Aim: To examine associations between periodontitis and developmental trajectories of glycated haemoglobin (HbA1c) during the third and fourth decades in an initially healthy sample.
Materials and methods: HbA1c data collected at ages 26, 32 and 38 in the prospective Dunedin Multidisciplinary Health and Development Study were used to assign study members (n = 893) to trajectories applying group-based trajectory modelling (GBTM). The model allowed the statistical linking of baseline demographic, smoking and waist-height ratio covariates to group membership probability; and added a time-varying covariate (periodontitis) to the trajectories themselves to examine whether events that occurred during the course of the trajectory altered its course.
Results: Three HbA1c trajectory groups were identified: "Low" (n = 98, 11.0%); "Medium" (n = 482, 54.0%); and "High" (n = 313, 35.0%) with mean HbA1c of 29.6, 34.1 and 38.7 mmol/mol, respectively, at age 38. Having periodontitis at 32 and 38 was associated with an upward shift in the trajectories. However, none of the associations were statistically significant.
Conclusions: Periodontitis was not found to be associated with dysglycaemia over 12 years from early adulthood into early middle age. This suggests that any influence periodontitis may have on dysglycaemia develops later in life.
Keywords: glycated haemoglobin; longitudinal; periodontitis; smoking; type 2 diabetes; waist-height ratio.
© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.