A nationwide registry-based observational study of thyroid disease incidence in the Faroe Islands.

OBJECTIVE: The occurrence of thyroid disease varies among populations. While the iodine nutrition level of the Faroese seems to have been decreasing over the past decades, there is no systematic evaluation of the thyroid disease pattern in the Faroe Islands. Such knowledge of thyroid disease occurrence in the North Atlantic region may support healthcare planning and prevention. To investigate incidence rates, including subtypes of thyroid diseases, and demographic characteristics of thyroid disease patients in the Faroe Islands, to improve understanding of the patterns and trends of these disorders. DESIGN AND METHOD: A registry-based observational study was conducted over 10 years, encompassing all adult Faroese individuals. PATIENTS AND MEASUREMENTS: Health records from general practitioners and hospitals were used to identify incident cases of thyroid diseases. Validation was performed using multiple data sources. The incidence rates were standardised using population data from the middle of the study period 2006-2018. RESULTS: Among the 1152 individuals diagnosed with thyroid disease, the standardised incidence rates per 100,000 person-years were 55 for hyperthyroidism and 112 for hypothyroidism, and around four times higher in women than in men. Hashimoto's thyroiditis was the dominant cause of hypothyroidism, while Graves' disease was the leading cause of hyperthyroidism. The incidence of hypothyroidism increases with age. A decreasing trend was observed over time for both hypothyroidism and hyperthyroidism. CONCLUSION: Considering the decrease in iodine nutrition levels over the past decades, we were surprised by the high incidence of autoimmune thyroid disease. The findings highlight the need for continuous monitoring of thyroid disease occurrence in coastal areas of the North Atlantic Ocean.

No association between long-chain n-3 fatty acid intake during pregnancy and risk of type 1 diabetes in offspring in two large Scandinavian pregnancy cohorts.

AIMS/HYPOTHESIS: The aim of this study was to investigate whether higher dietary intake of marine n-3 fatty acids during pregnancy is associated with a lower risk of type 1 diabetes in children. METHODS: The Danish National Birth Cohort (DNBC) and the Norwegian Mother, Father and Child Cohort Study (MoBa) together include 153,843 mother-child pairs with prospectively collected data on eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake during pregnancy from validated food frequency questionnaires. Type 1 diabetes diagnosis in children (n=634) was ascertained from national diabetes registries. RESULTS: There was no association between the sum of EPA and DHA intake during pregnancy and risk of type 1 diabetes in offspring (pooled HR per g/day of intake: 1.00, 95% CI 0.88, 1.14), with consistent results for both the MoBa and the DNBC. Robustness analyses gave very similar results. CONCLUSIONS/INTERPRETATION: Initiation of a trial of EPA and DHA during pregnancy to prevent type 1 diabetes in offspring should not be prioritised.

Childhood cancer incidence and survival in the Faroe Islands, 1960 to 2019.

BACKGROUND AND PURPOSE: This study is the first report regarding childhood cancer in the Faroe Islands and describes the incidence and survival of childhood cancer over the last 60 years in the Faroe Islands. MATERIAL AND METHODS: We included all Faroese children registered with a cancer diagnosis up to the age of 19 years in the Faroese Cancer Registry from 1960 to 2019 and in the Danish Childhood Cancer Registry from 1985 to 2019 in this study. We report the number of incident cancers classified according to the 12 main diagnostic groups in the International Classification of Childhood Cancer, third edition (ICCC-3), but due to small numbers some groups have been combined in the results shown. We report age-standardized incidence rates (world standard population) (ASIR). We also show all-cause survival by incidence stratified by 20-year periods. RESULTS: There were 114 childhood cancers in the Faroe Islands from 1960 to 2019, corresponding to an ASIR of 13.0 per 100,000 person-years. The most common cancer groups in Faroese children were brain and spinal tumors, followed by leukemias and lymphomas. All-cause survival improved for children diagnosed over time, with a 5-year survival of 43.5% for those diagnosed from 1960 to 1979 and 85.6% for children diagnosed from 2000 to 2019. CONCLUSION: Childhood cancer in the Faroes was slightly rarer than in most other high-income countries. Brain and spinal tumors were the most common cancer group in Faroese children. Survival for Faroese children with cancer has improved substantially in the study period.

Risk of malignancy in a high-incidence population-based cohort of Faroese patients with inflammatory bowel disease from 1960 to 2020 - a Faroese IBD cohort study.

BACKGROUND: The association between inflammatory bowel disease (IBD) and malignancy remains disputed despite many observational studies. The Faroese population exhibits the highest occurrence of IBD in the world. This study aimed to investigate the cancer risk in Faroese IBD patients in a nationwide IBD cohort. METHODS: This study included all IBD patients diagnosed in the Faroe Islands between 1960 and 2020. Clinical demographics and cancer diagnoses were retrieved from patient files and the Faroese cancer registry. Cancer risk in IBD patients was calculated as standardized incidence ratios (SIRs) based on the Faroese background population's age- and sex-specific cancer incidence rates, retrievable from NORDCAN. RESULTS: The cohort consisted of 699 patients with a total follow-up time of 9,629 person-years. Overall, the risk of cancer was not statistically significantly increased compared to the background population. Patients diagnosed with cancer at age 50-59 years had higher overall cancer risk (SIR 1.8; 95% CI, 1.02-2.99) as did UC patients diagnosed with IBD at 50-59 (SIR 2.1; 95% CI, 1.10-3.54). Absolute numbers were small and no estimates for site-specific cancers reached statistical significance, though lung, breast, and cancer of the female reproductive organs were elevated among IBD and UC patients, and colorectal cancer in CD patients. CONCLUSIONS: This nationwide study found no statistically significantly increased risk of cancer among Faroese patients with CD or UC, except from age 50 to 59 years. While the incidence of IBD is significantly higher in the Faroe Islands than in other countries, risk estimates of cancers are comparable.

The iodine content of Faroese food items to support iodine nutrition in the North Atlantic.

Iodine is essential for human health, and dietary iodine sources are critical. Living isolated on islands in the North Atlantic Ocean fostered unique dietary traditions in the Faroe Islands. The dietary peculiarities led us to collect and measure the iodine content of local foods and beverages and calculate daily iodine intakes based on four Faroese dietary scenarios. Marine foods and birds had iodine contents from 300 µg/kg and up, markedly higher than dairy, grains, terrestrial, vegetables, and liquid foods (p<0.001). Vegetables and beverages contained negligible iodine. Wind-dried fermented lamb meat iodine content varied by 100% depending on whether it was herded on an island with beaches (105 µg/kg) or with cliffs (53 µg/kg) facing the ocean. The daily iodine intake varied from around 50 µg to just over 200 µg with diets rich in fish and whales. In conclusion, the traditional diet has been a critical source of iodine on the Faroe Islands. The Faroese may be iodine replete with traditional diets but face the risk of iodine deficiency with dietary transition towards a more western diet. Locally produced Faroese foods are therefore relevant to promote health, and may additionally support food security, local involvement and knowledge, and long-term sustainability.

Effects of the COVID-19-induced lockdown period on general well-being, perceived stress and activity levels in the Faroe Islands.

AIMS: Detrimental effects on health and well-being were reported during the COVID-19-induced lockdown periods in several countries, but these associations have not been studied in small-scale island societies. This study aimed to examine the lockdown period's impact on general well-being, perceived stress and activity levels in the Faroe Islands. METHODS: We used cross-sectional data from two extensive population-based surveys of the general health conducted in November 2019 (the pre-COVID survey; n=2906), and four to six weeks into the first national lockdown (the lockdown survey; n=1204). RESULTS: A larger proportion of participants in the lockdown survey versus pre-COVID survey displayed excellent/very good self-rated health (68.1% vs. 62.0%; p<0.001), and the same pattern was observed for reporting good quality of life (85.7% vs. 82.7%; p<0.05). These associations remained statistically significant in a logistic regression model after adjusting for characteristics for which varying impact of the pandemic has been shown. Indicators of health behaviour showed that larger proportions of participants kept active during the lockdown survey versus pre-COVID survey, and these differences were statistically significant for physical, mental and spiritual activities (p<0.001). On the other hand, similar stress levels in the pre-COVID/lockdown periods were observed, but stratified analysis showed that participants with a high-stress level displayed better self-rated health in the lockdown period compared to the pre-COVID period (p=0.001). CONCLUSIONS: Findings indicate that self-reported health and quality of life improved during the early phase of the COVID lockdown, and individuals reported higher activity levels associated with good mental health during the COVID-19-induced lockdown period.

Cancer survival in the Faroe Islands over the last 50 years compared to the other Nordic countries.

As sustained development in cancer treatment protocols have led to improved survival in most areas of the world, surveillance is needed to ensure that small populations follow suit. Our study reports age-standardized relative cancer survival in the Faroe Islands compared to the other Nordic countries. We present 1- and 5-year survival estimates and corresponding 95% confidence intervals for the Faroe Islands and compare them with estimates for the Nordic countries. The data for this article has been obtained through the NORDCAN collaboration (2019 data). Age-standardized relative survival was estimated using shared R codes on individual-level data within each country. Ten-year calendar inclusion periods were used in addition to the usual 5-year calendar periods to include cancer sites with few cases, which is especially beneficial to the smaller populations. The primary findings were that 1- and 5-year survival were consistently lower in the Faroes for the summary group all sites but non-melanoma skin cancer for both women and men. Further, 5-year survival was lower for women with ovarian cancer and men with lung cancer than in other Nordic countries. Previously, breast cancer survival was low in the Faroes but has improved to a comparable level over the last few years. Colorectal cancer survival was relatively high for both sexes. The reported estimates in this article call for further research to investigate the cancers with lower survival and should call for actions to improve the survival of Faroese cancer patients.

Factors influencing the immune response over 15 months after SARS-CoV-2 infection: A longitudinal population-wide study in the Faroe Islands.

BACKGROUND: The durability of SARS-CoV-2 antibody response and the resulting immunity to COVID-19 is unclear. OBJECTIVES: To investigate long-term humoral immunity to SARS-CoV-2. METHODS: In this nationwide, longitudinal study, we determined antibody response in 411 patients aged 0-93 years from two waves of infections (March to December 2020) contributing 1063 blood samples. Each individual had blood drawn on 4-5 occasions 1-15 months after disease onset. We measured total anti-SARS-CoV-2 receptor-binding domain (RBD) antibody using a qualitative RBD sandwich ELISA, IgM, IgG and IgA levels using an quantitative in-house ELISA-based assay  and neutralizing antibodies (NAbs) using an in-house ELISA-based pseudoneutralizing assay. IgG subclasses were analyzed in a subset of samples by ELISA-based assay. We used nonlinear models to study the durability of SARS-CoV-2 antibody responses and its influence over time. RESULTS: After 15 months, 94% still had detectable circulating antibodies, mainly the IgG isotype, and 92% had detectable NAbs. The distribution of IgG antibodies varied significantly over time, characterized by a biphasic pattern with an initial decline followed by a plateau after approximately 7 months. However, the NAbs remained relatively stable throughout the period. The strength of the antibody response was influenced by smoking and hospitalization, with lower IgG levels in smokers and higher levels in hospitalized individuals. Antibody stability over time was mainly associated with male sex and older age with higher initial levels but more marked decrease. CONCLUSIONS: The humoral immune response to SARS-CoV-2 infection varies depending on behavioral factors and disease severity, and antibody stability over 15 months was associated with sex and age.

Long COVID in the Long Run-23-Month Follow-up Study of Persistent Symptoms.

Symptoms of long coronavirus disease (COVID) were found in 38% of 170 patients followed for a median of 22.6 months. The most prevalent symptoms were fatigue, affected taste and smell, and difficulties remembering and concentrating. Predictors for long COVID were older age and number of symptoms in the acute phase. Long COVID may take many months, maybe years, to resolve.

Cancer in the Faroe Islands from 1960-2019 - incidence, mortality, and comparisons with the other Nordic countries.

Purpose: In this paper, we present age-standardized cancer incidence and mortality rates in the Faroe Islands. We also compare with the Nordic rates and show incidence rate ratios (IRR) and mortality rate ratios (MRR).Materials and methods: The Faroese cancer registry (FCR) was established in 1994, with incidence available from 1960 and mortality from 1983. The FCR is a part of the NORDCAN collaboration, where the different Nordic countries all report anonymized cancer data by standardized methods, ensuring comparability. Validation efforts revealed that 13% of cases had not been reported to the FCR from 2006 to 2019, emphasizing the need for continued validation efforts of cancer registries. After validation, we submitted the updated cancer cases to NORDCAN and now present this data, taken directly from the NORDCAN website (2019 data).Results: We found that the incidence of the summary group all cancers in the Faroe Islands increased from 1960 to 2019, while cancer mortality decreased from 1983 to 2019. Comparisons with Nordic rates showed significantly lower IRRs for cancer in all cancers, bladder and urinary tract, and skin cancer for both sexes, while IRR was lower for breast cancer in women and prostate cancer in men. Contrary, IRR was higher for rectum and kidney cancer in women and esophagus and testicular cancer in men. There was an increased MRR for cancer in female organs, bladder and urinary tract, and kidney cancer in women, and esophagus and pancreas cancer in men. In contrast, malignant hematopoietic diseases and melanoma in women had a lower MRR.Conclusions: Cancer incidence in the Faroe Islands was lower than in the other Nordic countries. Of particular interest, the incidence of testicular cancer saw a steep increase during the last 20 years, and an investigation into possible causes for this is needed.

Prevalence of long COVID in a national cohort: longitudinal measures from disease onset until 8 months' follow-up.

OBJECTIVES: Persistence of COVID-19 symptoms in nonhospitalized individuals beyond a few months has not been well characterized. In this longitudinal study from the Faroe Islands, we present prevalence of long COVID in mainly nonhospitalized patients who were followed up for up to 8 months. METHODS: All Faroese individuals with confirmed COVID-19 diagnosis from August to December 2020 were invited to participate in this study (n = 297). Demographic and clinical characteristics and self-reported symptoms were ascertained prospectively using a detailed questionnaire administered at repeated phone interviews. RESULTS: A total of 226 individuals participated at baseline (226/297, 76% participation rate), of whom 170 participants had more than 3 months follow-up. Of these, 39% (n = 67/170, 95% confidence interval [CI] 32-37%) reported persistent symptoms (median [range] 168 [93-231] days) after the acute phase and 8% (n = 14/170, 95% CI 5-13%) reported severe persistent symptoms. The most prevalent symptoms were fatigue (17%) and smell (17%) and taste (14%) dysfunction. Long COVID was more common in people reporting daily medication use (odds ratio 2.34, 95% CI 1.02-5.37). CONCLUSION: Our results show that symptoms may take months to resolve, even among nonhospitalized individuals, with a mild illness in the acute phase. Continued monitoring for long COVID is needed to evaluate the added risk of a potential public health concern.

Low Seroprevalence among Undetected COVID-19 Cases, Faroe Islands, November 2020.

We conducted a second nationwide severe acute respiratory syndrome coronavirus 2 seroprevalence study in the Faroe Islands during November 2020. We found crude seroprevalence was 0.3% and prevalence was 0.4% after adjusting for test sensitivity and specificity. This low seroprevalence supports the prevention strategies used in the Faroe Islands.

Social inequality in type 2 diabetes mellitus in the Faroe Islands: a cross-sectional study.

Aims: The Faroe Islands is considered a homogeneous society and has a low Gini coefficient, but the knowledge about the social distribution of health and disease is sparse. In a large population-based sample we investigated: (a) the association between socioeconomic position defined by level of education and the prevalence of type 2 diabetes mellitus by self-report in the Faroe Islands; and (b) to what degree lifestyle factors mediate the association. Methods: We used cross-sectional data from the population-based Public Health Survey Faroes 2015 (n=1095). We present odds ratios for type 2 diabetes mellitus by socioeconomic position from logistic regression models. In our main model we adjusted for potential confounders and in a secondary model we additionally adjusted for potential mediating lifestyle factors. Results: Individuals with middle and low levels of education display higher odds ratios of type 2 diabetes mellitus of 2.80 (95% confidence interval 1.32-5.92) and 4.65 (95% confidence interval 1.93-11.17) in adjusted analysis, respectively, compared to their counterparts with high education. After adjustment for potentially mediating lifestyle factors the estimates were attenuated slightly, but a significant statistical association remained, with lifestyle-related mediating factors in total explaining 21% for middle education and 34% for low education participants. Conclusions: Our results demonstrate that there may be a social gradient in the distribution of type 2 diabetes mellitus in the Faroe Islands, and that the association is partly mediated by lifestyle factors.

Seroprevalence of SARS-CoV-2-Specific Antibodies among Quarantined Close Contacts of COVID-19 Patients, Faroe Islands, 2020.

Close contacts of coronavirus disease (COVID-19) patients are at high risk for severe acute respiratory syndrome 2 (SARS-CoV-2) infection. We assessed the seroprevalence of SARS-CoV-2-specific antibodies among quarantined close contacts of COVID-19 patients in the Faroe Islands. We invited quarantined close contacts of COVID-19 index patients identified during March 3-April 22, 2020, to participate in this study; 584 (81%) contacts consented and underwent serologic testing. Among the 584 participants, 32 (5.5%) were seropositive for total antibody against SARS-CoV-2. Household and young or elderly contacts had higher risk for seropositivity than other contacts. We found a secondary attack rate of 19.2%. Seroprevalence among close contacts was almost 10-fold higher than among the general population of the Faroe Islands. Regularly testing household close contacts of COVID-19 patients might help track the transmission of SARS-CoV-2.

Epidemiology and Clinical Course of First Wave Coronavirus Disease Cases, Faroe Islands.

The Faroe Islands was one of the first countries in the Western Hemisphere to eliminate coronavirus disease (COVID-19). During the first epidemic wave in the country, 187 cases were reported between March 3 and April 22, 2020. Large-scale testing and thorough contact tracing were implemented early on, along with lockdown measures. Transmission chains were mapped through patient history and knowledge of contact with prior cases. The most common reported COVID-19 symptoms were fever, headache, and cough, but 11.2% of cases were asymptomatic. Among 187 cases, 8 patients were admitted to hospitals but none were admitted to intensive care units and no deaths occurred. Superspreading was evident during the epidemic because most secondary cases were attributed to just 3 infectors. Even with the high incidence rate in early March, the Faroe Islands successfully eliminated the first wave of COVID-19 through the early use of contact tracing, quarantine, social distancing, and large-scale testing.

Long COVID in the Faroe Islands: A Longitudinal Study Among Nonhospitalized Patients.

BACKGROUND: Little is known about long-term recovery from coronavirus disease 2019 (COVID-19) disease, especially in nonhospitalized individuals. In this longitudinal study we present symptoms registered during the acute phase as well as long COVID (ie, long-lasting COVID-19 symptoms) in patients from the Faroe Islands. METHODS: All consecutive patients with confirmed reverse transcription-polymerase chain reaction testing from April to June 2020 were invited to participate in this study for the assessment of long COVID. Demographic and clinical characteristics and self-reported acute and persistent symptoms were assessed using a standardized detailed questionnaire administered at enrollment and at repeated phone interviews in the period 22 April to 16 August. RESULTS: Of the 180 participants (96.3% of the 187 eligible COVID-19 patients), 53.1% reported persistence of at least 1 symptom after a mean of 125 days after symptoms onset, 33.0% reported 1 or 2 symptoms, and 20.1% reported 3 or more symptoms. At the last follow-up, 46.9% were asymptomatic compared with 4.4% during the acute phase. The most prevalent persistent symptoms were fatigue, loss of smell and taste, and arthralgias. CONCLUSIONS: Our results show that it might take months for symptoms to resolve, even among nonhospitalized persons with mild illness course in the acute phase. Continued monitoring for long COVID is needed.

Seroprevalence of SARS-CoV-2-Specific Antibodies, Faroe Islands.

We conducted a nationwide study of the prevalence of severe acute respiratory syndrome coronavirus 2 infection in the Faroe Islands. Of 1,075 randomly selected participants, 6 (0.6%) tested seropositive for antibodies to the virus. Adjustment for test sensitivity and specificity yielded a 0.7% prevalence. Our findings will help us evaluate our public health response.