Background Obesity in late adolescence has been associated with an increased risk of multiple sclerosis (MS); however, it is not known if body size in childhood is associated with MS risk. Methods Using a prospective design we examined whether body mass index (BMI) at ages 7-13 was associated with MS risk among 303,998 individuals in the Copenhagen School Health Records Register (CSHRR).. Linking the CSHRR with the Danish MS registry yielded 774 MS cases (501 girls, 273 boys). We used Cox proportional hazards models, to estimate the hazard ratios (HR) and 95% confidence intervals. Results Among girls, at each age 7-13, a 1-unit increase in BMI z-score was associated with an increased risk of MS (HRage 7=1.20, 95%CI: 1.10-1.30; HRage 13=1.18, 95%CI: 1.08-1.28). Girls who were ≥95th percentile for BMI had a 1.61-1.95-fold increased risk of MS as compared to girls <85th percentile. The associations were attenuated in boys. The pooled HR for a 1-unit increase in BMI z-score was at age 7 was 1.17, 95%CI: 1.09-1.26, and at age 13, 1.15, 95%CI: 1.07-1.24. Conclusion Having a high BMI in early life is a risk factor for MS, but the mechanisms underlying the association remain to be elucidated.

Patients with multiple sclerosis (MS) may be at an increased risk of fracture owing to a greater risk of falling and decreased bone mineral density when compared with the general population. This study was designed to estimate the relative and absolute risk of fracture in patients with MS. We conducted a population-based cohort study using data from the UK General Practice Research Database linked to the National Hospital Registry (1997Registry ( -2008. Incident MS patients (n ¼ 5565) were matched 1:6 by year of birth, sex, and practice with patients without MS (controls). Cox proportional-hazards models were used to derive adjusted hazard ratios (HRs) for fracture associated with MS. Time-dependent adjustments were made for age, comorbidity, and drug use. Absolute 5-and 10-year risks of fracture were estimated for MS patients as a function of age. Compared with controls, MS patients had an almost threefold increased risk of hip fracture [HR ¼ 2.79, 95% confidence interval (CI) 1.83-4.26] and a risk of osteoporotic fracture that was increased 1.4-fold (HR ¼ 1.35, 95% CI 1.13-1.62). Risk was greater in patients who had been prescribed oral/intravenous glucocorticoids (GCs; HR ¼ 1.85, 95% CI 1.14-2.98) or antidepressants (HR ¼ 1.79, 95% CI 1.37-2.35) in the previous 6 months. Absolute fracture risks were low in younger MS patients but became substantial when patients were older than 60 years of age. It is concluded that MS is associated with an increased risk of fracture. Fracture risk assessment may be indicated in patients with MS, especially those prescribed GCs or antidepressants. ß

Multiple sclerosis is an inflammatory disease of the central nervous system of unknown aetiology. Its prevalence varies by ethnicity and place: persons of northern European descent are at increased risk while persons living at lower latitudes appear to be protected against the disease. The Danish Multiple Sclerosis Registry is a national registry established in 1956 after a population-based survey which receives information from numerous sources. It is considered to be more than 90% complete, with a validity of 94%. Using data from the Registry, we calculated prevalences per 100,000 inhabitants. The standardized prevalence of multiple sclerosis increased from 58.8 (95% confidence interval: 54.9-62.7) in 1950 to 154.5 per 100,000 (95% confidence interval: 148.8-160.2) in 2005, and the female to male ratio increased from 1.31 in 1950 to 2.02 in 2005. The increase in prevalence is due to both increased survival of multiple sclerosis patients and an increased incidence rate. The rise in prevalence in the past 50 years is probably due more to environmental factors than to genetic changes in the Danish population. Among women, environmental changes could include older age at first birth, use of oral contraceptives, or changes in sun behaviour and/or vitamin D status.

SummaryBackground Few questionnaires used in monitoring sun-related behaviour have been tested for validity. Objectives We established the criteria validity of a questionnaire developed for monitoring population sun-related behaviour. Methods During May-August 2013, 664 Danes wore a personal electronic ultraviolet radiation (UVR) dosimeter for 1 week that measured their outdoor time and dose of erythemal UVR exposure. In the following week, they answered a questionnaire on their sun-related behaviour in the measurement week. Results Outdoor time measured by dosimetry correlated strongly with both outdoor time and the developed exposure scale measured in the questionnaire. Exposure measured in standard erythema dose (SED) by dosimetry correlated strongly with the exposure scale. In a linear regression model of UVR (SED) received, 41% of the variation was explained by skin type, age, week of participation and exposure scale, with exposure scale as the main contributor. The weekly sunburn fraction correlated strongly with the number of ambient sun hours (r = 0Á73, P < 0Á001). Conclusions This criteria-validated questionnaire provides evidence of the exposure that the questionnaire aimed to measure. The evidence provided showed a strong link between the objectively measured behaviour and the behaviour measured by this survey construct. The questionnaire is the first validated tool to measure the UVR exposure in a national population-based sample.

Incidences of melanoma and nonmelanoma skin cancer are high and increasing in many countries including Denmark. The diseases are highly preventable. We have estimated the healthcare costs of these cancers by comparing costs for cohorts of patients and matched controls in a national register-based study in Denmark. All incident patients with a diagnosis of melanoma, basal cell carcinoma, or squamous cell carcinoma in the period 2004-2008 were included. Four control individuals for each case were matched in terms of sex, age, and area of residence. Healthcare costs and productivity loss for patients and controls were estimated using Danish health and social registries 3 years before and 3 years after diagnosis. The healthcare costs of melanoma and nonmelanoma skin cancer were &OV0556;33.3 million in the 3-year period after diagnosis, with male patients inducing the highest costs for all three cancers and costs increasing with age. The diagnoses of basal cell carcinoma and melanoma had almost the same healthcare costs, but per patient average healthcare costs were higher for melanoma. The costs of melanoma and nonmelanoma skin cancers, which can be prevented by sensible sun habits, exceed the costs of the preventive measures of the Danish SunSmart campaign manifold. Costs of melanoma and nonmelanoma skin cancer are expected to increase in the future with populations aging in the western world. The analyses provide a strong argument for the societal rationale of skin cancer prevention in Denmark.