Temporal changes in the risk of six-month post-covid symptoms: a national population-based cohort study.

It is unclear how the risk of post-covid symptoms evolved during the pandemic, especially before the spread of Severe Acute Respiratory Syndrome Coronavirus 2 variants and the availability of vaccines. We used modified Poisson regressions to compare the risk of six-month post-covid symptoms and their associated risk factors according to the period of first acute covid: during the French first (March-May 2020) or second (September-November 2020) wave. Non-response weights and multiple imputation were used to handle missing data. Among participants aged 15 or more in a national population-based cohort, the risk of post-covid symptoms was 14.6% (95% CI: 13.9%, 15.3%) in March-May 2020, versus 7.0% (95% CI: 6.3%, 7.7%) in September-November 2020 (adjusted RR: 1.36, 95% CI: 1.20, 1.55). For both periods, the risk was higher in the presence of baseline physical condition(s), and it increased with the number of acute symptoms. During the first wave, the risk was also higher for women, in the presence of baseline mental condition(s), and it varied with educational level. In France in 2020, the risk of six-month post-covid symptoms was higher during the first than the second wave. This difference was observed before the spread of variants and the availability of vaccines.

Parental mental health and reporting of their child's behaviour: measurement invariance of the French version of the parental strengths and difficulties questionnaire.

Symptomatic effects of mental disorders in parents could bias their reporting on their child's mental health. This study aimed to investigate the measurement invariance of the French version of the parental Strengths and Difficulties Questionnaire (SDQ) across parental mental health in a sample (N = 20,765) of parents of children aged 3 to 17 years in France. Confirmatory factor analysis (CFA) and Exploratory Structural Equation Modelling (ESEM) were used to evaluate the fit of three known alternative SDQ factor structures (five, three, or second-order factor structures). Invariance was tested across parental mental health (present anxiety and depressive symptoms, psychiatric history) and across socio-demographic characteristics (child's age, child's gender, parent's gender, parent's educational level). CFA models showed a poor fit, while all ESEM models achieved acceptable or good fit, with the five-factor model presenting the best fit. Invariance was observed for all characteristics tested, indicating that the SDQ can be used to study the links between parental mental health and their child's mental health without bias. However, ESEM showed that the hyperactivity/inattention and conduct problems dimensions were not well differentiated in the French version of the SDQ.

High screen time and internalizing and externalizing behaviours among children aged 3 to 14 years during the COVID-19 pandemic in France.

Children's screen time increased as a result of the COVID-19 pandemic. In the summer of 2021, we explored the association between high screen time over a period of one year since May 2020 and behavioural problems among children and adolescents. The data were derived from the French EpiCov cohort study, collected in spring 2020, autumn 2020, and spring 2021. Participants (N = 1089) responded to online or telephone interviews about one of their children aged 3 to 14 years. Screen time was categorized as high if the daily mean screen time exceeded recommendations at each collection time. The Strengths and Difficulties Questionnaire (SDQ) was completed by parents to identify internalizing (emotional or peer problems) and externalizing (conduct problems or hyperactivity/inattention) behaviours in their children. Among the 1,089 children, 561 (51.5%) were girls, the average age was 8.6 years (SD 3.7). Internalizing behaviours: High screen time was not associated with internalizing behaviours (OR [95% CI] 1.20 [0.90-1.59]) or emotional symptoms (1.00 [0.71-1.41]) while it was associated with peer problems (1.42 [1.04-1.95]). Externalizing behaviours: High screen time was associated with externalizing problems (1.63 [1.01-2.63]) and conduct problems (1.91 [1.15-3.22]) only among older children aged 11 to 14 years. No association with hyperactivity/inattention was found. In a French cohort, exploration of persistent high screen time in the first year of the pandemic and behaviour difficulties in Summer 2021 resulted in mixed findings according to behaviour's type and children's age. These mixed findings warrant further investigation into screen type and leisure/school screen use to enhance future pandemic responses appropriate for children.

Comparison of Depression and Anxiety Following Self-reported COVID-19-Like Symptoms vs SARS-CoV-2 Seropositivity in France.

Importance: The long-term consequences of COVID-19 on mental health are a critical issue given the number of people infected with SARS-CoV-2 worldwide since the beginning of the pandemic. Objective: To investigate the associations between self-reported COVID-19-like symptoms or SARS-CoV-2 seropositivity and subsequent depression or anxiety. Design, Setting, and Participants: This propensity score-matched cohort study began in May 2020, with follow-ups in November 2020 and July 2021. The study used data from a large, randomly selected, national population-based cohort from France, the EpiCoV (Epidémiologie et Conditions de Vie) study. Of 85 074 individuals 15 years or older who completed the questionnaires at the 3 collection times, 28 568 were excluded because they did not return a blood sample for serologic testing, 1994 because of missing data on outcomes or exposures, and 9252 to respect the temporal sequence (exposure must precede the outcome). Exposures: Propensity scores based on various socioeconomic, lifestyle, and health variables were computed to match participants who experienced COVID-19-like symptoms between February and November 2020 or showed SARS-CoV-2 seropositivity in November 2020. Main Outcomes and Measures: Logistic regression models were used to estimate associations between these occurrences and depression or anxiety assessed in July 2021 using the Patient Health Questionnaire 9-item and Generalized Anxiety Disorder 7-item scales, respectively. Results: Among the 45 260 included participants (mean [SD] age, 51.1 [18.9] years; 52.4% women; 8.0% with depression and 5.3% with anxiety in July 2021), COVID-19-like symptoms were associated with subsequent depression (adjusted odds ratio, 1.70; 95% CI, 1.45-1.99) and anxiety (adjusted OR, 1.57; 95% CI, 1.29-1.92), whereas SARS-CoV-2 seropositivity was not. Furthermore, COVID-19-like symptoms, but not anosmia or dysgeusia alone, were associated with subsequent depression and anxiety in both the seropositive and seronegative subgroups. Conclusions and Relevance: In this cohort study of more than 45 000 individuals drawn from the French general population, SARS-CoV-2 infection was not found as a risk factor of subsequent depression or anxiety. Moreover, self-reported COVID-19-like symptoms were associated with depression and anxiety assessed at least 8 months later in both seropositive and seronegative subgroups, suggesting that factors other than SARS-CoV-2 infection are implied in this association.

Suicidal ideation following self-reported COVID-19-like symptoms or serology-confirmed SARS-CoV-2 infection in France: A propensity score weighted analysis from a cohort study.

BACKGROUND: A higher risk of suicidal ideation associated with self-report of Coronavirus Disease 2019 (COVID-19)-like symptoms or COVID-19 infection has been observed in cross-sectional studies, but evidence from longitudinal studies remains limited. The aims of this study were 2-fold: (1) to explore if self-reported COVID-19-like symptoms in 2020 were associated with suicidal ideation in 2021; (2) to explore if the association also existed when using a biological marker of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in 2020. METHODS AND FINDINGS: A total of 52,050 participants from the French EpiCov cohort were included (median follow-up time = 13.7 months). In terms of demographics, 53.84% were women, 60.92% were over 45 years old, 82.01% were born in mainland France from parents born in mainland France, and 59.38% completed high school. COVID-19-like symptoms were defined as participant report of a sudden loss of taste/smell or fever alongside cough, shortness of breath, or chest oppression, between February and November 2020. Symptoms were self-reported at baseline in May 2020 and at the first follow-up in Autumn 2020. Serology-confirmed SARS-CoV-2 infection in 2020 was derived from Spike protein ELISA test screening in dried-blood-spot samples. Samples were collected from October 2020 to March 2021, with 94.4% collected in 2020. Suicidal ideation since December 2020 was self-reported at the second follow-up in Summer 2021. Associations of self-reported COVID-19-like symptoms and serology-confirmed SARS-CoV-2 infection in 2020 with suicidal ideation in 2021 were ascertained using modified Poisson regression models, weighted by inverse probability weights computed from propensity scores. Among the 52,050 participants, 1.68% [1.54% to 1.82%] reported suicidal ideation in 2021, 9.57% [9.24% to 9.90%] had a serology-confirmed SARS-CoV-2 infection in 2020, and 13.23% [12.86% to 13.61%] reported COVID-19-like symptoms in 2020. Self-reported COVID-19-like symptoms in 2020 were associated with higher risks of later suicidal ideation in 2021 (Relative Riskipw [95% CI] = 1.43 [1.20 to 1.69]), while serology-confirmed SARS-CoV-2 infection in 2020 was not (RRipw = 0.89 [0.70 to 1.13]). Limitations of this study include the use of a single question to assess suicidal ideation, the use of self-reported history of mental health disorders, and limited generalizability due to attrition bias. CONCLUSIONS: Self-reported COVID-19-like symptoms in 2020, but not serology-confirmed SARS-CoV-2 infection in 2020, were associated with a higher risk of subsequent suicidal ideation in 2021. The exact role of SARS-CoV-2 infection with respect to suicide risk has yet to be clarified. Including mental health resources in COVID-19-related settings could encourage symptomatic individuals to care for their mental health and limit suicidal ideation to emerge or worsen.

Labor market participation and depression during the COVID-19 pandemic among young adults (18 to 30 years): A nationally representative study in France.

Objective: To examine the relationship between young adults' labor force participation and depression in the context of the COVID-19 pandemic. Design setting participants: Data come from the nationally-representative EPICOV cohort study set up in France, and were collected in 2020 and 2021 (3 waves of online or telephone interviews: 02/05/2020-12/06/2020; 26/10/2020-14/12/2020; 24/06/2021-09/08/2021) among 2,217 participants aged 18-30 years. Participants with prior mental health disorder (n = 50) were excluded from the statistical analyses. Results: Using Generalized Estimating Equation (GEE) models controlled for participants' socio-demographic and health characteristics and weighted to be nationally-representative, we found that compared to young adults who were employed, those who were studying or unemployed were significantly more likely to experience depression assessed using the PHQ-9 (multivariable ORs, respectively: OR: 1.29, 95% CI 1.05-1.60 and OR: 1.50, 1.13-1.99). Stratifying the analyses by age, we observed that unemployment was more strongly associated with depression among participants 25-30 years than among those who were 18-24 years (multivariable ORs, respectively, 1.78, 95% CI 1.17-2.71 and 1.41, 95% CI 0.96-2.09). Being out of the labor force was, to the contrary, more significantly associated with depression among participants 18-24 years (multivariable OR: 1.71, 95% CI 1.04-2.82, vs. 1.00, 95% CI 0.53-1.87 among participants 25-30 years). Stratifying the analyses by sex, we found no significant differences in the relationships between labor market characteristics and depression (compared to participants who were employed, multivariable ORs associated with being a student: men: 1.33, 95% CI 1.01-1.76; women: 1.19, 95% CI 0.85-1.67, multivariable ORs associated with being unemployed: men: 1.60, 95% CI 1.04-2.45; women: 1.47, 95% CI 1.01-2.15). Conclusions and relevance: Our study shows that in addition to students, young adults who are unemployed also experience elevated levels of depression in the context of the COVID-19 pandemic. These two groups should be the focus of specific attention in terms of prevention and mental health treatment. Supporting employment could also be a propitious way of reducing the burden of the COVID-19 pandemic on the mental health of young adults.

Resilience of people with chronic medical conditions during the COVID-19 pandemic: a 1-year longitudinal prospective survey.

BACKGROUNDS: Individuals with chronic medical conditions are considered highly exposed to COVID-19 pandemic stress, but emerging evidence is demonstrating that resilience is common even among them. We aimed at identifying sustained resilient outcomes and their predictors in chronically ill people during the first year of the pandemic. METHODS: This international 4-wave 1-year longitudinal online survey included items on socio-demographic characteristics, economic and living situation, lifestyle and habits, pandemic-related issues, and history of mental disorders. Adherence to and approval of imposed restrictions, trust in governments and in scientific community during the pandemic were also investigated. The following tools were administered: the Patient Health Questionnaire, the Generalized Anxiety Disorder scale, the PTSD Checklist DSM-5, the Oslo Social Support Scale, the Padua Inventory, and the Portrait Values Questionnaire. RESULTS: One thousand fifty-two individuals reporting a chronic condition out of 8011 total participants from 13 countries were included in the study, and 965 had data available for the final model. The estimated probability of being "sustained-resilient" was 34%. Older male individuals, participants employed before and during the pandemic or with perceived social support were more likely to belong to the sustained-resilience group. Loneliness, a previous mental disorder, high hedonism, fear of COVID-19 contamination, concern for the health of loved ones, and non-approving pandemic restrictions were predictors of not-resilient outcomes in our sample. CONCLUSIONS: We found similarities and differences from established predictors of resilience and identified some new ones specific to pandemics. Further investigation is warranted and could inform the design of resilience-building interventions in people with chronic diseases.

Substance Use Among Residents of Homeless Shelters During the COVID-19 Pandemic: Findings From France.

Objectives: To record the prevalence and risk factors of substance use amongst homeless persons during the COVID-19 pandemic. Methods: The ECHO study consisted in two independent cross-sectional waves of data collection in the regions of Paris, Lyon, and Strasbourg during the Spring of 2020 (n = 530) and 2021 (n = 319). Factors associated with substance use were explored using generalised logistic regression models. Results: The most prevalent substance used was tobacco (38%-43%), followed by alcohol (26%-34%). The use of both substances positively associated with each other, although risk factors varied depending on the substance. The only factors consistently associated with alcohol and tobacco use were being male, exposure to theft/assault and participants' region of origin. Whilst the rate of tobacco use was relatively stable between Spring 2020 and 2021, alcohol use was more common in 2021. Conclusion: These findings highlight a high prevalence of substance use amongst homeless persons. People experiencing homelessness face specific challenges in the context of the pandemic, alongside greater vulnerability to illness and low healthcare access, therefore the need to improve prevention and support services for substance abuse within this population is vital.

LC-PUFA enrichment in infant formula and neurodevelopment up to age 3.5 years in the French nationwide ELFE birth cohort.

PURPOSE: For decades, consistent associations between breastfeeding and children's neurodevelopment have been attributed to breastmilk content in long-chain polyunsaturated fatty acids (LC-PUFAs). However, the beneficial effect of LC-PUFA enrichment of infant formula on neurodevelopment remains controversial. This study examined the association of LC-PUFA enrichment of infant formulas with neurodevelopment up to age 3.5 years. METHODS: Analyses were based on 9372 children from the French nationwide ELFE birth cohort. Monthly from 2 to 10 months, parents declared their infant's feeding mode, including breastfeeding and the name of the infant formula, which allowed for identifying formulas enriched in arachidonic (ARA), eicosapentaenoic (EPA) and/or docosahexaenoic (DHA) acids. Neurodevelopment was assessed at age 1 and 3.5 years with the Child Development Inventory (CDI-1 and CDI-3.5); at 2 years with the MacArthur-Bates Communicative Development Inventories (MB-2); and at 3.5 years with the Picture Similarities subtest of the British Ability Scale (BAS-3.5). Associations were assessed by linear regression adjusted for any breastfeeding duration and main confounding factors, including socioeconomic characteristics. RESULTS: One-third of formula-fed infants consumed LC-PUFA-enriched formulas. Most of these formulas were enriched in both DHA and ARA, and about 10% of infants consumed formula further enriched in EPA. LC-PUFA enrichment of infant formula was not associated with neurodevelopmental scores at age 1 (CDI-1, - 0.16 [- 0.39, 0.07]), age 2 (MB-2, 0.78 [- 0.33, 1.89]), or age 3.5 (CDI-3.5, - 0.05 [- 0.27, 0.17]; BAS-3.5, - 0.93 [- 2.85, 0.98]). CONCLUSION: In the ELFE study, LC-PUFA enrichment of infant formula was not associated with neurodevelopmental scores up to 3.5 years.

Enrichment of Formula in Probiotics or Prebiotics and Risk of Infection and Allergic Diseases up to Age 5.5 Years in the Nationwide Etude Longitudinale Française depuis l'Enfance (ELFE) Cohort.

BACKGROUND: An increasing number of infant and follow-on formulas are enriched with probiotics and/or prebiotics; however, evidence for health effects of such enrichment in early childhood remains inconclusive. OBJECTIVES: The present study aimed to assess whether the consumption of formula enriched with probiotics or prebiotics was associated with the risk of infection and allergic diseases in early childhood. METHODS: Analyses involved data for 8389 formula-fed children from the Etude Longitudinale Française depuis l'Enfance (ELFE) cohort. Enrichment of the formula with probiotics or prebiotics that was consumed from the age of 2-10 mo was identified by the formula ingredient list. Lower respiratory tract infection (LRTI), upper respiratory tract infection (URTI), gastrointestinal infection, wheezing, asthma, food allergy, and itchy rash were prospectively reported by parents up to the age of 5.5 y. Adjusted logistic regression models were used to assess associations between the consumption of enriched formula and risk of infection and allergic diseases. RESULTS: Aged 2 mo, more than half of formula-fed infants consumed the probiotic-enriched formula and only 1 in 10 consumed the prebiotic-enriched formula. Consumption of the Bifidobacterium lactis-enriched formula at 2 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.84 (0.73-0.96)]. Consumption of the Bifidobacterium breve-enriched formula up to 6 mo was associated with a higher risk of LRTI [OR (95% CI) = 1.75 (1.29-2.38)] and asthma [OR (95% CI) = 1.95 (1.28-2.97)], whereas its consumption from 6 to 10 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.64 (0.48-0.86)] and asthma [OR (95% CI) = 0.59 (0.40-0.88)]. Moreover, the consumption of Streptococcus thermophilus from 6 to 10 mo was associated with a higher risk of asthma [OR (95% CI) = 1.84 (1.29-2.63)]. No significant association was found for gastrointestinal infection, food allergy, and itchy rash. Overall, the consumption of prebiotic-enriched formula was not significantly associated with infection and allergy risk. CONCLUSIONS: Associations between the consumption of probiotic-enriched formula and risk of respiratory symptoms differ according to the strain considered and consumption period. Further well-designed studies are needed to confirm these results.

Enrichment of Formula in Probiotics or Prebiotics and Risk of Infection and Allergic Diseases up to Age 5.5 Years in the Nationwide Etude Longitudinale Française depuis l'Enfance (ELFE) Cohort.

BACKGROUND: An increasing number of infant and follow-on formulas are enriched with probiotics and/or prebiotics; however, evidence for health effects of such enrichment in early childhood remains inconclusive. OBJECTIVES: The present study aimed to assess whether the consumption of formula enriched with probiotics or prebiotics was associated with the risk of infection and allergic diseases in early childhood. METHODS: Analyses involved data for 8389 formula-fed children from the Etude Longitudinale Française depuis l'Enfance (ELFE) cohort. Enrichment of the formula with probiotics or prebiotics that was consumed from the age of 2-10 mo was identified by the formula ingredient list. Lower respiratory tract infection (LRTI), upper respiratory tract infection (URTI), gastrointestinal infection, wheezing, asthma, food allergy, and itchy rash were prospectively reported by parents up to the age of 5.5 y. Adjusted logistic regression models were used to assess associations between the consumption of enriched formula and risk of infection and allergic diseases. RESULTS: Aged 2 mo, more than half of formula-fed infants consumed the probiotic-enriched formula and only 1 in 10 consumed the prebiotic-enriched formula. Consumption of the Bifidobacterium lactis-enriched formula at 2 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.84 (0.73-0.96)]. Consumption of the Bifidobacterium breve-enriched formula up to 6 mo was associated with a higher risk of LRTI [OR (95% CI) = 1.75 (1.29-2.38)] and asthma [OR (95% CI) = 1.95 (1.28-2.97)], whereas its consumption from 6 to 10 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.64 (0.48-0.86)] and asthma [OR (95% CI) = 0.59 (0.40-0.88)]. Moreover, the consumption of Streptococcus thermophilus from 6 to 10 mo was associated with a higher risk of asthma [OR (95% CI) = 1.84 (1.29-2.63)]. No significant association was found for gastrointestinal infection, food allergy, and itchy rash. Overall, the consumption of prebiotic-enriched formula was not significantly associated with infection and allergy risk. CONCLUSIONS: Associations between the consumption of probiotic-enriched formula and risk of respiratory symptoms differ according to the strain considered and consumption period. Further well-designed studies are needed to confirm these results.

Enrichment of infant formula with long-chain polyunsaturated fatty acids and risk of infection and allergy in the nationwide ELFE birth cohort.

BACKGROUND: The new European regulations require the enrichment of formulas with docosahexaenoic acid (DHA) because of the positive effects of long-chain polyunsaturated fatty acids (LCPUFAs) on neurodevelopment and visual acuity. In this observational study, we aimed to evaluate whether the consumption of LCPUFA-enriched formula was associated with the risk of infection and allergy in early childhood. METHODS: Analyses involved data from 8389 formula-fed infants from the ELFE birth cohort. Formula enrichment was identified from the list of ingredients of the formula consumed at 2 months. Infections (gastrointestinal, lower respiratory tract [LRTI], upper respiratory tract) and allergies (wheezing, itchy rash, asthma medication, food allergy) from age 2 months to 5.5 years were reported by parents during follow-up surveys. Multivariable logistic regression models were used to assess associations between the consumption of LCPUFA-enriched formula and the risk of infection and allergy. RESULTS: Among formula-fed infants at 2 months, 36% consumed formula enriched with DHA and arachidonic acid (ARA), and 11% consumed formula additionally enriched with eicosapentaenoic acid (EPA). Enriched formula consumption was not associated with infection or allergy, except for an association between consumption of DHA/ARA/EPA-enriched formula and lower use of asthma medications. Furthermore, as compared with non-DHA/ARA/EPA-enriched formula, consumption of formula with high EPA content (≥3.2 mg/100 kcal) was related to lower risk of LRTI and lower use of asthma medications. CONCLUSION: This study suggests that consumption of DHA/ARA/EPA-enriched formula (especially those with high EPA content) is associated with a lower risk of LRTI and lower use of asthma medications.

Depression during the COVID-19 pandemic amongst residents of homeless shelters in France.

BACKGROUND: Accumulating evidence suggests that the COVID-19 pandemic has negatively affected global mental health and well-being. However, the impact amongst homeless persons has not been fully evaluated. The ECHO study reports factors associated with depression amongst the homeless population living in shelters in France during the spring of 2020. METHODS: Interview data were collected from 527 participants living in temporary and/or emergency accommodation following France's first lockdown (02/05/20 - 07/06/20), in the metropolitan regions of Paris (74%), Lyon (19%) and Strasbourg (7%). Interviews were conducted in French, English, or with interpreters (33% of participants, ∼20 languages). Presence of depression was ascertained using the Patient Health Questionnaire (PHQ-9). RESULTS: Amongst ECHO study participants, 30% had symptoms of moderate to severe depression (PHQ-9 ≥ 10). Multivariate analysis revealed depression to be associated with being female (aOR: 2.15; CI: 1.26-3.69), single (aOR: 1.60; CI: 1.01-2.52), chronically ill (aOR: 2.32; CI: 1.43: 3.78), facing food insecurity (aOR: 2.12; CI: 1.40-3.22) and participants' region of origin. Persons born African and Eastern Mediterranean regions showed higher levels of depression (30-33% of participants) than those migrating from other European countries (14%). Reduced rates of depression were observed amongst participants aged 30-49 (aOR: 0.60; CI: 0.38-0.95) and over 50 (aOR: 0.28; CI: 0.13-0.64), compared to 18-29-year-olds. LIMITATIONS: These data are cross-sectional, only providing information on a given moment in time. CONCLUSIONS: Our results indicate high levels of depression amongst homeless persons during the COVID-19 pandemic. Predicted future instability and economic repercussions could particularly impact the mental health of this vulnerable group.

Early growth according to protein content of infant formula: Results from the EDEN and ELFE birth cohorts.

BACKGROUND: In several systematic reviews, rapid weight gain in early life has been related to increased risk of later obesity. In line with this finding, the "early protein hypothesis" suggests that reducing early protein intake is a potential lever for obesity prevention. OBJECTIVE: To determine whether the variability of protein content of infant formula used in France over the period 2003-2012 is significantly associated with early growth in children. METHODS: A pooled sample of infants from the EDEN (Etude des Déterminants pré et postnatals de la santé et du développement de l'Enfant) mother-child cohort (born in 2003-2006) and the ELFE (Etude Longitudinale Française depuis l'Enfance) birth cohort (born in 2011) (ntotal  = 5846) was used. Protein content of the infant formula received at 4 months was classified into five groups. Associations between protein content (or breastfed status) at 4 months and weight-, length- and BMI-for-age z-scores at 6, 12 and 18 months were analysed by multivariable linear regression. RESULTS: This analysis showed a positive association between protein content and weight-, length- and BMI-for-age z-scores at 6 months and only for weight-for-age at 12 months. At 6 months, as compared with the intermediate protein-content group (2.1-2.5 g/100 kcal), infants receiving very-high protein content (>2.8 g/100 kcal) had higher BMI-for-age z-score and those from the very-low protein-content group (<2.0 g/100 kcal) had lower BMI-for-age z-score. Exclusively breastfed infants had lower length and weight z-scores than formula-fed infants at any age. CONCLUSIONS: Our findings show a positive association, under real conditions of use, between protein contents in infant formula still on the market and weight-, length- and BMI-for-age z-scores from 6 to 18 months.

Characteristics associated with feeding organic foods during complementary feeding: the nationwide Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort.

Organic food consumption and its effects on health remain understudied in adults and in children. The aim of this study was to describe family characteristics associated with feeding infants organic foods during the complementary feeding period. The analysis included 9764 children from the French Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort. In addition to telephone interviews conducted at 2, 12 and 24 months, a monthly questionnaire about milk feeding and complementary foods (including organic foods) was completed by parents between 3 and 10 months. Associations between family characteristics and feeding with organic foods during complementary feeding were analysed by multivariable multinomial logistic regression. Overall, 51 % of infants never consumed organic food during the complementary feeding period (up to 10 months), 24 % sometimes, 15 % often and 9 % always or almost always. As compared with infants never fed organic foods, those 'often' or 'always' fed organic foods were born to older mothers, with higher education level or family income, and lower pre-pregnancy BMI. As compared with never-smoking women, women who had stopped smoking before pregnancy were more likely to feed their infant organic foods. Feeding with organic foods was also related to long breast-feeding duration and later introduction to complementary foods. To conclude, associations between feeding with organic foods and family socio-economic position as well as infant feeding practices need to be considered when studying the impact of organic foods on children's health and development.

Infant feeding practices and sleep at 1 year of age in the nationwide ELFE cohort.

Sleep problems reported by parents affect 20% to 30% of infants. Few studies focused on the longitudinal association between infant feeding practices and sleep, especially in France. Analyses were based on 8,696 infants from the French national birth cohort ELFE. Collection of feeding practices from birth to 10 months allowed for the identification of trajectories of use of baby cereals and thickened formula by group-based trajectory modelling and calculation of duration of any breastfeeding (BF) and age at complementary feeding introduction (CFI) excluding baby cereals. Total sleep duration (TSD), night waking (NW) and sleep onset difficulties (SOD) were reported at age 1. Associations between feeding and sleep were tested by multinomial logistic regressions. BF duration ≥6 months was associated with parent-reported frequent NW, SOD and TSD ≤ 12 h/24 h at age 1. For TSD and SOD, this association was no longer significant after accounting for parental sleep-related practices. Early use of baby cereals (≤5 months) was associated with poor sleep. Early CFI (<4 months) was associated with shorter TSD and SOD but not NW. Early use of thickened formula (only <6 months) was related to poor sleep at age 1 (NW and SOD), whereas late (around 6 months) use of thickened formula was associated with better sleep. BF duration ≥6 months was related to poor sleep at age 1 but not after adjustment on 1-year parental sleep-related practices except for NW. The use of baby cereals or early CFI was not related to better sleep at age 1.

Characterization of Infant Feeding Practices and Related-Family Characteristics in the French Nationwide ELFE Birth Cohort.

Family characteristics such as education level or income are related to infant feeding practices. This study aimed to characterize infant feeding practices and investigate their associations with family characteristics. Analyses were performed with data from a French nationwide cohort, Etude Longitudinale Française depuis l'Enfance (ELFE). Feeding practices were characterized by two methods, a principal component analysis and a hierarchical ascendant classification (n = 8922). This characterization was conducted in three steps: considering firstly only introduction of main food groups, then also food pieces and finally adding the type of complementary food. The associations between family characteristics and the infant feeding patterns or clusters were tested by linear or multinomial regressions (n = 7556). Besides breastfeeding duration and age of first introduction of complementary foods, it appeared also important to consider specific food groups such as sweetened beverages and cow's milk, and the introduction of food pieces, to describe feeding practices. Recommended feeding practices (longer breastfeeding, complementary food in the right period) were related to higher maternal age and education level, so was migration status, the presence of older children, low income or the mothers' attendance to pre-birth preparation classes. The interrelations between feeding practices and family characteristics must be considered when examining the influence of feeding practices on child's health.

Breastfeeding initiation or duration and longitudinal patterns of infections up to 2 years and skin rash and respiratory symptoms up to 8 years in the EDEN mother-child cohort.

This paper aimed to examine the effect of breastfeeding on longitudinal patterns of common infections up to 2 years and respiratory symptoms up to 8 years. To assess the incidence and reoccurrence of infections and allergic symptoms in the first years of life among 1,603 children from the EDEN mother-child cohort, distinct longitudinal patterns of infectious diseases as well as skin rash and respiratory symptoms were identified by group-based trajectory modelling. To characterize infections, we considered the parent-reported number of cold/nasopharyngitis and diarrhoea from birth to 12 months and otitis and bronchitis/bronchiolitis from birth to 2 years. To characterize allergy-related symptoms, we considered the parent-reported occurrence of wheezing and skin rash from 8 months to 8 years and asthma from 2 to 8 years. Then associations between breastfeeding and these longitudinal patterns were assessed through adjusted multinomial logistic regression. Compared with never-breastfed infants, ever-breastfed infants were at a lower risk of diarrhoea events in early infancy as well as infrequent events of bronchitis/bronchiolitis throughout infancy. Only predominant breastfeeding duration was related to frequent events of bronchitis/bronchiolitis and infrequent events of otitis. We found no significant protective effect of breastfeeding on longitudinal patterns of cold/nasopharyngitis, skin rash, or respiratory symptoms. For an infant population with a short breastfeeding duration, on average, our study confirmed a protective effect of breastfeeding on diarrhoea events in early infancy, infrequent bronchitis/bronchiolitis and, to a lesser extent, infrequent otitis events up to 2 years but not on other infections, skin rash, or respiratory symptoms4.

Breastfeeding Status and Duration and Infections, Hospitalizations for Infections, and Antibiotic Use in the First Two Years of Life in the ELFE Cohort.

In low- and middle-income countries, the protective effect of breastfeeding against infections is well established, but in high-income countries, the effect could be weakened by higher hygienic conditions. We aimed to examine the association between breastfeeding and infections in the first 2 years of life, in a high-income country with relatively short breastfeeding duration. Among 10,349 young children from the nationwide Etude Longitudinale Française depuis l'Enfance (ELFE) birth cohort, breastfeeding and parent-reported hospitalizations, bronchiolitis and otitis events, and antibiotic use were prospectively collected up to 2 years. Never-breastfed infants were used as reference group. Any breastfeeding for <3 months was associated with higher risks of hospitalizations from gastrointestinal infections or fever. Predominant breastfeeding for <1 month was associated with higher risk of a single hospital admission while predominant breastfeeding for ≥3 months was associated with a lower risk of long duration (≥4 nights) of hospitalization. Ever breastfeeding was associated with lower risk of antibiotic use. This study confirmed the well-known associations between breastfeeding and hospitalizations but also highlighted a strong inverse association between breastfeeding and antibiotic use. Although we cannot infer causality from this observational study, this finding is worth highlighting in a context of rising concern regarding antibiotic resistance.