Neonatal folate, homocysteine, vitamin B12 levels and methylenetetrahydrofolate reductase variants in childhood asthma and eczema

OBJECTIVES

To assess the associations of folate, homocysteine and vitamin B12 levels of children at birth and their methylenetetrahydrofolate reductase (MTHFR) variants with asthma and eczema in childhood.

METHODS

This study was embedded in a population-based prospective cohort study (n = 2,001). Neonatal cord blood folate, homocysteine and vitamin B12 levels were measured, and MTHFR C677T and A1298C genotyped. Wheezing and physician-diagnosed eczema were annually obtained by questionnaire until 4 years. At 6 years, we collected information on physician-diagnosed asthma ever and self-reported eczema ever, measured fractional exhaled nitric oxide (FeNO), and interrupter resistance (Rint). Data were analysed with generalized estimating equations or logistic regression: continuous outcomes with linear regression models.

RESULTS

Folate, homocysteine and vitamin B12 levels of children at birth were not associated with wheezing or eczema until 4 years, asthma and eczema ever, or FeNO or Rint at 6 years. In children carrying C677T mutations in MTHFR, higher folate levels were associated with an increased risk of eczema (repeated eczema until 4 years: OR 1.40 (95% CI 1.09-1.80) (SD change) P-interaction = 0.003, eczema ever at 6 years: OR 1.41 (0.97-2.03) P-interaction = 0.011). No interactions between MTHFR and child folate and homocysteine levels were observed for wheezing and asthma.

CONCLUSIONS

Folate, homocysteine and vitamin B12 levels of children at birth did not affect asthma- and eczema-related outcomes up to the age of 6 years. Further studies are warranted to establish the role of MTHFR variants in these associations.

Parental depressive and anxiety symptoms during pregnancy and attention problems in children: a cross-cohort consistency study

BACKGROUND

Maternal depression and anxiety during pregnancy have been associated with offspring-attention deficit problems.

AIM

We explored possible intrauterine effects by comparing maternal and paternal symptoms during pregnancy, by investigating cross-cohort consistency, and by investigating whether parental symptoms in early childhood may explain any observed intrauterine effect.

METHODS

This study was conducted in two cohorts (Generation R, n = 2,280 and ALSPAC, n = 3,442). Pregnant women and their partners completed questionnaires to assess symptoms of depression and anxiety. Child attention problems were measured in Generation R at age 3 with the Child Behavior Checklist, and in ALSPAC at age 4 with the Strengths and Difficulties Questionnaire.

RESULTS

In both cohorts, antenatal maternal symptoms of depression (Generation R: OR 1.23, 95% CI 1.05-1.43; ALSPAC: OR 1.33, 95% CI 1.19-1.48) and anxiety (Generation R: OR 1.24, 95% CI 1.06-1.46; ALSPAC: OR 1.32, 95% CI 1.19-1.47) were associated with a higher risk of child attention problems. In ALSPAC, paternal depression was also associated with a higher risk of child attention problems (OR 1.11, 95% CI 1.00-1.24). After adjusting for maternal symptoms after giving birth, antenatal maternal depression and anxiety were no longer associated with child attention problems in Generation R. Moreover, there was little statistical evidence that antenatal maternal and paternal depression and anxiety had a substantially different effect on attention problems of the child.

CONCLUSIONS

The apparent intrauterine effect of maternal depression and anxiety on offspring-behavioural problems may be partly explained by residual confounding. There was little evidence of a difference between the strength of associations of maternal and paternal symptoms during pregnancy with offspring-attention problems. That maternal symptoms after childbirth were also associated with offspring-behavioural problems may indicate a contribution of genetic influences to the association.

Changing prediction of mortality by systolic blood pressure with increasing age: the Rotterdam study

There are indications that in persons of older age, systolic blood pressure (SBP) is no longer associated with mortality. This raises the question whether the predictive value of SBP changes from younger to older age groups. Analysis in the Rotterdam Study, a population-based prospective cohort study among 4,612 participants aged ≥55 years without previous cardiovascular disease and with a median follow-up of 14.9 (interquartile range, 11.1-15.8) years. Within four age groups (55-64, 65-74, 75-84, ≥85 years), the predictive value of baseline SBP for mortality was studied. From age 55 to ≥85 years, risk of all-cause mortality associated with SBP ≥160 mmHg decreased from HR 1.7 (95%CI 1.2-2.2) to HR 0.7 (95%CI 0.4-1.1), p for trend <0.001. For participants with SBP 140-159 mmHg, the risk decreased from HR 1.2 (95%CI 0.9-1.5) to HR 0.7 (95%CI 0.5-1.1), p for trend <0.001. Analyses in the 5-year age groups showed an increased risk with higher SBPs up to age 75 years. After 75 years, a trend towards SBP no longer being associated with an increased mortality risk was seen in our study. These findings need to be considered with recently reported beneficial effects of antihypertensive treatment in this age group.

Gait patterns in a community-dwelling population aged 50 years and older

Poor gait is an important risk factor for falls and associated with higher morbidity and mortality. It is well established that older age is associated with worse gait, but it remains unclear at what age this association is first seen. Moreover, previous studies focused mainly on normal walking, but gait also encompasses turning and tandem walking. In a large study of community-dwelling middle-aged and elderly persons we investigated the association of age with gait, focusing on normal walking, turning and tandem walking. In 1500 persons aged 50 years and over, we measured gait using an electronic walkway. Participants performed normal walks, turning and a tandem walk. With principal components analysis of 30 variables we summarized gait into five known gait factors: Rhythm, Variability, Phases, Pace and Base of Support; and uncovered two novel gait factors: Tandem and Turning. The strongest associations with age were found for Variability (difference in Z-score -0.29 per 10 years increase (95% confidence interval: -0.34; -0.24)), Phases (-0.31 per 10 years (-0.36; -0.27)) and Tandem (-0.25 per 10 years (-0.30; -0.20)). Additionally, these factors already showed association with the youngest age groups, from 55 to 60 years of age and older. Our study shows that Variability, Phases and Tandem have the strongest association with age and are the earliest to demonstrate a poorer gait pattern with higher age. Future research should further investigate how these gait factors relate with gait-related diseases in their earliest stages.

Attachment insecurity predicts child active resistance to parental requests in a compliance task

AIM

We studied the effects of early mother-child relationship quality and child temperament on the development of child compliance and active resistance in a large population-based cohort study (n = 534).

BACKGROUND

Parenting and the quality of the parent-child relationship can either hamper or support the development of child compliance directly or in interplay with child temperament.

METHODS

Mother-infant dyads were observed at 14 and 36 months and maternal and child behaviours were independently coded. The quality of compliance was assessed at 36 months in a clean-up task. Child behaviour was coded using a system differentiating between two dimensions: Compliance and Active Resistance.

RESULTS

Controlling for concurrent maternal sensitivity, child temperament, and gender children with a more insecure attachment relationship showed higher levels of active resistance during Clean-Up than more securely attached children. The effect was stronger for boys than for girls and mainly driven by attachment avoidance.

CONCLUSIONS

Early attachment is an important contributor to child socialization of moral behaviour.

GDF5 single-nucleotide polymorphism rs143383 is associated with lumbar disc degeneration in Northern European women

Objective

Lumbar disc degeneration (LDD) is a serious social and medical problem which has been shown to be highly heritable. It has similarities with peripheral joint osteoarthritis (OA) in terms of both epidemiology and pathologic processes. A few known genetic variants have been identified using a candidate gene approach, but many more are thought to exist. GDF5 is a gene whose variants have been shown to play a role in skeletal height as well as predisposing to peripheral joint OA. In vitro, the gene product growth differentiation factor 5 has been shown to promote growth and repair of animal disc. This study was undertaken to investigate whether the GDF5 gene plays a role in LDD.

Methods

We investigated whether the 5′ upstream single-nucleotide polymorphism (SNP) variant rs143383 was associated with LDD, using plain radiography and magnetic resonance imaging to identify disc space narrowing and osteophytes, in 5 population cohorts from Northern Europe.

Results

An association between LDD and the SNP rs143383 was identified in women, with the same risk allele as in knee and hip OA (odds ratio 1.72 [95% confidence interval 1.15–2.57], P = 0.008).

Conclusion

Our findings in 5 population cohorts from Northern Europe indicate that a variant in the GDF5 gene is a risk factor for LDD in women. Many more such variants are predicted to exist, but this result highlights the growth and differentiation cellular pathway as a possible route to a better understanding of the process behind lumbar disc degeneration.

Trajectories of maternal depressive symptoms predict child problem behaviour: the Generation R study

BACKGROUND

It is unclear how the course of maternal depressive symptoms affects child development. We modelled trajectories of maternal depressive symptoms from mid-pregnancy to 3 years after childbirth to better determine their associations with child problem behaviour.

METHOD

Mother-child dyads (n = 4167) participated in a population-based prospective cohort in The Netherlands. Depressive symptoms were assessed with the Brief Symptom Inventory during pregnancy and at 2, 6 and 36 months postnatally. When children were 3 years old, problem behaviour was assessed with the Child Behaviour Checklist completed by each parent. A group-based modelling technique was used to model trajectories of maternal depressive symptoms and to examine their association with child problem behaviour. The added value of trajectory modelling was determined with successive linear regressions.

RESULTS

We identified four trajectories of maternal depressive symptoms; 'no' (34%), 'low' (54%), 'moderate' (11%) and 'high' (1.5%). Child problem behaviour varied as a function of maternal trajectory membership. Whether rated by mother or father, children of mothers assigned to higher trajectories had significantly more problem behaviours than children of mothers assigned to lower trajectories. The model including trajectories had additive predictive value over a model relying only on a summed repeated measure of severity and a predefined chronicity variable.

CONCLUSIONS

Depending on their course, maternal depressive symptoms have different effects on child problem behaviour. More information is gained by studying trajectories of symptoms, than only predefined measures of severity and chronicity. Moreover, trajectories can help identifying clinically depressed mothers who are possible candidates for early interventions.

Genome-wide association analysis of coffee drinking suggests association with CYP1A1/CYP1A2 and NRCAM

Coffee consumption is a model for addictive behavior. We performed a meta-analysis of genome-wide association studies (GWASs) on coffee intake from 8 Caucasian cohorts (N=18 176) and sought replication of our top findings in a further 7929 individuals. We also performed a gene expression analysis treating different cell lines with caffeine. Genome-wide significant association was observed for two single-nucleotide polymorphisms (SNPs) in the 15q24 region. The two SNPs rs2470893 and rs2472297 (P-values=1.6 × 10(-11) and 2.7 × 10(-11)), which were also in strong linkage disequilibrium (r(2)=0.7) with each other, lie in the 23-kb long commonly shared 5' flanking region between CYP1A1 and CYP1A2 genes. CYP1A1 was found to be downregulated in lymphoblastoid cell lines treated with caffeine. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas CYP1A2 is involved in the primary metabolism of caffeine. Significant evidence of association was also detected at rs382140 (P-value=3.9 × 10(-09)) near NRCAM-a gene implicated in vulnerability to addiction, and at another independent hit rs6495122 (P-value=7.1 × 10(-09))-an SNP associated with blood pressure-in the 15q24 region near the gene ULK3, in the meta-analysis of discovery and replication cohorts. Our results from GWASs and expression analysis also strongly implicate CAB39L in coffee drinking. Pathway analysis of differentially expressed genes revealed significantly enriched ubiquitin proteasome (P-value=2.2 × 10(-05)) and Parkinson's disease pathways (P-value=3.6 × 10(-05)).

Association between genetic variation in a region on chromosome 11 and schizophrenia in large samples from Europe

Recent molecular studies have implicated common alleles of small to moderate effect and rare alleles with larger effect sizes in the genetic architecture of schizophrenia (SCZ). It is expected that the reliable detection of risk variants with very small effect sizes can only be achieved through the recruitment of very large samples of patients and controls (that is tens of thousands), or large, potentially more homogeneous samples that have been recruited from confined geographical areas using identical diagnostic criteria. Applying the latter strategy, we performed a genome-wide association study (GWAS) of 1169 clinically well characterized and ethnically homogeneous SCZ patients from a confined area of Western Europe (464 from Germany, 705 from The Netherlands) and 3714 ethnically matched controls (1272 and 2442, respectively). In a subsequent follow-up study of our top GWAS results, we included an additional 2569 SCZ patients and 4088 controls (from Germany, The Netherlands and Denmark). Genetic variation in a region on chromosome 11 that contains the candidate genes AMBRA1, DGKZ, CHRM4 and MDK was significantly associated with SCZ in the combined sample (n=11 540; P=3.89 × 10(-9), odds ratio (OR)=1.25). This finding was replicated in 23 206 independent samples of European ancestry (P=0.0029, OR=1.11). In a subsequent imaging genetics study, healthy carriers of the risk allele exhibited altered activation in the cingulate cortex during a cognitive control task. The area of interest is a critical interface between emotion regulation and cognition that is structurally and functionally abnormal in SCZ and bipolar disorder.

von Willebrand factor plasma levels, genetic variations and coronary heart disease in an older population

BACKGROUND

High von Willebrand factor (VWF) levels are associated with an increased risk of coronary heart disease (CHD). However, it remains unclear whether VWF is causally related to the occurrence of CHD or primarily mirrors endothelial dysfunction, which predisposes to atherosclerosis and subsequent CHD.

OBJECTIVES

Because VWF is largely determined by genetic factors, we investigated whether VWF antigen levels (VWF:Ag) and the risk of CHD are affected by common variations in the VWF gene.

METHODS

We included 7002 participants (≥ 55 years) from the large prospective population-based Rotterdam Study in the discovery cohort. The extension cohort of the Rotterdam Study, consisting of 3011 participants, was used as a replication cohort. We determined VWF:Ag levels and genotype data of 38 single-nucleotide polymorphisms (SNPs) in VWF. Subsequently, hazard ratios for CHD were calculated and genetic analyses were performed to assess the relationship between SNPs, VWF:Ag levels and CHD risk.

RESULTS

We identified and replicated three SNPs that were associated with VWF:Ag: rs216321 (β = 0.10 [95% confidence interval, CI, 0.06;0.13]) (Ala852Gln), rs1063856 (β = 0.05 [95% CI 0.03;0.07]) (Thr789Ala) and rs2283333 (β = 0.09 [95% CI 0.05;0.21]) (intron 15). However, genetic polymorphisms in the VWF gene were not associated with the risk of CHD.

CONCLUSIONS

In this study we have shown that genetic variations in VWF strongly affect VWF plasma levels, but are not associated with the risk of CHD. Our findings therefore do not support a strong causal relationship between VWF and CHD in elderly individuals of ≥ 55 years, but suggest that VWF is primarily a marker of CHD.

A gene variant near ATM is significantly associated with metformin treatment response in type 2 diabetes: a replication and meta-analysis of five cohorts

AIMS/HYPOTHESIS

In this study we aimed to replicate the previously reported association between the glycaemic response to metformin and the SNP rs11212617 at a locus that includes the ataxia telangiectasia mutated (ATM) gene in multiple additional populations.

METHODS

Incident users of metformin selected from the Diabetes Care System West-Friesland (DCS, n = 929) and the Rotterdam Study (n = 182) from the Netherlands, and the CARDS Trial (n = 254) from the UK were genotyped for rs11212617 and tested for an association with both HbA(1c) reduction and treatment success, defined as the ability to reach the treatment target of an HbA(1c) ≤ 7 % (53 mmol/mol). Finally, a meta-analysis including data from literature was performed.

RESULTS

In the DCS cohort, we observed an association between rs11212617 genotype and treatment success on metformin (OR 1.27, 95% CI 1.03, 1.58, p = 0.028); in the smaller Rotterdam Study cohort, a numerically similar but non-significant trend was observed (OR 1.45, 95% CI 0.87, 2.39, p = 0.15); while in the CARDS cohort there was no significant association. In meta-analyses of these three cohorts separately or combined with the previously published cohorts, rs11212617 genotype is associated with metformin treatment success (OR 1.24, 95% CI 1.04, 1.49, p = 0.016 and OR 1.25, 95% CI 1.33, 1.38, p = 7.8 × 10(-6), respectively).

CONCLUSIONS/INTERPRETATION

A gene variant near ATM is significantly associated with metformin treatment response in type 2 diabetic patients from the Netherlands and the UK. This is the first robustly replicated common susceptibility locus found to be associated with metformin treatment response.

Homocysteine and folate concentrations in early pregnancy and the risk of adverse pregnancy outcomes: the Generation R Study

OBJECTIVE

To investigate associations between early pregnancy homocysteine, folate and vitamin B12 concentrations and placental weight, birthweight and adverse pregnancy outcomes.

DESIGN

Population-based birth cohort study.

SETTING

Rotterdam, the Netherlands.

POPULATION

Cohort of 5805 pregnant women.

METHODS

To analyse homocysteine, folate and vitamin B12 concentrations, blood was drawn in early pregnancy. These concentrations were divided into quintiles. Information on birth outcomes was retrieved from medical records. Multivariate regression analyses were used.

MAIN OUTCOME MEASURES

Placental weight, birthweight, small for gestational age at birth (SGA) (<5th centile), prematurity and pre-eclampsia.

RESULTS

High homocysteine concentrations (highest quintile) were associated with lower placental weight (difference 30 g; P < 0.001) and birthweight (difference 110 g; P < 0.001), and increased risk of SGA [odds ratio (OR) 1.7; P = 0.006] compared with lowest quintile (reference). Low folate concentrations (lowest quintile) were associated with lower placental weight (difference 26 g; P = 0.001) and birthweight (difference 125 g; P < 0.001), and increased risks of SGA (OR 1.9; P = 0.002), prematurity (OR 2.2; P = 0.002) and pre-eclampsia (OR 2.1; P = 0.04) compared with highest quintile (reference). The risk of developing SGA and pre-eclampsia was substantially higher in women who had higher homocysteine and lower folate concentrations. No associations were found with vitamin B12.

CONCLUSIONS

Higher homocysteine and lower folate concentrations in early pregnancy are associated with lower placental weight and birthweight, and higher risk of adverse pregnancy outcomes. These findings suggest that high homocysteine and low folate concentrations in early pregnancy may adversely influence placentation and subsequently affect the success of pregnancy and birth outcomes.

The association between plasma homocysteine levels, methylation capacity and incident osteoporotic fractures

BACKGROUND

An elevated level of plasma homocysteine (Hcy) is a known risk factor for osteoporotic fractures. In addition, Hcy is related to DNA-methylation metabolism. To determine whether the association between Hcy and fractures is explained by an altered methylation capacity, we investigated the associations between levels of s-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) and fracture risk.

METHODS

We studied 503 females aged 55 years and over from the Rotterdam Study (RS) in whom plasma Hcy, SAM and SAH levels were measured. Bone mineral density (BMD) at the hip was assessed using DXA. Incident fractures were recorded over a mean period of 7.0 years. Cox proportional hazards analysis and linear regression were used to assess relationships between plasma metabolite levels, incident osteoporotic fractures and BMD.

RESULTS

Over a total of 3502 person-years of follow-up, 103 subjects sustained at least one osteoporotic fracture. Whereas incidence of osteoporotic fractures was associated with quartiles of Hcy (p=0.047), it was not associated with quartiles of SAM, SAH or SAM/SAH-ratio (all p for trend>0.6). Stepwise linear regression showed that SAM/SAH-ratio, but not Hcy, was independently associated with hip BMD (β=0.073, p=0.025).

CONCLUSION

Since SAM, SAH and SAM/SAH-ratio were not associated with osteoporotic fractures, alterations in methylation capacity most likely do not appear to be an important factor in the association between Hcy and fractures.

Interaction of a 17q12 variant with both fetal and infant smoke exposure in the development of childhood asthma-like symptoms

BACKGROUND

Gene variants on chromosome 17q12-21 are associated with an increased risk of childhood-onset asthma, a risk known to be modified by environmental tobacco smoke (ETS).

OBJECTIVES

To assess whether the association of rs2305480 on chromosome 17q12 in the GSDML gene with asthma-like symptoms in the first 4 years of life is modified by smoke exposure during fetal and early postnatal life.

METHODS

We used data from two independent prospective cohort studies from fetal life onwards in the Netherlands. We genotyped rs2305480 and assessed maternal smoking during pregnancy and ETS exposure at the age of 2. Asthma-like symptoms, defined as any reported wheezing, shortness of breath or dry nocturnal cough, were reported by parents when the children were 1, 2, 3, and 4 years. Analyses were based on a total group of 4461 Caucasian children.

RESULTS

The G risk-allele of rs2305480 was associated with asthma-like symptoms [overall odds ratio 1.17 (1.11, 1.24), 2.66E-9]. The effect of rs2305480 on asthma-like symptoms was stronger among children who were exposed to smoke during fetal life (P-interaction = 0.04). Smoke exposure in early postnatal life was also associated with an increased effect of the 17q12 single nucleotide polymorphism (SNP) on asthma-like symptoms (P-interaction = 5.06E-4). These associations were consistent in both cohorts.

CONCLUSION

A 17q12 variant, rs2305480, was associated with asthma-like symptoms in preschool children, and this association was modified by smoke exposure already during fetal life, and in infancy. Further investigation regarding SNPs in linkage disequilibrium with rs2305480 in relation to pathophysiological pathways is needed.

Is dementia incidence declining?: Trends in dementia incidence since 1990 in the Rotterdam Study

OBJECTIVE

To investigate whether dementia incidence has changed over the last 2 decades.

METHODS

We compared dementia incidence in 2 independent subcohorts of persons aged 60-90 years from the Rotterdam Study, a population-based cohort study. The first subcohort started in 1990 (n = 5,727), the second in 2000 (n = 1,769). Participants were dementia-free at baseline and followed for at maximum 5 years. We calculated age-adjusted dementia incidence rates for the 2 subcohorts in total, in 10-year age strata, and for men and women separately. We also compared mortality rates, differences in prevalence of vascular risk factors, and medication use. Finally, we compared brain volumes and the extent of cerebral small vessel disease in participants who underwent brain imaging 5 years after the baseline examinations.

RESULTS

In the 1990 subcohort (25,696 person-years), 286 persons developed dementia, and in the 2000 subcohort (8,384 person-years), 49 persons. Age-adjusted dementia incidence rates were consistently, yet nonsignificantly, lower in the 2000 subcohort in all strata, reaching borderline significance in the overall analysis (incidence rate ratio 0.75, 95% confidence interval [CI] 0.56-1.02). Mortality rates were also lower in the 2000 subcohort (rate ratio 0.63, 95% CI 0.52-0.77). The prevalence of hypertension and obesity significantly increased between 1990 and 2000. This was paralleled by a strong increase in use of antithrombotics and lipid-lowering drugs. Participants in 2005-2006 had larger total brain volumes (p < 0.001) and less cerebral small vessel disease (although nonsignificant in men) than participants in 1995-1996.

CONCLUSIONS

Although the differences in dementia incidence were nonsignificant, our study suggests that dementia incidence has decreased between 1990 and 2005.

Genetic determinants of von Willebrand factor plasma levels and the risk of stroke: the Rotterdam Study

BACKGROUND

High von Willebrand factor (VWF) plasma levels are associated with an increased risk of stroke. VWF levels are strongly heritable. A previous meta-analysis of five large genome-wide association studies identified single-nucleotide polymorphisms (SNPs) within eight genetic loci as determinants of VWF levels. Whether these SNPs are associated with stroke risk is not known. The aim of our study was to investigate the association between genetic determinants of VWF levels and stroke risk.

METHODS

The study was part of the Rotterdam Study, a large population-based cohort study among subjects aged ≥ 55 years. A total of 5763 participants for whom DNA was available, and who were free of stroke at baseline, were eligible for analysis. VWF antigen (VWF:Ag) levels were measured in 3379 eligible participants. Within each of the eight loci, one top SNP was defined. The association between the eight SNPs and the risk of stroke was analyzed. Then, a genetic score, based on these eight SNPs, was constructed, and its total contribution to VWF plasma levels and stroke risk was investigated.

RESULTS

None of the eight SNPs was individually associated with stroke risk. A higher genetic score was significantly associated with a higher VWF:Ag level, but was not associated with an increased risk of stroke.

CONCLUSION

Eight SNPs that strongly determine VWF levels are not associated with stroke risk, either individually, or combined in a genetic score.

Deciduous Molar Hypomineralization and Molar Incisor Hypomineralization

This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. This study focused on the relationship between Deciduous Molar Hypomineralization (DMH) and Molar Incisor Hypomineralization (MIH). First permanent molars develop during a period similar to that of second primary molars, with possible comparable risk factors for hypomineralization. Children with DMH have a greater risk of developing MIH. Clinical photographs of clean, moist teeth were taken with an intra-oral camera in 6,161 children (49.8% girls; mean age 74.3 mos, SD ± 5.8). First permanent molars and second primary molars were scored with respect to DMH or MIH. The prevalence of DMH and MIH was 9.0% and 8.7% at child level, and 4.0% and 5.4% at tooth level. The Odds Ratio for MIH based on DMH was 4.4 (95% CI, 3.1-6.4). The relationship between the occurrence of DMH and MIH suggests a shared cause and indicates that, clinically, DMH can be used as a predictor for MIH.

The effect of common genetic variation in 11β-hydroxysteroid dehydrogenase type 1 on hypothalamic-pituitary-adrenal axis activity and incident depression

BACKGROUND

Accumulating evidence suggests that hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA axis) is involved in depression. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts inert cortisone to active cortisol and is implicated in HPA axis regulation in animal studies. The aim of our study was to identify polymorphisms in 11β-HSD1 gene (HSD11B1) with consistent associations with increased HPA axis activity and relate those polymorphisms to depression.

METHODS

Twelve single-nucleotide polymorphisms (SNPs), including 11 tagging SNPs, were selected using the HapMap database and genotyped in 4228 participants of the population-based Rotterdam Study. The outcome measures were salivary cortisol levels after awakening, 30 min later, at 1700 h, at bedtime, and plasma levels of androstenedione (in women only). SNPs that were significantly associated with cortisol as well as androstenedione levels were also related to incident depression.

RESULTS

rs11119328 was associated with higher cortisol saliva samples collected at bedtime as well as higher androstenedione levels (P value after correction for multiple testing: 0.01 and 0.04, respectively). Carriers of this polymorphism had an increased risk of an incident depression (hazard ratio 1.28, 95% confidence interval 1.03-1.59). Two other SNPs, which were in high linkage disequilibrium with rs11119328, were related to higher cortisol levels but not with androstenedione levels.

CONCLUSIONS

We identified one SNP, which was associated with increased salivary cortisol levels at nadir as well as higher androstenedione levels. Moreover, this SNP was also associated with a higher risk of an incident depression. This suggests that 11β-HSD1 is implicated in human HPA axis regulation and susceptibility to depression.

Cerebral microbleeds are associated with worse cognitive function: the Rotterdam Scan Study

OBJECTIVE

Cerebral microbleeds are frequently found in the general elderly population and may reflect underlying vascular disease, but their role in cognitive function is unknown.

METHODS

We investigated the association between cerebral microbleeds and performance in multiple cognitive domains in 3,979 persons without dementia (mean age, 60.3 years). Mini-Mental State Examination (MMSE) score and neuropsychological tests were used to assess global cognition and the following cognitive domains: memory, information processing speed, executive function, and motor speed. We used number of microbleeds as continuous variable, and additionally distinguished between persons with no microbleeds, 1 microbleed, 2-4 microbleeds, and ≥5 microbleeds. The association of microbleeds with different cognitive domains was estimated using linear regression models. Additional adjustments were made for vascular risk factors, brain atrophy, and other imaging markers of cerebral small vessel disease. We stratified analyses by location of microbleeds.

RESULTS

A higher number of microbleeds was associated with lower MMSE score and worse performance on tests of information processing speed and motor speed. When analyzed per category, presence of 5 or more microbleeds was associated with worse performance in all cognitive domains, except memory. These associations were most robust in participants with strictly lobar microbleeds, whereas after additional adjustments associations disappeared for deep or infratentorial microbleeds.

CONCLUSIONS

Presence of numerous microbleeds, especially in a strictly lobar location, is associated with worse performance on tests measuring cognitive function, even after adjustments for vascular risk factors and other imaging markers of small vessel disease. These results suggest an independent role for microbleed-associated vasculopathy in cognitive impairment.

Explaining ethnic differences in late antenatal care entry by predisposing, enabling and need factors in The Netherlands. The Generation R Study

Despite compulsory health insurance in Europe, ethnic differences in access to health care exist. The objective of this study is to investigate how ethnic differences between Dutch and non-Dutch women with respect to late entry into antenatal care provided by community midwifes can be explained by need, predisposing and enabling factors. Data were obtained from the Generation R Study. The Generation R Study is a multi-ethnic population-based prospective cohort study conducted in the city of Rotterdam. In total, 2,093 pregnant women with a Dutch, Moroccan, Turkish, Cape Verdean, Antillean, Surinamese Creole and Surinamese Hindustani background were included in this study. We examined whether ethnic differences in late antenatal care entry could be explained by need, predisposing and enabling factors. Subsequently, logistic regression analysis was used to assess the independent role of explanatory variables in the timing of antenatal care entry. The main outcome measure was late entry into antenatal care (gestational age at first visit after 14 weeks). With the exception of Surinamese-Hindustani women, the percentage of mothers entering antenatal care late was higher in all non-Dutch compared to Dutch mothers. We could explain differences between Turkish (OR = 0.95, CI: 0.57–1.58), Cape Verdean (OR = 1.65. CI: 0.96–2.82) and Dutch women. Other differences diminished but remained significant (Moroccan: OR = 1,74, CI: 1.07–2.85; Dutch Antillean OR 1.80, CI: 1.04–3.13). We found that non-Dutch mothers were more likely to enter antenatal care later than Dutch mothers. Because we are unable to explain fully the differences regarding Moroccan, Surinamese-Creole and Antillean women, future research should focus on differences between 1st and 2nd generation migrants, as well as on language barriers that may hinder access to adequate information about the Dutch obstetric system.

Genetic variation in the ABCC2 gene is associated with dose decreases or switches to other cholesterol-lowering drugs during simvastatin and atorvastatin therapy

Several statins are substrates for the multidrug resistance-associated protein 2 transporter, encoded by the ABCC2 gene. We analyzed in the Rotterdam Study whether the common polymorphisms -24C>T, 1249G>A and 3972C>T in the ABCC2 gene were associated with a dose decrease or switch to another cholesterol-lowering drug in simvastatin and atorvastatin users. These events could indicate an adverse effect or a too strong reduction in cholesterol level. We identified 1014 simvastatin and atorvastatin users during the period 1 January 1991 to 1 January 2010. Associations between genetic variation and the risk of these events were analyzed using Cox proportional hazards modelling. The ABCC2 -24C>T genotype (HR 1.32 95% CI 1.04-1.69) and the H12 haplotype versus the H2 haplotype (HR 1.49; 95% CI 1.06-2.09) were associated with these events in simvastatin users. A similar but not significant association was found in atorvastatin users. To conclude, genetic variation in the ABCC2 gene is associated with these events in simvastatin users.

Statin use is associated with reduced incidence and progression of knee osteoarthritis in the Rotterdam study

BACKGROUND

Osteoarthritis is the most frequent chronic joint disease causing pain and disability. Besides biomechanical mechanisms, the pathogenesis of osteoarthritis may involve inflammation, vascular alterations and dysregulation of lipid metabolism. As statins are able to modulate many of these processes, this study examines whether statin use is associated with a decreased incidence and/or progression of osteoarthritis.

METHODS

Participants in a prospective population-based cohort study aged 55 years and older (n=2921) were included. x-Rays of the knee/hip were obtained at baseline and after on average 6.5 years, and scored using the Kellgren and Lawrence score for osteoarthritis. Any increase in score was defined as overall progression (incidence and progression). Data on covariables were collected at baseline. Information on statin use during follow-up was obtained from computerised pharmacy databases. The overall progression of osteoarthritis was compared between users and non-users of statins. Using a multivariate logistic regression model with generalised estimating equation, OR and 95% CI were calculated after adjusting for confounding variables.

RESULTS

Overall progression of knee and hip osteoarthritis occurred in 6.9% and 4.7% of cases, respectively. The adjusted OR for overall progression of knee osteoarthritis in statin users was 0.43 (95% CI 0.25 to 0.77, p=0.01). The use of statins was not associated with overall progression of hip osteoarthritis.

CONCLUSIONS

Statin use is associated with more than a 50% reduction in overall progression of osteoarthritis of the knee, but not of the hip.

Exhaled nitric oxide and the risk of wheezing in infancy: the Generation R Study

We assessed whether exhaled nitric oxide fraction (F(eNO)), a marker of eosinophilic airway inflammation, at 6 months was associated with the risk of wheezing during the first 2 yrs of life. In the Generation R birth cohort, pre- and post-natal risk factors for respiratory morbidity and respiratory symptoms were assessed by questionnaires at 6 and 24 months. In 428 infants, off-line mixed oral/nasal F(eNO) was successfully measured during tidal breathing at 6 months. Complete data on F(eNO) and respiratory symptoms within the first 6 months of life were available for 294 infants. F(eNO) was higher in males, was positively associated with age and was negatively associated with upper and lower respiratory symptoms within the first 6 months. Logistic regression analysis showed that for every ppb increase of F(eNO) measured at 6 months, infants had a 1.06 (95% confidence interval 1.01-1.11)-fold increased risk of wheezing in the second year of life. High F(eNO) (>17.5 ppb) showed a limited added value in predicting wheezing in the second year. We conclude that F(eNO) at 6 months is positively associated with the risk of wheezing, but has limited added value in predicting wheezing in the second year of life in individual children.

Streptococcus pneumoniae exposure is associated with human metapneumovirus seroconversion and increased susceptibility to in vitro HMPV infection

It remains largely unknown which factors determine the clinical outcome of human metapneumovirus (HMPV) infections. The aim of the present study was to analyse whether exposure to bacterial pathogens can influence HMPV infections. From 57 children, serum samples and colonization data for Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Streptococcus pneumoniae were collected at 1.5, 6, 14 and 24 months of age. Seroconversion rates to HMPV were determined and related to bacterial carriage. Frequent nasopharyngeal carriage (≥2 times in the first 2 years of life) of S. pneumoniae, but not of the other three pathogens, was associated with increased seroconversion rates of infants to HMPV at the age of 2 years (frequently vs. less exposed, 93% vs. 59%; p <0.05). Subsequently, the susceptibility of well-differentiated normal human bronchial epithelial cells (wd-NHBE) pre-incubated with bacterial pathogens to in vitro HMPV infection was evaluated. Pre-incubation of wd-NHBE with S. pneumoniae resulted in increased susceptibility to infection with HMPV-enhanced green fluorescent protein (EGFP), as determined by enumeration of EGFP-positive cells. This was not the case for cells pre-incubated with H. influenzae, M. catarrhalis on S. aureus. We conclude that exposure to S. pneumoniae can modulate HMPV infection.

Duration and exclusiveness of breastfeeding and childhood asthma-related symptoms

The aim of our study was to examine the associations of breastfeeding duration and exclusiveness with the risks of asthma-related symptoms in preschool children, and to explore whether these associations are explained by atopic or infectious mechanisms. This study was embedded in a population-based prospective cohort study of 5,368 children. Information on breastfeeding duration, exclusiveness and asthma-related symptoms, including wheezing, shortness of breath, dry cough and persistent phlegm, was obtained by questionnaires. Compared with children who were breastfed for 6 months, those who were never breastfed had overall increased risks of wheezing, shortness of breath, dry cough and persistent phlegm during the first 4 yrs (OR 1.44 (95% CI 1.24-1.66), 1.26 (1.07-1.48), 1.25 (1.08-1.44) and 1.57 (1.29-1.91), respectively). Similar associations were observed for exclusive breastfeeding. The strongest associations per symptom per year were observed for wheezing at 1 and 2 yrs. Additionally adjusted analyses showed that the associations of breastfeeding with asthma-related symptoms were not explained by eczema but partly by lower respiratory tract infections. Shorter duration and nonexclusivity of breastfeeding were associated with increased risks of asthma-related symptoms in preschool children. These associations seemed, at least partly, to be explained by infectious, but not by atopic, mechanisms.

Association of an APOC3 promoter variant with type 2 diabetes risk and need for insulin treatment in lean persons

AIMS/HYPOTHESIS

An APOC3 promoter haplotype has been previously associated with type 1 diabetes. In this population-based study, we investigated whether APOC3 polymorphisms increase type 2 diabetes risk and need for insulin treatment in lean participants.

METHODS

In the Rotterdam Study, a population-based prospective cohort (n = 7,983), Cox and logistic regression models were used to analyse the associations and interactive effects of APOC3 promoter variants (-482C > T, -455T > C) and BMI on type 2 diabetes risk and insulin treatment. Analyses were followed by replication in an independent case-control sample (1,817 cases, 2,292 controls) and meta-analysis.

RESULTS

In lean participants, the -482T allele was associated with increased risk of prevalent and incident type 2 diabetes: OR -482CT 1.47 (95% CI 1.13-1.92), -482TT 1.40 (95% CI 0.83-2.35), p = 0.009 for trend; HR -482CT 1.35 (95% CI 0.96-1.89), -482TT 1.68 (95% CI 0.91-3.1), p = 0.03 for trend, respectively. These results were confirmed by replication. Meta-analysis was highly significant (-482T meta-analysis p = 1.1 × 10(-4)). A borderline significant interaction was observed for insulin use among participants with type 2 diabetes (-482CT*BMI p = 0.06, -455TC*BMI p = 0.02).

CONCLUSIONS/INTERPRETATION

At a population-based level, the influence of APOC3 promoter variants on type 2 diabetes risk varies with the level of adiposity. Lean carriers of the -482T allele had increased type 2 diabetes risk, while such an effect was not observed in overweight participants. Conversely, in overweight participants the -455C allele seemed protective against type 2 diabetes. The interaction of the variants with need for insulin treatment may indicate beta cell involvement in lean participants. Our findings suggest overlap in the genetic backgrounds of type 1 diabetes and type 2 diabetes in lean patients.

Impact of different descriptions of the Kellgren and Lawrence classification criteria on the diagnosis of knee osteoarthritis

OBJECTIVES

Although the Kellgren and Lawrence (K&L) criteria for defining radiological osteoarthritis are widely used in epidemiological and clinical studies, the authors previously documented the existence of five different versions of these criteria. This study identifies the impact of the use of alternative versions of the K&L criteria and evaluates which description has the highest association with knee complaints.

METHODS

Two readers scored most radiographs of the knees of participants of the Rotterdam Study with the original K&L description (90%). In addition, each alternative description was used in a random part (20%) of the radiographs. The authors calculated reproducibility of all descriptions, and compared sensitivity and specificity of the alternative descriptions for three cut-off points with the original description as reference standard (K&L≥1, K&L≥2 and K&L≥3). The authors calculated κ statistics to compare agreement between the original and alternative descriptions, and evaluated the association with knee complaints.

RESULTS

The dataset comprises radiographs of knees of 3071 people. For cut-off K&L≥1 all four alternatives classified more people as having osteoarthritis than the original description; κ was low, and sensitivity and specificity were moderate to good. For cut-offs K&L≥2 and K&L≥3 there was little difference in the number of cases and κ, sensitivity and specificity were good to perfect. The original description and alternative 3 showed the strongest association with knee complaints.

CONCLUSIONS

The different descriptions of the K&L criteria have impact on the classification of osteoarthritis in the lowest grade (K&L≥1). All descriptions have strengths and weaknesses. It depends on the purpose which is the best description.

Measures of body composition and risk of heart failure in the elderly: the Rotterdam study

OBJECTIVES

The incidence of heart failure increases with aging. Aim of the present study was to determine whether measures body composition predict incident heart failure in older adults.

SETTING

Prospective community-based cohort study. 5, 868 men and women aged 55 years and older participating the Rotterdam study. Measures of body mass index and waist circumference were obtained at baseline. Information on incident heart failure was obtained during follow-up. Cox regression analyses were performed to investigate the possible association between measure of body composition and incident heart failure.

RESULTS

During a mean follow up of 10.9 (SD ±4.4) years, 765 participants had heart failure. After adjustment for age and gender, 1-standard deviation of body mass index, waist circumference and the waist-hip ratio predicted heart failure (HR 1.25; 95% CI 1.17-1.34; HR 1.26; 95% CI 1.18-1.36; and HR 1.17; 95% CI 1.08-1.27), respectively. In age-stratified analyses, 1-standard deviation of body mass index (1.17; 95% CI 1.06- 1.29) and waist circumference (1.16; 95% CI 1.05- 1.29) were still associated with the risk of heart failure in the oldest participants, whereas the waist-hip ratio was not (1.06; 95% CI 0.945-1.18).

CONCLUSION

Although estimates decrease with age, measures of overall and central adiposity predict incident heart failure among community dwelling older adults.

Heart failure and the risk of stroke: the Rotterdam Study

Patients with heart failure used to have an increased risk of stroke, but this may have changed with current treatment regimens. We assessed the association between heart failure and the risk of stroke in a population-based cohort that was followed since 1990. The study uses the cohort of the Rotterdam Study and is based on 7,546 participants who at baseline (1990–1993) were aged 55 years or over and free from stroke. The associations between heart failure and risk of stroke were assessed using time-dependent Cox proportional hazards models, adjusted for cardiovascular risk factors (smoking, diabetes mellitus, BMI, ankle brachial index, blood pressure, atrial fibrillation, myocardial infarction and relevant medication). At baseline, 233 participants had heart failure. During an average follow-up time of 9.7 years, 1,014 persons developed heart failure, and 827 strokes (470 ischemic, 75 hemorrhagic, 282 unclassified) occurred. The risk of ischemic stroke was more than five-fold increased in the first month after diagnosis of heart failure (age and sex adjusted HR 5.79, 95% CI 2.15–15.62), but attenuated over time (age and sex adjusted HR 3.50 [95% CI 1.96–6.25] after 1–6 months and 0.83 [95% CI 0.53–1.29] after 0.5–6 years). Additional adjustment for cardiovascular risk factors only marginally attenuated these risks. In conclusion, the risk of ischemic stroke is strongly increased shortly after the diagnosis of heart failure but returns to normal within 6 months after onset of heart failure.

Erosive hand osteoarthritis: its prevalence and clinical impact in the general population and symptomatic hand osteoarthritis

OBJECTIVE

To estimate the prevalence of erosive hand osteoarthritis (EOA) in the general population and its relation to symptomatic hand osteoarthritis (HOA), hand pain and disability.

METHODS

Baseline data of participants from a population-based study (age ≥55 years) were used. Symptomatic HOA was defined as hand pain and in addition to radiographic HOA (at least one interphalangeal (IP) joint or 1st carpometacarpal joint with Kellgren-Lawrence grade ≥2). EOA was defined as having at least one IP joint with erosions according to the Verbruggen-Veys scoring method. Hand pain and disability were self-reported. Multivariate logistic regression analyses were used to estimate the effect of EOA on pain and disability. Results were presented as OR with a 95% CI, adjusted for age and sex.

RESULTS

Of 3430 participants, radiographic HOA was seen in 56% (n=1916) and symptomatic HOA in 11% (n=371). Erosions were seen in 96 subjects. The prevalence of EOA in the general, radiographic and symptomatic HOA population was 2.8%, 5.0% and 10.2%, respectively. Presence of EOA led to adjusted ORs for pain of 3.6 (95% CI 2.4 to 5.6) and for disability 2.4 (95% CI 1.1 to 5.4). In radiographic HOA, people with erosion(s) had more hand pain (adjusted OR=3.1, 95% CI 2.0 to 4.8) or disability (adjusted OR=2.5, 95% CI 1.1 to 5.8) than people without erosion(s).

CONCLUSION

The prevalence of EOA is 2.8% in the general population and 10.2% in individuals with symptomatic HOA. It has a substantial impact on hand pain and disability.

High prevalence of vertebral fractures despite normal bone mineral density in patients with long-term controlled acromegaly

OBJECTIVE

To establish the prevalence of osteoporosis, vertebral fractures (VFs), and non-VFs in acromegaly patients with long-term controlled disease and factors potentially influencing fracture risk.

DESIGN

Case-control study. Patients and measurements Eighty-nine patients (46% male, mean age: 58 years) were included. We studied VFs and non-VFs, bone mineral density (BMD), and markers of bone turnover. In 48 patients, BMD assessment was also obtained 7 years prior to the current study. To compare VF prevalence, data from a sample of the Dutch population (n=3469) were used.

RESULTS

VF prevalence was 59% (men 64% and women 54%), significantly increased when compared with controls (odds ratio up to 6.5), and independent of the duration of disease control, BMD, markers of bone turnover, and acromegalic disease characteristics. Mean number of VFs per patient was 3.4±0.3 (range 1-8). There was no relationship between the number and severity of fractures, parameters of bone turnover, and follow-up BMD measurements. BMD did not change during prolongation of follow-up by 7 years of controlled acromegaly.

CONCLUSION

There is a very high prevalence of VFs in acromegaly patients with long-term controlled disease, independently of BMD. In view of the significant morbidity and mortality associated with VFs in general and the inability of BMD to predict fracture risk in acromegalic patients, we propose to include VF assessment, for example by lateral conventional radiographs of the spine in the screening of patients with acromegaly, both at diagnosis and during follow-up after establishment of disease control.

Maternal smoking during pregnancy, fetal arterial resistance adaptations and cardiovascular function in childhood

OBJECTIVE

To unravel the mechanisms underlying the previously demonstrated associations between low birthweight and cardiovascular disease in adulthood, we examined whether maternal smoking during pregnancy leads to fetal arterial resistance adaptations, and subsequently to fetal growth retardation and changes in postnatal blood pressure and cardiac development.

DESIGN

Prospective cohort study from early fetal life onwards.

SETTING

Academic hospital.

POPULATION

Analyses were based on 1120 children aged 2 years.

METHODS

Maternal smoking during pregnancy [non-smoking, first trimester smoking, continued smoking (< 5 and ≥ 5 cigarettes/day)] was assessed by questionnaire.

MAIN OUTCOME MEASURES

Third trimester placental and fetal arterial resistance indices and fetal growth were assessed by ultrasound and Doppler measurements. Postnatal blood pressure and cardiac structures (aortic root diameter, left atrial diameter, left ventricular mass) were measured at 2 years of age.

RESULTS

First trimester smoking was not associated with third trimester placental and fetal blood flow adaptations. Continued smoking of ≥ 5 cigarettes/day was associated with an increased resistance in uterine, umbilical and middle cerebral arteries, and with a decreased flow and diameter of the ascending aorta. Among mothers who continued to smoke, the third trimester estimated fetal weights and birthweights were most affected in children with the highest umbilical artery resistance. Fetal arterial resistance indices were also associated with aortic root diameter and left atrial diameter.

CONCLUSIONS

Fetal arterial resistance adaptations may be involved in the pathways leading from maternal smoking during pregnancy to low birthweight and cardiovascular developmental changes in childhood in the offspring.