Parity, infertility, age at first birth and risk of atrial fibrillation: data from the HUNT study.

AIMS: Although parity, infertility, and age at first birth are important for later development of cardiovascular disease, research on their association with atrial fibrillation (AF) is limited. METHODS: We linked data from the population-based HUNT study, the Medical Birth Registry of Norway (MBRN) and validated medical records from local hospitals. A total of 24,015 women aged 45 years or older were followed for verified incident AF. Parity and age at first birth were retrieved from the MBRN or from self-reported questionnaires in the HUNT. History of infertility was self-reported on the HUNT questionnaire. Cox-proportional hazard models were used to calculate hazard ratios (HR) for the multivariable-adjusted associations of parity, infertility, and age at first birth with risk of AF. RESULTS: During a median follow-up of 12.8 years, 1,448 (6.0%) participants developed AF. Women with higher parity (four or more births vs. two births) were at 21% higher risk of AF (HR 1.21, 95% confidence interval (CI), 1.05-1.39). History of infertility was also associated with risk of AF (HR 1.20, 95% CI, 1.02-1.42). Among parous women, younger age at first birth (<20 years vs. 20-29 years) was associated with a 20% higher risk of AF (HR 1.20, 95% CI, 1.03-1.40). CONCLUSION: Women with four or more births, or a history of infertility, or younger age at first birth have approximately a 20% higher risk of AF among women over 45 years old.

A higher number of births and younger age at first birth are associated with a higher risk of cardiovascular disease (CVD). However, there is limited evidence on the associations between parity, age at first birth and atrial fibrillation (AF). Moreover, the association between infertility and AF remains largely unexplored. We have investigated the association between parity, infertility, age at first birth and AF in the population-based cohort from Norway (the HUNT study) among women over 45 years old. Our findings reveal that women with four or more births, or a history of infertility, or younger age at first birth have approximately a 20% higher risk of AF.

Serum vitamin D, blood pressure and hypertension risk in the HUNT study using observational and Mendelian randomization approaches.

Limited studies have triangulated the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels and systolic blood pressure (SBP), diastolic blood pressure (DBP) or hypertension risk utilizing both observational and Mendelian randomization (MR) approaches. We employed data from the Norwegian Trøndelag Health Study (HUNT) to conduct cross-sectional (n = 5854) and prospective (n = 3592) analyses, as well as one-sample MR (n = 86,324). We also used largest publicly available data for two-sample MR. Our cross-sectional analyses showed a 25 nmol/L increase in 25(OH)D was associated with a 1.73 mmHg decrease in SBP (95% CI - 2.46 to - 1.01), a 0.91 mmHg decrease in DBP (95% CI - 1.35 to - 0.47) and 19% lower prevalence of hypertension (OR 0.81, 95% CI 0.74 to 0.90) after adjusting for important confounders. However, these associations disappeared in prospective analyses. One-sample and two-sample MR results further suggested no causal relationship between serum vitamin D levels and blood pressure or hypertension risk in the general population.

Association of age at menarche, reproductive lifespan and age at menopause with the risk of atrial fibrillation: The HUNT study.

BACKGROUND: Age at menarche, reproductive lifespan, and age at menopause are associated with several cardiovascular diseases, but their relationship with atrial fibrillation (AF) is uncertain. METHODS: We linked information on all women who participated in the third survey of the population-based, longitudinal HUNT study in Norway with medical records from all local hospitals. A total of 14,632 women aged 60 or more were followed for validated incident AF. We retrieved age at menarche and age at menopause from the HUNT questionnaires. Reproductive lifespan was defined as the difference between age at menarche and age at menopause. We used Cox proportional hazards regression models to assess associations between AF and age at menarche, reproductive lifespan, and age at menopause. RESULTS: During a median follow-up of 8.17 years (136,494 person-years), 1217 (8.3 %) participants developed AF. In multivariable-adjusted analyses, we observed no associations between early or late age at menarche and AF (hazard ratios (HRs): <12 years: 0.85 [95 % confidence interval (CI), 0.65-1.12]; ≥16 years: 0.99 [95 % CI, 0.80-1.24] compared to those who attained menarche at 13-14 years). The HR for a reproductive lifespan shorter than 30 years was 0.91 [95 % CI, 0.72-1.15] compared to 34-37 years. Likewise, there was no clear association between premature or early age at menopause and AF (HRs: <40 years: 1.21 [95 % CI, 0.83-1.75]; 40-44 years: 0.97 [95 % CI, 0.77-1.22] compared to 50-54 years). CONCLUSIONS: In this population of women aged 60 years and over, the risk of AF was not associated with age at menarche, reproductive lifespan, or age at menopause.

Insomnia symptoms and risk for atrial fibrillation - The HUNT study.

Studies on the effect of insomnia on atrial fibrillation risk in the general population are limited, therefore we investigated the association between insomnia and the risk of atrial fibrillation in a large-scale population-based study with valid atrial fibrillation measure. A total of 33,983 participants (55% women) reported their insomnia symptoms in the third wave of the HUNT study (between 2006 and 2008) in Norway, and they were followed for their first atrial fibrillation diagnosis until 2020 using hospital registers. Atrial fibrillation diagnoses were validated by physicians based on medical records and electrocardiograms. Insomnia symptoms were assessed by four questions, and analysed both individually and as cumulative symptoms. Cox regression, adjusted for age, sex, social and marital status, working in shiftwork, alcohol consumption, smoking, physical activity, body mass index, systolic blood pressure, and symptoms of anxiety and depression, was conducted. Overall, 1592 atrial fibrillation cases were identified during the follow-up and 31.6% of individuals reported at least one insomnia symptom. In our analysis, we did not detect meaningful associations between insomnia symptoms and the risk of atrial fibrillation. In conclusion, in this population there was no evidence for an association between insomnia symptoms and the risk of subsequent atrial fibrillation.