Does insomnia modify the association between C-reactive protein and migraine? The Tromsø Study 2015-2016.

BACKGROUND: The relationship between high sensitivity C-reactive protein and migraine is unclear. The aim of this cross-sectional population-based study was to investigate the association between high sensitivity C-reactive protein and types of headache, and to evaluate the impact of insomnia on this association. METHODS: A total of 20,486 (63%) out of 32,591 invited, aged ≥40 years or older, participated in the seventh wave of the Tromsø study conducted in 2015-2016 and had valid information on headache, insomnia and high sensitivity C-reactive protein. The influence of insomnia on the association between questionnaire-based diagnoses of headache and elevated high sensitivity C-reactive protein defined as >3.0 mg/L was assessed using multiple logistic regression, estimating prevalence odds ratio with 95% confidence intervals. RESULTS: A total of 6290 participants (30.7%) suffered from headache during the last year. Among these, 1736 (8.5%) fulfilled the criteria of migraine, 991 (4.8%) had migraine with aura, 746 (3.6%) migraine without aura (3.8%), and 4554 (22.2%) had non-migrainous headache. In the final multi-adjusted analysis, elevated high sensitivity C-reactive protein was associated with headache (odds ratio 1.10, 95% confidence interval 1.01-1.20), migraine (odds ratio 1.17, 95% confidence interval 1.01-1.35), and migraine with aura (odds ratio 1.23, 95% confidence interval 1.01-1.53). No association was found between elevated high sensitivity C-reactive protein and migraine without aura or non-migrainous headache. The association between high sensitivity C-reactive protein and migraine was strongly dependent on insomnia status. Among individuals with insomnia, elevated high sensitivity C-reactive protein was associated with migraine (odds ratio 1.49, 95% confidence interval 1.02-2.17), and migraine with aura (odds ratio 1.59, 95% confidence interval 1.03-2.45), whereas no such relationship was found among those without insomnia. CONCLUSIONS: In this cross-sectional study, participants with migraine, in particular migraine with aura, were more likely to have elevated high sensitivity C-reactive protein, evident only among those with insomnia.

Why do sales of lipid-lowering drugs vary between counties in Norway? Evidence from the OPPHED Health Study 2000-2001.

OBJECTIVE: To study and compare plausible factors that might explain varying sales of lipid-lowering drugs (LLDs) in the two neighbouring counties of Hedmark and Oppland in Norway, with a similar age distribution, socioeconomic structure, and access to healthcare services. DESIGN, SETTING, SUBJECTS: Cross-sectional population study comprising 10 598 attendants aged 40, 45, 60, and 75 years in the OPPHED Health Study, 2000-2001 (attendance rate 61%). MAIN OUTCOME MEASURE: Treatment eligibility (cardiovascular morbidity and risk score), treatment frequency in treatment-eligible subgroups and treatment intensity in terms of achievement of total cholesterol (TC) goal. RESULTS: Proportions eligible for LLD treatment in Hedmark and Oppland were similar. There was no difference in prevalence of LLD use among participants with cardiovascular disease or diabetes (secondary prevention subgroup). However, LLD use among men in the primary prevention subgroup was higher in Hedmark compared with Oppland, 6.3% and 4.1%, respectively (p < 0.05). The same tendency was seen among women. In both sexes, more LLD users in the primary prevention subgroup achieved the TC goal in Hedmark compared with Oppland (p < 0.05). CONCLUSION AND IMPLICATIONS: The proportion of the population eligible for LLD treatment in the two counties should imply similar treatment rates in both. Higher LLD treatment frequency and intensity in the primary prevention subgroup in Hedmark are probably both contributing factors that explain the higher sales of LLDs in Hedmark compared with Oppland. Feasible intervention thresholds for primary prevention with concurrent reimbursement rules should be defined in guidelines to avoid unintentional variation in LLD use in the future.