Fluid intake and hydration status in obese vs normal weight children.

BACKGROUND/OBJECTIVES: Little is known on the relationship between obesity and hydration levels in children. This study assessed whether and by which mechanisms hydration status differs between obese and non-obese children. SUBJECTS/METHODS: Hydration levels of 86 obese and 89 normal weight children (age: 7-11 years) were compared. Hydration was measured as the average free water reserve (FWR=urine output/24 h minus the obligatory urine output [total 24 h excreted solutes/97th percentile of urine osmolality of children with adequate water intake, that is, 830 mOsm/kg]) over 2 days. Three days of weighed dietary and fluid intakes were recorded. Non-parametric tests were used to compare variables that were skewed and to assess which variables correlated with hydration. Variables mediating the different hydration levels of obese and normal weight children were assessed by co-variance analysis. RESULTS: Obese children were less hydrated than normal weight peers [FWR=median (IQR): 0.80 (-0.80-2.80) hg/day vs 2.10 (0.10-4.45) hg/day, P<0.02; 32% of obese children vs 20% of non-obese peers had negative FWR, P<0.001]. Body mass index (BMI) z-score (z-BMI) and water intake from fluids correlated with FWR (ρ=-0.18 and 0.45, respectively, both P<0.05). Water intake from fluids completely explained the different hydration between obese and normal weight children [FWR adjusted for water from fluids and z-BMI=2.44 (0.44) hg vs 2.10 (0.50) hg, P=NS; B coefficient of co-variation between FWR (hg/day) and water intake from fluids (hg/day)=0.47, P<0.001]. CONCLUSIONS: Obese children were less hydrated than normal weight ones because, taking into account their z-BMI, they drank less. Future prospective studies are needed to explore possible causal relationships between hydration and obesity.

Early diagnosis and treatment of celiac disease in type 1 diabetes. A longitudinal, case-control study.

OBJECTIVES: Subjects with type 1 diabetes mellitus (DM) are at increased risk to develop celiac disease (CD). However, most of the published investigations on the association between type 1 DM and CD are cross-sectional ones. In this paper, longitudinal data are presented on the effects of gluten-free diet (GFD) on growth and metabolic control in children and adolescents with type 1 DM screened for CD. METHODS: Clinical records of 27 patients with type 1 DM+CD (7% of a population of 385 subjects with type 1 DM) were reviewed. The following variables were considered at the diagnosis of CD (T0) and after 24 (T24) and 48 (T48) months of GFD according to the length of available follow-up: weight, height, body mass index (BMI), Hb and HbA1c levels and per kg/day dose of insulin. Forty-three patients with type 1 DM alone, matched for sex, age and duration of diabetes were chosen as controls. RESULTS: In patients with type 1 DM+CD, mean (SD) age at type 1 DM diagnosis was 8 (3.3) years. Median time interval between diagnosis of type 1 DM and of CD was 1.8 years (range 0.1-23.9 years). At T0 (n = 23), height and BMI z-score, HbA1c levels and daily insulin dose were comparable in type 1 DM+CD and in control subjects. Mean Hb concentration was significantly lower in subjects with type 1 DM+CD (12.6 (1.3) vs. 13.3 (0.7) g/dl, p < 0.05). At T24 (n = 22) and T48 (n = 16), no difference was detectable in height, BMI, HbAlc and insulin dose and also Hb concentration was comparable in both groups. CONCLUSIONS: This study shows that, at diagnosis of CD, screened subjects with type 1 DM had only minor signs of malnutrition and metabolic disturbances were uncommon. Dietary treatment of CD can allow a growth and diabetes control comparable with subjects with diabetes alone.