Annamari Lundqvist

Prenatal and post‐natal exposure to antibiotics and risk of asthma in childhood

Evidence on the association between post‐natal exposure to antibiotics and the development of asthma is extensive, but inconsistent and even less is known about prenatal exposure.

Mother's and Offspring's Use of Antibiotics and Infant Allergy to Cow's Milk

Background: Evidence on the association between antibiotics and the risk of food allergies is limited. We explored the associations between mother’s and offspring’s use of antibiotics and the risk of cow’s milk allergy in infancy. Methods: We used a national registry to identify all children who were born in 1996–2004 in Finland and diagnosed with cow’s milk allergy after 1 month of age by November 2005 (n = 15,672). For each case, we selected one control matched for birth date, sex, and hospital district. Information on antibiotic purchases and putative confounders was obtained from registries. The associations were analyzed using conditional logistic regression. Results: Maternal use of antibiotics before and during pregnancy was associated with an increased risk of cow’s milk allergy in the offspring (odds ratio = 1.26 [95% confidence interval = 1.20–1.33] and 1.21 [1.14–1.28], respectively, adjusting for putative confounders). The risk of cow’s milk allergy increased with increasing number of child’s antibiotics used from birth to diagnosis (test for trend P < 0.001). Conclusions: Both maternal and child’s use of antibiotics were associated with an increased risk of cow’s milk allergy. Future studies are needed to confirm these novel findings and to explore the potential biologic mechanisms behind the association.

Sociodemographic and socioeconomic differences in sleep duration and insomnia-related symptoms in Finnish adults

BackgroundPoor sleep tends to be patterned by sociodemographic and socioeconomic factors. The aim of this study was to examine the associations of sociodemographic and socioeconomic factors with sleep duration and insomnia-related symptoms across life course.MethodsWe used cross-sectional Health 2000 Survey (2000–2001) among a total of 5,578 adult Finns, aged 30–79 years, representative of adult Finnish population. Data about sociodemographic and socioeconomic circumstances, insomnia-related symptoms over the previous month as well as average sleep duration were collected by questionnaires. Multinomial logistic regression models were adjusted first for gender and age, second for sociodemographic factors, third additionally for socioeconomic factors, and fourth for all covariates and self-perceived health simultaneously.ResultsOn average 70% of Finnish adults slept 7–8 hours a day. Frequent insomnia-related symptoms were more prevalent among women (14%) than men (10%). Not being married, not having children, having low education, low income, being unemployed, and being a disability retiree were associated with frequent insomnia-related symptoms. Similar factors were associated with short and long sleep duration. However, childhood socioeconomic position was mostly unrelated to sleep in adulthood except parental education had some associations with short sleep duration.ConclusionsDisadvantaged socioeconomic position in adulthood, in particular income and employment status, is associated with poorer sleep. When promoting optimal sleep duration and better sleep quality, families with low incomes, unemployed people, and disability retirees should be targeted.

Standardizing serum 25-hydroxyvitamin D data from four Nordic population samples using the Vitamin D Standardization Program protocols: Shedding new light on vitamin D status in Nordic individuals

Abstract Knowledge about the distributions of serum 25-hydroxyvitamin D (25(OH)D) concentrations in representative population samples is critical for the quantification of vitamin D deficiency as well as for setting dietary reference values and food-based strategies for its prevention. Such data for the European Union are of variable quality making it difficult to estimate the prevalence of vitamin D deficiency across member states. As a consequence of the widespread, method-related differences in measurements of serum 25(OH)D concentrations, the Vitamin D Standardization Program (VDSP) developed protocols for standardizing existing serum 25(OH)D data from national surveys around the world. The objective of the present work was to apply the VDSP protocols to existing serum 25(OH)D data from a Danish, a Norwegian, and a Finnish population-based health survey and from a Danish randomized controlled trial. A specifically-selected subset (n 100–150) of bio-banked serum samples from each of the studies were reanalyzed for 25(OH)D by LC-MS/MS and a calibration equation developed between old and new 25(OH)D data, and this equation was applied to the entire data-sets from each study. Compared to estimates based on the original serum 25(OH)D data, the percentage vitamin D deficiency (< 30 nmol/L) decreased by 21.5% in the Danish health survey but by only 1.4% in the Norwegian health survey; but was relatively unchanged (0% and 0.2%) in the Finish survey or Danish RCT, respectively, following VDSP standardization. In conclusion, standardization of serum 25(OH)D concentrations is absolutely necessary in order to compare serum 25(OH)D concentrations across different study populations, which is needed to quantify and prevent vitamin D deficiency.Knowledge about the distributions of serum 25-hydroxyvitamin D (25(OH)D) concentrations in representative population samples is critical for the quantification of vitamin D deficiency as well as for setting dietary reference values and food-based strategies for its prevention. Such data for the European Union are of variable quality making it difficult to estimate the prevalence of vitamin D deficiency across member states. As a consequence of the widespread, method-related differences in measurements of serum 25(OH)D concentrations, the Vitamin D Standardization Program (VDSP) developed protocols for standardizing existing serum 25(OH)D data from national surveys around the world. The objective of the present work was to apply the VDSP protocols to existing serum 25(OH)D data from a Danish, a Norwegian, and a Finnish population-based health survey and from a Danish randomized controlled trial. A specifically-selected subset (n 100-150) of bio-banked serum samples from each of the studies were reanalyzed for 25(OH)D by LC-MS/MS and a calibration equation developed between old and new 25(OH)D data, and this equation was applied to the entire data-sets from each study. Compared to estimates based on the original serum 25(OH)D data, the percentage vitamin D deficiency (< 30 nmol/L) decreased by 21.5% in the Danish health survey but by only 1.4% in the Norwegian health survey; but was relatively unchanged (0% and 0.2%) in the Finish survey or Danish RCT, respectively, following VDSP standardization. In conclusion, standardization of serum 25(OH)D concentrations is absolutely necessary in order to compare serum 25(OH)D concentrations across different study populations, which is needed to quantify and prevent vitamin D deficiency.

Maternal and Perinatal Characteristics and the Risk of Cow's Milk Allergy in Infants up to 2 Years of Age: A Case-Control Study Nested in the Finnish Population

This study examined whether maternal background and perinatal factors were associated with the risk of cows milk allergy (CMA) in infants up to 2 years of age in a nested case-control study. All children born in 1996-2004 in Finland and diagnosed with CMA by 2006 were identified (n = 16,237). For each case, one matched control was selected. Information on maternal and perinatal factors was derived from the Medical Birth Register. The associations were analyzed by conditional logistic regression. Cesarean section (adjusted odds ratio (OR) = 1.18, 95% confidence interval (CI): 1.10, 1.27) and high maternal age (> or =35 years; adjusted OR = 1.23, 95% CI: 1.11, 1.36) were associated with increased risk, whereas low maternal socioeconomic status (adjusted OR = 0.65, 95% CI: 0.59, 0.71), smoking (adjusted OR = 0.72, 95% CI: 0.67, 0.79), high number of previous deliveries (> or =5; adjusted OR = 0.71, 95% CI: 0.59, 0.86), and multiple pregnancy (adjusted OR = 0.70, 95% CI: 0.60, 0.82) were associated with decreased risk of CMA. In conclusion, maternal background and perinatal factors may play a role in the development of CMA, but further research is needed to clarify these associations and the underpinning biologic mechanisms.

A cohort study on diet and the risk of Parkinson's disease: the role of food groups and diet quality

Previous studies on individual foods and nutrients and Parkinsons disease (PD) risk have been inconsistent. Furthermore, only one study has examined the association between the quality of diet and PD. We investigated the prediction of food groups and diet quality on PD in the Finnish Mobile Clinic Survey (1966-72). The population comprised 4524 individuals, aged 40-79 years and free from PD at baseline. Data collection included health examinations, a questionnaire and a 1-year dietary history interview. A modified Alternate Healthy Eating Index was formed to assess diet quality. Statistical analyses were based on Coxs model. During a 41-year follow-up, eighty-five incident cases of PD occurred. No statistically significant associations were found between PD incidence and most of the food groups examined. A few exceptions were fruits and berries in men and milk in women, which showed positive associations. An inverse association between the intake of meat products and PD was found in women. The diet quality index did not predict PD, the adjusted relative risk between the highest and lowest quartiles being 1.83 (95 % CI 0.65, 5.18) in men and 0.97 (95 % CI 0.38, 2.48) in women. The present study suggests that since most of the single food groups or the quality of diet did not predict PD occurrence, the role of diet is apparently rather modest.

The positive impact of general vitamin D food fortification policy on vitamin D status in a representative adult Finnish population: evidence from an 11-y follow-up based on standardized 25-hydroxyvitamin D data

Background: A systematic vitamin D fortification of fluid milk products and fat spreads was started in 2003 in Finland to improve vitamin D status. Objective: We investigated the effects of the vitamin D fortification policy on vitamin D status in Finland between 2000 and 2011.Design: Serum 25-hydroxyvitamin D [S-25(OH)D] concentrations of a nationally representative sample comprising 6134 and 4051 adults aged ≥30 y from the Health 2000 and Health 2011 surveys, respectively, were standardized according to the Vitamin D Standardization Program with the use of liquid chromatography-tandem mass spectrometry. Linear and logistic regression models were used to assess the change in S-25(OH)D concentrations.Results: Between 2000 and 2011, the mean S-25(OH)D increased from 48 nmol/L (95% CI: 47, 48 nmol/L) to 65 nmol/L (95% CI: 65, 66 nmol/L) (P < 0.001). The prevalence of vitamin D supplement users increased from 11% to 41% (P < 0.001). When analyzing the effect of fortification of fluid milk products, we focused on supplement nonusers. The mean increase in S-25(OH)D in daily fluid milk consumers (n = 1017) among supplement nonusers was 20 nmol/L (95% CI: 19, 21 nmol/L), which was 6 nmol/L higher than nonconsumers (n = 229) (14 nmol/L; 95% CI: 12, 16 nmol/L) (P < 0.001). In total, 91% of nonusers who consumed fluid milk products, fat spreads, and fish based on Finnish nutrition recommendations reached S-25(OH)D concentrations >50 nmol/L in 2011.Conclusions: The vitamin D status of the Finnish adult population has improved considerably during the time period studied. The increase is mainly explained by food fortification, especially of fluid milk products, and augmented vitamin D supplement use. Other factors, such as the difference in the ultraviolet radiation index between 2000 and 2011, may partly explain the results. When consuming vitamin D sources based on the nutritional recommendations, vitamin D status is sufficient [S-25(OH)D ≥50 nmol/L], and supplementation is generally not needed.

Associations Between Serum 25-Hydroxyvitamin D and Periodontal Pocketing and Gingival Bleeding: Results of a Study in a Non-Smoking Population in Finland

BACKGROUND Apart from the effects of vitamin D on bone metabolism, it is also known for its immunomodulatory properties. However, so far, it is not clear whether serum 25-hydroxyvitamin D [25(OH)D] exerts any beneficial effect on the periodontium. The aim of the present study is to investigate whether the serum level of 25(OH)D is related to periodontal condition, measured by means of pocketing and gingival bleeding. METHODS This cross-sectional study is based on a non-smoking subpopulation without diabetes of the Finnish Health 2000 Survey (N = 1,262). Periodontal condition was measured as the number of teeth with deep (≥4 mm) periodontal pockets and the number of bleeding sextants per individual. Serum 25(OH)D level was determined by means of a standard laboratory measurement. Prevalence rate ratios and 95% confidence intervals were estimated using Poisson regression models. RESULTS There were practically no associations between serum 25(OH)D level and teeth with deep (≥4 mm) periodontal pockets or bleeding sextants. A somewhat lower proportion of teeth with deep periodontal pockets was found in higher serum 25(OH)D quintiles among individuals with a good oral hygiene level. CONCLUSION Serum 25(OH)D did not seem to be related to periodontal condition, measured as periodontal pocketing and gingival bleeding in this low-risk, low-25(OH)D status population.

Dieting attempts modify the association between quality of diet and obesity

Evidence on the nature of the relationship between obesity and the quality of diet remains controversial. Likewise, the possible effect of dieting attempts on this association is poorly understood. This study investigates the possible modifying effect of dieting attempts on the association between the quality of diet and obesity. The authors hypothesize that among dieters the association may be biased. The study was based on a Finnish cohort, including 5910 men and women aged 30 to 99 years, with information on diet and body mass index (BMI). Using data from a food frequency questionnaire (FFQ), an Alternate Healthy Eating Index (AHEI) applicable to the Finnish regimen was formed. Obesity was defined as a BMI ≥30 kg/m2. Information on dieting attempts was collected using a questionnaire. The statistical analyses were based on linear and logistic regression. We found a positive association between the quality of the diet and obesity, the relative odds of obesity between the highest and lowest quintiles of AHEI being 1.48 (95% CI, 1.20-1.82) after adjustment for confounding factors. However, in the interaction analysis of dieting attempts and AHEI, no association was observed in non-dieters (OR, 0.92; 95% CI, 0.69-1.24) but among dieters a slightly elevated risk was found (OR, 1.40; 95% CI, 0.98-1.98). We found no association between a high quality diet and obesity among non-dieters, but a tendency for a positive association in dieters. Dieting thus seems to modify the association between diet and obesity, which should be further studied using a longitudinal design.

Genetic support for the causal role of insulin in coronary heart disease.

Aims/hypothesisEpidemiological studies have identified several traits associated with CHD, but few of these have been shown to be causal risk factors and thus suitable targets for treatment. Our aim was to evaluate the causal role of a large set of known CHD risk factors using single-nucleotide polymorphisms (SNPs) as instrumental variables.MethodsBased on published genome-wide association studies (GWASs), we estimated the associations between the established risk factors (blood lipids, obesity, glycaemic traits and BP) and CHD with two complementary approaches: (1) using summary statistics from GWASs to analyse the accordance of SNP effects on risk factors and on CHD; and (2) individual-level analysis where we constructed genetic risk scores (GRSs) in a large Finnish dataset (N = 26,554, CHD events n = 4016).We used a weighted regression-based method for summary-level data to evaluate the causality of risk factors. The associations between the GRSs and CHD in the Finnish dataset were evaluated with logistic and conditional logistic regression models.ResultsThe summary-level data analysis revealed causal effects between glycaemic traits (insulin and glucose) and CHD. The individual-level data analysis supported the causal role of insulin, but not of glucose, on CHD. The GRS for insulin was associated with CHD in the Finnish cohort (OR 1.06 per SD in GRS, 95% CI 1.02, 1.10, p = 0.002).Conclusions/interpretationThese results support the causal role of insulin in the pathogenesis of CHD. Efficient treatment and prevention of insulin resistance is essential to prevent future CHD events.