Adiposity, Leptin and Gingival Crevicular Fluid TNF-α in Children

Objectives: The mechanisms involved in the association between obesity and periodontal disease remain unclear. The main explanation for this link lies in the inflammatory process and may involve leptin, a hormone secreted by the adipocytes. Leptin has been positively correlated to body fat and can modulate tumour necrosis factor‐alpha (TNF‐α) production and macrophage activation. Aim: To examine the extent to which circulating leptin level and adiposity are associated with gingival crevicular fluid (GCF) TNF‐α concentration among children.
Methods: We used data from the QUebec Adipose and Lifestyle InvesTigation in Youth cohort, an ongoing longitudinal study investigating the natural history of obesity among Caucasian children in Quebec, Canada. This cross-sectional analysis from the baseline visit includes 432 children aged 8–10 years, for whom data was available for obesity, serum leptin and TNF-α. Body mass index (BMI) was calculated as weight/height² (kg/m²). Sex-age-specific BMI was categorized into normal (<85th percentile), overweight (85th–95th percentile) and obese (≥ 95th percentile) as defined by the 2000 US-CDC growth charts. Serum leptin level was determined using blood samples collected after an overnight fast. GCF samples were collected from the gingival sulcus using a paper strip and the concentration of TNF‐α was determined by enzyme‐linked immunosorbent assay. Analyses included descriptive statistics and linear regression analyses adjusting for potential confounders.
Results: 38.8% of our sample was overweight or obese. Leptin level was significantly higher in overweight or obese compared to normal weight children (1.20 versus 0.57μg/L, p=0.003). Being overweight or obese was associated with a 8.9% (p=0.037) increase of GCF-TNF-α level in our sample of 8-10 year-old children. However, when accounting for serum leptin, this association was reduced and no longer statistically significant.
Conclusions: These findings suggest that circulating leptin level may influence the link between adiposity and periodontal health in children.