acute stress and intercurrent illness; second, increased risk of a late appearance of de novo malignant brain tumors in patients who previously received radiotherapy. Both of these causes may be in part preventable by changes in the management of pituitary disease.

Importance of circulating IGF-1 for normal cardiac morphology, function and post infarction remodeling

IGF-1 plays an important role in cardiovascular homeostasis, and plasma levels of IGF-1 correlate inversely with systolic function in heart failure. It is not known to what extent circulating IGF-1 secreted by the liver and local autocrine/paracrine IGF-1 expressed in the myocardium contribute to these beneficial effects on cardiac function and morphology. In the present study, we used a mouse model of liver-specific inducible deletion of the IGF-1 gene (LI-IGF-1 -/- mouse) in an attempt to evaluate the importance of circulating IGF-I on cardiac morphology and function under normal and pathological conditions, with an emphasis on its regulatory role in myocardial phosphocreatine metabolism. Echocardiography was performed in LI-IGF-1 -/- and control mice at rest and during dobutamine stress, both at baseline and post myocardial infarction (MI). High-energy phosphate metabolites were compared between LI-IGF-1 -/- and control mice at 4 weeks post MI. We found that LI-IGF-1 -/- mice had significantly greater left ventricular dimensions at baseline and showed a greater relative increase in cardiac dimensions, as well as deterioration of cardiac function, post MI. Myocardial creatine content was 17.9% lower in LI-IGF-1 -/- mice, whereas there was no detectable difference in high-energy nucleotides. These findings indicate an important role of circulating IGF-1 in preserving cardiac structure and function both in physiological settings and post MI.

Trends in childhood type 1 diabetes incidence in Europe during 1989-2008: evidence of non-uniformity over time in rates of increase

AIMS/HYPOTHESIS

The aim of the study was to describe 20-year incidence trends for childhood type 1 diabetes in 23 EURODIAB centres and compare rates of increase in the first (1989-1998) and second (1999-2008) halves of the period.

METHODS

All registers operate in geographically defined regions and are based on a clinical diagnosis. Completeness of registration is assessed by capture-recapture methodology. Twenty-three centres in 19 countries registered 49,969 new cases of type 1 diabetes in individuals diagnosed before their 15th birthday during the period studied.

RESULTS

Ascertainment exceeded 90% in most registers. During the 20-year period, all but one register showed statistically significant changes in incidence, with rates universally increasing. When estimated separately for the first and second halves of the period, the median rates of increase were similar: 3.4% per annum and 3.3% per annum, respectively. However, rates of increase differed significantly between the first half and the second half for nine of the 21 registers with adequate coverage of both periods; five registers showed significantly higher rates of increase in the first half, and four significantly higher rates in the second half.

CONCLUSIONS/INTERPRETATION

The incidence rate of childhood type 1 diabetes continues to rise across Europe by an average of approximately 3-4% per annum, but the increase is not necessarily uniform, showing periods of less rapid and more rapid increase in incidence in some registers. This pattern of change suggests that important risk exposures differ over time in different European countries. Further time trend analysis and comparison of the patterns in defined regions is warranted.

Superior beta cell proliferation, function and gene expression in a subpopulation of rat islets identified by high blood perfusion

AIMS/HYPOTHESIS

The blood perfusion of individual pancreatic islets is highly variable, with a subgroup of islets having high perfusion and blood vessels responsive to further blood flow increase induced by glucose. This study tested the hypothesis that there is heterogeneity between islets with regard to beta cell proliferation, function and gene expression based on differences in their blood perfusion.

METHODS

Fluorescent microspheres were injected into the ascending aorta, and then microsphere-containing and non-microsphere-containing pancreatic islets were isolated for investigation. By this procedure, the 5% of islets with the greatest blood perfusion were identified for study. Islet endothelial cells were isolated separately to investigate the role of improved vascular support in the observed differences.

RESULTS

The vascular network was found to be more dense and tortuous in microsphere-containing than other islets. The most highly blood-perfused islets also had a higher rate of beta cell proliferation, superior beta cell function and a markedly different gene expression from other islets. Cultured islets exposed to islet endothelial cell products had a similarly increased beta cell proliferation rate, yet significantly fewer changes in gene expression than observed in the most highly blood-perfused islets.

CONCLUSIONS/INTERPRETATION

A novel heterogeneity between islets was observed, with superior beta cell proliferation, function and gene expression in a subpopulation of islets identified by high blood perfusion. In contrast with a previously described population of low-oxygenated, sleeping islets, which are recruited into functionality when needed, the presently described heterogeneity is shown to remain in vitro after islet isolation.

Importance of epoch length and registration time on accelerometer measurements in younger children

AIM

The aim of this study was to investigate the effect of epoch length on accumulation of minutes of physical activity per day over a spectrum of intensities, and the effect that selection of number of hours of acceptable registration required per day had on number of days that were considered acceptable.

METHODS

Participants were 696 children (369 boys and 327 girls) aged 6.7±0.4 yrs, from a population-based cohort. Physical activity was assessed by the Actigraph accelerometer for four days.

RESULTS

Main findings were that epoch length had a profound impact on accumulation of minutes of physical activity per day for higher intensities, whereas it had no effect on mean counts per minute. The chosen number of hours for an acceptable registration per day heavily influenced the number of days that were considered acceptable.

CONCLUSION

The findings in the present investigation should be taken into consideration when planning objective measurements of daily physical activity in younger children, and highlight the need for setting international recommendations for physical activity measurements with accelerometers, if different studies are to be comparable.

Drug and treatment costs in Parkinson's disease patients in Sweden

BACKGROUND

Parkinson's disease (PD) is a chronic neurodegenerative disease expected to cause great costs. The aim of this study was to calculate drug and treatment costs in patients with PD in Sweden.

METHOD

All healthcare contacts of patients with PD in Stockholm County, Sweden, were extracted from registers together with information on reimbursements from the authorities to the caregivers. PD-related costs were calculated together with non-PD-related costs. Cost per patient was calculated and extrapolated to the whole Swedish population, taking population demographics into consideration. In addition, nationwide PD drug sales statistics were included.

RESULTS

The PD prevalence of Stockholm County was estimated to 196 per 100,000 inhabitants, resulting in an estimated total of about 22,000 patients with PD in Sweden. The cost per patient was estimated to SEK 76,000 of which drug costs accounted for SEK 15,880. The annual direct costs in patients with PD in Sweden were SEK 1.7 billion in 2009.

CONCLUSION

Our study estimates high direct costs in patients with PD in Sweden, SEK 1.7 billion, 52% for inpatient care, 27% for outpatient care and 21% for drugs. With an ageing population and the medical progress, the financial burden on society will most probably increase in the future. This study might initiate and provide information for discussions about future cost allocations and healthcare priorities.

Longitudinal assessment of femoral knee cartilage quality using contrast enhanced MRI (dGEMRIC) in patients with anterior cruciate ligament injury--comparison with asymptomatic volunteers

OBJECTIVE

In this observational longitudinal study we estimate knee joint cartilage glycosaminoglycan (GAG) content, in patients with an acute anterior cruciate ligament (ACL) injury, with or without a concomitant meniscus injury.

METHODS

29 knees (19 men/10 women) were prospectively examined by repeat delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), approximately 3 weeks and 2.3±1.3 (range 4.5) years after the injury. We estimated the GAG content (T1Gd) in the central weight-bearing parts of the medial and lateral femoral cartilage and compared results with a reference cohort (n=24) with normal knees and no history of injury examined by dGEMRIC at one occasion previously.

RESULTS

The healthy reference group had longer T1Gd values compared with the ACL-injured patients at follow-up both medially: 428±38 vs 363±61ms (P<0.0001) and laterally: 445±41 vs 396±48ms (P=0.0002). At follow-up T1Gd was lower in meniscectomized patients compared to those without a meniscectomy, both medially (-84ms, P=0.002) and laterally (-38ms, P=0.05). In the injured group, the medial femoral cartilage showed similar T1Gd at the two dGEMRIC investigations: 357±50 vs 363±61ms (P=0.57), whereas the lateral femoral cartilage T1Gd increased: 374±48 vs 396±48ms (P=0.04).

CONCLUSIONS

The general decrease in cartilage T1Gd in ACL-injured patients compared with references provide evidence for structural matrix GAG changes that seem more pronounced if a concomitant meniscal injury is present. The fact that post-traumatic OA commonly develops in ACL-injured patients, in particularly those with meniscectomy, suggests that shorter T1Gd may be an early biomarker for OA.