Comorbities of overweight/obesity in Australian preschoolers: a cross-sectional population study

Copyright © 2008 BMJ Publishing Group Ltd & Royal College of Paediatrics and Child HealthObjective: To determine relationships between body mass index (BMI) status and indicators of health and morbidity in a nationally-representative population sample of preschool children. Methods: Data from the 4–5-year-old cohort in the first wave (2004) of the Longitudinal Study of Australian Children were studied. Main outcome measures were: measured child BMI, categorised as non-overweight, overweight and obese using International Obesity TaskForce cutpoints; parent-reported child global health, health-related quality of life, mental health problems, asthma, sleep problems, injuries, special health care needs, and level of parental concern about the child’s weight. Regression methods were used to assess associations with child’s BMI status, adjusted for sociodemographic factors. Results: BMI was available for 4934 (99%) children; 756 (15.3%) were overweight and 258 (5.2%) obese. Compared to non-overweight children, parents of overweight and obese children reported a higher prevalence of special health care needs (adj OR 1.72, 95% CI 1.20 to 2.46), but other health outcomes were similar. Parental concern about the child’s weight was low among the overweight (14.4%) and non-overweight (17.8%) children, but rose to 52.7% in the obese. However, parental concern was unrelated to any of the specific health problems studied. Conclusions: Despite a high prevalence of overweight/obesity, parents of overweight and obese children reported relatively few additional health burdens over and above those of the non-overweight preschoolers. These findings may shed light on the disparity between strong public concern and parents’ expressed lack of concern about overweight/obesity in their own children around the time of school entry. Childhood obesity’s "ominous implications for the development of serious diseases, both during youth and later in adulthood"1 are perhaps most serious for the large numbers of children who are already overweight by the preschool years.2 This threat is at odds with an apparent lack of concern by parents about the weight of their own overweight and obese children.3–5 One possible explanation for this seeming paradox is that, regardless of future risk, most parents perceive the current physical and psychological health of their overweight and obese young children to be satisfactory. However, although potential comorbidities of childhood overweight and obesity have been summarised in expert documents,6–8 no large population study of preschoolers has considered a broad range of potential morbidities simultaneously. The systematic review of the immediate health consequences of obesity in childhood by Reilly et al in 2003 concluded that obese children appear more likely to experience psychological or psychiatric problems than children of normal weight,6 but none of the reviewed studies included preschoolers. Five high-quality studies reported increased symptoms suggestive of asthma in obese children, two of which included 4-year-olds in large population-based studies.9 10 Older overweight/obese children may experience more daytime tiredness, snoring, less sleep11 12 and more injury-related morbidity than non-overweight children.13 US hospital costs for conditions associated with obesity (diabetes, sleep apnoea, asthma, gallbladder diseases) in 6–17-year-old patients were estimated to rise from $35 million in 1979–81 to $127 million in 1997–99,14 but there are no data directly related to measured weight status or regarding younger children. While cardiovascular and metabolic risk factors are known to cluster in obese children, the evidence for this in children around the time of school entry is much less strong.15 Accurately ascertaining the extent of comorbidity is important, since approaches to tackling established overwei ght/obesity in young children are likely to differ according to whether parents perceive their children to be less healthy or to be directly affected by their weight. This paper aims to determine the...M Wake, P Hardy, M G Sawyer and J B Carli