The Danish investigation on iodine intake and thyroid disease (DanThyr): history and implications.

Due to mild-to-moderate iodine deficiency in Denmark, health authorities initiated a voluntary iodine fortification (IF) program in 1998, which became mandatory in 2000. In line with recommendations from the World Health Organization, the Danish investigation on iodine intake and thyroid disease (DanThyr) was established to monitor the effect on thyroid health and disease. The program involved different study designs and followed two Danish sub-populations in the years before IF and up till 20 years after. Results showed that the IF was successfully implemented and increased the level of iodine intake from mild-moderate iodine deficiency to low adequacy. The level of thyroglobulin and thyroid volume decreased following IF, and there was an indication of fewer thyroid nodules. The incidence of hyperthyroidism increased transiently following IF but subsequently decreased below the pre-fortification level. Conversely, thyroid-stimulating hormone levels and the prevalence of thyroid autoimmunity increased along with an increase in the incidence of hypothyroidism. These trends were mirrored in the trends in treatments for thyroid disease. Most differences in thyroid health and disease between regions with different iodine intake levels before IF attenuated. This review illustrates the importance of a monitoring program to detect both beneficial and adverse effects and exemplifies how a monitoring program can be conducted when a nationwide health promotion program - as IF - is initiated.

Protocol for the combined cardiometabolic deep phenotyping and registry-based 20-year follow-up study of the Inter99 cohort.

INTRODUCTION: The population-based Inter99 cohort has contributed extensively to our understanding of effects of a systematic screening and lifestyle intervention, as well as the multifactorial aetiology of type 2 diabetes (T2D) and cardiovascular disease. To understand causes, trajectories and patterns of early and overt cardiometabolic disease manifestations, we will perform a combined clinical deep phenotyping and registry follow-up study of the now 50-80 years old Inter99 participants. METHODS AND ANALYSIS: The Inter99 cohort comprises individuals aged 30-60 years, who lived in a representative geographical area of greater Copenhagen, Denmark, in 1999. Age-stratified and sex-stratified random subgroups were invited to participate in either a lifestyle intervention (N=13 016) or questionnaires (N=5264), while the rest served as a reference population (N=43 021). Of the 13 016 individuals assigned to the lifestyle intervention group, 6784 (52%) accepted participation in a baseline health examination in 1999, including screening for cardiovascular risk factors and prediabetic conditions. In total, 6004 eligible participants, who participated in the baseline examination, will be invited to participate in the deep phenotyping 20-year follow-up clinical examination including measurements of anthropometry, blood pressure, arterial stiffness, cardiometabolic biomarkers, coronary artery calcification, heart rate variability, heart rhythm, liver stiffness, fundus characteristics, muscle strength and mass, as well as health and lifestyle questionnaires. In a subsample, 10-day monitoring of diet, physical activity and continuous glucose measurements will be performed. Fasting blood, urine and faecal samples to be stored in a biobank. The established database will form the basis of multiple analyses. A main purpose is to investigate whether low birth weight independent of genetics, lifestyle and glucose tolerance predicts later common T2D cardiometabolic comorbidities. ETHICS AND DISSEMINATION: The study was approved by the Medical Ethics Committee, Capital Region, Denmark (H-20076231) and by the Danish Data Protection Agency through the Capital Region of Denmark's registration system (P-2020-1074). Informed consent will be obtained before examinations. Findings will be disseminated in peer-reviewed journals, at conferences and via presentations to stakeholders, including patients and public health policymakers. TRIAL REGISTRATION NUMBER: NCT05166447.

Cohort study of postural sway and low back pain: the Copenhagen City Heart Study.

PURPOSE: Low back pain is a significant health problem with a high prevalence. Studies of smaller cohorts of low back pain patients have indicated increased body sway. The present paper tests the hypothesis of an association between low back pain and postural sway in a large randomly selected population. METHODS: The current study used the fifth examination (2011-2015) of The Copenhagen City Heart Study where 4543 participated. The participants answered a self-administered questionnaire regarding pain, physical activity, smoking, alcohol consumption, education, and other lifestyle factors. Measurement of postural body sway was performed using the CATSYS system. RESULTS: Totally 1134 participants (25%) reported to have low back pain. Subjects with low back pain had higher sway area and sway velocity than subjects without. CONCLUSION: When using multivariate statistical analysis, confounding factors such as male gender, higher age, larger body height, low education level, smoking, and low activity level explained the association between low back pain and postural sway.

Symptoms and biomarkers associated with undiagnosed celiac seropositivity.

BACKGROUND: Studies have indicated that underdiagnosis and diagnostic delay are common in celiac disease. Therefore, it is important to increase our knowledge of what symptoms and biomarkers could identify undiagnosed cases of celiac disease. METHODS: We screened for celiac disease antibodies in stored blood samples from 16,776 participants in eight population-based studies examined during 1976-2012. Undiagnosed celiac seropositivity was defined as celiac disease antibody positivity (IgG-deamidated gliadin peptide above 10.0 U/mL and/or IgA-tissue transglutaminase (TTG) or IgG-TTG above 7.0 U/mL) without a known diagnosis of celiac disease in the National Patient Register. In all studies general health symptoms were recorded by participant-completed questionnaire, including self-perceived health, tiredness, headache and gastrointestinal symptoms. Furthermore, blood samples were drawn for analyses of biomarkers e.g. hemoglobin, blood glucose, cholesterol, liver parameters and vitamins. The participants with undiagnosed celiac seropositivity were matched by sex, age and study with four controls among the celiac disease antibody negative participants. RESULTS: We excluded, five participants with known celiac disease, resulting in a population of 16,771 participants. In this population 1% (169/16,771) had undiagnosed celiac seropositivity. There were no statistically significant differences in symptoms between cases and controls. Undiagnosed celiac seropositivity was associated with low blood cholesterol (< 5 mmol/L) and low hemoglobin (< 7.3 mmol/L for women and < 8.3 mmol/L for men). CONCLUSION: In this general population study, undiagnosed cases of celiac seropositivity did not have more symptoms than controls, confirming the diagnostic difficulties of celiac disease and the low prognostic value of symptoms for a diagnosis of celiac disease. Furthermore, decreased levels of cholesterol and/or hemoglobin in the blood were associated with undiagnosed celiac seropositivity.

Long-term Consequences of Undiagnosed Celiac Seropositivity.

INTRODUCTION: Diagnosed celiac disease (CD) is associated with lymphoproliferative malignancy and gastrointestinal cancer, but little is known about the long-term consequences of undiagnosed CD. We aimed to investigate long-term consequences of undiagnosed CD for mortality and incidence of cancer and other chronic diseases. METHODS: We screened biobank serum samples for immunoglobulin (Ig) A and IgG tissue transglutaminase (TTG) and IgG deamidated gliadin peptide in a study of 8 population-based cohort studies comprising 16,776 participants examined during 1976-2012 and followed with >99% complete follow-up in Danish nationwide registries until December 31, 2017, regarding vital status and incidence of diseases. Undiagnosed CD was defined as antibody positivity (IgA-TTG or IgG-TTG ≥ 7 U/mL and/or IgG deamidated gliadin peptide ≥ 10 U/mL) in individuals without a diagnosis of CD recorded in the National Patient Register. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated by Cox regression analyses with age as the underlying time scale. RESULTS: The prevalence of undiagnosed CD was 1.0% with no statistically significant increase over time. Undiagnosed CD was associated with increased risk of cancer overall (HR, 1.57; 95% CI, 1.16-2.11), gastrointestinal cancer (HR, 2.33; 95% CI, 1.35-4.04), cancer of the uterus (HR, 3.95; 95% CI, 1.46-10.69), breast cancer (HR, 1.98; 95% CI, 1.02-3.82), head and neck cancer (HR, 3.12; 95% CI, 1.15-8.43), and cardiovascular disease (HR, 1.37; 95% CI, 1.01-1.85). We found no statistically significant association between undiagnosed CD and mortality (HR, 1.19; 95% CI, 0.87-1.61). DISCUSSION: Undiagnosed CD was associated with increased risk of cardiovascular disease and cancer suggesting that untreated CD has serious long-term health consequences not only affecting the gastrointestinal tract (see Visual Abstract, Supplementary Digital Content, http://links.lww.com/AJG/B566).

Adverse life events in the general population - a validation of the cumulative lifetime adversity measure.

Background: Negative life events are a predictor for mental illness. However, most research has focused on selected domains, e.g. childhood or recent adversity. The Cumulative Lifetime Adversity Measure (CLAM), a newly introduced questionnaire not yet validated, examines cumulative effect of a range of events including number of exposure to the same event. This measure gives opportunity to collect detailed data on lifetime adversity in large cohort studies. Objective: The aim of this study was translation of the CLAM into Danish and validation of the CLAM in a large general population cohort. Secondly, we aimed to describe the occurrence of adverse life events in a large representative sample of the general population in Denmark. Methods: Translation and validation followed the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) for formative models. Content and construct validity were evaluated including hypothesis testing of accumulated lifetime adversity having a U-shaped pattern with low levels of cumulated lifetime adversity as opposed to no or high levels being associated with lower emotional distress, functional impairment, and pain impairment. The field testing sample was the DanFunD cohort (n = 7493) randomly drawn in a Danish population and examined between 2012 and 2015. Results: Pilot interviews showed that the questions were confronting but not offensive, straight forward, and easy to answer. Acceptability was good. U-shaped patterns between accumulated lifetime adversity and the outcome measures were found. Quadratic term: Emotional distress (ß(95%CI) 0.007(0.002;0.012), p < 0.007), functional impairment (ß(95%CI) -0.002(-0.003;-0.001), p < 0.001), and pain impairment (ß(95%CI) 0.004(0.002;0.006), p = 0.001). Field testing provided basic numbers for adverse life events for the Danish general population, with a cumulated lifetime adversity mean (SD), 5.9 (3.7). Compared to the US there were lower rates of violence, social/environmental stress, and disaster. Conclusions: The results from the original version were replicated, indicating high construct validity. Furthermore, content validity was good.

Antecedentes: Los eventos vitales negativos son un predictor de trastorno mental. Sin embargo, la mayoría de las investigaciones se han centrado en dominios seleccionados, por ej. infancia o adversidad reciente. La Medida de Adversidad Acumulada a lo Largo de la Vida (CLAM en su sigla en inglés), un cuestionario recientemente introducido que no ha sido validado todavía, examina el efecto acumulado de un rango de eventos, incluyendo el número de exposiciones al mismo evento. Esta medida permite recolectar información detallada sobre la adversidad a lo largo de la vida en estudios de cohorte grandes.Objetivo: El objetivo de este estudio fue la traducción de la CLAM al idioma danés y la validación de la CLAM en una cohorte grande de población general. En segundo lugar, buscamos describir la ocurrencia de los eventos vitales adversos en una muestra representativa grande de la población general en Dinamarca.Métodos: La traducción y la validación siguió los Estándares basados en Consensos para la selección de los Instrumentos de Medición en Salud (COSMIN en su sigla en inglés) para modelos formativos. La validez de contenido y constructo fueron evaluadas incluyendo la puesta a prueba de la hipótesis de que la adversidad acumulada a lo largo de la vida tiene un patrón de forma en U con bajos niveles de adversidad acumulada a lo largo de la vida, en lugar de niveles nulos o altos, está asociado con más baja angustia emocional, discapacidad funcional, y deterioro del dolour. La muestra de prueba de campo fue una cohorte de DanFunD (n=7493) obtenida aleatoriamente de una población danesa y examinada entre el 2012-2015.Resultados: Las entrevistas piloto mostraron que las preguntas fueron confrontativas pero no ofensivas, directas, y fáciles de contestar. La aceptabilidad fue buena. Se encontraron patrones en forma de U entre la adversidad acumulada a lo largo de la vida y las medidas de los resultados. En términos cuadráticos: Angustia emocional (ß(IC 95%) 0,007(0,002;0,012), p<0.007), discapacidad funcional (ß(IC 95%) −0,002(−0,003;-0,001), p<0.001), y deterioro del dolour (ß(IC 95%) 0,004(0,002;0,006), p=0.001). La prueba de campo proporcionó los números básicos para los eventos vitales adversos para la población general danesa, con una adversidad acumulada a lo largo de la vida promedio (DE), 5.9 (3.7). En comparación con los Estados Unidos, se reportan tasas más bajas de violencia, estrés social/ambiental, y desastre.Conclusiones: Los resultados de la versión original fueron replicados, indicando una validez de constructo alta. Además, la validez de contenido fue buena.

The association of celiac disease and allergic disease in a general adult population.

Background: The relationship between allergy and celiac disease (CD) is not clear. Objective: The objective of this article is to investigate the association of CD and CD antibody positivity with hay fever, asthma and immunoglobulin (Ig)E sensitization in a general adult population. Methods: A total of 2297 individuals were screened for CD antibodies and underwent allergy testing. CD antibody-positive participants were invited to undergo clinical evaluation including biopsies. Additionally, biobank blood samples from four population-based studies (6423, 973, 1718 and 1101 participants) with data on IgE sensitization to inhalant allergens were screened for CD antibodies. CD antibody-positive participants were screened for serum IgE against food allergens in three biobank studies. CD-antibody positivity was defined as IgA or IgG tissue transglutaminase ≥7 U/ml and/or IgG deamidated gliadin peptide ≥10 U/ml. Results: The nine participants (0.4%) diagnosed with CD had significantly higher prevalence of IgE sensitization to wheat and dust mites. The prevalence of CD antibody positivity was 0.8% (18/2297), and these participants had a significantly higher prevalence of IgE sensitization to food allergens (Fx5), egg, dust mites and mugwort. In the biobank studies, the prevalence of CD antibody positivity was 0.8% to 1.2%. One study showed a positive association between CD antibody positivity and IgE sensitization for dog, horse and food allergens. Conclusion: We found a possible association of CD and IgE sensitization to some food and inhalant allergens in the Health2006 study. In further studies, however, we could not consistently replicate these associations.

Cohort description: The Danish study of Functional Disorders.

The Danish study of Functional Disorders (DanFunD) cohort was initiated to outline the epidemiology of functional somatic syndromes (FSS) and is the first larger coordinated epidemiological study focusing exclusively on FSS. FSS are prevalent in all medical settings and can be defined as syndromes that, after appropriate medical assessment, cannot be explained in terms of a conventional medical or surgical disease. FSS are frequent and the clinical importance varies from vague symptoms to extreme disability. No well-described medical explanations exist for FSS, and how to delimit FSS remains a controversial topic. The specific aims with the cohort were to test delimitations of FSS, estimate prevalence and incidence rates, identify risk factors, delimitate the pathogenic pathways, and explore the consequences of FSS. The study population comprises a random sample of 9,656 men and women aged 18-76 years from the general population examined from 2011 to 2015. The survey comprises screening questionnaires for five types of FSS, ie, fibromyalgia, whiplash-associated disorder, multiple chemical sensitivity, irritable bowel syndrome, and chronic fatigue syndrome, and for the unifying diagnostic category of bodily distress syndrome. Additional data included a telephone-based diagnostic interview assessment for FSS, questionnaires on physical and mental health, personality traits, lifestyle, use of health care services and social factors, and a physical examination with measures of cardiorespiratory and morphological fitness, metabolic fitness, neck mobility, heart rate variability, and pain sensitivity. A biobank including serum, plasma, urine, DNA, and microbiome has been established, and central registry data from both responders and nonresponders are similarly available on morbidity, mortality, reimbursement of medicine, heath care use, and social factors. A complete 5-year follow-up is scheduled to take place from year 2017 to 2020, and further reexaminations will be planned. Several projects using the DanFunD data are ongoing, and findings will be published in the coming years.