Crevicular Fluid Resorption Marker: Correlation with Alveolar and Systemic Bone

Objective: To examine the association between a gingival crevicular fluid (GCF) bone resorption marker and periodontal and systemic bone loss. Methods: 128 postmenopausal osteopenic, estrogen-deficient women on periodontal maintenance therapy for moderate-advanced periodontitis participated in a two-year randomized, double-blind, placebo-controlled, clinical trial with subantimicrobial dose doxycycline (SDD; 20 mg bid; n=64) and placebo treatment arms (n=64). The following were measured at baseline, 1 year and 2 years at posterior interproximal sites: type 1 collagen bone resorption marker (ICTP pooled from 2 sites with probing depths 5 mm or greater; RIA), alveolar bone density (ABD; computer-assisted densitometric image analysis), alveolar bone height (ABH), and systemic bone mineral density (BMD; dual-energy x ray absorptiometry). The exploratory analyses used Generalized Estimating Equations. Regression coefficients are interpreted for a 500 (or 350) pg ICTP/pool increase in baseline ICTP (or 1-year ICTP change from baseline). Results: Higher baseline GCF ICTP was marginally associated with higher odds of progressive ABD loss in placebo subjects (OR=1.04, 95% CI: 0.99 to 1.10, p=0.1) and higher odds of ABH loss in all subjects (OR=1.05, 95% CI: 1.00 to 1.10, p=0.07) over 2 years. Also, increased baseline ICTP was associated with a two-year reduction in lumbar spine BMD among all subjects (mean reduction -0.42%, 95% CI: -0.66% to -0.18%, p=0.0007) and in femoral neck BMD among SDD subjects(-0.69%,95% CI:-0.95% to 0.42%, p<0.0001). Interestingly, one-year changes in GCF ICTP among SDD and placebo subjects were positively associated with improvements in lumbar spine BMD (0.30%, 95% CI: 0.12% to 0.48%, p = 0.001) and among SDD subjects only for femoral neck BMD (0.66%, 95% CI: 0.39% to 0.92%, p< 0.0001). Conclusions: Elevated baseline GCF ICTP showed an association with future periodontal and systemic bone loss, which should be studied further in longer-term trials. Supported by NIDCR/NIH grant (R01DE012872).