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Background: Stroke lesions might alter pain processing and modulation by affecting the widely distributed network of brain regions involved. We aimed to compare pain tolerance in stroke survivors and stroke‐free persons in the general population, with and without chronic pain. Methods: We included all participants of the sixth and seventh wave of the population‐based Tromsø Study who had been tested with the cold pressor test (hand in cold water bath, 3°C, maximum time 106 s in the sixth wave and 120 s in the seventh) and who had information on previous stroke status and covariates. Data on stroke status were obtained from the Tromsø Study Cardiovascular Disease Register and the Norwegian Stroke Register. Cox regression models were fitted using stroke prior to study attendance as the independent variable, cold pressor endurance time as time variable and hand withdrawal from cold water as event. Statistical adjustments were made for age, sex, diabetes, hypertension, hyperlipidaemia, body mass index and smoking. Results: In total 21,837 participants were included, 311 of them with previous stroke. Stroke was associated with decreased cold pain tolerance time, with 28% increased hazard of hand withdrawal (hazard ratio [HR] 1.28, 95% CI 1.10–1.50). The effect was similar in participants with (HR 1.28, 95% CI 0.99–1.66) and without chronic pain (HR 1.29, 95% CI 1.04–1.59). Conclusions: Stroke survivors, with and without chronic pain, had lower cold pressor pain tolerance, with possible clinical implications for pain in this group. Significance: We found lower pain tolerance in participants with previous stroke compared to stroke‐free participants of a large, population‐based study. The association was present both in those with and without chronic pain. The results may warrant increased awareness by health professionals towards pain experienced by stroke patients in response to injuries, diseases and procedures. [ABSTRACT FROM AUTHOR]

Aims: Although absolute (AID) and functional iron deficiency (FID) are known risk factors for patients with cardiovascular (CV) disease, their relevance for the general population is unknown. The aim was to assess the association between AID/FID with incident CV disease and mortality in the general population. Methods and results: In 12 164 individuals from three European population‐based cohorts, AID was defined as ferritin < 100 μg/L or as ferritin < 30 μg/L (severe AID), and FID was defined as ferritin < 100 μg/L or ferritin 100–299 μg/L and transferrin saturation < 20%. The association between iron deficiency and incident coronary heart disease (CHD), CV mortality, and all‐cause mortality was evaluated by Cox regression models. Population attributable fraction (PAF) was estimated. Median age was 59 (45–68) years; 45.2% were male. AID, severe AID, and FID were prevalent in 60.0%, 16.4%, and 64.3% of individuals. AID was associated with CHD [hazard ratio (HR) 1.20, 95% confidence interval (CI) 1.04–1.39, P = 0.01], but not with mortality. Severe AID was associated with all‐cause mortality (HR 1.28, 95% CI 1.12–1.46, P < 0.01), but not with CV mortality/CHD. FID was associated with CHD (HR 1.24, 95% CI 1.07–1.43, P < 0.01), CV mortality (HR 1.26, 95% CI 1.03–1.54, P = 0.03), and all‐cause mortality (HR 1.12, 95% CI 1.01–1.24, P = 0.03). Overall, 5.4% of all deaths, 11.7% of all CV deaths, and 10.7% of CHD were attributable to FID. Conclusions: In the general population, FID was highly prevalent, was associated with incident CHD, CV death, and all‐cause death, and had the highest PAF for these events, whereas AID was only associated with CHD and severe AID only with all‐cause mortality. This indicates that FID is a relevant risk factor for CV diseases in the general population. [ABSTRACT FROM AUTHOR]

Purpose To provide sex-stratified normative data on retinal thickness and study the relationship with sex, age and refractive status. Methods Population-based study including 2617 women and 1891 men, aged 38-87 (mean 61 ± 8) years, without diabetes, glaucoma and retinal diseases, and spherical equivalent refraction ( SER) within ±6 dioptres. Retinal thickness was measured with optical coherence tomography (spectral domain Cirrus HD- OCT). Results Women had thinner retina than men. Retinal thickness was significantly associated with refraction, where mean change in retinal thickness per 1 D increase in SER was −1.3 (0.2) μm in the fovea, 0.7 (0.1) μm in the pericentral ring and 1.4 (0.1) μm in the peripheral ring. In the fovea, there was a non-monotonic curved relationship between retinal thickness and age in both sexes with a maximum at about 60 years (p < 0.001). In the pericentral ring, the mean reduction in retinal thickness per 10-year increase was 2.7 (0.3) μm in women and 4.0 (0.4) μm in men and corresponding results in the peripheral ring were 2.3 (0.3) μm in women and 2.6 (0.4) μm in men. In both regions, there was evidence for a nonlinear pattern with an increased rate of change with higher age. There was a significant interaction between sex and age for retinal thickness of the pericentral ring (p = 0.041). Conclusion Women had thinner retina than men, and thickness varied with refractive status. Retinal thickness was associated with age in all macular regions, and the rate of change in retinal thickness varied at different ages. [ABSTRACT FROM AUTHOR]

. Purpose: To investigate whether retinal vessel calibre measurements on optical retinal photography are affected by light and dark exposure prior to photography and whether the vessel calibre changes during an imaging sequence of several images. Methods: Digital optical retinal photographs were obtained from 32 healthy adults in two separate image sequences of six images during 1 min; one sequence with 10 min of dark exposure and one with 10 min of light exposure prior to imaging. Retinal arteriolar and venular calibres were measured computer-assisted and summarized as central retinal artery and vein equivalents (CRAE and CRVE). Outcome measures were difference in calibres after prior light versus prior dark exposure and difference in calibre during each of the two imaging sequences. Results: CRVE was wider with prior light exposure (2.7%, p = 0.0001), comparing the first image in each image sequence. Within each sequence, there was a venular dilatation from first to last image, both with prior light exposure (1.7%, p = 0.0003) and prior dark exposure (3.1%, p < 0.0001), with the change less pronounced with prior light exposure (p = 0.0164). CRAE showed no significant change in either outcome. Conclusions: Retinal venular calibre was wider with light exposure prior to imaging and increased slightly during the imaging sequences, less pronounced after prior light than dark exposure. Measurement error due to these effects will probably be reduced by avoiding dark prior to imaging, and a possible bias effect of endothelial dysfunction may possibly be reduced by measuring calibre on an image taken early in the image sequence. [ABSTRACT FROM AUTHOR]

. Purpose: To describe the association between retinal vascular calibres and cardiovascular risk factors. Methods: Population-based cross-sectional study including 6353 participants of the Tromsø Eye Study in Norway aged 38-87 years. Retinal arteriolar calibre (central retinal artery equivalent) and retinal venular calibre (central retinal vein equivalent) were measured computer-assisted on retinal photographs. Data on blood pressure, body mass index (BMI), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, glycosylated haemoglobin (HbA1c) and smoking were collected. Association between retinal vessel calibre and the cardiovascular risk factors was assessed by multivariable linear and logistic regression analyses. Results: Retinal arteriolar calibre was independently associated with age, blood pressure, HbA1c and smoking in women and men, and with HDL cholesterol in men only. Blood pressure had the strongest effect on arteriolar calibre, with a decrease in calibre of 3.6 μm (women)/4.1 μm (men) per standard deviation increase in mean arterial blood pressure. Retinal venular calibre was independently associated with age, blood pressure, BMI, HDL and LDL cholesterol and smoking in men and women. The effect of BMI and HDL cholesterol on venular calibre was significantly stronger in men than in women. Current smoking was the most important factor for venular calibre, where smokers had 13.2 μm (women)/15.2 μm (men) wider calibre than nonsmokers. Conclusion: All the explored cardiovascular risk factors were independently associated with retinal vascular calibre, with stronger effect of HDL cholesterol and BMI in men than in women. Blood pressure and smoking contributed most to the explained variance. [ABSTRACT FROM AUTHOR]

. Purpose: To describe the study design and methodology of the Tromsø Eye Study (TES), and to describe visual acuity and refractive error in the study population. Methods: The Tromsø Eye Study is a sub-study of the Tromsø Study, a population-based multipurpose longitudinal study in the municipality of Tromsø, Norway. The Tromsø Eye Study was a part of the sixth survey of the Tromsø Study, conducted from October 2007 through December 2008. The eye examination included information on self-reported eye diseases, assessment of visual acuity and refractive errors, retinal photography and optical coherence tomography. Retinal images were graded for diabetic retinopathy and age-related macular degeneration, and with computer-assisted measurements of arteriolar and venular diameters. In addition, TES researchers have access to the large comprehensive Tromsø Study database including physical examination results, carotid artery ultrasound, electrocardiogram, bone densitometry, cognitive tests, questionnaires, DNA, blood and urine samples and more from the present and the five previous surveys. Results: Visual acuity was assessed in 6459 subjects and refraction in 6566 subjects aged 38-87 years. Snellen visual acuity <20/60 was found in 1.2% (95% CI 0.95-1.5) of the participants and there was no gender difference. Visual impairment increased with age, and in the age group 80-87 years, the overall visual acuity <20/60 was 7.3% (95% CI 3.3-11.2). Spherical equivalent showed an increasing trend with age and there was no clinically relevant difference between men and women. Retinal photography was performed in 6540 subjects. Conclusion: Prevalence of visual impairment was low but increased with age. There was a trend towards hyperopia with age and no clinically relevant difference in refraction between the sexes. TES aims to provide epidemiological research on several eye and eye-related diseases. Owing to a comprehensive data collection, it has the opportunity to explore issues related to environmental factors, cognition and their interaction with diseases in this community. [ABSTRACT FROM AUTHOR]

Background.- High prevalence of headache has been associated with high latitude, thus suggesting a relation with vitamin D. However, there are so far no reports on the association between serum 25-hydroxyvitamin D (25[OH]D) and headache. Objective.- To investigate the association between headache and serum 25(OH)D in a general population. Methods.- Cross-sectional study based on questionnaires from 11,614 persons who participated in the sixth survey of the Tromsø Study (Tromsø 6) carried out in 2007-2008. The data were stratified according to smoking status and analyzed with regard to migraine and non-migraine headache. Adjustments were done for age, body mass index (BMI), gender, season, chronic diseases, education, physical exercise, and alcohol consumption. Results.- Headache of non-migraine type was associated with low levels of serum 25(OH)D with an odds ratio (OR) of 1.20 (1.04-1.39) in the lowest quartile as compared to the highest serum 25(OH)D quartile. No significant association was found between migraine and serum 25(OH)D. Conclusion.- Non-migraine headache was associated with low levels of serum 25(OH)D. Although adjustment were done for possible confounders, this finding may still reflect lifestyle rather than causality, and further studies are needed to investigate this. No association was found between serum 25(OH)D and migraine. [ABSTRACT FROM AUTHOR]

Purpose: To provide sex-stratified normative data on retinal thickness and study the relationship with sex, age and refractive status., Methods: Population-based study including 2617 women and 1891 men, aged 38-87 (mean 61 ± 8) years, without diabetes, glaucoma and retinal diseases, and spherical equivalent refraction (SER) within ±6 dioptres. Retinal thickness was measured with optical coherence tomography (spectral domain Cirrus HD-OCT)., Results: Women had thinner retina than men. Retinal thickness was significantly associated with refraction, where mean change in retinal thickness per 1 D increase in SER was -1.3 (0.2) μm in the fovea, 0.7 (0.1) μm in the pericentral ring and 1.4 (0.1) μm in the peripheral ring. In the fovea, there was a non-monotonic curved relationship between retinal thickness and age in both sexes with a maximum at about 60 years (p < 0.001). In the pericentral ring, the mean reduction in retinal thickness per 10-year increase was 2.7 (0.3) μm in women and 4.0 (0.4) μm in men and corresponding results in the peripheral ring were 2.3 (0.3) μm in women and 2.6 (0.4) μm in men. In both regions, there was evidence for a nonlinear pattern with an increased rate of change with higher age. There was a significant interaction between sex and age for retinal thickness of the pericentral ring (p = 0.041)., Conclusion: Women had thinner retina than men, and thickness varied with refractive status. Retinal thickness was associated with age in all macular regions, and the rate of change in retinal thickness varied at different ages., (© 2016 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)