Common risk indicators for oral diseases and obesity in 12-year-olds: a South Pacific cross sectional study

Background: Despite the increasing need to prevent obesity and oral diseases in adolescents worldwide, few studies have investigated the link existing between these conditions and their common risk factors. This study aims to evaluate the oral health and weight status of New Caledonian Children (aged 6,9,12 years) and to identify, amongst 12-year-olds, risk indicators that may characterize the groups of children affected by oral diseases, obesity or both diseases. Methods: This survey evaluated in 2011-2012 the oral health and stature-weight status and related risk indicators in a national representative sample of 6, 9 and 12 years-old children in New Caledonia. Dental status, chewing efficiency, height, weight and waist circumference were clinically recorded at school. The body mass index (BMI) and the waist to height ratio (WtHR) were calculated. For BMI the WHO Cut-offs were used. Twelve years-old participants responded to a questionnaire concerning socio-demographic and behavioural variables. For statistical analysis, the Clinical Oral and Global Health Index (COGHI) was developed and used. Twelve years-old children were categorised into four groups; Oral Diseases (ODG), Obesity (OG), Obesity and Oral Diseases (ODOG) and a Healthy Group (HG). A multivariate analysis was conducted using mixed-effects multinomial logistic regression models. Results: Prevalence of overweight and obesity was greatly increasing from 6 years (respectively 10.8% [8.8;13.3] and 7.8% [6.0;9.9]) to 12 years (respectively 22.2% [19.9;24.7] and 20.5% [18.2;22.9]) and one third of the 12-yr-olds had an excess of abdominal adiposity. At age 12, 36.6% of the children were healthy (HG), 27.3% had oral diseases (ODG), 19.7% were obese (OG) and 16.5% had both conditions (ODOG). Geographical location, ethnicity, tooth-brushing frequency and masticatory disability were significant risk factors for the OG, ODOG and ODG groups. Ethnicity and masticatory impairment were common risk indicators for the association of oral diseases and obesity. Conclusions: In NC health promotion programs should be specifically addressed towards Native populations who are particularly exposed to oral diseases and obesity, integrating a multiple risk factors approach, in order to prevent the onset of chronic diseases in adulthood. The impact of masticatory ability on children's weight status is a major issue for future research.