Rikke Kart Jacobsen

Effect of screening and lifestyle counselling on incidence of ischaemic heart disease in general population: Inter99 randomised trial

Objective To investigate the effect of systematic screening for risk factors for ischaemic heart disease followed by repeated lifestyle counselling on the 10 year development of ischaemic heart disease at a population level. Design Randomised controlled community based trial. Setting Suburbs of Copenhagen, Denmark Participants 59 616 people aged 30-60 years randomised with different age and sex randomisation ratios to an intervention group (n=11 629) and a control group (n=47 987). Intervention The intervention group was invited for screening, risk assessment, and lifestyle counselling up to four times over a five year period. All participants with an unhealthy lifestyle had individually tailored lifestyle counselling at all visits (at baseline and after one and three years); those at high risk of ischaemic heart disease, according to predefined criteria, were furthermore offered six sessions of group based lifestyle counselling on smoking cessation, diet, and physical activity. After five years all were invited for a final counselling session. Participants were referred to their general practitioner for medical treatment, if relevant. The control group was not invited for screening. Main outcome measures The primary outcome measure was incidence of ischaemic heart disease in the intervention group compared with the control group. Secondary outcome measures were stroke, combined events (ischaemic heart disease, stroke, or both), and mortality. Results 6091 (52.4%) people in the intervention group participated at baseline. Among 5978 people eligible at five year follow-up (59 died and 54 emigrated), 4028 (67.4%) attended. A total of 3163 people died in the 10 year follow-up period. Among 58 308 without a history of ischaemic heart disease at baseline, 2782 developed ischaemic heart disease. Among 58 940 without a history of stroke at baseline, 1726 developed stroke. No significant difference was seen between the intervention and control groups in the primary end point (hazard ratio for ischaemic heart disease 1.03, 95% confidence interval 0.94 to 1.13) or in the secondary endpoints (stroke 0.98, 0.87 to 1.11; combined endpoint 1.01, 0.93 to 1.09; total mortality 1.00, 0.91 to 1.09). Conclusion A community based, individually tailored intervention programme with screening for risk of ischaemic heart disease and repeated lifestyle intervention over five years had no effect on ischaemic heart disease, stroke, or mortality at the population level after 10 years. Trial registration Clinical trials NCT00289237.

Investigating the possible causal association of smoking with depression and anxiety using Mendelian randomisation meta-analysis: the CARTA consortium

Objectives To investigate whether associations of smoking with depression and anxiety are likely to be causal, using a Mendelian randomisation approach. Design Mendelian randomisation meta-analyses using a genetic variant (rs16969968/rs1051730) as a proxy for smoking heaviness, and observational meta-analyses of the associations of smoking status and smoking heaviness with depression, anxiety and psychological distress. Participants Current, former and never smokers of European ancestry aged ≥16 years from 25 studies in the Consortium for Causal Analysis Research in Tobacco and Alcohol (CARTA). Primary outcome measures Binary definitions of depression, anxiety and psychological distress assessed by clinical interview, symptom scales or self-reported recall of clinician diagnosis. Results The analytic sample included up to 58 176 never smokers, 37 428 former smokers and 32 028 current smokers (total N=127 632). In observational analyses, current smokers had 1.85 times greater odds of depression (95% CI 1.65 to 2.07), 1.71 times greater odds of anxiety (95% CI 1.54 to 1.90) and 1.69 times greater odds of psychological distress (95% CI 1.56 to 1.83) than never smokers. Former smokers also had greater odds of depression, anxiety and psychological distress than never smokers. There was evidence for positive associations of smoking heaviness with depression, anxiety and psychological distress (ORs per cigarette per day: 1.03 (95% CI 1.02 to 1.04), 1.03 (95% CI 1.02 to 1.04) and 1.02 (95% CI 1.02 to 1.03) respectively). In Mendelian randomisation analyses, there was no strong evidence that the minor allele of rs16969968/rs1051730 was associated with depression (OR=1.00, 95% CI 0.95 to 1.05), anxiety (OR=1.02, 95% CI 0.97 to 1.07) or psychological distress (OR=1.02, 95% CI 0.98 to 1.06) in current smokers. Results were similar for former smokers. Conclusions Findings from Mendelian randomisation analyses do not support a causal role of smoking heaviness in the development of depression and anxiety.

Association of subcutaneous allergen-specific immunotherapy with incidence of autoimmune disease, ischemic heart disease, and mortality

BACKGROUND Subcutaneous allergen-specific immunotherapy (SCIT) is a well-documented treatment of IgE-mediated allergic disease. Little is known about potential effects of SCIT on the risk of other chronic immune-related diseases. Over the years, a few casuistic reports have caused concern that SCIT might act as a trigger of autoimmune disease. OBJECTIVE We aimed to investigate the association of SCIT with the incidence of autoimmune disease and ischemic heart disease (IHD), as well as all-cause mortality. METHODS All Danish citizens without other known diseases were linked and followed through central registries on medications and hospital admissions. Persons receiving SCIT and persons receiving conventional allergy treatment (CAT; nasal steroids or oral antihistamines) were compared with regard to mortality and development of autoimmune diseases, acute myocardial infarction (AMI), and IHD. Cox regression (survival analysis) with age as the underlying time scale was used to estimate relative risks (hazard ratios [HRs] with 95% CIs) associated with SCIT compared with CAT adjusted for age, sex, vocational status, and income. RESULTS During the 10-year study period (1997-2006), a total of 18,841 and 428,484 persons were followed in the SCIT and CAT groups, respectively. Receiving SCIT was associated with lower mortality (HR, 0.71; 95% CI, 0.62-0.81) and lower incidence of AMI (HR, 0.70; 95% CI, 0.52-0.93), IHD (HR, 0.88; 95% CI, 0.73-1.05), and autoimmune disease (HR, 0.86; 95% CI, 0.74-0.99). CONCLUSION In this registry-based observational study, receiving SCIT compared with CAT was associated with lower risk of autoimmune disease and AMI, as well as decreased all-cause mortality.

Separate and Joint Associations of Occupational and Leisure-Time Sitting with Cardio-Metabolic Risk Factors in Working Adults: A Cross-Sectional Study

Background The workplace is a main setting for prolonged sitting for some occupational groups. Convincing evidence has recently accumulated on the detrimental cardio-metabolic health effects of leisure-time sitting. Yet, much less is known about occupational sitting, and the potential health risk attached compared to leisure-time sitting. Objective To explore the separate and joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors in working adults. Methods All working adults (N = 2544) from the Health2006, a Danish population-based study, were included in this cross-sectional study. Participants reported hours of sitting during work, during leisure-time along with socio-demographic and behavioral characteristics, including physical activity. Cardio-metabolic risk factors (waist circumference, body mass index, body fat percentage, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, insulin, hemoglobin A1c and plasma glucose) were measured. Associations were explored by linear regression for leisure-time, occupational, and overall sitting time. Results Statistically significant (p<.05) detrimental associations of leisure-time sitting were observed with all cardio-metabolic risk factors, except hemoglobin A1c and plasma glucose. Similarly, occupational sitting time was significantly detrimentally associated with HDL cholesterol, triglycerides, and insulin. For categories of sitting time, a joint adverse association of sitting much during both work-time and leisure-time was observed. Conclusion The associations of occupational sitting time with cardio-metabolic risk factors were fewer and weaker compared to leisure-time sitting. Yet, the joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors were higher than the separate. Our findings amplify the need for further focus in this area prior to making assumptions about equivalent health risks across sedentary behaviors. To our knowledge, this is the first study to contrast the deleterious associations of prolonged occupational and leisure-time sitting, both separately and jointly.

Effect of Smoking on Blood Pressure and Resting Heart Rate - A Mendelian Randomization Meta-Analysis in the CARTA Consortium

Background— Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. Methods and Results— Data on 141 317 participants (62 666 never, 40 669 former, 37 982 current smokers) from 23 population-based studies were included in observational and Mendelian randomization meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure, hypertension, and resting heart rate. For the Mendelian randomization analyses, a genetic variant rs16969968/rs1051730 was used as a proxy for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower systolic blood pressure and diastolic blood pressure and lower hypertension risk, but with higher resting heart rate. In observational analyses among current smokers, 1 cigarette/day higher level of smoking heaviness was associated with higher (0.21 bpm; 95% confidence interval 0.19; 0.24) resting heart rate and slightly higher diastolic blood pressure (0.05 mm Hg; 95% confidence interval 0.02; 0.08) and systolic blood pressure (0.08 mm Hg; 95% confidence interval 0.03; 0.13). However, in Mendelian randomization analyses among current smokers, although each smoking increasing allele of rs16969968/rs1051730 was associated with higher resting heart rate (0.36 bpm/allele; 95% confidence interval 0.18; 0.54), there was no strong association with diastolic blood pressure, systolic blood pressure, or hypertension. This would suggest a 7 bpm higher heart rate in those who smoke 20 cigarettes/day. Conclusions— This Mendelian randomization meta-analysis supports a causal association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate.Background—Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. Methods and Results—Data on 141 317 participants (62 666 never, 40 669 former, 37 982 current smokers) from 23 population-based studies were included in observational and Mendelian randomization meta-analyses of the associations of smoking status and smoking heaviness with systolic and diastolic blood pressure, hypertension, and resting heart rate. For the Mendelian randomization analyses, a genetic variant rs16969968/rs1051730 was used as a proxy for smoking heaviness in current smokers. In observational analyses, current as compared with never smoking was associated with lower systolic blood pressure and diastolic blood pressure and lower hypertension risk, but with higher resting heart rate. In observational analyses among current smokers, 1 cigarette/day higher level of smoking heaviness was associated with higher (0.21 bpm; 95% confidence interval 0.19; 0.24) resting heart rate and slightly higher diastolic blood pressure (0.05 mm Hg; 95% confidence interval 0.02; 0.08) and systolic blood pressure (0.08 mm Hg; 95% confidence interval 0.03; 0.13). However, in Mendelian randomization analyses among current smokers, although each smoking increasing allele of rs16969968/rs1051730 was associated with higher resting heart rate (0.36 bpm/allele; 95% confidence interval 0.18; 0.54), there was no strong association with diastolic blood pressure, systolic blood pressure, or hypertension. This would suggest a 7 bpm higher heart rate in those who smoke 20 cigarettes/day. Conclusions—This Mendelian randomization meta-analysis supports a causal association of smoking heaviness with higher level of resting heart rate, but not with blood pressure. These findings suggest that part of the cardiovascular risk of smoking may operate through increasing resting heart rate.

Effect of general health screening and lifestyle counselling on incidence of diabetes in general population: Inter99 randomised trial.

We aimed to examine the effect of a large population-based multifactorial screening and lifestyle intervention programme on 10-year incidence of diabetes. In a randomised trial of the general Danish population initiated in 1999-2001 59,616 men and women aged 30-60years were assigned to a five year screening and lifestyle counselling programme (n=11,629) or control group (n=47,987) and followed for ten years in nationwide registers. Intention to treat was applied and risk of diabetes was modeled by Cox regression and expressed as hazard ratios (HRs). We found that 1692 individuals had diabetes at baseline. Among 57,924 individuals without diabetes at baseline, 1267 emigrated, 2593 died and 3369 (Intervention group=684, Control group=2685) developed diabetes. We saw no significant difference in diabetes incidence between the groups after 10-year follow-up (Greys test: p=0.22). In the first year of follow-up, incidence of diabetes was significantly higher in the intervention group than the control group (HR=1.68, 95%CI 1.29 to 2.29). We observed no difference in incidence of diabetes between the groups in the follow-up intervals from 1 to 6years or after 6-10years (HR=0.94, 0.83 to 1.06; HR=1.03, 0.91 to 1.17). Inviting the general population to participate in a repeated screening and lifestyle counselling programme over five years did not result in lower incidence of diabetes after 10years of follow-up. As expected, significantly more individuals were diagnosed with diabetes in the intervention group during the first year, but this was not followed by a decrease in the following years. TRIALS REGISTRATION Clinical trials NCT00289237.

Work and leisure time sitting and inactivity: Effects on cardiorespiratory and metabolic health:

Background Prospective relationships between sedentary behaviour and cardiorespiratory and metabolic markers need to be better delineated in adults with different physical activity levels. We examined the separate and combined relationships of work and leisure time sitting and moderate to vigorous physical activity (MVPA) with cardiorespiratory fitness and cardiometabolic risk factors. Methods A total of 2308 adults from the Health2006 cohort were followed for five years. Work sitting, leisure time sitting and MVPA were self-reported and cardiorespiratory fitness (Vo 2 max) was estimated by a submaximal step test. Cardiometabolic risk factors included body mass index, waist circumference, systolic and diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol and insulin levels. Prospective associations with each sitting domain alone and in combination with MVPA level were investigated by multiple linear regression analyses, as were the reverse associations with weight status (body mass index and waist circumference). Results Baseline leisure time sitting predicted increased insulin (p < 0.05) and decreased estimated Vo 2 max (p < 0.05), whereas work sitting predicted decreased waist circumference (p < 0.05) and increased estimated Vo 2 max (p < 0.01) over the five-year study. Low baseline leisure time sitting, but not work sitting, predicted increased estimated Vo 2 max regardless of the MVPA level. Weight status predicted increased leisure time sitting (p < 0.01), but leisure time sitting did not predict weight. Conclusions These findings emphasize sedentary behaviour during leisure time, rather than at work, as a risk behaviour in relation to cardiorespiratory and metabolic health. For cardiorespiratory fitness, it may be important not only to promote MVPA, but also to discourage sedentary behaviour during leisure time.

The influence of housing characteristics on leisure-time sitting. A prospective cohort study in Danish adults

OBJECTIVE Built environmental attributes have been studied in relation to domestic time spent sedentary. An indoor behaviour has thus been linked to an outdoor setting. Yet, attributes of the actual domestic environment may also influence the time spent sedentary at home. Therefore, the aim was to examine if housing characteristics were cross-sectionally and prospectively related to leisure-time sitting in adults. METHODS In the Danish Health2006 cohort, 2308 adults were followed for 5 years. At baseline, subjects self-reported housing characteristics (habitat type, habitat surface area and household size), moderate-to-vigorous physical activity (MVPA) and socio-demographic factors. Leisure-time sitting was self-reported at baseline and 5-year follow-up. Multiple linear regression was used to assess cross-sectional and prospective associations. RESULTS At baseline habitat surface area and household size were inversely associated with leisure-time sitting (p<0.01). Living in an apartment was associated with higher leisure-time sitting compared to living in a house (p<0.01). Household size was a predictor of 5-year leisure-time sitting (p<0.01), after adjustment for confounders and the other housing characteristics. CONCLUSIONS Habitat type, habitat surface area and household size were associated with leisure-time sitting in adults, while especially household size was a predictor of leisure-time sitting five years later. The findings highlight the importance of home-environmental attributes when targeting a reduction in sedentary behaviours.

Psychological consequences of screening for cardiovascular risk factors in an un-selected general population: results from the Inter99 randomised intervention study

Background: Concerns that general health checks, including screening for risk factors to ischemic heart disease (IHD), have negative psychological consequences seem widely unfounded; however, previous studies are only based on self-reports from participants. Aim: To investigate if risk factor screening in healthy adults leads to mental distress in the study population, independent of participation. Methods: The Inter99 study (1999 – 2006) was a randomised intervention in the general population, aiming to prevent IHD by a healthier lifestyle. We included the whole study population, independent of participation (n = 60,915). We merged data with information on the use of psychotropic medication and/or hospitalisation due to psychiatric diagnoses, as retrieved from national registers in Denmark, 4 years before and 5 years after the study began. We conducted analyses using generalised estimating equations. Results: There was no significant difference between the intervention and control groups in their use of antipsychotics, hypnotics/sedatives, antidepressants or anxiolytics. As regards admission to the hospital with mental disorders, no significant difference was seen. These findings were true based on a yearly basis, and when investigating both short-term and a long-term effects of the intervention. There was no interaction with socioeconomic status. Of the 918 persons with a psychiatric diagnosis before the study start, 303 (33%) were re-admitted in the intervention period. Pre-screening of psychological status did not influence the psychological impact of screening. Conclusions: This large, randomised intervention study supports that screening for risk factors to IHD does not increase mental distress, not even in the mentally or socioeconomically most vulnerable persons. This study included the whole Inter99 study population (not only study participants).

Investigating the causal effect of smoking on hay fever and asthma: A Mendelian randomization meta-analysis in the CARTA consortium

Observational studies on smoking and risk of hay fever and asthma have shown inconsistent results. However, observational studies may be biased by confounding and reverse causation. Mendelian randomization uses genetic variants as markers of exposures to examine causal effects. We examined the causal effect of smoking on hay fever and asthma by using the smoking-associated single nucleotide polymorphism (SNP) rs16969968/rs1051730. We included 231,020 participants from 22 population-based studies. Observational analyses showed that current vs never smokers had lower risk of hay fever (odds ratio (OR) = 0·68, 95% confidence interval (CI): 0·61, 0·76; P < 0·001) and allergic sensitization (OR = 0·74, 95% CI: 0·64, 0·86; P < 0·001), but similar asthma risk (OR = 1·00, 95% CI: 0·91, 1·09; P = 0·967). Mendelian randomization analyses in current smokers showed a slightly lower risk of hay fever (OR = 0·958, 95% CI: 0·920, 0·998; P = 0·041), a lower risk of allergic sensitization (OR = 0·92, 95% CI: 0·84, 1·02; P = 0·117), but higher risk of asthma (OR = 1·06, 95% CI: 1·01, 1·11; P = 0·020) per smoking-increasing allele. Our results suggest that smoking may be causally related to a higher risk of asthma and a slightly lower risk of hay fever. However, the adverse events associated with smoking limit its clinical significance.