Mikael Lilja

Large Outbreak of Cryptosporidium hominis Infection Transmitted through the Public Water Supply, Sweden

In November 2010, ≈27,000 (≈45%) inhabitants of Östersund, Sweden, were affected by a waterborne outbreak of cryptosporidiosis. The outbreak was characterized by a rapid onset and high attack rate, especially among young and middle-aged persons. Young age, number of infected family members, amount of water consumed daily, and gluten intolerance were identified as risk factors for acquiring cryptosporidiosis. Also, chronic intestinal disease and young age were significantly associated with prolonged diarrhea. Identification of Cryptosporidium hominis subtype IbA10G2 in human and environmental samples and consistently low numbers of oocysts in drinking water confirmed insufficient reduction of parasites by the municipal water treatment plant. The current outbreak shows that use of inadequate microbial barriers at water treatment plants can have serious consequences for public health. This risk can be minimized by optimizing control of raw water quality and employing multiple barriers that remove or inactivate all groups of pathogens.

Trends in obesity and its distribution : data from the Northern Sweden MONICA survey, 1986–2004

Objective: Obesity, especially abdominal, is a risk factor for many diseases. This study explored trends in the prevalence of general and abdominal obesity, 1986–2004, in northern Sweden.

The Impact of Leptin and Adiponectin on Incident Type 2 Diabetes Is Modified by Sex and Insulin Resistance

BACKGROUND Adiponectin and leptin and their ratio have been associated with incident type 2 diabetes (T2DM), although the data presented are conflicting and the populations studied have been small. In this large, prospective, nested, case referent study, we hypothesized that these associations are sex specific and may be modified by insulin resistance. METHODS Men and women aged 30-60 years with incident T2DM (n=640) and a prior health survey within the Västerbotten Intervention Programme (VIP) and matched referents (n=1564) were identified. Using conditional logistic regression analyses, we tested whether baseline plasma adiponectin and leptin levels and their ratio independently predicted incident T2DM, stratified for gender and insulin resistance. RESULTS Adjusted for traditional risk factors, fourth-quartile levels of adiponectin were associated with a reduced risk of T2DM in men [odds ratio (OR) 0.55 (0.36-0.86)] and women [OR 0.47 (0.27-0.83)]. Quartile four of the leptin/adiponectin ratio predicted T2DM in both men [OR 3.08 (1.68-5.67)] and women [OR 3.31 (1.56-7.03)], whereas quartile-four levels of leptin predicted T2DM only in men [OR 2.30 (1.32-4.02)]. When stratified for insulin sensitivity and adjusted for body mass index (BMI), log(e)-transformed leptin predicted T2DM in insulin-sensitive men [OR 1.56 (1.13-2.17)] but not in insulin-resistant men [OR 1.03 (0.76-1.39)]. The effect of adiponectin and the leptin/adiponectin ratio was not influenced by the insulin sensitivity status. CONCLUSIONS Leptin in men and adiponectin in both sexes were independent predictors of T2DM. The association was modified by the degree of insulin sensitivity. The leptin/adiponectin ratio may add predictive information beyond the separate hormones.

Higher leptin levels in Asian Indians than Creoles and Europids: a potential explanation for increased metabolic risk

Background and purpose:Leptin predicts cardiovascular diseases and type 2 diabetes, diseases to which Asian Indians are highly susceptible. As a risk marker, leptins intra-individual and seasonal stability is unstudied and only small studies have compared leptin levels in Asian Indians with other populations. The aim of this study was to explore ethnicity related differences in leptin levels and its intra-individual and seasonal stability.Methods:Leptin and anthropometric data from the northern Sweden MONICA (3513 Europids) and the Mauritius Non-communicable Disease (2480 Asian Indians and Creoles) studies were used. In both studies men and women, 25- to 74-year old, participated in both an initial population survey and a follow-up after 5–13 years. For the analysis of seasonal leptin variation, a subset of 1780 participants, 30- to 60-year old, in the Västerbotten Intervention Project was used.Results:Asian Indian men and women had higher levels of leptin, leptin per body mass index (BMI) unit (leptin/BMI) or per cm in waist circumference (WC; leptin/waist) than Creoles and Europids when adjusted for BMI (all P<0.0005) or WC (all P<0.005). In men, Creoles had higher leptin, leptin/BMI and leptin/waist than Europids when adjusted for BMI or WC (all P<0.0005). In women, Creoles had higher leptin/BMI and leptin/waist than Europids only when adjusted for WC (P<0.0005). Asian Indian ethnicity in both sexes, and Creole ethnicity in men, was independently associated with high leptin levels. The intra-class correlation for leptin was similar (0.6–0.7), independently of sex, ethnicity or follow-up time. No seasonal variation in leptin levels was seen.Conclusion:Asian Indians have higher levels of leptin, leptin/BMI and leptin/waist than Creoles and Europids. Leptin has a high intra-individual stability and seasonal leptin variation does not appear to explain the ethnic differences observed here.

Immunochemical faecal occult blood tests in primary care and the risk of delay in the diagnosis of colorectal cancer

Abstract Objective. To evaluate the value, risks, and shortcomings of immunochemical faecal occult blood tests (iFOBTs) in the diagnosis of colorectal cancer (CRC) and adenomas with high-grade dysplasia (HGD) in patients initially presenting to primary care. Design. A retrospective population-based study. Setting and subjects. All 495 cases of CRC and adenomas with HGD diagnosed in the county of Jämtland, Sweden from 2005 to 2009. Results. Of 495 patients 323 (65%) initially presented to primary care. IFOBTs were performed in 215 of 323 (67%) patients. The sensitivity of iFOBT for CRC and adenomas with HGD was 88% (83% when patients with a history of rectal bleeding were excluded). Of 34 patients with anaemia found en passant, 10 had negative iFOBTs. Time to diagnosis was longer for patients with negative iFOBTs (p < 0.0005). Conclusion. IFOBT might be helpful in selecting which patients to refer for colonoscopy. However, iFOBT has a limited sensitivity as a diagnostic test for CRC and adenomas with HGD. Relying only on iFOBT for colonoscopy referral could delay diagnosis, especially for patients with anaemia found en passant.

Cardiovascular risk factors differ between rural and urban Sweden: the 2009 Northern Sweden MONICA cohort.

BackgroundRural communities have a higher burden of cardiovascular risk factors than urban communities. In Sweden, socioeconomic transition and urbanization have led to decreased populations in rural areas and changing characteristics of the remaining inhabitants. We investigated the risk factors in urban and rural populations in Northern Sweden.MethodsThe 2009 Northern Sweden MONICA Study invited a random sample of 2,500 people, 25 to 74 years and 69.2% participated. Community size was classified as rural = <1,000 inhabitants, town = 1,000-15,000, or urban/city= >15,000. We adjusted our analysis for age, gender and education.ResultsThe rural population was older and the proportion of men was higher than in the urban areas. Having only primary education was more common in rural areas than in urban areas (26.2% vs. 12.3%). Waist and hip circumference, body mass index (BMI), and total cholesterol levels were higher in rural areas than in urban areas, even after adjusting for differences in age and gender. The largest differences between rural and urban dwellers were seen in waist circumference of women (4.8 cm), BMI of women (1.8 units) and cholesterol of men (0.37 mmol/l). Blood pressure was higher in rural areas, but not after adjusting for age and gender.Participants in rural areas were more often treated for hypertension and hyperlipidaemia, hospitalized for myocardial infarction and diagnosed with diabetes. However, after adjusting for age and gender, there were no differences. The odds ratio for being physically active comparing rural areas to urban areas was 0.73 (95% CI 0.53; 1.01). Smoking, snuff use and the prevalence of pathological glucose tolerance did not differ between community sizes. Middle-sized communities often had values in between those found in rural and urban communities, but overall they were more similar to the rural population. Further adjustment for education did not change the results for any variable.ConclusionsIn 2009 the rural population in northern Sweden was older, with less education, higher BMI, more sedentary lifestyle, and had higher cholesterol levels than the urban population. The rural population should be considered targets for focused preventive interventions, but with due consideration of the socioeconomic and cultural context.

A rightward shift of the distribution of fasting and post-load glucose in northern Sweden between 1990 and 2009 and its predictors. Data from the Northern Sweden MONICA study

Most Swedish studies show stable diabetes prevalence despite increasing obesity, but glucose levels may shift upwards below the diagnostic threshold for diabetes. Our aim was to explore trends in glucose distribution in northern Sweden; whether these trends were uniformly distributed throughout the spectrum of glucose concentrations; and to relate trends to traditional risk factors and the obesity‐related adipokine leptin.

Relationship between functional disability and costs one and two years post stroke

Background and purpose Stroke affects mortality, functional ability, quality of life and incurs costs. The primary objective of this study was to estimate the costs of stroke care in Sweden by level of disability and stroke type (ischemic (IS) or hemorrhagic stroke (ICH)). Method Resource use during first and second year following a stroke was estimated based on a research database containing linked data from several registries. Costs were estimated for the acute and post-acute management of stroke, including direct (health care consumption and municipal services) and indirect (productivity losses) costs. Resources and costs were estimated per stroke type and functional disability categorised by Modified Rankin Scale (mRS). Results The results indicated that the average costs per patient following a stroke were 350,000SEK/€37,000–480,000SEK/€50,000, dependent on stroke type and whether it was the first or second year post stroke. Large variations were identified between different subgroups of functional disability and stroke type, ranging from annual costs of 100,000SEK/€10,000–1,100,000SEK/€120,000 per patient, with higher costs for patients with ICH compared to IS and increasing costs with more severe functional disability. Conclusion Functional outcome is a major determinant on costs of stroke care. The stroke type associated with worse outcome (ICH) was also consistently associated to higher costs. Measures to improve function are not only important to individual patients and their family but may also decrease the societal burden of stroke.

Improved metabolic health among the obese in six population surveys 1986 to 2009: the Northern Sweden MONICA study

BackgroundThe incidence of CVD is decreasing in spite of increasing BMI in the population. We examined trends in metabolic health among overweight and obese individuals and the influence of lifestyle and socioeconomic status. Six cross sectional population surveys in the Northern Sweden MONICA Study between 1986 and 2009. 8 874 subjects 25 to 64 years participated (74% participation rate). Metabolic health was defined as a total cholesterol level below 5.0 mmol/l, blood pressure below 140/90 mmHg and not having diabetes. In 2009 the age span 25 to 74 years was studied.ResultsThe prevalence of metabolic health among obese subjects increased by 7.9 % per year (95% confidence interval 5.4; 10.5), reaching 21.0% in 2009. The corresponding figures for overweight subjects were 5.9% per year (4.6; 7.3), reaching 18% in 2009, whereas for the normal-weight subjects, the increase was 6.2% per year (5.3; 7.2), reaching 39% in 2009. The prevalence of metabolic health among subjects with abdominal obesity increased by 5.8% (4.6; 7.0) per year, reaching 17.3% in 2009. Among those with no abdominal obesity the increase was 6.2% (5.2; 7.1), reaching 38% in 2009 (p = <0.001 for all groups). Only among non-obese men and obese women did the increase continue between 2004 and 2009. In the other groups a slight decline or levelling off was noted.In 2009 women had a 27% higher prevalence of metabolic health than men. The prevalence of metabolic health among the obese was 19.8% which declined to 15.8% if subjects treated for hypertension or hypercholesterolemia were classified as not healthy. Overweight and obese subjects were less often metabolically healthy (odds ratio 0.54 and 0.59 respectively) compared with normal-weight subjects, independent of sex and age as were subjects with abdominal obesity (odds ratio 0.52). Adjustments for smoking, physical activity and education level did not influence any estimates.ConclusionsThis report shows a large increase in prevalence of metabolic health from 1986 to 2009 for all anthropometric categories. Metabolic health remains considerably less prevalent among overweight and obese subjects than among those with normal weight.

Could it be colorectal cancer? General practitioners’ use of the faecal occult blood test and decision making – a qualitative study

BackgroundAbdominal complaints are common reasons for contacting primary care physicians, and it can be challenging for general practitioners (GPs) to identify patients with suspected colorectal cancer (CRC) for referral to secondary care. The immunochemical faecal occult blood test (iFOBT) is used as a diagnostic aid in primary care, but it is unclear how test results are interpreted. Studies show that negative tests are associated with a risk of delayed diagnosis of CRC and that some patients with positive tests are not investigated further. The aim of this study was to explore what makes GPs suspect CRC and to investigate their practices regarding investigation and referral, with special attention on the use of iFOBTs.MethodSemi-structured individual interviews were conducted with eleven purposely selected GPs and registrars in Region Jämtland Härjedalen, Sweden, and subjected to qualitative content analysis.ResultsIn the analysis of the interviews four categories were identified that described what made the physicians suspect CRC and their practices. Careful listening—with awareness of the pitfalls: Attentive listening was described as essential, but there was a risk of being misled by, for example, the patient’s own explanations. Tests can help—the iFOBT can also complicate the diagnosis: All physicians used iFOBTs to various extents. In the absence of guidelines, all found their own ways to interpret and act on the test results. To refer or not to refer—safety margins are necessary: Uncertainty was described as a part of everyday work and was handled in different ways. Common vague symptoms could be CRC and thus justified referral with safety margins. Growing more confident—but also more humble: With increasing experience, the GPs described becoming more confident in their decisions but they were also more cautious.ConclusionsListening carefully to the patient’s history was essential. The iFOBT was frequently used as support, but there were considerable variations in the interpretation and handling of the results. The diagnostic process can be described as navigating uncertain waters with safety margins, while striving to keep the patient’s best interests in mind. The iFOBT may be useful as a diagnostic aid in primary care, but more research and evidence-based guidelines are needed.