Ben Michael Brumpton

General and abdominal obesity and incident asthma in adults: the HUNT study

Measures of body mass index (BMI) and waist circumference define general obesity and abdominal obesity respectively. While high BMI has been established as a risk factor for asthma in adults, waist circumference has seldom been investigated. To determine the association between BMI, waist circumference and incident asthma in adults, we conducted a prospective study (n=23,245) in a population living in Nord-Trøndelag, Norway in 1995–2008. Baseline BMI and waist circumference were measured and categorised as general obesity (BMI ≥30.0 kg·m2) and abdominal obesity (waist circumference ≥88 cm in females and ≥102 cm in males). Incident asthma was self-reported new-onset cases during an 11-yr follow-up period. Odds ratios for asthma associated with obesity were calculated using multivariable logistic regression. General obesity was a risk factor for asthma in females (OR 1.96, 95% CI 1.52–2.52) and males (OR 1.84, 95% CI 1.30–2.59). In females, after additional adjustment for BMI, abdominal obesity remained a risk factor for asthma development (OR 1.46, 95% CI 1.04–2.05). Abdominal obesity seems to increase the risk of incident asthma in females in addition to BMI, indicating that using both measures of BMI and waist circumference in females may be a superior clinical assessment for asthma risk than any measure alone.

The associations of anxiety and depression symptoms with weight change and incident obesity: The HUNT Study

OBJECTIVE:To investigate the associations of anxiety and depression symptoms with weight change and incident obesity in men and women.DESIGN:We conducted a prospective cohort study using the Norwegian Nord-Trøndelag Health Study (HUNT).SUBJECTS:The study cohort included 25 180 men and women, 19–55 years of age from the second survey of the HUNT (1995–1997).MEASUREMENTS:Anxiety and depression symptoms were measured using the Hospital Anxiety and Depression Scale. Weight change was determined for the study period of an average 11 years. Incident obesity was new-onset obesity classified as having a body mass index of ⩾30.0 kg m2 at follow-up. The associations of anxiety or depression with weight change in kilograms (kg) was estimated using linear regression models. Risk ratios (RRs) for incident obesity associated with anxiety or depression were estimated using log-binomial regression.RESULTS:In men, any anxiety or depression was associated with an average 0.81 kg (95% confidence interval (CI) 0.27–1.34) larger weight change after 11 years compared with those without such symptoms (mean weight change: 5.04 versus 4.24 kg). Women with any anxiety or depression had an average 0.98 kg (95% confidence interval (CI) 0.49–1.47) larger weight change compared with those without such symptoms (mean weight change: 5.02 versus 4.04 kg). Participants with any anxiety or depression had a significantly elevated cumulative incidence of obesity (men: RR 1.37, 95% CI 1.13–1.65; women: RR 1.18, 95% CI 1.00–1.40).CONCLUSION:We found that symptoms of anxiety and depression were associated with larger weight change and an increased cumulative incidence of obesity in both men and women.

Metabolic syndrome and incidence of asthma in adults: the HUNT study

Obesity is a risk factor for incident asthma in adults, and obesity is a major component of metabolic syndrome. This study aimed to explore the associations of metabolic syndrome and its components with the cumulative incidence of asthma in adults. We conducted a prospective cohort study of participants who were asthma-free at baseline (n = 23 191) in the Nord-Trøndelag Health Study from 1995 to 2008. Baseline metabolic syndrome was categorised using the definition of the Joint Interim Statement from several international organisations. Incident asthma was self-reported at follow-up, which averaged 11 years. Metabolic syndrome was a risk factor for incident asthma (adjusted OR 1.57, 95% CI 1.31–1.87). This association was consistent in sensitivity analyses using a stricter asthma definition (adjusted OR 1.42, 95% CI 1.13–1.79). Among the components of metabolic syndrome, two remained associated with incident asthma after mutual adjustment for the other metabolic components: high waist circumference (adjusted OR 1.62, 95% CI 1.36–1.94) and elevated glucose or diabetes (adjusted OR 1.43, 95% CI 1.01–2.04). Metabolic syndrome and two of its components (high waist circumference and elevated glucose or diabetes) were associated with an increased risk of incident asthma in adults. Metabolic syndrome and two of its components were associated with an increased risk of incident asthma in adults http://ow.ly//p2RNy

GOLD classifications and mortality in chronic obstructive pulmonary disease: the HUNT Study, Norway

Background How different Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifications of chronic obstructive pulmonary disease (COPD) predict mortality is unclear. Objective To examine the association of spirometric GOLD grades and the new ABCD groups with mortality, and to compare their informativeness in relation to mortality. Methods We studied 1540 people with post-bronchodilator COPD who participated in the Norwegian Nord-Trøndelag Health Study 1995–1997 and were followed up on all-cause mortality until May 2012. The associations of spirometric GOLD grades and ABCD groups with mortality were estimated by sex specific adjusted HRs from Cox regression and standardised mortality ratios. To assess the informativeness of spirometric GOLD grades and ABCD groups at predicting mortality we used the difference in twice the log-likelihood of a Cox regression model with and without each COPD classification. Results The distribution of participants was 28% in GOLD 1, 57% in GOLD 2, 13% in GOLD 3 and 2% in GOLD 4, in contrast to 61% in group A, 18% in group B, 12% in group C and 10% in group D. During a median of 14.6 years of follow-up, 837 people (54%) died. Mortality increased gradually from GOLD 1 to 4, while it was generally similar in groups A and B, and in groups C and D. Spirometric GOLD grades were substantially more informative than ABCD groups at predicting mortality. Conclusions Spirometric GOLD grades predicted mortality better than the new ABCD groups among people with COPD from a Norwegian general population.

Shared genetic origin of asthma, hay fever and eczema elucidates allergic disease biology.

Asthma, hay fever (or allergic rhinitis) and eczema (or atopic dermatitis) often coexist in the same individuals, partly because of a shared genetic origin. To identify shared risk variants, we performed a genome-wide association study (GWAS; n = 360,838) of a broad allergic disease phenotype that considers the presence of any one of these three diseases. We identified 136 independent risk variants (P < 3 × 10−8), including 73 not previously reported, which implicate 132 nearby genes in allergic disease pathophysiology. Disease-specific effects were detected for only six variants, confirming that most represent shared risk factors. Tissue-specific heritability and biological process enrichment analyses suggest that shared risk variants influence lymphocyte-mediated immunity. Six target genes provide an opportunity for drug repositioning, while for 36 genes CpG methylation was found to influence transcription independently of genetic effects. Asthma, hay fever and eczema partly coexist because they share many genetic risk variants that dysregulate the expression of immune-related genes.

The joint association of anxiety, depression and obesity with incident asthma in adults: the HUNT Study

BACKGROUND Anxiety or depression symptoms may increase the risk of developing asthma, and their interaction with obesity is not known. We aimed to assess the association of anxiety or depression symptoms and the joint association of these symptoms and obesity with incident asthma. METHODS We conducted a prospective cohort study of 23 599 adults who were 19-55 years old and free from asthma at baseline in the Norwegian Nord-Trøndelag Health Study. The Hospital Anxiety and Depression Scale was used to measure anxiety or depression symptoms. Obesity was defined as a body mass index≥30.0 kg/m2. Incident asthma was self-reported new cases of asthma during the 11-year follow-up. RESULTS Having anxiety or depression symptoms was associated with incident asthma [odds ratio (OR) 1.39, 95% confidence interval (CI) 1.09-1.78). Obese participants with anxiety or depression symptoms had a substantially higher risk of incident asthma (OR 2.93, 95% CI 2.20-3.91) than any other group (non-obese participants without anxiety or depression symptoms [reference], non-obese participants with anxiety or depression symptoms (OR 1.20, 95% CI 1.00-1.45) and obese participants without anxiety or depression symptoms (OR 1.47, 95% CI 1.19-1.82)]. The relative excess risk for incident asthma due to interaction between anxiety or depression symptoms and obesity was 1.26 (95% CI 0.39-2.12). CONCLUSIONS This study suggests that having anxiety or depression symptoms contributes to the development of asthma in adults. The risk of asthma may be further increased by the interaction between anxiety or depression symptoms and obesity.

Vitamin D and Lung Function Decline in Adults With Asthma The HUNT Study

We investigated whether low 25-hydroxyvitamin D (25(OH)D) levels were associated with more lung function decline in adults with asthma and whether this association was modified by smoking status or inhaled corticosteroid (ICS) use. We analyzed data on 395 adults with asthma from the Nord-Trøndelag Health Study (1995-2008), Norway. Plasma 25(OH)D and lung function were measured at baseline, and lung function measurements were repeated at follow-up, approximately 11 years later. Linear regression was used to estimate lung function decline. Participants with low 25(OH)D (<50 nmol/L) had more decline in lung function measurements for forced expiratory volume in 1 second (FEV1) (388 mL), forced vital capacity (298 mL), and the FEV1/forced vital capacity ratio (3.7%) over the follow-up, compared with those with high 25(OH)D (≥50 nmol/L) who declined 314 mL, 246 mL, and 3.0%, respectively (P = 0.08, 0.30, and 0.23, respectively). The associations were stronger in never smokers and non-ICS users. In never smokers, low 25(OH)D levels were associated with more decline in FEV1 (445 vs. 222 mL) (P = 0.01). In non-ICS users, low 25(OH)D levels were associated with more decline in FEV1 (467 vs. 320 mL) (P = 0.02). Low serum 25(OH)D levels were weakly associated with more lung function decline in adults with asthma, and stronger associations were observed in never smokers and non-ICS users.

Physical activity and lung function decline in adults with asthma: The HUNT Study

People with asthma may seek advice about physical activity. However, the benefits of leisure time physical activity on lung function are unclear. We investigated the association between leisure time physical activity and lung function decline in adults with asthma.

Serum 25-hydroxyvitamin D level, smoking and lung function in adults: the HUNT Study.

The association between serum 25-hydroxyvitamin D (25(OH)D) level and lung function changes in the general population remains unclear. We conducted cross-sectional (n=1220) and follow-up (n=869) studies to investigate the interrelationship of serum 25(OH)D, smoking and lung function changes in a random sample of adults from the Nord-Trøndelag Health (HUNT) Study, Norway. Lung function was measured using spirometry and included forced expiratory volume in 1 s (FEV1) % predicted, forced vital capacity (FVC) % pred and FEV1/FVC ratio. Multiple linear and logistic regression models estimated the adjusted difference in lung function measures or lung function decline, adjusted odds ratios for impaired lung function or development of impaired lung function and 95% confidence intervals. 40% of adults had serum 25(OH)D levels <50 nmol·L−1. Overall, those with a serum 25(OH)D level <50 nmol·L−1 showed worse lung function and increased odds of impaired lung function compared to the ≥50 nmol·L−1 group. These associations tended to be stronger among ever-smokers, including greater decline in FEV1/FVC ratio and greater odds of the development of impaired lung function (FEV1/FVC <70% OR 2.4, 95% CI 1.2–4.9). Associations among never-smokers were null. Results from cross-sectional and follow-up studies were consistent. There were no associations between serum 25(OH)D levels and lung function or lung function changes in never-smokers, whereas significant associations were observed in ever-smokers. Lower serum 25(OH)D levels are associated with greater lung function decline and impaired lung function in smokers http://ow.ly/MaUaq

Prospective study of insomnia and incident asthma in adults: the HUNT study

Insomnia is highly prevalent among asthmatics; however, few studies have investigated insomnia symptoms and asthma development. We aimed to investigate the association between insomnia and the risk of incident asthma in a population-based cohort. Among 17 927 participants free from asthma at baseline we calculated odds ratios and 95% confidence intervals for the risk of incident asthma among those with insomnia compared to those without. Participants reported sleep initiation problems, sleep maintenance problems and nonrestorative sleep. Chronic insomnia was defined as those reporting one or more insomnia symptom at baseline and 10 years earlier. Incident asthma was defined by questions on asthma at baseline and follow-up (average 11 years). The prevalence of sleep initiation problems, sleep maintenance problems and nonrestorative sleep were 1%, 1% and 5%, respectively. The multi-adjusted odds ratios were 1.18 (95% CI 0.97–1.44), 1.30 (95% CI 1.03–1.64) and 1.70 (95% CI 1.37–2.11) for people with one, two and three insomnia symptoms, respectively, compared with people without symptoms (p<0.01 for trend). The risk of developing asthma in those with chronic insomnia was three times higher (adjusted OR 3.16, 95% CI 1.37–6.40) than those without. Insomnia symptoms were associated with increased risk of incident asthma in this study. People experiencing insomnia symptoms had a higher risk of developing asthma than those without such symptoms http://ow.ly/JNEe306bCmf