Anna Horwitz

Screening for celiac disease in Danish adults

Abstract Objective. The prevalence of celiac disease (CD) as recorded in the Danish National Patient Registry is ∼50/100,000 persons. This is much lower than the reported prevalence of CD in other Nordic countries and underdiagnosis is suspected. Our aim was to estimate the prevalence of CD in a population-based study of Danish adults. Methods. A total of 2297 adults aged 24–76 years living in the southwestern part of Copenhagen were screened for CD by immunoglobulin (Ig)A and IgG antibodies to transglutaminases and deamidated gliadin. IgA/IgG-positive participants were invited to a clinical evaluation, including biopsies, by a gastroenterologist. Results. Of the invited 56 participants, 40 underwent a full clinical evaluation and 8 persons were diagnosed with CD; 2 of the 16 persons, who did not complete the clinical evaluation, were considered by experts to have probable CD. None of the above 56 participants had a known history of CD or a recorded diagnosis of CD in National Patient Registry. By combining cases of biopsy-proven CD (n = 8), probable CD (n = 2), and registry-recorded CD (n = 1), the prevalence of CD was estimated to be 479/100,000 (11/2297) persons (95% CI: 197–761). Conclusion. In this general adult population, the prevalence of CD as estimated by screening and clinical evaluation was 10 times higher than the registry-based prevalence of CD. Of 11 participants diagnosed with CD in our screening study, 10 were unaware of the diagnosis prior to the study. Thus, our study suggests that CD is markedly underdiagnosed in Danish adults.

The Prevalence and Incidence of Glaucoma in Denmark in a Fifteen Year Period: A Nationwide Study

Purpose The purpose of the present study was to describe the prevalence, incidence and geographic variation of glaucoma in Denmark in the period from 1996 to 2011. Moreover, the aim was to identify the treatment patterns of glaucoma within the studied period. Methods All Danish citizens were included throughout the study period. The National Prescription Registry was used to identify all claimed prescriptions for glaucoma medication. Results A total of 116,592 incident glaucoma patients were identified. Average age at onset was 66 years (range: 0–105 years), 55% were women. The prevalence of glaucoma increased from 0.79% to 1.72% during the investigated period. In 2011 glaucoma affected 3.76% of the population above 50 years and 10% in patients above 80 years. The age-specific incidence rate of glaucoma seemed to be constant and the increasing prevalence was primarily attributed to an aging population. We found the highest prevalence of glaucoma in the capital region of Denmark. Within the studied period the use of prostaglandin analogs and combination drugs increased, whereas the use of β-blockers, carbon anhydrase inhibitors and parasympathomimetic drugs decreased (p<0.001). Finally, the use of α2-adrenergic agonists remained unchanged. A total of 75% of the patients were treated with two or more glaucoma medications. Conclusions Over all, the present study is the first to assess the frequency and the development of glaucoma in Denmark over a 15-year period. We find that glaucoma affects a little less than 2% of the total population and increases with age to reach a prevalence of more than 10% amongst people above 80 years. Generally, the present study is the largest nation-wide study ever made and must be a close-to-real-life-picture of the utilization of glaucoma medication on a national scale. Our findings confirm other recent estimations on an increasing burden of glaucoma globally.

Danish Nationwide Data Reveal a Link between Diabetes Mellitus, Diabetic Retinopathy, and Glaucoma

Aims. To determine the association between treatment against diabetes mellitus (DM) and treatment with antiglaucomatous drugs in the entire Danish population and to investigate the comorbidity between DM and its complications with antiglaucomatous treatment. Methods. Retrospective nationwide cohort study with data over a 16-year follow-up period. The National Danish Registry of Medicinal Products Statistics was used to identify all claimed prescriptions for antiglaucomatous medication and DM drugs. ICD-10 classifications were furthermore used to identify comorbidities between antiglaucomatous medication and the DM complications, diabetic retinopathy (DR), and nephropathy. Results. A total of 6,343,747 individuals in the period between 1996 and 2012 were analyzed. The overall incidence rate of new-onset glaucoma patients was 0.07 per 1000 person-years for the reference population compared to 36 per 1000 person-years for all diagnosed DM cases. Patients treated with DM drugs had about two times higher relative risk of glaucoma, when adjusting for a range of factors. The presence of DR alone or in combination with nephropathy increased the risk of glaucoma. Conclusions. The present study reports a strong association between DM and onset of glaucoma treatment in the entire Danish population.

Visual steady state in relation to age and cognitive function

Neocortical gamma activity is crucial for sensory perception and cognition. This study examines the value of using non-task stimulation-induced EEG oscillations to predict cognitive status in a birth cohort of healthy Danish males (Metropolit) with varying cognitive ability. In particular, we examine the steady-state VEP power response (SSVEP-PR) in the alpha (8Hz) and gamma (36Hz) bands in 54 males (avg. age: 62.0 years) and compare these with 10 young healthy participants (avg. age 27.6 years). Furthermore, we correlate the individual alpha-to-gamma difference in relative visual-area power (ΔRV) with cognitive scores for the older adults. We find that ΔRV decrease with age by just over one standard deviation when comparing young with old participants (p<0.01). Furthermore, intelligence is significantly negatively correlated with ΔRV in the older adult cohort, even when processing speed, global cognition, executive function, memory, and education (p<0.05). In our preferred specification, an increase in ΔRV of one standard deviation is associated with a reduction in intelligence of 48% of a standard deviation (p<0.01). Finally, we conclude that the difference in cerebral rhythmic activity between the alpha and gamma bands is associated with age and cognitive status, and that ΔRV therefore provide a non-subjective clinical tool with which to examine cognitive status in old age.

The prognosis following amphetamine poisoning

Aims: This study investigated the long-term mortality following poisoning by amphetamine or substituted amphetamines. Furthermore, we examined the social problems and somatic and psychiatric co-morbidity related to amphetamine poisoning, and their impact on the long-term survival. Methods: We identified amphetamine poisoned patients from the Danish Poison Information Centre database and correlated their personal identification numbers with seven Danish national registries related to different social and health aspects. For each case, we sampled 100 age and gender matched controls from the background population. Results: From August 2006 to December 2013 we identified 1444 patients (70% males) who experienced amphetamine poisoning; 52% of the cases were classified as mixed poisonings and the average age at first contact was 24.8 years (SD 8.6). The prevalence of psychiatric disorders, HIV, viral hepatitis, and previous prison incarceration was approximately 10 times higher than among healthy controls. After seven years 11% were deceased as opposed to 0.6% in the control group, and 64% of the patients died from unnatural causes. Male gender (HR 2.29, 95% CI (1.07-4.90)), age (HR 1.06, 95% CI (1.03-1.09)), opioid dependence (HR 2.88, 95% CI (1.42-5.85)), schizophrenia (HR 3.09,95% CI (1.63-5.86)), affective disorders (HR 2.65, 95% CI (1.44-4.90)) and HIV (HR 5.45, 95% CI (1.19-24.90)) were associated with a high mortality. Furthermore, a significant proportion of these patients experienced social and health related deterioration in the years following poisoning. Conclusions: Amphetamine poisoning is associated with a poor long-term prognosis and is complicated by additional social and health related issues.

Antihypertensive Medication Postpones the Onset of Glaucoma

The aim was to investigate the impact of antihypertensive medication on the onset of glaucoma. Data from the complete Danish population between 40 and 95 years of age were used in the period from 1996 to 2012, covering >2.6 million individuals. The National Danish Registry of Medicinal Products Statistics was used to identify all claimed prescriptions for glaucoma medication and antihypertensive drugs. We first investigated basic correlations in the data and found that patients treated with antihypertensive medication, at any time during the study period, had a significantly higher overall relative risk (RR) of glaucoma, even when controlling for age and sex (with a RR of 1.31 and P<0.0001). Furthermore, our data confirm the well-known positive association between age and glaucoma. To investigate the causal effect of antihypertensive treatment on the onset of treatment for glaucoma, we used a regression discontinuity study design. This analysis provides our main finding, namely that prescription of antihypertensive medication leads to a significant reduction in the risk of developing glaucoma. Therefore, although hypertension—as indicated by the use of antihypertensive medication—is positively correlated with glaucoma, our study indicates that antihypertensive medication itself may have a preventive effect on the development of glaucoma.

Antihypertensive Medication Postpones the Onset of GlaucomaNovelty and Significance: Evidence From a Nationwide Study

The aim was to investigate the impact of antihypertensive medication on the onset of glaucoma. Data from the complete Danish population between 40 and 95 years of age were used in the period from 1996 to 2012, covering >2.6 million individuals. The National Danish Registry of Medicinal Products Statistics was used to identify all claimed prescriptions for glaucoma medication and antihypertensive drugs. We first investigated basic correlations in the data and found that patients treated with antihypertensive medication, at any time during the study period, had a significantly higher overall relative risk (RR) of glaucoma, even when controlling for age and sex (with a RR of 1.31 and P<0.0001). Furthermore, our data confirm the well-known positive association between age and glaucoma. To investigate the causal effect of antihypertensive treatment on the onset of treatment for glaucoma, we used a regression discontinuity study design. This analysis provides our main finding, namely that prescription of antihypertensive medication leads to a significant reduction in the risk of developing glaucoma. Therefore, although hypertension—as indicated by the use of antihypertensive medication—is positively correlated with glaucoma, our study indicates that antihypertensive medication itself may have a preventive effect on the development of glaucoma.

Passive double-sensory evoked coherence correlates with long-term memory capacity

HIGHLIGHTS Memory correlates with the difference between single and double-sensory evoked steady-state coherence in the gamma range (ΔC). The correlation is most pronounced for the anterior brain region (ΔCA). The correlation is not driven by birth size, education, speed of processing, or intelligence. The sensitivity of ΔCA for detecting low memory capacity is 90%. Cerebral rhythmic activity and oscillations are important pathways of communication between cortical cell assemblies and may be key factors in memory. We asked whether memory performance is related to gamma coherence in a non-task sensory steady-state stimulation. We investigated 40 healthy males born in 1953 who were part of a Danish birth cohort study. Coherence was measured in the gamma range in response to a single-sensory visual stimulation (36 Hz) and a double-sensory combined audiovisual stimulation (auditive: 40 Hz; visual: 36 Hz). The individual difference in coherence (ΔC) between the bimodal and monomodal stimulation was calculated for each subject and used as the main explanatory variable. ΔC in total brain were significantly negatively correlated with long-term verbal recall. This correlation was pronounced for the anterior region. In addition, the correlation between ΔC and long-term memory was robust when controlling for working memory, as well as a wide range of potentially confounding factors, including intelligence, length of education, speed of processing, visual attention and executive function. Moreover, we found that the difference in anterior coherence (ΔCA) is a better predictor of memory than power in multivariate models. The sensitivity of ΔCA for detecting low memory capacity is 92%. Finally, ΔCA was also associated with other types of memory: verbal learning, visual recognition, and spatial memory, and these additional correlations were also robust enough to control for a range of potentially confounding factors. Thus, the ΔC is a predictor of memory performance may be useful in cognitive neuropsychological testing.