Smoking history and all-cause, ischaemic heart disease and lung cancer mortality: follow-up study of 358 551 men and women aged 40-43 years.

AIMS: We studied the health consequences of quitting smoking before age 43 by time since quitting, number of years smoked and cigarettes smoked per day. The outcomes were all-cause, ischaemic heart disease and lung cancer mortality. DESIGN: Prospective study. SETTING: Norwegian counties. PARTICIPANTS: Men and women aged 40-43 years who participated in a national cardiovascular screening programme and who were followed from 1985 to 2018. MEASUREMENTS: Self-reports from questionnaire on time since quitting smoking, years smoked and number of cigarettes per day, and measurements of height, weight and blood pressure, and a blood sample where serum was analysed for total serum cholesterol and triglycerides. FINDINGS: The all-cause mortality rate was 30% higher among quitters less than 1 year ago compared with never smokers (adjusted HR=1.30, 95% CI 1.18-1.43 in men and HR=1.31, 95% CI 1.16 to 1.50 in women). Quitters who had smoked longer than 20 years had 23% higher mortality in men (HR=1.23, 95% CI 1.14 to 1.34) and 32% higher mortality in women (HR=1.32, 95% CI 1.18 to 1.49). Past smoking of more than 20 cigarettes/day was associated with HR=1.14 (1.05-1.23) in men and HR=1.16 (1.01-1.32) in women. The HR for lung cancer was 6.77 (95% CI 4.86 to 9.45) for quitting men who had smoked for more than 20 years compared with never smokers. The corresponding figure for women was 5.75 (95% CI 4.08 to 8.09). CONCLUSIONS: The mortality among quitters was close to that of never smokers, except for a higher mortality for lung cancer, which on the other hand was much lower than the lung cancer mortality in current smokers.

Associations between serum high-density lipoprotein cholesterol levels and cause-specific mortality in a general population of 345 000 men and women aged 20-79 years.

BACKGROUND: Benefits of elevated high-density lipoprotein cholesterol (HDL-C) levels are challenged by reports demonstrating U-shaped relations between HDL-C levels and all-cause mortality; the association with cause-specific mortality is less studied. METHODS: A total of 344 556 individuals (20-79 years, 52 % women) recruited from population-based health screening during 1985-2003 were followed until the end of 2018 for all-cause and cause-specific mortality by serum HDL-C level at inclusion of <30, 30-39, 40-49, 50-59, 60-69, 70-79, 80-89, 90-99 and >99 mg/dl (< 0.78, 0.78-1.01, 1.04-1.27, 1.30-1.53, 1.55-1.79, 1.81-2.04, 2.07-2.31, 2.33-2.56, >2.56 mmol/L). Hazard ratios (HRs) were adjusted for sex, age, calendar period, smoking, total cholesterol, triglycerides, systolic blood pressure, physical activity, educational length, body mass index and ill health. RESULTS: During a mean follow-up of 22 years, 69 505 individuals died. There were U-shaped associations between HDL-C levels and all-cause, cancer and non-cardiovascular disease/non-cancer mortality (non-CVD/non-cancer), whereas for CVD there was increased risk of death only at lower levels. With HDL-C stratum 50-59 mg/dl (1.30-1.53 mmol/L) as reference, HRs [95% confidence intervals (CIs)] for levels >99 mg/dl (>2.56 mmol/L) were 1.32 (1.21-1.43), 1.05 (0.89-1.24), 1.26 (1.09-1.46) and 1.68 (1.48-1.90) for all-cause, CVD, cancer and non-CVD/non-cancer mortality, respectively. For HDL-C levels <30 mg/dl (0.78 mmol/L), the corresponding HRs (95% CIs) were 1.30 (1.24-1.36), 1.55 (1.44-1.67), 1.14 (1.05-1.23) and 1.19 (1.10-1.29). The mortality from alcoholic liver disease, cancers of mouth-oesophagus-liver, chronic liver diseases, chronic obstructive pulmonary disease, accidents and diabetes increased distinctly with increasing HDL-C above the reference level. HDL-C levels lower than the reference level were mainly associated with increased mortality of ischaemic heart disease (IHD), other CVDs, stomach cancer and diabetes. CONCLUSIONS: Higher HDL-C levels were associated with increased mortality risk of several diseases which also have been associated with heavy drinking, and lower HDL-C levels were associated with increased mortality from IHD, other CVDs, gastric cancer and diabetes.

Alcohol consumption and incidence of pancreatic cancer.

Purpose: The association between alcohol consumption and pancreatic cancer is unsettled. Methods: Altogether 243,169 men and women 20-79 years, without cancer at baseline, were followed with respect to pancreatic cancer by linkage to the Cancer Registry of Norway and the Norwegian Cause of Death Registry. They participated in a cardiovascular survey where information on alcohol consumption, smoking habits, anthropometric measures, and some biological variables were recorded. During 20 years of follow-up, 991 incident pancreatic cancers were registered. We estimated the hazard ratios with the Cox proportional hazards model, and graphed spline curves between glass-units/d of alcohol and hazard ratio of incident pancreatic cancer. Results: The multivariable adjusted hazard per 1 glass-unit/d was 1.08 (95% confidence interval 1.02-1.15) for men and 1.04 (0.97-1.13) for women. The association between alcohol consumption and incident pancreatic cancer was present in ex- and current smokers, but the association could be ascribed to smoking habits. The multivariable adjusted spline curves increased with increasing glass-units/d and with confidence bands not encompassing 1.0 above one glass-unit/day. Conclusion: Our findings of an association between higher level of alcohol consumption and incident pancreatic cancer, could be attributed to confounding by smoking habits.

Biomarker-assessed passive smoking in relation to cause-specific mortality: pooled data from 12 prospective cohort studies comprising 36 584 individuals.

AIMS: While investigators have typically quantified the health risk of passive (secondhand) smoking by using self-reported data, these are liable to measurement error. By pooling data across studies, we examined the prospective relation of a biochemical assessment of passive smoking, salivary cotinine, with mortality from a range of causes. METHODS: We combined data from 12 cohort studies from England and Scotland initiated between 1998 and 2008. A total of 36 584 men and women aged 16-85 years of age reported that they were non-smoking at baseline, provided baseline salivary cotinine and consented to mortality record linkage. RESULTS: A mean of 8.1 years of mortality follow-up of 36 584 non-smokers (16 792 men and 19 792 women) gave rise to 2367 deaths (775 from cardiovascular disease, 779 from all cancers and 289 from smoking-related cancers). After controlling for a range of covariates, a 10 ng/mL increase in salivary cotinine was related to an elevated risk of total (HRs; 95% CI) (1.46; 1.16 to 1.83), cardiovascular disease (1.41; 0.96 to 2.09), cancer (1.49; 1.00 to 2.22) and smoking-related cancer mortality (2.92; 1.77 to 4.83). CONCLUSIONS: Assessed biomedically, passive smoking was a risk factor for a range of health outcomes known to be causally linked to active smoking.

Alcohol Consumption, HDL-Cholesterol and Incidence of Colon and Rectal Cancer: A Prospective Cohort Study Including 250,010 Participants.

AIMS: Alcohol consumption has been linked to colorectal cancer (CRC) and also to the high-density lipoprotein cholesterol level (HDL-C). HDL-C has been associated with the incidence of CRC. The aim of this study was to investigate the association between self-reported alcohol consumption, HDL-C and incidence of CRC, separately for the two sites. METHODS: Altogether, 250,010 participants in Norwegian surveys have been followed-up for an average of 18 years with respect to a first-time outcome of colon or rectal cancer. During follow-up, 3023 and 1439 colon and rectal cancers were registered. RESULTS: For men, the HR per 1 drink per day was 1.05 with 95% confidence interval (0.98-1.12) for colon and 1.08 (1.02-1.15) for rectal cancer. The corresponding figures for women were 1.03 (0.97-1.10) and 1.05 (1.00-1.10). There was a positive association between alcohol consumption and HDL-C. HDL-C was inversely associated with colon cancer in men (0.74 (0.62-0.89) per 1 mmol/l) and positively associated with rectal cancer, although not statistically significant (1.15 (0.92-1.44). A robust regression that assigned weights to each observation and exclusion of weights ≤ 0.1 increased the HRs per 1 drink per day and decreased the HR per 1 mmol/l for colon cancer. The associations with rectal cancer remained unchanged. CONCLUSION: Our results support a positive association between alcohol consumption and colon and rectal cancer, most pronounced for rectal cancer. Considering the positive relation between alcohol consumption and HDL-C, the inverse association between HDL-C and colon cancer in men remains unsettled.

Quantifying the contribution of established risk factors to cardiovascular mortality differences between Russia and Norway.

Surprisingly few attempts have been made to quantify the simultaneous contribution of well-established risk factors to CVD mortality differences between countries. We aimed to develop and critically appraise an approach to doing so, applying it to the substantial CVD mortality gap between Russia and Norway using survey data in three cities and mortality risks from the Emerging Risk Factor Collaboration. We estimated the absolute and relative differences in CVD mortality at ages 40-69 years between countries attributable to the risk factors, under the counterfactual that the age- and sex-specific risk factor profile in Russia was as in Norway, and vice-versa. Under the counterfactual that Russia had the Norwegian risk factor profile, the absolute age-standardized CVD mortality gap would decline by 33.3% (95% CI 25.1-40.1) among men and 22.1% (10.4-31.3) among women. In relative terms, the mortality rate ratio (Russia/Norway) would decline from 9-10 to 7-8. Under the counterfactual that Norway had the Russian risk factor profile, the mortality gap reduced less. Well-established CVD risk factors account for a third of the male and around a quarter of the female CVD mortality gap between Russia and Norway. However, these estimates are based on widely held epidemiological assumptions that deserve further scrutiny.

Coffee consumption and mortality from cardiovascular diseases and total mortality: Does the brewing method matter?

AIM: The aim of this study was to investigate whether the coffee brewing method is associated with any death and cardiovascular mortality, beyond the contribution from major cardiovascular risk factors. METHODS AND RESULTS: Altogether, 508,747 men and women aged 20-79 participating in Norwegian cardiovascular surveys were followed for an average of 20 years with respect to cause-specific death. The number of deaths was 46,341 for any cause, 12,621 for cardiovascular disease (CVD), 6202 for ischemic heart disease (IHD), and 2894 for stroke. The multivariate adjusted hazard ratios (HRs) for any death for men with no coffee consumption as reference were 0.85 (082-0.90) for filtered brew, 0.84 (0.79-0.89) for both brews, and 0.96 (0.91-1.01) for unfiltered brew. For women, the corresponding figures were 0.85 (0.81-0.90), 0.79 (0.73-0.85), and 0.91 (0.86-0.96) for filtered, both brews, and unfiltered brew, respectively. For CVD, the figures were 0.88 (0.81-0.96), 0.93 (0.83-1.04), and 0.97 (0.89-1.07) in men, and 0.80 (0.71-0.89), 0.72 (0.61-0.85), and 0.83 (0.74-0.93) in women. Stratification by age raised the HRs for ages ≥60 years. The HR for CVD between unfiltered brew and no coffee was 1.19 (1.00-1.41) for men and 0.98 (0.82-1.15) for women in this age group. The HRs for CVD and IHD were raised when omitting total cholesterol from the model, and most pronounced in those drinking ≥9 of unfiltered coffee, per day where they were raised by 9% for IHD mortality. CONCLUSION: Unfiltered brew was associated with higher mortality than filtered brew, and filtered brew was associated with lower mortality than no coffee consumption.

The association between parity, CVD mortality and CVD risk factors among Norwegian women and men.

BACKGROUND: Several studies have shown that women and men with two children have lower mortality than the childless, but there is less certainty about mortality, including CVD mortality, at higher parities and meagre knowledge about factors underlying the parity-mortality relationship. METHODS: The association between parity and CVD mortality was analyzed by estimating discrete-time hazard models for women and men aged 40-80 in 1975-2015. Register data covering the entire Norwegian population were used, and the models included a larger number of relevant sociodemographic control variables than in many previous studies. To analyze the relationship between parity and seven CVD risk factors, logistic models including the same variables as the mortality models were estimated from the CONOR collection of health surveys, linked to the register data. RESULTS: Men (but not women) who had four or more children had higher mortality from CVD than those with two, although this excess mortality was not observed for the heart disease sub-group. Overweight, possibly in part a result of less physical activity, seems to play a role in this. All CVD risk factors except smoking and alcohol may contribute to the relatively high CVD mortality among childless. CONCLUSIONS: Childbearing is related to a number of well-known CVD risk factors, and becoming a parent or having an additional child is, on the whole, associated with lower-or at least not higher-CVD mortality in Norway. However, for men family sizes beyond three children are associated with increased CVD mortality, with risks of overweight one possible pathway.

Blood pressure changes during 22-year of follow-up in large general population - the HUNT Study, Norway.

BACKGROUND: While hypertension still is a major health problem worldwide, some studies have indicated that the blood pressure level has decreased in some populations. This population based cohort study aims at analysing blood pressure changes in a large Norwegian population over a 22 year period. METHODS: Data is acquired from three comprehensive health surveys of the HUNT Study conducted from 1984-86 to 2006-08. All citizens of Nord-Trøndelag County, Norway, >20 years were invited: 74,549 individuals participated in 1984-86; 64,523 in 1995-97; and 43,905 in 2006-08. RESULTS: Both systolic and diastolic blood pressure levels decreased substantially from mid 1980s to mid 2000s, with the most pronounced decrease from 1995-97 to 2006-08 (from 136.0/78.9 to 128.3/70.9 mmHg in women and from 140.1/82.1 to 133.7/76.5 mmHg in men). Although the use of blood pressure lowering medication increased, there was a considerable decrease even in those who reported never use of medication (mean decrease 6.8/7.2 mmHg in women and 6.3/5.3 mmHg in men), and the decrease was most pronounced in the elderly (mean decrease 16.1/12.4 mmHg in women and 14.7/10.4 mmHg in men aged 80+). Mean heart rate, total cholesterol and daily smoking decreased, self-reported hard physical activity increased, while body weight and the prevalence of diabetes increased during the same period. CONCLUSIONS: The BP decrease might seem paradoxically, as body weight and prevalence of diabetes increased during the same period. Salt consumption might have decreased, but no salt data is available. The parallel decrease in mean heart rate might indicate reduction in the white-coat phenomenon, or increased use of beta blockers or calcium channel blockers for other diagnosis than hypertension. Additionally, the data could support the "healthy obese" hypothesis, i.e., that subgroups in the population can sustain obesity without serious health consequences.

Cardiovascular risk estimation in older persons: SCORE O.P.

AIMS: Estimation of cardiovascular disease risk, using SCORE (Systematic COronary Risk Evaluation) is recommended by European guidelines on cardiovascular disease prevention. Risk estimation is inaccurate in older people. We hypothesized that this may be due to the assumption, inherent in current risk estimation systems, that risk factors function similarly in all age groups. We aimed to derive and validate a risk estimation function, SCORE O.P., solely from data from individuals aged 65 years and older. METHODS AND RESULTS: 20,704 men and 20,121 women, aged 65 and over and without pre-existing coronary disease, from four representative, prospective studies of the general population were included. These were Italian, Belgian and Danish studies (from original SCORE dataset) and the CONOR (Cohort of Norway) study. The variables which remained statistically significant in Cox proportional hazards model and were included in the SCORE O.P. model were: age, total cholesterol, high-density lipoprotein cholesterol, systolic blood pressure, smoking status and diabetes. SCORE O.P. showed good discrimination; area under receiver operator characteristic curve (AUROC) 0.74 (95% confidence interval: 0.73 to 0.75). Calibration was also reasonable, Hosmer-Lemeshow goodness of fit test: 17.16 (men), 22.70 (women). Compared with the original SCORE function extrapolated to the ≥65 years age group discrimination improved, p = 0.05 (men), p < 0.001 (women). Simple risk charts were constructed. On simulated external validation, performed using 10-fold cross validation, AUROC was 0.74 and predicted/observed ratio was 1.02. CONCLUSION: SCORE O.P. provides improved accuracy in risk estimation in older people and may reduce excessive use of medication in this vulnerable population.

Changes in synovial fluid biomarker concentrations following arthroscopic surgery in horses with osteochondritis dissecans of the distal intermediate ridge of the tibia.

OBJECTIVE: To quantify concentrations of cartilage oligomeric matrix protein (COMP) and fibromodulin in synovial fluid from the tarsocrural joints (TCJs) of horses with osteochondritis dissecans (OCD) of the distal intermediate ridge of the tibia and determine whether concentrations would change following arthroscopic removal of osteochondral fragments. ANIMALS: 115 client-owned horses with OCD of the TCJ and 29 control horses euthanized for unrelated reasons. PROCEDURES: COMP and fibromodulin concentrations were measured in synovial fluid from the TCJs of the affected horses before and after osteochondral fragments were removed arthroscopically and in synovial fluid from the TCJs of the control horses after euthanasia. Synovial biopsy specimens from the TCJs of affected and control horses were examined histologically for evidence of inflammation. RESULTS: Synovial fluid COMP and fibromodulin concentrations prior to surgery in horses with OCD were not significantly different from concentrations in control horses. Fibromodulin, but not COMP, concentration in horses with OCD was significantly decreased after surgery, compared with the concentration before surgery. Fibromodulin concentration was significantly correlated with joint effusion score but not with lameness score or results of a flexion test and was correlated with histologic score for number of synoviocytes on the surface of the synovium but not with score for degree of infiltration of inflammatory cells in the synovium. Synovial fluid COMP concentration was not significantly correlated with clinical or histologic findings. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that fibromodulin, but not COMP, could potentially be a biomarker of joint inflammation in horses with OCD of the TCJ.

Smoking increases rectal cancer risk to the same extent in women as in men: results from a Norwegian cohort study.

BACKGROUND: Smoking has recently been established as a risk factor for rectal cancer. We examined whether the smoking-related increase in rectal cancer differed by gender. METHODS: We followed 602,242 participants (49% men), aged 19 to 67 years at enrollment from four Norwegian health surveys carried out between 1972 and 2003, by linkage to Norwegian national registries through December 2007. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by fitting Cox proportional hazard models and adjusting for relevant confounders. Heterogeneity by gender in the effect of smoking and risk of rectal cancer was tested with Wald χ2. RESULTS: During a mean follow-up of 14 years, 1,336 men and 840 women developed invasive rectal cancer. Ever smokers had a significantly increased risk of rectal cancer of more than 25% for both men (HR = 1.27, 95% CI = 1.11-1.45) and women (HR = 1.28, 95% CI = 1.11-1.48) compared with gender-specific never smokers. Men smoking ≥20 pack-years had a significantly increased risk of rectal cancer of 35% (HR = 1.35, 95% CI = 1.14-1.58), whereas for women, it was 47% (HR = 1.47, 95% CI = 1.13-1.91) compared with gender-specific never smokers. For both men and women, we observed significant dose-response associations between the risk of rectal cancer for four variables [Age at smoking initiation in years (both ptrend <0.05), number of cigarettes smoked per day (both ptrend <0.0001), smoking duration in years (ptrend <0.05, <0.0001) and number of pack-years smoked (both ptrend <0.0001)]. The test for heterogeneity by gender was not significant between smoking status and the risk of rectal cancer (Wald χ2, p -value; current smokers = 0.85; former smokers = 0.87; ever smokers = 1.00). CONCLUSIONS: Smoking increases the risk of rectal cancer to the same extent in women as in men.

Cigarette smoking and colorectal cancer mortality among 602,242 Norwegian males and females.

BACKGROUND: Colorectal cancer (CRC) is one of the main cancer types, with high incidence and mortality in Norway. We examined the association between different measures of smoking exposure and CRC mortality overall and by subsite in a large Norwegian cohort. METHODS: We followed 602,242 participants from four Norwegian health surveys, aged 19-67 years at enrollment between 1972 and 2003 by linkage to the national registries through December 2007. We used Cox proportional hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) by smoking categories for different CRC endpoints. RESULTS: During a mean follow-up of 14 years, 2,333 Norwegian males and females died of CRC (60% men). Male and female ever smokers had a 20% (HR 1.23, CI 1.08-1.40 and HR 1.22, 95% CI 1.06-1.40, respectively) increased risk of death from CRC compared with sex-specific never smokers. For proximal colon cancer mortality, female ever smokers had a 50% (HR 1.49, 95% CI 1.20-1.87) increased risk compared with female never smokers. The increased risk of rectal cancer mortality was about 40% higher for male ever smokers (HR 1.43, 95% CI 1.14-1.81) compared with male never smokers. A test for heterogeneity by sex showed an increased risk of rectal cancer mortality among men which was significant for former smokers (Wald χ(2) =0.02) and an increased risk of proximal colon cancer mortality among women which was significant for ever and former smokers (Wald χ(2) =0.02 and χ(2) =0.04, respectively). CONCLUSION: Smoking is associated with increased CRC mortality in both sexes. The risk of rectal and proximal colon cancer mortality was most pronounced among male and female smokers respectively.

Drug exposure: inclusion of dispensed drugs before pregnancy may lead to underestimation of risk associations.

OBJECTIVES: To assess the impact of exposure misclassification on risk associations when using prescription databases as the source for drug exposure in pregnancy by applying results from a validation analysis of exposure classification. STUDY DESIGN AND SETTING: Linkage of data on 27,656 participants in the Norwegian Mother and Child Cohort Study (MoBa) with the Norwegian Prescription Database (NorPD). Exposure to selective serotonin reuptake inhibitors (SSRIs) was defined by dispensed drugs during pregnancy including different time windows before pregnancy. The validity of NorPD data was estimated using self-reported use in MoBa as the reference standard. We applied the results from the validation analysis on data from a Nordic study on SSRI use in pregnancy and risk of persistent pulmonary hypertension in the newborn. RESULTS: Sensitivity increased and specificity decreased when the time window in NorPD was expanded before pregnancy. Using the same time window as in the Nordic study (+90 days before pregnancy), for use in early pregnancy, the odds ratio (OR) corrected for misclassification was 2.6 compared with the OR of 1.6 in the Nordic study. CONCLUSION: Expansion of the time window to include intervals before pregnancy can lead to lower specificity and underestimation of risk associations.

The increased risk of colon cancer due to cigarette smoking may be greater in women than men.

BACKGROUND: Smoking is a recently established risk factor for colon cancer. We wanted to explore the hypothesis that women may be more susceptible to smoking-attributed colon cancer than men as one of the possible explanations for the high colon cancer risk of Norwegian women. METHODS: We followed 602,242 participants aged 19 to 67 years at enrollment in 1972-2003, by linkage to national registries through December 2007. We used Cox proportional hazard models to estimate HRs and 95% confidence intervals (CI). RESULTS: During a mean follow-up of 14 years, altogether 3,998 (46% women) subjects developed colon cancer. Female ever-smokers had a 19% (HR = 1.19, 95% CI = 1.09-1.32) and male ever-smokers an 8% (HR = 1.08, CI = 0.97-1.19) increased risk of colon cancer compared with never smokers. For all the four dose-response variables examined, female ever-smokers in the most exposed category of smoking initiation, (HR = 1.48, 95% CI = 1.21-1.81), of daily cigarette consumption (HR = 1.28, 95% CI = 1.06-1.55), of smoking duration (HR = 1.47, 95% CI = 1.11-1.95), and of pack-years of smoking (HR = 1.33, 95% CI = 1.11-1.57) had a significantly increased risk of more than 20% for colon cancer overall and of more than 40% for proximal colon cancer, compared with never smokers. A test for heterogeneity by gender was statistically significant only for ever smoking and risk of proximal colon cancer (Wald χ(2), P = 0.02). CONCLUSIONS: Female smokers may be more susceptible to colon cancer and especially to proximal colon cancer than male smokers. IMPACT: Women who smoke are more vulnerable to colon cancer than men.

Systematic screening with information and home sampling for genital Chlamydia trachomatis infections in young men and women in Norway: a randomized controlled trial.

BACKGROUND: As most genital Chlamydia trachomatis infections are asymptomatic, many patients do not seek health care for testing. Infections remain undiagnosed and untreated. We studied whether screening with information and home sampling resulted in more young people getting tested, diagnosed and treated for chlamydia in the three months following the intervention compared to the current strategy of testing in the health care system. METHOD: We conducted a population based randomized controlled trial among all persons aged 18-25 years in one Norwegian county (41 519 persons). 10 000 persons (intervention) received an invitation by mail with chlamydia information and a mail-back urine sampling kit. 31 519 persons received no intervention and continued with usual care (control). All samples from both groups were analysed in the same laboratory. Information on treatment was obtained from the Norwegian Prescription Database (NorPD). We estimated risk ratios and risk differences of being tested, diagnosed and treated in the intervention group compared to the control group. RESULTS: In the intervention group 16.5% got tested and in the control group 3.4%, risk ratio 4.9 (95% CI 4.5-5.2). The intervention led to 2.6 (95% CI 2.0-3.4) times as many individuals being diagnosed and 2.5 (95% CI 1.9-3.4) times as many individuals receiving treatment for chlamydia compared to no intervention in the three months following the intervention. CONCLUSION: In Norway, systematic screening with information and home sampling results in more young people being tested, diagnosed and treated for chlamydia in the three months following the intervention than the current strategy of testing in the health care system. However, the study has not established that the intervention will reduce the chlamydia prevalence or the risk of complications from chlamydia.

Body mass index, smoking, and risk of death between 40 and 70 years of age in a Norwegian cohort of 32,727 women and 33,475 men.

Overweight-obesity and smoking are two main preventable causes of premature death. Because the relationship between smoking and body mass index (BMI) complicates the interpretation of associations between BMI and death risks, direct estimates of risks associated with joint exposures are helpful. We have studied the relationships of BMI and smoking to middle age (40-69 years) death risk-overall and by causes-in a Norwegian cohort of 32,727 women and 33,475 men who were 35-49 years old when baseline measurements and lifestyle information were collected in 1974-1988. Individuals with a history of cancer, cardiovascular disease or diabetes at baseline were excluded. Mortality follow-up was through 2009. The relationship between BMI and middle age death risk was U-shaped. Overall middle age death risks were 11% in women and 21 % in men. The combination of obesity and heavy smoking resulted in fivefold increase in middle age death risks in both women and men: For women middle age death risk ranged from 6 % among never smokers in the 22.5-24.9 BMI group to 31% (adjusted 28%) in obese (BMI > 30 kg/m(2)) heavy smokers (≥20 cigarettes/day). The corresponding figures in men were 10% and 53% (adjusted 45%). Obese never smokers and light (1-9 cigarettes/day) smokers in the 22.5-24.9 BMI groups both experienced a twofold increase in middle age risks of death. For women, cancer (56%) was the most common cause of death followed by cardiovascular disease (22%). In men, cardiovascular disease was most common (41%) followed by cancer (34%). Cardiovascular disease deaths were more strongly related to BMI than were cancer deaths.

Cardiovascular mortality in relation to birth weight of children and grandchildren in 500,000 Norwegian families.

AIMS: Cardiovascular diseases (CVDs) have been related to low birth weight, suggesting the foetal environment may program future risk. Alternatively, common genetic factors for both low birth weight and CVD could explain such associations. We investigated associations between offspring birth weight and paternal and maternal cardiovascular mortality and offspring birth weight and cardiovascular mortality among all four grandparents, and further assessed the mediating role of maternal smoking during pregnancy. METHODS AND RESULTS: All births from 1967 to 2008 that could be linked to parents and grandparents comprised the population (n = 1,004,255). The mortality follow-up among parents was from 1970 to 2008 and among grandparents from 1960 to 2008. The association of grandparental mortality with maternal smoking during pregnancy was analysed in a subpopulation of those born after 1997 (n = 345,624). Per quintile higher in birth weight was related to 0.82 (0.75-0.89) hazard ratio from coronary heart disease in mothers and 0.94 (0.92-0.97) in fathers. For stroke, these were 0.85 (0.78-0.92) and 0.94 (0.89-1.00), respectively. In grandparents for cardiovascular causes, the effects were 0.95 (0.93-0.96) (maternal grandmother), 0.97 (0.96-0.98) (maternal grandfather), 0.96 (0.94-0.98) (paternal grandmother), and 0.98 (0.98-1.00) (paternal grandfather). Adjusting for maternal smoking in pregnancy in the subpopulation accounted for much of the effect on grandparental cardiovascular mortality in all categories of birth weight. For grandparental diabetes mortality, U-shaped associations were seen with grandchild birth weight for the maternal grandmother and inverse associations for all other grandparents. CONCLUSION: Associations between CVD mortality in all four grandparents and grandchild birth weight exist, and while genetic and environmental factors may contribute to these, it appears that there is an important role for maternal smoking during pregnancy (and associated paternal smoking) in generating these associations. For diabetes, however, it appears that intrauterine environmental influences and genetic factors contribute to the transgenerational associations.

A prospective study of intake of trans-fatty acids from ruminant fat, partially hydrogenated vegetable oils, and marine oils and mortality from CVD.

Trans-fatty acids (TFA) have adverse effects on blood lipids, but whether TFA from different sources are associated with risk of CVD remains unresolved. The objective of the present study was to evaluate the association between TFA intake from partially hydrogenated vegetable oils (PHVO), partially hydrogenated fish oils (PHFO) and ruminant fat (rTFA) and risks of death of CVD, CHD, cerebrovascular diseases and sudden death in the Norwegian Counties Study, a population-based cohort study. Between 1974 and 1988, participants were examined for up to three times. Fat intake was assessed with a semi-quantitative FFQ. A total of 71,464 men and women were followed up through 2007. Hazard ratios (HR) and 95 % CI were estimated with Cox regression. Energy from TFA was compared to energy from all other sources, carbohydrates or unsaturated cis-fatty acids with different multivariable models. During follow-up, 3870 subjects died of CVD, 2383 of CHD, 732 of cerebrovascular diseases and 243 of sudden death. Significant risks, comparing highest to lowest intake category, were found for: TFA from PHVO and CHD (HR 1.23 (95 % CI 1.00, 1.50)) and cerebrovascular diseases (HR 0.65 (95 % CI 0.45, 0.94)); TFA from PHFO and CVD (HR 1.14 (95 % CI 1.03, 1.26)) and cerebrovascular diseases (HR 1.32 (95 % CI 1.04, 1.69)); and rTFA intake and CVD (HR 1.30 (95 % CI 1.05, 1.61)), CHD (HR 1.50 (95 % CI 1.11, 2.03)) and sudden death (HR 2.73 (95 % CI 1.19, 6.25)) in women. These associations with rTFA intake were not significant in men (P interaction ≥ 0.01). The present study supports that TFA intake, irrespective of source, increases CVD risk. Whether TFA from PHVO decreases risk of cerebrovascular diseases warrants further investigation.

Cigarette smoking and risk of subsequent use of antibacterials: a follow-up of 365,117 men and women.

OBJECTIVES: Antibacterial prescribing is driving antibiotic resistance. We aimed to analyse whether smoking habits are associated with susceptibility to be prescribed antibacterials in primary care and to examine whether patients' smoking habits influence physicians' choice of therapy. METHODS: Information on smoking habits from health surveys in 1985-99 was related to use of antibacterials 5-25 years later by linkage to the Norwegian Prescription Database. The study population included 365 117 men and women, 40-45 years old. Individuals likely to have chronic obstructive airway disease were excluded. Relative risk (RR) of being dispensed antibacterials for systemic use was calculated for five levels of smoking intensity with never smokers as reference. Adjustments were made for age, education, marital status, household size, body mass index and residence (rural/urban). RESULTS: Fifty-six percent of the male and 69% of the female never smokers received at least one antibacterial prescription in the whole period, increasing to 68% and 82%, respectively, in heavy smokers (>19 cigarettes/day) (adjusted RR 1.17 and 1.16). The percentage receiving at least one antibacterial prescription every year was 0.5% in male and 1.9% in female never smokers, increasing to 1.1% and 4.0%, respectively, in heavy smokers (adjusted RR 2.07 and 1.89). The proportion of antibacterial users who were prescribed broad-spectrum antibacterials increased with increasing cigarette consumption. CONCLUSIONS: Smoking habits influenced the usage of antibacterials years later with a dose-response relationship. Prescribers seem to acknowledge smoking as a risk factor for resistant bacteria since broad-spectrum antibacterials are more frequently prescribed to smokers than never smokers.