Point estimates and 95% confidence bounds (grey areas) for increase in fat mass index (FMI) at 9 years per obesity-risk-allele (n = 4,613).

<p>The dots represent specific FMI percentiles (0.03 percentile, 0.1 to 0.9 deciles, and 0.97 percentile) in the quantile regression model with adjustment for sex, age and height and are connected by dashes to visualize trends by outcome percentiles. The grey horizontal lines represent the linear regression coefficients and their respective confidence intervals (dashed).</p

Characteristics of the study population (n = 4,837).

<p>*n = 4,613</p><p>**classified using IOTF cut-off values <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0019057#pone.0019057-Cole2" target="_blank">[16]</a></p

Regression coefficients [95% confidence intervals] of the obesity-risk-allele score on sex- and age-specific BMI-SDS or fat mass index [kg/m²] at 9 years as estimated by linear regression (LR) and quantile regression at specific percentiles p.

<p>*p>0.05</p><p>Models with fat mass index and fat-free mass index as outcome variable were adjusted for sex, age and height.</p

Association between maternal pre-pregnancy BMI and dog ownership during gestation, univariable and multivariable (adjusted).

*<p>Maternal overweight/obesity adjustment for maternal education, maternal social class, mother worked during pregnancy, maternal age at delivery, previous living children, number of people in household, house type, mother had pets as a child.</p>$<p>Likelihood ratio P-value.</p

Characteristics (number and percentage) of the pregnant women who submitted pet ownership and activity information (n = 11,466).

<p>Characteristics (number and percentage) of the pregnant women who submitted pet ownership and activity information (n = 11,466).</p

Association between maternal activity at 18 weeks and dog ownership during gestation, univariable and multivariable (adjusted).

*<p>Adjustment after inclusion of maternal education, maternal social class, mother worked during pregnancy, maternal age at delivery, number of people in household, previous living children, house type and whether mother had pets as a child.</p>$<p>Likelihood ratio P-value.</p

Characteristics of 4,835 children with data on genetic markers, asthma, and BMI and risks of current asthma at 7½ y.

a<p>Number of children with data available.</p>†<p>BMI cut points for overweight and obese defined by Cole et al. <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.1001669#pmed.1001669-Cole2" target="_blank">[16]</a>.</p>‡<p>Median lean mass and median fat mass were calculated and used separately for females and males.</p><p>*Educated to General Certificate of Education level (school leaving certificate at 16 y) or lower.</p

Main Mendelian randomization features and results of the study.

<p>(A) depicts the IV assumptions, and (B) shows the two unconfounded associations used to estimate causal effects of BMI on asthma: the association of the allele score with BMI and the association of the allele score with asthma.</p

Associations of the weighted allele score with BMI at age 7½ and 9 y.

†<p>Linear regression coefficient, adjusted for gender. RR for number non-asthma/asthma and number non-atopic/atopic.</p><p>*Based on residuals from regression models of mass measure (fat/lean mass) on height, height squared, and gender. Fat mass was divided by two so that its standard deviation was similar to that of BMI and lean mass.</p>a<p>Controls were children with no current asthma at 7½ y.</p>b<p>Chi-squared test comparing estimate effects for non-atopic and atopic asthma.</p>c<p>Controls were children with no current asthma at 9 y.</p

Observational and instrumental variable estimates of the effect of BMI on current asthma at ages 11 to 14-diagnosed asthma at ages 7½ to 15 y in boys and girls and stratified by atopy at 7½ y.

†<p>Adjusted for gender, birth weight, pre- and postnatal maternal exposure to smoking, and maternal education.</p><p>*Derived using ever doctor-diagnosed asthma (available at 7½, 11, 14, and 15 y) and parent-reported current asthma or wheezing or treatment in last 12 mo.</p><p>DDA, doctor-diagnosed asthma; NA, not available.</p