L. L. N. Husemoen

Determinants of vitamin D status in a general population of Danish adults

BACKGROUND AND AIMS Danish legislation regarding food fortification has been very restrictive and vitamin D deficiency is thought to be common in Denmark due to inadequate dietary intakes and the fact that in Denmark (latitude 56°N) vitamin D is only synthesized in the skin after exposure to solar radiation during summertime (April-September). The purpose of this study was to evaluate the vitamin D status of a general adult population in Denmark and, in addition, associations between vitamin D status and distinct lifestyle factors were studied. METHODS A random sample of 6784 persons from a general population aged 30-60 years participated in a health examination in 1999-2001. Serum samples from all participants were stored and levels of 25-hydroxyvitamin D (25(OH)D) were measured by HPLC in 2009. The method was compared to another HPLC method. Information on dietary intake of vitamin D and other lifestyle factors were obtained by questionnaires. A total of 6146 persons defined as ethnic Danes and with successful measurements of 25(OH)D were included in the analyses. RESULTS The overall prevalence of vitamin D deficiency (25(OH)D<25 nmol/l) and insufficiency (25(OH)D<50 nmol/l) were 13.8% and 52.2%, respectively. A marked seasonal fluctuation was seen in serum levels of 25(OH)D - median values of 25(OH)D were lowest in February and highest in August. In multiple logistic regression models (n=5506), low vitamin D status was significantly associated with obesity (BMI≥30), daily smoking and a sedentary lifestyle. However, measurements of 25(OH)D were not associated with the estimated dietary intake of vitamin D. Comparison of two HPLC methods demonstrated considerable differences in accuracy. DISCUSSION AND CONCLUSIONS Our results suggest that poor vitamin D status is common among adults in a Northern European country without food fortification with vitamin D. Methodological issues are, however, of great importance when using cut-off values to define poor vitamin D status. In addition, we demonstrated that low serum levels of 25(OH)D were associated with several lifestyle factors.

Association of obesity and insulin resistance with asthma and aeroallergen sensitization.

Background: It has been hypothesized that obesity and insulin resistance may play a role in the development of asthma and allergy. The aim of the study was to examine the association of obesity and insulin resistance with asthma and aeroallergen sensitization.

Insulin resistance as a predictor of incident asthma-like symptoms in adults.

Background There is accumulating evidence that obesity is associated with an increased risk of asthma. It has been hypothesized that insulin resistance may be involved in obesity‐induced asthma, but till date there is no prospective data on this issue.

Temporal trends of aeroallergen sensitization over twenty-five years.

Background Little is known about time trends of allergic respiratory disease in adults, in particular in older adults. Furthermore, few trend studies have used objective measurements of IgE sensitization against inhalant allergens.

Genetic determinants of both ethanol and acetaldehyde metabolism influence alcohol hypersensitivity and drinking behaviour among Scandinavians

Background Although hypersensitivity reactions following intake of alcoholic drinks are common in Caucasians, the underlying mechanisms and clinical significance are not known. In contrast, in Asians, alcohol‐induced asthma and flushing have been shown to be because of a single nucleotide polymorphism (SNP), the acetaldehyde dehydrogenase 2 (ALDH2) 487lys, causing decreased acetaldehyde (the metabolite of ethanol) metabolism and high levels of histamine. However, the ALDH2 487lys is absent in Caucasians.

Atopy, asthma, and lung function in relation to folate and vitamin B12 in adults

To cite this article: Thuesen BH, Husemoen LLN, Ovesen L, Jørgensen T, Fenger M, Gilderson G, Linneberg A. Atopy, asthma, and lung function in relation to folate and vitamin B12 in adults. Allergy 2010; 65: 1446–1454.

Effect of lifestyle factors on plasma total homocysteine concentrations in relation to MTHFR(C677T) genotype. Inter99 (7)

Objective: To examine the associations between various lifestyle factors—smoking habits, physical activity, dietary habits, coffee, tea, and alcohol consumption—and homocysteine (tHcy) in relation to MTHFR(C677T) genotype.Design: Cross-sectional population-based study.Setting: Residents of Copenhagen County, Denmark.Subjects: A random sample of 6457 men and women aged 30–60 years drawn from the Civil Registration System and invited to a health examination in 1999–2001. A total of 2788 participants were included in the statistical analysis.Main outcome measures: tHcy was measured using a Fluorescent Polarization Immuno Assay. MTHFR-genotype was determined by PCR and RFLP analysis. Information about lifestyle factors was obtained from a self-administered questionnaire.Results: Daily smoking, less healthy dietary habits, and coffee drinking were associated with elevated tHcy concentrations independent of other determinants. Wine consumption was related to tHcy in a J-shaped manner, whereas beer consumption was negatively associated with tHcy after multiple adjustments. Interaction was observed between smoking status and MTHFR-genotype, smoking status and sex, and beer consumption and age. The effect of smoking was more pronounced in persons with the TT genotype and in women. The effect of beer consumption was more pronounced at younger than at older ages.Conclusions: Smoking status, dietary habits, coffee intake, wine, and beer consumption were major lifestyle determinants of tHcy. Changes in these lifestyle factors may reduce tHcy concentrations, thereby lowering cardiovascular risk in the general population.Sponsorship: Danish Medical Research Council, Danish Centre for Evaluation and Health Technology Assessment, and Danish Heart Foundation.

Serum 25(OH)D and incident type 2 diabetes: a cohort study.

BACKGROUND/OBJECTIVES:Mild to moderate vitamin D insufficiency has been proposed as a risk factor for several common chronic diseases including type 2 diabetes. This study aimed to examine the association between serum 25-hydroxy vitamin D (25(OH)D) and incident diabetes.SUBJECTS/METHODS:The MONICA10 cohort consists of 2656 participants (men and women aged 41–71 years) who participated in a 10-year follow-up examination during 1993–1994 as part of the MONICA 1 population survey. A total of 2571 participants free of diabetes at baseline and with successful measurement of serum 25(OH)D were included in the current study. The Danish National Diabetes register enabled identification of 288 cases of incident diabetes during follow-up (median: 16.4 years). Data were analysed by Cox proportional hazard models and associations were expressed as hazard ratios (HRs) with 95% confidence intervals (CIs).RESULTS:Serum 25(OH)D was inversely associated with incident diabetes adjusted for potential confounders (HR per 25 nmol/l=0.83; 95% CI: 0.72–0.95; P=0.009). A statistically significant interaction was observed between 25(OH)D and waist circumference (WC) (Pinteraction=0.042) suggesting an association in persons with a high WC (HR (95%CI) per 25 nmol/l=0.74 (0.63–0.88), 218 incident cases) and not in persons with a normal WC (HR (95%CI) per 25 nmol/l=0.98 (0.78–1.24), 70 incident cases).CONCLUSIONS:Low serum 25(OH)D was associated independently with incident diabetes. The inverse association was only found in overweight-obese and not in normal weight individuals, suggesting that obesity may modify the effect of vitamin D status on the risk of diabetes.

Exploring the obesity‐asthma link: do all types of adiposity increase the risk of asthma?

Obesity and risk of asthma are linked. Different distributions of adiposity, such as visceral, subcutaneous or ectopic adiposity, may affect asthma risk differently.

Association between alcohol consumption and aeroallergen sensitization in Danish adults

Background It has been proposed that alcohol consumption may be one of the lifestyle factors associated with a westernized, urban, and affluent lifestyle contributing to the rise in atopic disease.