Louise Bennet

Increased incidence of Lyme borreliosis in southern Sweden following mild winters and during warm, humid summers

The aim of the present study was to investigate the long-term incidence rate of Lyme borreliosis and, additionally, to determine whether a correlation exists between climatic factors and summer-season variations in the incidence of Lyme borreliosis. Climatic variability acts directly on tick population dynamics and indirectly on human exposure to Lyme borreliosis spirochetes. In this study, conducted in primary healthcare clinics in southeastern Sweden, electronic patient records from 1997–2003 were searched for those that fulfilled the criteria for erythema migrans. Using a multilevel Poisson regression model, the influence of various climatic factors on the summer-season variations in the incidence of erythema migrans were studied. The mean annual incidence rate was 464 cases of erythema migrans per 100,000 inhabitants. The incidence was significantly higher in women than in men, 505 and 423 cases per 100,000 inhabitants, respectively (p<0.001). The summer-season variations in the erythema migrans incidence rate correlated with the monthly mean summer temperatures (incidence rate ratio 1.12; p<0.001), the number of winter days with temperatures below 0°C (incidence rate ratio 0.97; p<0.001), the monthly mean summer precipitation (incidence rate ratio 0.92; p<0.05), and the number of summer days with relative humidity above 86% (incidence rate ratio 1.04; p<0.05). In conclusion, Lyme borreliosis is highly endemic in southeastern Sweden. The climate in this area, which is favourable not only for human tick exposure but also for the abundance of host-seeking ticks, influences the summer-season variations in the incidence of Lyme borreliosis.

Determination of 14 Circulating microRNAs in Swedes and Iraqis with and without Diabetes Mellitus Type 2

Background Recent reports suggest that immigrants from Middle Eastern countries are a high-risk group for type 2 diabetes (T2D) compared with Swedes, and that the pathogenesis of T2D may be ethnicity-specific. Deregulation of microRNA (miRNA) expression has been demonstrated to be associated with T2D but ethnic differences in miRNA have not been investigated. The aim of this study was to explore the ethnic specific expression (Swedish and Iraqi) of a panel of 14 previously identified miRNAs in patients without T2D (including those with prediabetes) and T2D. Methods A total of 152 individuals were included in the study (84 Iraqis and 68 Swedes). Nineteen Iraqis and 14 Swedes were diagnosed with T2D. Expression of the 14 selected miRNAs (miR-15a, miR-20, miR-21, miR-24, miR-29b, miR-126, miR-144, miR-150, miR-197, miR-223, miR-191, miR-320a, miR-486-5p, and miR-28-3p) in plasma samples was measured by real-time PCR. Results In the whole study population, the expression of miR-24 and miR-29b was significantly different between T2D patients and controls after adjustment for age, sex, waist circumference, family history of T2D, and a sedentary lifestyle. Interestingly, when stratifying the study population according to country of birth, we found that higher expression of miR-144 was significantly associated with T2D in Swedes (OR = 2.43, p = 0.035), but not in Iraqis (OR = 0.54, p = 0.169). The interaction test was significant (p = 0.017). Conclusion This study suggests that the association between plasma miR-144 expression and T2D differs between Swedes and Iraqis.

Lyme borreliosis reinfection: might it be explained by a gender difference in immune response?

Lyme borreliosis is a tick‐borne disease often manifesting as a circular skin lesion. This cutaneous form of the disease is known as erythema migrans. In a 5‐year follow‐up study in southern Sweden, 31 of 708 individuals initially diagnosed with erythema migrans and treated with antibiotics were found to be reinfected with Borrelia burgdorferi. Although men and women were tick‐bitten to the same extent, 27 of the 31 reinfected individuals were women, all of whom were over 44 years of age. The aim of this study was to determine whether this discrepancy in gender distribution could be a result of differences in immunological response. Twenty single‐infected and 21 reinfected women and 18 single‐infected and three reinfected men were included in the study. None of the participants showed any sign of an ongoing B. burgdorferi infection, and thus the habitual response was captured. Lymphocytes were separated from blood and stimulated with antigens. The secretion of interleukin (IL)‐4, IL‐6, IL‐10, interferon (IFN)‐γ and tumour necrosis factor (TNF)‐α was measured by enzyme‐linked immunosorbent assay (ELISA), enzyme‐linked immunosorbent spot‐forming cell assay (ELISPOT) or Immulite. No difference was detected in cytokine secretion between single‐infected and reinfected individuals. We also compared the immunological response in men and women, regardless of the number of B. burgdorferi infections. Women displayed a significantly higher spontaneous secretion of all cytokines measured. The ratios of IL‐4:IFN‐γ and IL‐10:TNF‐α were significantly higher in women. Gender differences in immune reactivity might in part explain the higher incidence of reinfection in women. The higher IL‐4:IFN‐γ and IL‐10:TNF‐α ratios seen in women indicate that postmenopausal women have T helper type 2 (Th2)‐directed reactivity with impaired inflammatory responses which might inhibit the elimination of spirochetes.

Leisure time and occupational physical activity in relation to obesity and insulin resistance: a population-based study from the Skaraborg Project in Sweden

The objective was to study obesity and insulin resistance in relation to leisure time physical activity (LTPA) and occupational physical activity (OPA) in a Swedish population, with particular focus on sex differences. Using a cross-sectional design, waist circumference, body mass index (BMI), glucose/insulin metabolism, blood pressure, heart rate, self-reported education, smoking, alcohol consumption, LTPA, and OPA were assessed in 1745 men and women (30-74 years) randomly chosen from 2 municipalities in southwestern Sweden. In both men and women, LTPA was inversely associated with BMI, waist circumference, and the homeostasis model assessment of insulin resistance (HOMA-IR), respectively. These associations remained statistically significant after adjustments for age, OPA, education, alcohol consumption, smoking, and study area, and also for BMI in the analyses concerning waist circumference and HOMA-IR. A statistically significant interaction term (P = .030), adjusted for multiple confounders, revealed a stronger association between LTPA and HOMA-IR in women compared with men. Occupational physical activity was positively associated with BMI (P < .001), waist circumference (P < .001), and HOMA-IR (P = .001), however, only in women. These associations remained when adjusting for multiple confounders. The sex differences were confirmed by statistically significant interaction terms between sex and OPA in association with BMI, waist circumference, and HOMA-IR, respectively. The observed sex differences regarding the strength of the association between LTPA and insulin resistance, and the positive association between OPA and obesity and insulin resistance found solely in women, warrant further investigation. Although exploration of the metabolic effects of OPA appears to be needed, thorough measurement of potential confounders is also vital to understand contextual effects.

Resistance to activated protein C, highly prevalent amongst users of oral contraceptives with venous thromboembolism

Bennet L, Odeberg H (Blekinge Hospital, Karlskrona, Sweden). Resistance to activated protein C, highly prevalent amongst users of oral contraceptives with venous thromboembolism. J Intern Med 1998; 244: 27–32.

High prevalence of type 2 diabetes in Iraqi and Swedish residents in a deprived Swedish neighbourhood - a population based study

BackgroundImmigrants from the Middle-East are at high risk of developing type 2 diabetes (T2D). The aim of the present survey was to measure, in a single deprived neighbourhood, the prevalence rates of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and T2D in residents originating from Iraq and to compare them to those in residents born in Sweden. An additional aim was to identify metabolic, lifestyle and socioeconomic risk factors associated with IFG/IGT and T2D in these residents.MethodsThe study was conducted February 1st to March 31st 2010. Men and women aged 45 to 65 years of Swedish or Iraqi origin, living in the neighbourhood of Rosengård, Malmö, Sweden, were randomly selected from the census register. Each participant signed a written informed consent form, underwent a physical examination and an oral glucose tolerance test (OGTT), provided blood samples and filled in a questionnaire. A total of 175 subjects participated (Swedish origin n = 79, Iraqi origin n = 96), reflecting an overall response rate of almost 60%.ResultsIn total, 21.9% and 19.0% of the Iraqi and Swedish participants, respectively, suffered from T2D, while 24.0% of the Iraqi participants and 25.3% of the Swedish participants had IFG/IGT. There were no significant differences in prevalence rates relating to country of origin.Obesity (BMI ≥30 kg/m2) and sedentary leisure time physical activity were highly prevalent in both groups, while a family history of diabetes was more prevalent in participants from Iraq (49.2%) than in those from Sweden (22.8%) (p = 0.001).Being obese or having a sedentary leisure time were, independently associated with T2D (OR 5.43 (95% CI 2.10-14.02) and 2.89 (95% CI 1.03-8.10) respectively), while economic difficulties were independently associated with IFG/IGT (OR 2.55 (95% CI 1.06-6.15)) after adjustment for the confounding effects of other common risk factors for T2D.ConclusionsThis study reveals a high prevalence of T2D, independently of country of origin (Iraq or Sweden), in a socially vulnerable area and additionally presents a risk factor profile that is markedly different from that of Sweden in general.

Ethnicity is an independent risk indicator when estimating diabetes risk with FINDRISC scores: a cross sectional study comparing immigrants from the Middle East and native Swedes.

AIMS This study sought to compare type 2 diabetes (T2D) risk indicators in Iraqi immigrants with those in ethnic Swedes living in southern Sweden. METHODS Population-based, cross-sectional cohort study of men and women, aged 30-75 years, born in Iraq or Sweden conducted in 2010-2012 in Malmö, Sweden. A 75g oral glucose tolerance test was performed and sociodemographic and lifestyle data were collected. T2D risk was assessed by the Finnish Diabetes Risk Score (FINDRISC). RESULTS In Iraqi versus Swedish participants, T2D was twice as prevalent (11.6 vs. 5.8%, p<0.001). A large proportion of the excess T2D risk was attributable to larger waist circumference and first-degree family history of diabetes. However, Iraqi ethnicity was a risk factor for T2D independently of other FINDRISC factors (odds ratio (OR) 2.5, 95% CI 1.6-3.9). The FINDRISC algorithm predicted that more Iraqis than Swedes (16.2 vs. 12.3%, p<0.001) will develop T2D within the next decade. The total annual costs for excess T2D risk in Iraqis are estimated to exceed 2.3 million euros in 2005, not accounting for worse quality of life. CONCLUSIONS Our study suggests that Middle Eastern ethnicity should be considered an independent risk indicator for diabetes. Accordingly, the implementation of culturally tailored prevention programs may be warranted.

Reinfection with Lyme Borreliosis: A Retrospective Follow-up Study in Southern Sweden

In a 5-y retrospective follow-up study in southern Sweden that initially included > 1000 individuals with previously diagnosed erythema migrans, factors that influenced the risk of reinfection with Lyme borreliosis were elucidated. The total frequency of reinfection was 4% and the number of tick bites influenced the risk of reinfection: those bitten > 10 times during the observation period had a 4-8-fold increased risk compared with those bitten < 5 times. Women manifested to a greater extent than men although both genders were bitten equally by ticks, thus indicating that women may be more susceptible to reinfection. All reinfected women were > 44 y old. The county of Kalmar including O ¨ land was found to be highly endemic for reinfection with Lyme borreliosis. Thus the number of tick bites, gender, age and study area influenced the risk of reinfection.

Clinical Outcome of Erythema Migrans After Treatment with Phenoxymethyl Penicillin

In a 5 y retrospective follow-up study in southern Sweden of 708 adult individuals with erythema migrans as the single manifestation of Lyme borreliosis, the clinical outcome and the antibiotic treatment were studied. 80% were treated with phenoxymethyl penicillin, 15% with doxycycline and 5% with other antibiotics. Phenoxymethyl penicillin and doxycycline were extremely effective: 98 and 94% of the individuals reported complete recovery without complications. Few individuals reported the development of new symptoms following treatment and none developed any late manifestation of Lyme borreliosis during the observation period. Thus, in the area studied the treatment of the early localized manifestation of Lyme borreliosis (erythema migrans) with antibiotics was extremely successful. The current Swedish recommendation to use phenoxymethyl penicillin, when no sign of disseminated infection or coinfection with other tick-borne pathogens is present, seems excellent.

Ethnic differences in the contribution of insulin action and secretion to type 2 diabetes in immigrants from the Middle East compared to native Swedes.

AIMS We investigated insulin action (insulin sensitivity index, ISI) and insulin secretion (oral disposition indices, DIo) and studied metabolic, demographic and lifestyle-related risk factors for type 2 diabetes and insulin action, in the largest non-European immigrant group to Sweden, immigrants from Iraq and native Swedes. METHODS Population-based, cross-sectional study conducted 2010-2012 including residents 30-75 years of age born in Iraq or Sweden, in whom oral glucose tolerance tests were performed and sociodemography and lifestyle behaviors were characterized. RESULTS In Iraqis compared to Swedes, ISI was more impaired (76.9 vs. 102.3, p<.001) whereas corrected insulin response CIR was higher (226.6 vs. 188.6, p=.016). However, insulin secretion was inadequate given the substantial insulin resistance, as indicated by lower DIo indices in Iraqis than in Swedes (DIo 12,712.9 vs. 14,659.2, p<.001). The crude ethnic difference in ISI was not offset by traditional risk factors like waist circumference, body mass index or family history of diabetes. In Iraqis, ISI conveyed somewhat higher odds of type 2 diabetes than in Swedes (odds ratio OR 0.98, 95% CI 0.97-0.99) vs. OR 0.95, 0.92-0.99), as indicated by an interaction between country of birth and ISI (Pinteraction=.044). CONCLUSION This study reports ethnic differences in the contribution of insulin action to type 2 diabetes. Our data suggests that the impaired insulin action observed in immigrants from the Middle East to Sweden is not fully explained by established risk factors.