Association of obesity and weight gain with alveolar bone loss: Results of the Northern Finland Birth Cohort 1966 study

Aim: To investigate whether long-term obesity, long-term central obesity and weight gain are associated with alveolar bone loss. Materials and Methods: A sub-population (n = 1318) of the Northern Finland Birth Cohort 1966 was categorized based on body mass index (BMI: normal weight, overweight and obesity) and waist circumference (WC: no central obesity, central obesity) at ages 31 and 46. These categories were combined to define whether the participants stayed in the same categories or passed on to a higher category (weight gain). Alveolar bone level (BL) data were collected at age 46. Results: The associations of long-term obesity and weight gain with BL = 5 mm were stronger in smokers than in the total population and in never smokers. Males who passed on to higher BMI and WC categories showed a higher likelihood for BL = 5 mm (range in relative risks [RRs] 1.3-2.2) than males who stayed in the same categories (range in RRs 0.7-1.1). The associations with BL = 5 mm were weak or non-existent in females. Conclusions: The relation between obesity and periodontal diseases seems more complex than previously presumed. The role of gender and smoking should be taken into account in future studies.