BACKGROUND: Research on health equity which mainly utilises population-based surveys, may be hampered by serious selection bias due to a considerable number of invitees declining to participate. ...Sufficient information from all the non-responders is rarely available to quantify this bias. Predictors of attendance, magnitude and direction of non-response bias in prevalence estimates and association measures, are investigated based on information from all 40 888 invitees to the Oslo Health Study. METHODS: The analyses were based on linkage between public registers in Statistics Norway and the Oslo Health Study, a population-based survey conducted in 2000/2001 inviting all citizens aged 30, 40, 45, 59-60 and 75-76 years. Attendance was 46%. Weighted analyses, logistic regression and sensitivity analyses are performed to evaluate possible selection bias. RESULTS: The response rate was positively associated with age, educational attendance, total income, female gender, married, born in a Western county, living in the outer city residential regions and not receiving disability benefit. However, self-rated health, smoking, BMI and mental health (HCSL) in the attendees differed only slightly from estimated prevalence values in the target population when weighted by the inverse of the probability of attendance.Observed values differed only moderately provided that the non-attending individuals differed from those attending by no more than 50%. Even though persons receiving disability benefit had lower attendance, the associations between disability and education, residential region and marital status were found to be unbiased. The association between country of birth and disability benefit was somewhat more evident among attendees. CONCLUSIONS: Self-selection according to sociodemographic variables had little impact on prevalence estimates. As indicated by disability benefit, unhealthy persons attended to a lesser degree than healthy individuals, but social inequality in health by different sociodemographic variables seemed unbiased. If anything we would expect an overestimation of the odds ratio of chronic disease among persons born in non-western countries.
Intake of trans fatty acids (TFA) may influence systemic inflammation, insulin resistance and adiposity, but whether TFA intake influences cancer risk is insufficiently studied. We examined the ...association between TFA intake from partially hydrogenated vegetable oils (PHVO‐TFA), partially hydrogenated fish oils (PHFO‐TFA), and ruminant fat (rTFA) and cancer risk in the Norwegian counties study, a large cohort study with a participation rate >80%. TFA intake was assessed three times in 1974–1988 by questionnaire. A total of 77,568 men and women were followed up through 2007, during which time 12,004 cancer cases occurred. Hazard ratios (HRs) and confidence intervals (CIs) were estimated with Cox regression for cancer sites with ≥150 cases during follow‐up. Significantly increased or decreased risks were found when comparing the highest and lowest intake categories (HRs, 95% CIs) for PHVO‐TFA and pancreatic cancer in men (0.52, 0.31–0.87) and non‐Hodgkin lymphoma (NHL) in both genders (0.70, 0.50–0.98); PHFO‐TFA and rectal cancer (1.43, 1.09–1.88), prostate cancer (0.82, 0.69–0.96), and multiple myeloma (2.02, 1.24–3.28); and rTFA and all cancers (1.09, 1.02–1.16), cancer of the mouth/pharynx (1.59, 1.08–2.35), NHL (1.47, 1.06–2.04) and multiple myeloma (0.45, 0.24–0.84). Furthermore, positive trends were found for PHFO‐TFA and stomach cancer (ptrend = 0.01) and rTFA and postmenopausal breast cancer (ptrend = 0.03). Inverse trends were found for PHVO‐TFA and all cancers (ptrend = 0.006) and cancer of the central nervous system in women (ptrend = 0.005). PHFO‐TFA, but not PHVO‐TFA, seemed to increase cancer risk. The increased risks observed for rTFA may be linked to saturated fat.
What's new?
The unfavorable effects of trans fatty acids (TFAs) on cardiovascular disease risk factors have been studied extensively, but whether these substances also influence risk factors related to other diseases, particularly cancer, is poorly understood. Here, intake of TFA from partially hydrogenated fish oils, but not from partially hydrogenated vegetable oils, was associated with increased cancer risk. While the carcinogenic mechanism is unclear, the results support the idea that different sources of TFA have distinct affects on cancer risk.
Studies suggest that high occupational physical activity increases mortality risk. However, it is unclear whether this association is causal or can be explained by a complex network of socioeconomic ...and behavioural factors. We aimed to examine the association between occupational physical activity and longevity, taking a complex network of confounding variables into account.
In this prospective cohort study, we linked data from Norwegian population-based health examination surveys, covering all parts of Norway with data from the National Population and Housing Censuses and the Norwegian Cause of Death Registry. 437 378 participants (aged 18–65 years; 48·7% men) self-reported occupational physical activity (mutually exclusive groups: sedentary, walking, walking and lifting, and heavy labour) and were followed up from study entry (between February, 1974, and November, 2002) to death or end of follow-up on Dec 31, 2018, whichever came first. We estimated differences in survival time (death from all causes, cardiovascular disease, and cancer) between occupational physical activity categories using flexible parametric survival models adjusted for confounding factors.
During a median of 28 years (IQR 25–31) from study entry to the end of follow-up, 74 203 (17·0%) of the participants died (all-cause mortality), of which 20 111 (27·1%) of the deaths were due to cardiovascular disease and 29 886 (40·3%) were due to cancer. Crude modelling indicated shorter mean survival times among men in physically active occupations than in those with sedentary occupations. However, this finding was reversed following adjustment for confounding factors (birth cohort, education, income, ethnicity, prevalent cardiovascular disease, smoking, leisure-time physical activity, body-mass index), with estimates suggesting that men in occupations characterised by walking, walking and lifting, and heavy labour had life expectancies equivalent to 0·4 (95% CI −0·1 to 1·0), 0·8 (0·3 to 1·3), and 1·7 (1·2 to 2·3) years longer, respectively, than men in the sedentary referent category. Results for mortality from cardiovascular disease and cancer showed a similar pattern. No clear differences in survival times were observed between occupational physical activity groups in women.
Our results suggest that moderate to high occupational physical activity contributes to longevity in men. However, occupational physical activity does not seem to affect longevity in women. These results might inform future physical activity guidelines for public health.
The Norwegian Research Council (grant number 249932/F20).
Abstract Objective Validation studies of self-reported medication use in adolescents have been scarce. The objective of this study was to estimate the sensitivity and specificity of self-reported use ...of medication using a prescription database as reference standard. Study Design and Setting The study population consisted of a cohort of 2,613 adolescents aged 15–16 years from the Norwegian youth health survey in 2004 and 2005. Self-reported data on medication use were compared with data from the Norwegian Prescription Database which contains information from all prescription dispensed at Norwegian pharmacies. Results Sensitivity for self-reported questions on medication use was highest for contraceptive pills 99.2% (95% CI 97.7–100) compared to antiasthmatics 79.1% (66.9–91.2), painkillers 48.5% (36.7–60.4), and psychotropic drugs 75.0% (35.6–95.6). Specificity values of self-reported information of psychotropic drugs 89.6% (87.8–91.5) and antiasthmatics 87.4% (85.4–89.5) were higher than for painkillers 80.0% (77.5–82.4) and contraceptive pills 76.2% (72.3–80.1). Conclusion Validity of self-reported previous medication use among adolescents differed by the therapeutic classes of medication. The highest sensitivity was observed for contraceptive pills and lowest for prescribed painkillers.
Purpose The aim of this study was to evaluate prospectively smoking dependence as a predictor of repeated use of prescribed opioids in non-cancer patients. Methods We conducted a prospective ...population-based study cohort of 12,848 men and 15,894 women 30–75 years of age in health surveys in Norway during 2000–2002 with repeated opioid prescriptions (12+, during 2004–2007) recorded in the Norwegian Prescription Database as the outcome measure. Information on history of smoking and potential confounders was obtained at baseline by self-administered questionnaires. For smoking, participants were divided into categories: never; previously heavy (stopped maximum of 5 years earlier; 10+ cigarettes daily); daily not heavy (1–9 cigarettes); dependent daily smokers (10+ cigarettes), and other (previously and/or not daily). Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated by logistic regression. Results During follow-up, 335 (1.5%) of survey participants were registered with 12+ prescriptions of opioids during the period 2004–2007. The prevalence of repeated prescription frequency of opioids was higher for men and women with a history of smoking. The adjusted OR for prescribed opioids for dependent daily smokers was 3.1 (95% CI: 2.3–4.1), for daily non-heavy smokers 1.8 (1.2–2.7), and for previous heavy smokers 1.8 (1.1–3.0), compared with never-smokers as reference. Conclusions Results of the study suggest that smoking dependence may predict more frequent use of opioids.
There is a lack of comprehensive patient-datasets regarding prevalence of severe hypertriglyceridemia (sHTG; triglycerides ≥10 mmol/L), frequency of co-morbidities, gene mutations, and gene ...characterization in sHTG. Using large surveys combined with detailed analysis of sub-cohorts of sHTG patients, we here sought to address these issues.
We used data from several large Norwegian surveys that included 681,990 subjects, to estimate the prevalence. Sixty-five sHTG patients were investigated to obtain clinical profiles and candidate disease genes. We obtained peripheral blood mononuclear cells (PBMC) from six male patients and nine healthy controls and examined expression of mRNAs involved in lipid metabolism.
The prevalence of sHTG was 0.13 (95% CI 0.12-0.14)%, and highest in men aged 40-49 years and in women 60-69 years. Among the 65 sHTG patients, a possible genetic cause was found in four and 11 had experienced acute pancreatitis. The mRNA expression levels of carnitine palmitoyltransferase (CPT)-1A, CPT2, and hormone-sensitive lipase, were significantly higher in patients compared to controls, whereas those of ATP-binding cassette, sub-family G, member 1 were significantly lower.
In Norway, sHTG is present in 0.1%, carries considerable co-morbidity and is associated with an imbalance of genes involved in lipid metabolism, all potentially contributing to increased cardiovascular morbidity in sHTG.
Abstract Background Little is known about the association between metabolic risk factors and cervical cancer carcinogenesis. Material and methods During mean follow-up of 11 years of the Me–Can ...cohort (N = 288,834) 425 invasive cervical cancer cases were diagnosed. Hazard ratios (HRs) were estimated by the use of Cox proportional hazards regression models for quintiles and standardized z-scores (with a mean of 0 and a SD of 1) of BMI, blood pressure, glucose, cholesterol, triglycerides and MetS score. Risk estimates were corrected for random error in the measurements. Results BMI (per 1SD increment) was associated with 12%, increase of cervical cancer risk, blood pressure with 25% and triglycerides with 39%, respectively. In models including all metabolic factors, the associations for blood pressure and triglycerides persisted. The metabolic syndrome (MetS) score was associated with 26% increased corrected risk of cervical cancer. Triglycerides were stronger associated with squamous cell carcinoma (HR 1.48; 95% CI, 1.20–1.83) than with adenocarcinoma (0.92, 0.54–1.56). Among older women cholesterol (50–70 years 1.34; 1.00–1.81), triglycerides (50–70 years 1.49, 1.03–2.16 and ≥ 70 years 1.54, 1.09–2.19) and glucose (≥ 70 years 1.87, 1.13–3.11) were associated with increased cervical cancer risk. Conclusion The presence of obesity, elevated blood pressure and triglycerides were associated with increased risk of cervical cancer.
ObjectivesTo evaluate a Framingham 5-year cardiovascular disease (CVD) risk score in Indians and Europeans in New Zealand, and determine whether body mass index (BMI) and socioeconomic deprivation ...were independent predictors of CVD risk.MethodsWe included Indians and Europeans, aged 30–74 years without prior CVD undergoing risk assessment in New Zealand primary care during 2002–2015 (n=256 446). Risk profiles included standard Framingham predictors (age, sex, systolic blood pressure, total cholesterol/high-density lipoprotein ratio, smoking and diabetes) and were linked with national CVD hospitalisations and mortality datasets. Discrimination was measured by the area under the receiver operating characteristics curve (AUC) and calibration examined graphically. We used Cox regression to study the impact of BMI and deprivation on the risk of CVD with and without adjustment for the Framingham score.ResultsDuring follow-up, 8105 and 1156 CVD events occurred in Europeans and Indians, respectively. Higher AUCs of 0.76 were found in Indian men (95% CI 0.74 to 0.78) and women (95% CI 0.73 to 0.78) compared with 0.74 (95% CI 0.73 to 0.74) in European men and 0.72 (95% CI 0.71 to 0.73) in European women. Framingham was best calibrated in Indian men, and overestimated risk in Indian women and in Europeans. BMI and deprivation were positively associated with CVD, also after adjustment for the Framingham risk score, although the BMI association was attenuated.ConclusionsThe Framingham risk model performed reasonably well in Indian men, but overestimated risk in Indian women and in Europeans. BMI and socioeconomic deprivation could be useful predictors in addition to a Framingham score.
Purpose: Little is known about the association between the metabolic syndrome (MetS) and the risk of gastric adenocarcinoma. The aim of this study was to investigate whether metabolic risk factors, ...together or combined, were associated with the risk of gastric adenocarcinoma. Methods: The Metabolic Syndrome and Cancer Project (Me-Can) is a pooling of prospective cohorts in Austria, Norway, and Sweden with information on blood pressure, lipids, glucose, and BMI available in 578,700 individuals. Cox proportional hazards analysis was used to calculate hazard ratio (HR) of gastric adenocarcinoma using metabolic risk factors categorized into quintiles and transformed into z-scores (with mean = 0 and SD = 1). The standardized sum of all z-scores created a composite MetS score. Results: In total, 1,210 incident cases of gastric adenocarcinoma were identified. Glucose was significantly associated with the risk of gastric adenocarcinoma calibrated HR 1.58 (1.14–2.20) per one unit increment in z-score in women. There was a statistically significant association between triglycerides and risk of gastric adenocarcinoma per mmol increment in triglycerides HR 1.20 (1.06–1.36) per mmol but not for the adjusted z-score in women. There were no significant association between any metabolic factors and gastric cancer among men. The composite MetS score was associated with the risk of gastric adenocarcinoma in women HR 1.18 (1.00–1.38) per one unit increment in z-score but not in men. Conclusions: Glucose and high levels of the composite MetS score were associated with an increased risk of gastric adenocarcinoma in women but not in men.
PDF
