Cohort Profile: The Finnish Health in Teens (Fin-HIT) study: a population-based study

Delayed bedtime on non-school days associates with higher weight and waist circumference in children: Cross-sectional and longitudinal analyses with Mendelian randomisation

Sleep duration has been linked with obesity in population-based studies. Less is known about bedtimes and, especially, if discrepancy between bedtimes on school and non-school days associate with adiposity in children. The associations of self-reported bedtimes with the body mass index z-score (BMIz) and waist-to-height ratio (WtHr) were examined among children with a mean (SD) age of 11.2 (0.85) years in cross-sectional (n = 10,245) and longitudinal (n = 5085) study settings. The causal relationship of whether BMIz contributes to bedtimes, was further examined in a subset of 1064 participants by exploiting Mendelian randomisation (MR). After adjusting for sleep duration and other confounders, every 0.5 h later bedtime on non-school nights and a delay in bedtime in non-school nights compared with school nights associated with 0.048 (95% CI 0.027; 0.069) and 0.08 (95% CI 0.056; 0.105) higher BMIz as well as 0.001 (95% CI 0; 0.002) and 0.004 (95% CI 0.003; 0.005) with higher WtHr, respectively. Moreover, every 0.5-h delay in bedtime in non-school nights compared with school nights associated with 0.001 (95% CI 0; 0.002) greater increase in WtHr in the 2.5 years follow-up. Thus, a 2-h delay in bedtime at the age of 11 years corresponds with a 0.6 cm increase in waist circumference. The MR analysis did not indicate an opposite causal relationship: higher BMIz was not causing delayed bedtimes. Later bedtime on non-school days and discrepancy in bedtimes associated with increased BMIz and WtHr, while longitudinally these predicted higher WtHr, independently of sleep duration. Promoting early bedtimes, especially on weekends, should be considered in obesity prevention among school-aged children.

Associations of central obesity and habitual food consumption with saliva microbiota and its enzymatic profiles - a pilot study in Finnish children

Background

Variation in diversity and composition of saliva microbiota has been linked to weight status, but findings have been inconsistent. Focusing on clinically relevant conditions such as central obesity and using advanced sequencing techniques might fill in the gaps of knowledge.

Aims

We investigated saliva microbiota with shallow metagenome sequencing in children with (n = 14) and without (n = 36) central obesity. Additionally, we examined the role of habitual food consumption on microbial enzymatic repertoire.

Methods

Data comprised 50 children (50% male) with a mean age of 14.2 (SD 0.3) years, selected from the Finnish Health in Teens (Fin-HIT) cohort. Dietary scores for consumption frequency of sweet treats (STI), dairy products (DCI) and plants (PCI) were derived based on a self-administered food frequency questionnaire. Central obesity was defined based on waist-height ratio using the cut-off 0.5. Saliva samples were subjected to whole-metagenome shotgun sequencing, and taxonomic and functional profiling was achieved with METAnnotatorX2 bioinformatics platform.

Results

Groups had an average 20 (95% CI 14-27) cm difference in waist circumference. We identified the lack of Pseudomonas guguagenesis and Prevotella scopos, oulorum and oris as putative biomarkers associated with central obesity and observed a total of 16 enzymatic reactions differing between the groups. DCI was associated with the highest number of enzyme profiles (122), followed by STI (60) and DCI (25) (Pearson correlation p < 0.05). Intriguingly, STI showed a high positive/negative correlation ratio (5.09), while DCI and PCI showed low ratios (0.54 and 0.33, respectively). Thus, the main driver of enzymatic reactions was STI, and the related pathways involved nitrate metabolism induced by Haemophilus parainfluenzae and Veilonella dispar among others.

Conclusion

Clinically relevant differences in central obesity were only modestly reflected in the composition of saliva microbiota. Habitual consumption of sweet treats was a strong determinant of enzymatic reactions of saliva microbiota in children with and without central obesity. The clinical relevance of these findings warrants further studies.

Interaction between genetic susceptibility to obesity and food intake on BMI in Finnish school-aged children

Diet modulates the genetic risk of obesity, but the modulation has been rarely studied using genetic risk scores (GRSs) in children. Our objectives were to identify single nucleotide polymorphisms (SNPs) that drive the interaction of specific foods with obesity and combine these into GRSs. Genetic and food frequency data from Finnish Health in Teens study was utilized. In total, 1142 11-year-old subjects were genotyped on the Metabochip array. BMI-GRS with 30 well-known SNPs was computed and the interaction of individual SNPs with food items and their summary dietary scores were examined in relation to age- and sex-specific BMI z-score (BMIz). The whole BMI-GRS interacted with several foods on BMIz. We identified 7-11 SNPs responsible for each interaction and these were combined into food-specific GRS. The most predominant interaction was witnessed for pizza (p < 0.001): the effect on BMIz was b - 0.130 (95% CI - 0.23; - 0.031) in those with low-risk, and 0.153 (95% CI 0.072; 0.234) in high-risk. Corresponding, but weaker interactions were verified for sweets and chocolate, sugary juice drink, and hamburger and hotdog. In total 5 SNPs close to genes NEGR1, SEC16B, TMEM18, GNPDA2, and FTO were shared between these interactions. Our results suggested that children genetically prone to obesity showed a stronger association of unhealthy foods with BMIz than those with lower genetic susceptibility. Shared SNPs of the interactions suggest common differences in metabolic gene-diet interactions, which warrants further investigation.

Oral and craniofacial research in the Generation R study: an executive summary

OBJECTIVES

Oral conditions are of high prevalence and chronic character within the general population. Identifying the risk factors and determinants of oral disease is important, not only to reduce the burden of oral diseases, but also to improve (equal access to) oral health care systems, and to develop effective oral health promotion programs. Longitudinal population-based (birth-)cohort studies are very suitable to study risk factors on common oral diseases and have the potential to emphasize the importance of a healthy start for oral health. In this paper, we provide an overview of the comprehensive oral and craniofacial dataset that has been collected in the Generation R study: a population-based prospective birth cohort in the Netherlands that was designed to identify causes of health from fetal life until adulthood.

METHODS

Within the multidisciplinary context of the Generation R study, oral and craniofacial data has been collected from the age of 3 years onwards, and continued at the age of six, nine, and thirteen. Data collection is continuing in 17-year-old participants.

RESEARCH OUTCOMES

In total, the cohort population comprised 9749 children at birth, and 7405 eligible participants at the age of seventeen. Based on questionnaires, the dataset contains information on oral hygiene, dental visits, oral habits, oral health-related quality of life, orthodontic treatment, and obstructive sleep apnea. Based on direct measurements, the dataset contains information on dental caries, developmental defects of enamel, objective orthodontic treatment need, dental development, craniofacial characteristics, mandibular cortical thickness, and 3D facial measurements.

CONCLUSIONS

Several research lines have been set up using the oral and craniofacial data linked with the extensive data collection that exists within the Generation R study.

CLINICAL RELEVANCE

Being embedded in a multidisciplinary and longitudinal birth cohort study allows researchers to study several determinants of oral and craniofacial health, and to provide answers and insight into unknown etiologies and oral health problems in the general population.

Pre-Diagnostic Saliva Microbiota of School-Aged Children Who Developed Type 1 Diabetes or Inflammatory Bowel Diseases

Altered commensal microbiota composition has been associated with pediatric type 1 diabetes mellitus (T1D) and inflammatory bowel diseases (IBD), but the causal relationship is still unclear. To search for potential pre-diagnostic biomarkers for pediatric T1D or IBD, we compared microbiota in saliva samples in a nested case-control design comprising children developing T1D (n_children = 52) or IBD (n_children = 21) and controls with a similar age, sex, and residential area (n_children = 79). The pre-diagnostic saliva microbiota alpha- and beta-diversity of children who would develop T1D (n_samples = 27) or IBD (n_samples = 14) minimally varied from that of controls. The relative abundances of Abiotrophia were higher, while those of Veillonella, Actinomyces, Megasphaera, Butyrivibrio, and Candidatus ancillula were lower in children who would develop T1D. Within 2 years before diagnosis, the metabolic PWY-5677 pathway (converting succinate into butyrate) was lower in pre-T1D samples than in controls (q = 0.034). No significant pre-IBD differences were found. In conclusion, saliva microbiota diversity or composition were not successful predictors for pediatric T1D nor IBD. Intriguingly, the succinate fermentation pathway was predicted to be lowered before the onset of T1D. Thus, investigating functional pathways might provide a better approach in searching for biomarkers for autoimmune disease in the future.

Antibiotic exposures and the development of pediatric autoimmune diseases: a register-based case-control study

BACKGROUND

Antibiotics have been associated with several individual autoimmune diseases (ADs). This study aims to discover whether pre-diagnostic antibiotics are associated with the onset of ADs in general.

METHODS

From a cohort of 11,407 children, 242 developed ADs (type 1 diabetes, autoimmune thyroiditis, juvenile idiopathic arthritis (JIA), or inflammatory bowel diseases) by a median age of 16 years. Antibiotic purchases from birth until the date of diagnosis (or respective date in the matched controls n = 708) were traced from national registers.

RESULTS

Total number of antibiotic purchases was not related to the onset of ADs when studied as a group. Of specific diagnoses, JIA was associated with the total number of antibiotics throughout the childhood and with broad-spectrum antibiotics before the age of 3 years. Intriguingly, recent and frequent antibiotic use (within 2 years before diagnosis and ≥3 purchases) was associated with the onset of ADs (OR 1.72, 95% CI 1.08-2.74). Regardless of frequent use in childhood (40% of all antibiotics), penicillin group antibiotics were not related to any ADs.

CONCLUSIONS

Use of antibiotics was relatively safe regarding the overall development of ADs. However, broad-spectrum antibiotics should be used considerately as they may associate with an increased likelihood of JIA.

IMPACT

Increasing numbers of antibiotic purchases before the age of 3 years or throughout childhood were not associated with the development of pediatric autoimmune diseases. Broad-spectrum antibiotics were related to the development of autoimmune diseases, especially juvenile idiopathic arthritis in children, while penicillin group antibiotics were not. The use of broad-spectrum antibiotics in children should be cautious as they may carry along a risk for autoimmune disease development.

Exposure to proton pump inhibitors is associated with the development of pediatric autoimmune diseases

Proton pump inhibitors (PPIs) have been associated with decreased gut microbiota diversity. Disrupted gut microbiota composition has been reported in several autoimmune diseases (ADs), such as type 1 diabetes mellitus (DM), autoimmune thyroiditis (AIT), juvenile idiopathic arthritis (JIA), and inflammatory bowel diseases (IBD). We investigated whether PPIs are associated with the development of ADs in children and concluded that PPI exposures could be related to the onset of ADs, especially IBD and potentially AIT as well.

The Composition and Functional Capacities of Saliva Microbiota Differ Between Children With Low and High Sweet Treat Consumption

Excess sugar consumption—common in youth—is associated with poor health. Evidence on the relationship between sugar consumption and the oral microbiome, however, remains scarce and inconclusive. We explored whether the diversity, composition, and functional capacities of saliva microbiota differ based on the consumption of select sugary foods and drinks (“sweet treats”). Using 16S rRNA gene sequencing, we characterized saliva microbiota from 11 to 13-year-old children who participated in the Finnish Health in Teens (Fin-HIT) cohort study. The sample comprised children in the lowest (n = 227) and highest (n = 226) tertiles of sweet treat consumption. We compared differences in the alpha diversity (Shannon, inverse Simpson, and Chao1 indices), beta diversity (principal coordinates analysis based on Bray–Curtis dissimilarity), and abundance (differentially abundant operational taxonomic units (OTUs) at the genus level) between these low and high consumption groups. We performed PICRUSt2 to predict the metabolic pathways of microbial communities. No differences emerged in the alpha diversity between low and high sweet treat consumption, whereas the beta diversity differed between groups (p = 0.001). The abundance of several genera such as Streptococcus, Prevotella, Veillonella, and Selenomonas was higher in the high consumption group compared with the low consumption group following false discovery rate correction (p < 0.05). Children with high sweet treat consumption exhibited higher proportions of nitrate reduction IV and gondoate biosynthesis pathways compared with the low consumption group (p < 0.05). To conclude, sweet treat consumption shapes saliva microbiota. Children who consume a high level of sweet treats exhibited different compositions and metabolic pathways compared with children who consume low levels of sweet treats. Our findings reveal novel insights into the relationship between sugary diets and oral microbiota.

Central obesity in school-aged children increases the likelihood of developing paediatric autoimmune diseases

BACKGROUND

The incidences of both paediatric obesity and autoimmune diseases have been increasing, but their relationship with one another is unclear.

OBJECTIVE

To determine whether obesity or particular dietary patterns in school-aged children are potential risk factors for autoimmune diseases during adolescence.

METHODS

This matched case-control study included 525 children, followed up from a median age of 11.3 to 16.7 years. Of them, 105 children received primary autoimmune diagnoses (diabetes, thyroiditis, arthritis, or inflammatory bowel diseases) after baseline and generated the case group. Four children with matching age, sex, and residential area generated the control group of 420 children. At baseline, age- and sex-specific body mass index categories were acquired and waist-to-height ratio (WHTR) was calculated. Central obesity was present when WHTR ≥0.5. Dietary patterns were analysed using a food frequency questionnaire (FFQ).

RESULTS

School-aged children with central obesity were 2.11 (OR, 95% CI 1.11-3.98) times more likely to develop autoimmune diseases before age of 19 years than those without central obesity. Being overweight was not related to the onset of these diseases (OR 1.60, 95% CI 0.89-2.87, nor were dietary patterns.

CONCLUSION

Central obesity in school-aged children was related to the development of autoimmune diseases, while being overweight and dietary patterns were not.

Body Mass Index, Physical Activity, and Body Image in Adolescents

Body image dissatisfaction is a concern for adolescents’ mental and physical well-being, and the role of body mass index (BMI) and physical activity (PA) in it is still unclear. This study investigates the associations of BMI and PA with body image, separately for boys and girls, in a large sample of Finnish adolescents. We also examine the associations of BMI with body image in varying PA levels. A total of 10,496 adolescents (girls 52.6%) were included in the analyses. Body image was assessed using a pictorial tool, and categorized as wishing for a smaller body, being satisfied, and wishing for a bigger body. BMI (kg/m²) was categorized as thin, normal weight, and overweight/obese. Self-reported PA was divided into three similar-sized categories as low, moderate, and high PA levels. Adjusted ordinal regression analyses were conducted. Our results show that adolescents with thinness had higher odds of wishing for a bigger body compared to their normal-weight peers, while adolescents with overweight/obesity had smaller odds of wishing for a bigger body. Adolescents in low and middle PA levels had lower odds of wishing for a bigger body compared to adolescents in the high PA level. Yet, the PA level modified the associations between BMI and body image, especially in adolescents with thinness and more so in girls than in boys. These findings highlight the need to pay attention to healthy weight gain and PA in adolescents to support their body image satisfaction.

Physical Activity Among Preadolescents Modifies the Long-Term Association Between Sedentary Time Spent Using Digital Media and the Increased Risk of Being Overweight

BACKGROUND

This study aimed to examine whether sedentary digital media use in preadolescence increases the risk of being overweight 3 years later, and whether this association differs based on preadolescents' leisure-time physical activity (LTPA) levels.

METHODS

The authors conducted a 3-year follow-up study among 4661 participants with a mean (SD) age of 11 (1) years at baseline and 14 (1) years at follow-up. A web-based questionnaire assessed sedentary digital media use and LTPA. The authors categorized baseline LTPA duration into 3 levels: 0 to 5 (low), 6 to 8 (moderate), and ≥9 (high) hours per week. In addition, the authors categorized adolescents as normal weight or overweight/obese at follow-up.

RESULTS

Greater amounts of sedentary digital media use at baseline associated with an increased risk of being overweight 3 years later even after adjusting for confounders. This only held for preadolescents with low baseline LTPA (OR = 1.14; 95% confidence interval, 1.05-1.24), but not among those with moderate (OR = 1.02; 0.91-1.15) or high (OR = 0.96; 0.85-1.08) LTPA.

CONCLUSIONS

Preadolescent LTPA modified the long-term association between sedentary digital media use and being overweight; specifically, 6 hours per week or more of LTPA mitigated the increased risk of being overweight associated with higher amounts of digital media use.

Association of maternal polycystic ovary syndrome or anovulatory infertility with obesity and diabetes in offspring: a population-based cohort study

STUDY QUESTION

Are children of mothers with polycystic ovary syndrome (PCOS) or anovulatory infertility at increased risks of obesity or diabetes?

SUMMARY ANSWER

Maternal PCOS/anovulatory infertility is associated with an increased risk of offspring obesity from early age and diabetes in female offspring from late adolescence.

WHAT IS KNOWN ALREADY

Women with PCOS often have comorbid metabolic disorders such as obesity and diabetes, and children of mothers with PCOS have an increased risk of subtle signs of cardiometabolic alterations.

STUDY DESIGN, SIZE, DURATION

This was a nationwide cohort study of all live births (n = 1 105 997) during 1996-2014 in Finland, excluding those with maternal diagnoses sharing signs and symptoms with PCOS (n = 8244). A total of 1 097 753 births were included and followed up until 31 December 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

National registries were linked to identify births with maternal PCOS or anovulatory infertility (n = 24 682). The primary outcomes were diagnoses of obesity (ICD-10: E65, E66) and diabetes (ICD-10: E10-E14) in offspring recorded in the Finnish Care Register for Health Care. Cox proportional hazards regression was modeled to analyze the risk of offspring obesity and diabetes in relation to prenatal exposure to maternal PCOS/anovulatory infertility. Differently adjusted models and stratified analyses were used to assess whether the risk was modified by maternal obesity or diabetes diagnoses, pre-pregnancy BMI, fertility treatment or perinatal problems.

MAIN RESULTS AND THE ROLE OF CHANCE

Exposure to maternal PCOS/anovulatory infertility was associated with a higher cumulative incidence of obesity in the children (exposed: 1.83%; 95% CI 1.66-2.00% vs unexposed: 1.24%; 95% CI 1.22-1.26%). Accounting for birth factors and maternal characteristics such as obesity and diabetes diagnoses, the hazard ratio (HR) for obesity was increased in offspring below 9 years of age (HR 1.58; 95% CI 1.30-1.81), and in those 10-16 years of age (HR 1.37; 95% CI 1.19-1.57), but not in those aged 17-22 years (HR 1.24; 95% CI 0.73-2.11). Sex-stratified analyses revealed similar risk estimates for boys (HR 1.48; 95% CI 1.31-1.68) and girls (HR 1.45; 95% CI 1.26-1.68). Notably, the joint effect of PCOS/anovulatory infertility and BMI-based pre-pregnancy obesity on offspring obesity (HR 8.89; 95% CI 7.06-11.20) was larger than that of either PCOS/anovulatory infertility or obesity alone. Furthermore, PCOS/anovulatory infertility was associated with offspring obesity in children without perinatal problems (HR 1.27; 95% CI 1.17-1.39), with larger effect size for maternal PCOS/anovulatory infertility and joint perinatal problems (HR 1.61; 95% CI 1.35-1.91). However, the risk estimates were comparable between maternal PCOS/anovulatory infertility with (HR 1.54; 95% CI 1.17-2.03) and without fertility treatment (HR 1.46; 95% CI 1.32-1.61). For offspring diabetes, the HR was increased only between 17 and 22 years of age (HR 2.06; 95% CI 1.23-3.46), and specifically for Type 1 diabetes in females (HR 3.23; 95% CI 1.41-7.40).

LIMITATIONS, REASONS FOR CAUTION

The prevalence of PCOS/anovulatory infertility in this study was 2.2%, lower than that reported in previous studies. In addition, the incidence of obesity in offspring was lower than that reported in studies based on measured or self-reported weight and height and may include mainly moderate and severe obesity cases who needed and/or actively sought medical care. Moreover, mothers with PCOS/anovulatory infertility were identified based on ICD codes, with no information on PCOS phenotypes. Furthermore, maternal pre-pregnancy BMI was available only from 2004. The PCOS/anovulatory infertility association with female offspring diabetes was based on only a few cases. Mothers' weight gain during pregnancy, use of fertility treatment other than fresh or frozen IVF/ICSI, offspring lifestyle, as well as fathers' age, medical disorders or medication prescriptions were not available for this study.

WIDER IMPLICATIONS OF THE FINDINGS

These findings support that prenatal PCOS/anovulatory infertility exposure influences metabolic health in the offspring from early age.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Shandong Provincial Natural Science Foundation, China [ZR2020MH064 to X.C.], Shandong Province Medical and Health Technology Development Plan [2018WS338 to X.C.], the joint research funding of Shandong University and Karolinska Institute [SDU-KI-2019-08 to X.C. and C.L.], the Finnish Institute for Health and Welfare: Drug and Pregnancy Project [M.G.], the Swedish Research Council [2014-10171 to C.L.], the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska Institute Stockholm County Council [SLL20170292 and SLL20190589 to C.L.], the Swedish Brain Foundation [FO2018-0141 and FO2019-0201 to C.L.]. X.C. received grants from the China Scholarship Council at the beginning of the study. The authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Sex- and weight-specific changes in the frequency of sweet treat consumption during early adolescence: a longitudinal study

The transition from childhood to adolescence is a sensitive period, triggering changes in health- and weight-related behaviours including eating habits which likely vary between girls and boys. We aimed to characterise the changes in the frequency of consumption of select sugary foods and drinks ('sweet treats') among 4237 Finnish girls and boys during a 2-year follow-up period. Additionally, we examined four subgroups: children whose weight or waist normalised as well as children whose weight or waist circumference increased during follow-up. An FFQ was completed at 11·1 (sd 0·9) and again at 13·4 (sd 1·1) years of age. A sum variable sweet treat index (STI, range 0-84) captured the weekly consumption frequencies of sweet treats. From baseline to follow-up, the mean STI decreased among girls from 7·1 (95 % CI 6·9, 7·3) to 6·0 (95 % CI 5·9, 6·2) (P < 0·001) and boys from 8·5 (95 % CI 8·3, 8·8) to 7·8 (95 % CI 7·6, 7·8) (P < 0·001), although both sexes increased their chocolate/sweets consumption: girls from 1·3 (95 % CI 1·3, 1·4) to 1·6 (95 % CI 1·5, 1·6) (P < 0·001) and boys from 1·4 (95 % CI 1·3, 1·4) to 1·6 (95 % CI 1·6, 1·7) (P < 0·001), and boys increased their soft drink consumption from 1·4 (95 % CI 1·3, 1·4) to 1·5 (95 % CI 1·4, 1·5) (P = 0·020). We found similar decreases in both the weight and waist subgroups. To conclude, the total frequency of consumption of sweet treats decreased during early adolescence. A similar trend across subgroups suggests that the frequency of consumption of sweet treats is unrelated to becoming overweight.

Lifetime antimicrobial use is associated with weight status in early adolescence-A register-based cohort study

BACKGROUND

Antimicrobial agents (AMs) are the most prescribed drugs to children. Early and repeated exposure to AMs in infancy is associated with increased risk of childhood overweight and obesity.

AIMS

We extended the investigation of AMs use, from birth to early adolescence, and evaluated their association with weight status.

MATERIALS & METHODS

A total of 10093 children from Finnish Health in Teens cohort (Fin-HIT) with register-based data on AMs purchases and measured weight status at the mean age of 11.2 y (SD 0.82) were included in the study. The key exposures were the number AM purchases at a given age or the sum of these during the entire follow-up time to describe lifetime exposure / use. Outcome was weight status in early adolescence defined with International Obesity Task Force cut-offs for the age- and sex-specific body mass index. Odds Ratio (OR) and 95% confidence intervals (CI) were estimated using Multinomial Logistic Regression.

RESULTS

Of children, 73.7% were normal weight, 11.1% thin and 15.2% overweight/obese. AMs use was highest during the second year of life, when 65% of all children used AMs, but thereafter decreased with age. The highest mean purchases and prevalence at any given age along with the highest lifetime use were consistently seen among overweight children. Each episode of AMs use throughout life increased the risk of being overweight in adolescence [OR = 1.02 (1.02-1.03)]. However, there was an inverse association between AMs use and thinness [OR = 0.98 (0.97-0.99)].

DISCUSSION

Despite a high prevalence of AMs use during the early years, lifetime-use was associated with weight status in early adolescence in a dose response manner.

CONCLUSION

Future studies should address mechanisms underlying the relationship between AM use and weight.

High abundance of sugar metabolisers in saliva of children with caries

Dental caries is a biofilm-mediated, dynamic disease with early onset. A balanced salivary microbiota is a foundation of oral health, while dysbiosis causes tooth decay. We compared the saliva microbiota profiles in children with and without caries. The study consisted of 617 children aged 9–12 years from the Finnish Health in Teens (Fin-HIT) study with available register data on oral health. Caries status was summarised based on Decayed, Missing, and Filled Teeth (DMFT) index in permanent dentition. The children were then classified into the following two groups: DMFT value ≥ 1 was considered as cavitated caries lesions (hereafter called ‘caries’) (n = 208) and DMFT = 0 as ‘cavity free’ (n = 409). Bacterial 16S rRNA gene (V3–V4 regions) was amplified using PCR and sequenced by Illumina HiSeq. The mean age (SD) of the children was 11.7 (0.4) years and 56% were girls. The children had relatively good dental health with mean DMFT of 0.86 (1.97). Since sex was the key determinant of microbiota composition (p = 0.014), we focused on sex-stratified analysis. Alpha diversity indexes did not differ between caries and cavity free groups in either sexes (Shannon: p = 0.40 and 0.58; Inverse Simpson: p = 0.51 and 0.60, in boys and girls, respectively); neither did the composition differ between the groups (p = 0.070 for boys and p = 0.230 for girls). At the genus level, Paludibacter and Labrenzia had higher abundances in the caries group compared to cavity free group in both sexes (p < 0.001). Taken together, there were minor differences in saliva microbiota between children with and without caries. Potential biomarkers of caries were the sugar metabolisers Paludibacter and Labrenzia. These bacteria presumably enhance salivary acidification, which contributes to progression of dental caries. The clinical relevance of our findings warrants further studies.

Perinatal risk factors for pediatric onset type 1 diabetes, autoimmune thyroiditis, juvenile idiopathic arthritis, and inflammatory bowel diseases

Type 1 diabetes mellitus (DM), autoimmune thyroiditis (AIT), juvenile idiopathic arthritis (JIA), and inflammatory bowel diseases (IBD) are common pediatric autoimmune diseases with unknown risk factors. Using nationwide registers, we searched for their perinatal risk factors. Our study followed up 11,407 children (born 2000-2005) for a median of 16.6 years (from birth to 2018). Of them, 2.15% received primary diagnosis and 0.08% also secondary: 0.89% had DM, 0.60% had AIT, 0.48% had JIA, and 0.25% had IBD. The incidences per 100,000 children/year were 106.1 for DM, 46.0 for AIT, 55.0 for JIA, and 23.7 for IBD. There were more preterm births (< 37 weeks) among children with studied autoimmune diseases compared with the rest of the cohort (8.6% vs. 5.3%, p = 0.035). Among those born preterm, children with studied autoimmune diseases received more postnatal antibiotics compared with other preterm children in the cohort (47.6% vs. 27.7%, p = 0.046). Children with IBD were born to older mothers compared with those without studied diagnoses (33.0 vs 30.2, p = 0.004).Conclusion: Preterm birth was a shared risk factor for autoimmune diseases in our study, especially when combined with postnatal antibiotic treatments. High maternal age was associated with IBD. What is Known: • Type 1 diabetes (DM), autoimmune thyroiditis (AIT), juvenile idiopathic arthritis (JIA), and inflammatory bowel diseases (IBD) are common pediatric autoimmune diseases • It is unclear whether these diseases have shared risk factors, since there are no previous simultaneous epidemiological nor follow-up studies on them in one cohort  What is New: • Preterm births were more common in children with DM, AIT, JIA, or IBD compared with other children in the cohort, and preterm children who developed these diseases recieved more postnatal antibiotics compared with other preterm children • High maternal age was associated with IBD.

Frequent use of selected sugary products associates with thinness, but not overweight during preadolescence: a cross-sectional study

Convincing evidence suggests that diets laden with added sugar, specifically sugar-sweetened beverages, associate with excess weight in children. The relationships between sugar consumption frequency and BMI remain less well studied. We, therefore, evaluated children's consumption frequency of selected sugary products (n 8461; mean age 11·1 (sd 0·9) years) selected from the Finnish Health in Teens cohort study. Using a sixteen-item FFQ including six sugary products (chocolate/sweets, biscuits/cookies, ice cream, sweet pastry, sugary juice drinks and sugary soft drinks), we calculated a Sweet Treat Index (STI) for the frequency of weekly sugary product consumption and categorised children based on quartiles (Q) into low (Q1, cut-off < 4·0), medium (Q2 + Q3, range 4·0-10·5) and high STI (Q4, cut-off > 10·5), and as thin, normal and overweight/obese based on the measured BMI. Through multinomial logistic regression analyses, we found that subjects with a high STI exhibited a higher risk of being thin (OR 1·20, 95 % CI 1·02, 1·41) and lower risk of being overweight (OR 0·79, 95 % CI 0·67, 0·92), while subjects with a low STI were at higher risk of being overweight (OR 1·32, 95 % CI 1·14, 1·53). High consumption frequencies of salty snacks, pizza and hamburgers most closely were associated with a high STI. Our findings suggest that consuming sugary products at a high frequency does not associate with being overweight. The relationship between a low consumption frequency and being overweight suggests that overweight children's consumption frequency of sugary products may be controlled, restricted or underreported.

Antimicrobial drug use in the first decade of life influences saliva microbiota diversity and composition

BACKGROUND

The human microbiota contributes to health and well-being. Antimicrobials (AM) have an immediate effect on microbial diversity and composition in the gut, but next to nothing is known about their long-term contribution to saliva microbiota. Our objectives were to investigate the long-term impact of AM use on saliva microbiota diversity and composition in preadolescents. We compared the lifetime effects by gender and AMs. We used data from 808 randomly selected children in the Finnish Health In Teens (Fin-HIT) cohort with register-based data on AM purchases from the Social Insurance Institution of Finland. Saliva microbiota was assessed with 16S rRNA (V3-V4) sequencing. The sequences were aligned to the SILVA ribosomal RNA database and classified and counted using the mothur pipeline. Associations between AM use and alpha-diversity (Shannon index) were identified with linear regression, while associations between beta-diversity (Bray-Curtis dissimilarity) and low, medium or high AM use were identified with PERMANOVA.

RESULTS

Of the children, 53.6% were girls and their mean age was 11.7 (0.4) years. On average, the children had 7.4 (ranging from 0 to 41) AM prescriptions during their lifespan. The four most commonly used AMs were amoxicillin (n = 2622, 43.7%), azithromycin (n = 1495, 24.9%), amoxicillin-clavulanate (n = 1123, 18.7%) and phenoxymethylpenicillin (n = 408, 6.8%). A linear inverse association was observed between the use of azithromycin and Shannon index (b - 0.015, p value = 0.002) in all children, the effect was driven by girls (b - 0.032, p value = 0.001), while not present in boys. Dissimilarities were marked between high, medium and low users of all AMs combined, in azithromycin users specifically, and in boys with amoxicillin use. Amoxicillin and amoxicillin-clavulanate use was associated with the largest decrease in abundance of Rikenellaceae. AM use in general and phenoxymethylpenicillin specifically were associated with a decrease of Paludibacter and pathways related to amino acid degradations differed in proportion between high and low AM users.

CONCLUSIONS

A systematic approach utilising reliable registry data on lifetime use of AMs demonstrated long-term effects on saliva microbiota diversity and composition. These effects are gender- and AM-dependent. We found that frequent lifelong use of AMs shifts bacterial profiles years later, which might have unforeseen health impacts in the future. Our findings emphasise a concern for high azithromycin use, which substantially decreases bacterial diversity and affects composition as well. Further studies are needed to determine the clinical implications of our findings. Video Abstract.

Children's Eating Attitudes Test (ChEAT): a validation study in Finnish children

PURPOSE

To validate the Children's Eating Attitudes Test (ChEAT) in the Finnish population.

MATERIALS AND METHODS

In total 339 children (age 10-15 years) from primary schools in Southern Finland were evaluated at two time points. They answered the ChEAT and SCOFF test questions, and had their weight, height and waist circumference measured. Retesting was performed 4-6 weeks later. Test-retest reliability was evaluated using intra-class correlation (ICC), and internal consistency was examined using Cronbach's alpha coefficient (C-alpha). ChEAT was cross-calibrated against SCOFF and background variables. Factor analysis was performed to examine the factor structure of ChEAT.

RESULTS

The 26-item ChEAT showed high internal consistency (C-alpha 0.79), however, a 24-item ChEAT showed even better internal consistency (C-alpha 0.84) and test-retest reliability (ICC 0.794). ChEAT scores demonstrated agreement with SCOFF scores (p < 0.01). The mean ChEAT score was higher in overweight children than normal weight (p < 0.001). Exploratory factor analysis yielded four factors (concerns about weight, limiting food intake, pressure to eat, and concerns about food), explaining 57.8% of the variance.

CONCLUSIONS

ChEAT is a valid and reliable tool for measuring eating attitudes in Finnish children. The 24-item ChEAT showed higher reliability than the 26-item ChEAT.

LEVEL OF EVIDENCE

Level 5, cross-sectional, descriptive study.

Breastfeeding may have a long-term effect on oral microbiota: results from the Fin-HIT cohort

BACKGROUND

Breastfeeding contributes to gastrointestinal microbiota colonization in early life, but its long-term impact is inconclusive. We aimed to evaluate whether the type of feeding during the first six months of life was associated with oral microbiota in adolescence.

METHODS

This is a cross-sectional sub-study using baseline information of 423 adolescents from the Finnish Health in Teens (Fin-HIT) cohort. Type of feeding was recalled by parents and dichotomized as (i) No infant formula; (ii) Infant formula (breastmilk + formula or only formula). Saliva microbiota was analysed using 16S rRNA (V3-V4) sequencing. Alpha diversity and beta diversity were compared between feeding type groups using ANCOVA and PERMANOVA, respectively. Differential bacteria abundance was tested using appropriate general linear models.

RESULTS

Mean age and body mass index were 11.7 years and 18.0 kg/m2, respectively. The No formula group contained 41% of the participants. Firmicutes (51.0%), Bacteroidetes (19.1%), and Proteobacteria (16.3%) were the most abundant phyla among all participants. Alpha and beta diversity indices did not differ between the two feeding groups. Three Operational Taxonomic Units (OTUs) belonging to Eubacteria and Veillonella genera (phylum Firmicutes) were more abundant in the No formula than in the Infant formula group (log2fold changes/ p - values - 0.920/ < 0.001, - 0.328/ 0.001, - 0.577/ 0.004).

CONCLUSION

Differences exist in abundances of some OTUs in adolescence according to feeding type during the first six months of life, but our findings do not support diversity and overall oral microbiota composition in adolescents being affected by early feeding type.

Heavy Screen Use on Weekends in Childhood Predicts Increased Body Mass Index in Adolescence: A Three-Year Follow-Up Study

PURPOSE

We aimed to examine whether sedentary screen time changes when transitioning from childhood to adolescence and whether children's screen time, separately for school days and weekends, affects body mass index (BMI) in adolescents.

METHODS

This prospective 3-year follow-up study included 5,084 children with a mean (standard deviation) age of 11 (1) years at baseline and 14 (1) years at follow-up. Children reported screen time, more specifically, time spent viewing TV programs and using a computer outside school while sitting. We categorized children into light, medium, and heavy TV viewers and computer users separately for school days and weekends. We also calculated the age- and gender-specific BMI z-score (BMIz).

RESULTS

Time spent viewing TV changed from baseline to follow-up on school days and on weekends (p < .001 for both); the proportion of heavy TV viewers on school days (≥3 h/d) increased from 16% to 23% and on weekends (≥4 h/d) from 19% to 30%. Heavy TV viewers and computer users on both school days and on weekends had a higher BMIz 3 years later (p < .001 for all). After adjusting for age, gender, language, baseline BMIz, sleep duration, eating habits, exercise, and the other screen-time variables, heavy TV viewing on weekends remained significantly associated with an increased BMIz at follow-up (B = .078; p = .013).

CONCLUSIONS

The proportion of heavy screen users increases when transitioning from childhood to adolescence. Moreover, heavy screen use, especially on weekends in 11-year-old children, is associated with an increased BMI 3 years later.

Meal Regularity Plays a Role in Shaping the Saliva Microbiota

BACKGROUND

Diet may influence health directly or indirectly via the human microbiota, emphasizing the need to unravel these complex relationships for future health benefits. Associations between eating habits and gut microbiota have been shown, but less is known about the association between eating habits and saliva microbiota.

OBJECTIVE

The aim of this study was to investigate if eating habits and meal patterns are associated with the saliva microbiota.

METHODS

In total, 842 adolescents, aged 11-14 years, from the Finnish Health in Teens (Fin-HIT) study cohort were included in this study. Eating habits and breakfast and dinner patterns were derived from a web-based questionnaire answered in school. Three major eating habit groups were identified: fruit and vegetable avoiders (FV avoiders), healthy and unhealthy. Microbiota profiles were produced from 16S rRNA gene (V3-V4) sequencing of DNA from the saliva samples. Statistical models were adjusted for gender, age, parental language, body mass index (BMI) categories, and sequencing depth.

RESULTS

Regular breakfast eaters had a higher alpha diversity (Shannon index with mean (standard error of means) 2.27 (0.03) vs. 2.22 (0.03), p = 0.06, inverse Simpson's index with 6.27 (0.17) vs. 5.80 (0.02), p = 0.01), and slight differences in bacterial composition (PERMANOVA: p = 0.001) compared with irregular breakfast eaters. A similar trend in alpha diversity was observed between regular and irregular dinner eaters (Shannon index with 2.27 (0.03) vs. 2.22 (0.03), p = 0.054, inverse Simpson's index with 6.23 (0.17) vs. 6.04 (0.22), p = 0.28), while no difference was found in composition (PERMANOVA: p = 0.08). No differences were identified between eating habit groups and saliva microbiota diversity (Shannon index p = 0.77, inverse Simpson's index p = 0.94) or composition (PERMANOVA: p = 0.13). FV avoiders, irregular breakfast eaters and irregular dinner eaters had high abundances of Prevotella.

CONCLUSION

Regularity of eating, especially breakfast eating, was associated with more diverse saliva microbiota and different composition compared with irregular eaters. However, the dissimilarities in composition were small between regular and irregular breakfast eaters. Our results suggest that Prevotella abundances in saliva were common in FV avoiders and meal skippers. However, the clinical implications of these findings need to be evaluated in future studies.

Genetic risk score predicts risk for overweight and obesity in Finnish preadolescents

Common genetic variants predispose to obesity with varying contribution by age. We incorporated known genetic variants into genetic risk scores (GRSs) and investigated their associations with overweight/obesity and central obesity in preadolescents. Furthermore, we compared GRSs with lifestyle factors, and tested if they predict the change in body size and shape in a 4-year follow-up. We utilized 1142 subjects from the Finnish Health in Teens (Fin-HIT) cohort. Overweight and obesity were defined with age- and gender-specific body mass index (BMI) z-score (BMIz), while central obesity by the waist-to-height ratio (WHtR). Background data on parental language, eating habits, leisure-time physical activity (LTPA) and sleep duration were included. Genotyping was performed with the Metabochip platform. Weighted, standardized GRSs were derived. Of the11-year-old children, 25.5% were at least overweight and 90.8% had Finnish speaking background. BMI-GRS was associated with higher risk for overweight with odds ratio (95% confidence interval) of 1.39 (1.20; 1.60) and obesity 1.41 (1.08; 1.83), but not with central obesity. BMI-GRS was weakly and inversely associated with the changes in BMIz and WHtR in the 4-year follow-up. Waist-to-hip ratio-GRS was not related to any obesity measures at baseline nor in the follow-up. The effect of BMI-GRS is similar to that of low LTPA on overweight. An interaction between parental language and BMI-GRS was noted (P = .019): BMI-GRS associated more strongly with overweight in Swedish than in Finnish speakers. We further identified two suggestive genetic variants near LOC101926977 and LOC105369677 associated with BMIz in preadolescents which were replicated in the adult population. In preadolescents, known genetic predisposing factors induce a risk for overweight comparable to low LTPA. However, the GRS was poor in predicting short-term changes in BMI or WHtR.

Heavy screen users are the heaviest among 10,000 children

This cross-sectional study examined the associations of recreational screen time (viewing TV programs on any screen-based device and computer use, performed while sitting) with body mass index (BMI) categories and waist-to-height ratio (WHtR) tertiles in 10,228 children (mean age 11.1 years, SD 0.8). We categorized the children into Light, Medium and Heavy TV viewers and computer users, and into Low, Medium and High exercise groups. Compared with Light TV viewers, Medium (OR: 1.30, 95% CI: 1.11–1.52, when adjusted for age, sex, language, sleep duration and exercise) and Heavy (OR: 1.57, 95% CI: 1.34–1.83) TV viewers had a higher risk of being overweight. Similarly, Heavy computer users had a higher risk of being overweight (OR: 1.42, 95% CI: 1.21–1.67). We observed interactions between exercise and TV viewing (p = 0.012) or computer use (p = 0.010). However, Heavy TV viewers had a higher risk of being overweight in all exercise groups. The associations of TV viewing and computer use were similar with BMI and WHtR. To conclude, heavy sedentary screen time is associated with overweight and central adiposity in children. Moreover, heavy TV viewers have a higher risk for overweight and central adiposity, regardless of weekly exercise duration.

Eating habits and weight status in Finnish adolescents

Objective:

To investigate the association between eating habits and weight status in adolescents in Finland.

Design:

Cross-sectional study.

Setting:

The Finnish Health in Teens (Fin-HIT) study is a cohort study conducted in adolescents attending third to sixth grade in 496 schools in forty-four municipalities in Southern, Middle and Northern Finland in 2011–2014.

Participants:

Analyses included 10 569 adolescents from the Fin-HIT study aged 9–14 years (5005 boys and 5564 girls). Adolescents were categorized by their eating habits: healthy eaters (44·1 %; n 4661), unhealthy eaters (12·3 %; n 1298), and fruit and vegetable avoiders (43·6 %; n 4610); and they were grouped into weight status: underweight (11·1 %), normal weight (73·6 %) and excess weight (15·3 %).

Results:

We found an increased risk of underweight in fruit and vegetable avoiders (OR = 1·28; 95 % CI 1·12, 1·46). An irregular breakfast pattern showed an inverse association with underweight (OR = 0·70; 95 % CI 0·59, 0·84) and an increased risk of excess weight (OR = 1·56; 95 % CI 1·37, 1·77) compared with a regular breakfast pattern. An irregular dinner pattern was inversely associated with underweight (OR = 0·83; 95 % CI 0·69, 0·99) compared with a regular dinner pattern.

Conclusions:

Avoiding fruits and vegetables and following irregular breakfast and dinner patterns were associated with underweight and excess weight in adolescents.

Gender-Specific Associations Between Saliva Microbiota and Body Size

OBJECTIVE

The human intestinal microbiota likely play an important role in the development of overweight and obesity. However, the associations between saliva microbiota and body mass index (BMI) have been sparsely studied. The aim of this study was to identify the associations between saliva microbiota and body size in Finnish children.

METHODS

The saliva microbiota of 900 Finnish children, aged 11-14 years with measured height and weight, was characterized using 16S rRNA (V3-V4) sequencing.

RESULTS

The core saliva microbiota consisted of 14 genera that were present in more than 95% of the Finnish children. The saliva microbiota profiles were gender-specific with higher alpha-diversity in boys than girls and significant differences between the genders in community composition and abundances. Alpha-diversity differed between normal weight and overweight girls and between normal weight and obese boys. The composition was dissimilar between normal weight and obese girls, but not in boys. The relative abundance profiles differed according to body size. Decrease in commensal saliva bacteria were observed in all the body sizes when compared to normal weight children. Notably, the relative abundance of bacteria related to, Veillonella, Prevotella, Selenomonas, and Streptococcus was reduced in obese children.

CONCLUSION

Saliva microbiota diversity and composition were significantly associated with body size and gender in Finnish children. Body size-specific saliva microbiota profiles open new avenues for studying the potential roles of microbiota in weight development and management.

Identifying eating habits in Finnish children: a cross-sectional study

Background

We aimed to identify different eating habits among Finnish children and to evaluate their association with meal patterns, breakfast consumption, and socio-demographic characteristics in a large, nationwide cohort of children.

Methods

We evaluated 10,569 children aged 9–14 years into the Finnish Health in Teens cohort in a cross-sectional design. The hierarchical K-means method was used to identify groups of children with different eating habits, based on five factors obtained through factor analysis of 10 food items. Multiple correspondence analysis was used to show associations between groups with different eating habits and meal patterns, breakfast patterns, gender, age, and language spoken at home.

Results

Analyses identified three groups: unhealthy eaters (12.3%), fruit and vegetable avoiders (43.3%), and healthy eaters (44.1%). Most children had regular meal and breakfast patterns. The proportion of boys was higher among unhealthy eaters. Unhealthy eaters also showed irregular meal and breakfast patterns, and had parents with low education level. There was a higher proportion of girls among healthy eaters. Healthy eaters also showed regular meal and breakfast patterns, and had parents with high education level.

Conclusions

Although the number of unhealthy eaters was small, special attention should be still paid to these, mostly male children, as they have poor eating habits and they lack regular eating routine. Skipping breakfast was more common among older children and girls, although girls had healthier eating habits overall. Our results can contribute to public health efforts to improve eating behaviours, especially among children with poor eating habits and those skipping healthy food items.