Dietary calcium intake and adiposity in children and adolescents: Cross-sectional and longitudinal results from IDEFICS/I.Family cohort

BACKGROUND AND AIMS

Studies in children and adolescents suggest that higher dairy consumption may exert a protective effect on adiposity. However, only few studies examined the association between dietary calcium intake and body mass measures with conflicting results. We evaluated the association between total dietary calcium, calcium from dairy and non-dairy sources and anthropometric indices in a large European cohort of children and adolescents.

METHODS AND RESULTS

As many as 6,696 children belonging to the IDEFICS study were eligible for the cross-sectional analysis (Boys = 51%; age 6.0 ± 1.8 years; mean ± SD). Of these, 2,744 were re-examined six years later (Boys = 49.6%; age = 11.7 ± 1.8 years) in the framework of the I.Family study. The exposures were the baseline energy-adjusted total, dairy and non-dairy calcium intakes measured by a validated 24-h dietary recall. Multivariable linear regression was used to determine the association between calcium intake and z-scores of anthropometric indices (body mass index, BMI; waist circumference, WC; sum of skinfolds, SS; fat mass index, FMI) at baseline, and their variation over the 6 years follow-up. The association of dietary calcium with the incidence of overweight/obesity was also assessed. At baseline, an inverse association between total calcium intake and all the adiposity indices was consistently observed in boys, while only SS and FMI were significant in girls. The prevalence of overweight/obesity decreased significantly (P < 0.0001) across tertiles of calcium intake, in both sexes. Over the follow-up, boys with higher baseline calcium intake value showed significantly lower increase in BMI, WC and FMI z-scores, while in girls only a lower increase in WC z-score was observed. Only in boys, the risk to become overweight/obese decreased significantly across tertiles of calcium intake. Similar results were observed by analyzing only dietary calcium from dairy, while no association was observed between non-dairy calcium and adiposity indices.

CONCLUSIONS

We showed in a large cohort of European children and adolescents that dietary calcium intake may play a role in the modulation of body fat in developmental age. The association between dietary calcium and adiposity indices was driven by dairy calcium, while no effect was observed for non-dairy calcium intake. The existence of a sex-related difference in the association deserves further investigations.

Gestational weight gain and adiposity, fat distribution, metabolic profile, and blood pressure in offspring: the IDEFICS project

OBJECTIVE

To investigate the association between gestational weight gain (GWG) and total adiposity, body fat distribution, blood pressure (BP), and metabolic profile in offspring.

DESIGN

Cross-sectional study.

METHODS

Body mass index (BMI), waist, subscapular and tricipital skinfolds, and BP were measured and blood samples drawn in 12 775 children (aged 2-9 years) from the IDEFICS cohort. Overweight/obesity was defined by IOTF criteria. Parents filled in a questionnaire investigating child and familiar medical history and lifestyle. A section was dedicated to pregnancy history (including GWG).

RESULTS

Anthropometric indices linearly and significantly increased across GWG tertiles (BMI z-score: tertile I =0.08, 0.03-0.13; tertile II =0.16, 0.12-0.21; tertile III =0.34, 0.28-0.40, P<0.01, mean, 95% CI) by analysis of covariance (ANCOVA) adjusted by child sex, age and practice of sport, birth weight, current maternal BMI, parental education, gestational age, age at delivery, alcohol and smoking during pregnancy, maternal diabetes mellitus, gestational hypertension, and breastfeeding duration. After inclusion of BMI z-score among covariates, HbA1c significantly increased across tertiles (P=0.009) while no differences were observed for BP, serum insulin, HOMA index, blood glucose and lipids. The adjusted risk of overweight/obesity significantly increased by 14 and 22% in tertiles II and III respectively, in comparison with tertile I by logistic regression analysis controlling for covariates.

CONCLUSION

Maternal GWG is an independent predictor of total adiposity and body fat distribution in offspring during infancy. Exposure to perinatal factors should be taken into account for early prevention of overweight and obesity.

Low serum high-density lipoprotein cholesterol in childhood is associated with adolescent asthma

BACKGROUND

Whilst emerging evidence from animal and cell experiments has shown high-density lipoprotein cholesterol to have anti-inflammatory effects consistent with a protective role in asthma, human studies investigating the relationship of high-density lipoprotein cholesterol with asthma have produced conflicting results.

OBJECTIVE

To examine the association between serum lipids among Cypriot children aged 11-12 years and prevalence of asthma at age 15-17 years.

METHODS

In 3982 children, we assessed serum lipids, body mass index and maximal oxygen consumption at baseline (2001-2003) and explored associations with respiratory health at follow-up (2007) using multiple logistic regression models.

RESULTS

Lower levels of high-density lipoprotein cholesterol at age 11-12 years were found in subjects who reported ever asthma (58.2 vs. 60.0 mg/dL, P = 0.005) and active asthma (57.5 vs. 59.9 mg/dL, P = 0.010) in adolescence, in comparison with their respective reference groups. Total cholesterol, low-density lipoprotein and triglycerides had no association with any of the asthma outcomes. In contrast, with estimated odds ratios of 1.89 (95% CI 1.19-3.00) and 1.89 (95% CI 1.02-3.53), ever asthma and active asthma respectively appeared particularly pronounced among those who at baseline had high-density lipoprotein cholesterol <40 mg/dL, even after adjusting for potential confounders including body mass index and maximal oxygen consumption.

CONCLUSIONS & CLINICAL RELEVANCE

Low-serum high-density lipoprotein cholesterol in childhood is associated with an increased risk for asthma in adolescence, suggesting a potential role of this lipoprotein in the pathogenesis of paediatric asthma.

Prevalence and socio-demographic associations of undernutrition and obesity among preschool children in Cyprus

OBJECTIVE

To estimate the prevalence of undernutrition and obesity in preschool children in Cyprus and identify possible associations.

DESIGN

Cross-sectional study.

SETTING

Private and public nursery schools.

SUBJECTS

A representative sample (n=1412) stratified by age, gender, district and area of residence.

INTERVENTIONS

Weight (kg) and height (cm) were obtained and BMI (kg/m2) was calculated. Z scores for weight-for-age, height-for-age, and weight-for-height were calculated using the cutoffs from the CDC/WHO 1978 reference. Socio-demographic associations with nutritional status were examined in a logistic regression analysis.

RESULTS

The prevalence of undernutrition (WHO definition, Z-scores <-2) was low. Specifically the prevalence of underweight was 2.3%, wasting 2.8%, and stunting 1.1%. Undernutrition was associated with a low birth weight (LBW); odds ratio (OR) for underweight 4.1 (95% CI: 1.4, 12.2), P=0.012, stunting 5.2 (95% CI: 1.1, 23.3), P=0.033, and wasting 4.2 (95% CI: 1.3, 14.3), P=0.021. The prevalence of obesity (IOTF definition) was higher than undernutrition, and increased with age: 1.3% in 2 y olds to 10.4% in 6 y olds. Overweight and obesity prevalence were higher in rural (16.1%) than urban children (12.8%; P=0.046). Obesity in preschool children was associated with paternal obesity, OR 3.24 (95% CI: 1.59, 6.61), P=0.001, and maternal obesity 3.91 (95% CI: 1.78, 8.59), P=0.001. A birth weight (BW)> or =4000 g was associated with obesity compared to a BW between 2501 and 3000 g, OR 7.63 (95% CI: 1.91, 30.52), P=0.004.

CONCLUSIONS

The prevalence of undernutrition among preschool children in Cyprus was low but obesity prevalence was higher. Parental obesity and high BW were significantly associated with obesity while LBW was associated with undernutrition in preschool children.