Association of periodontitis with blood pressure: Response

We respectfully respond to Professor Bautista's comments as follows:

1. Antihypertensive treatment clearly has an influence on blood pressure; however, it does not seem to influence periodontitis, at least to the same extent. Moreover, although such treatment should be taken into account, we aimed to examine the association between periodontitis and blood pressure (BP) in the status quo. Nonetheless, we did re‐analyze our subject data taking his comments into consideration. At baseline, the systolic and diastolic BP were both significantly higher in subjects receiving antihypertensive treatment than in subjects who were not. We also redid our analysis (ANCOVA, as shown in our Table III; [1]) excluding subjects receiving antihypertensive treatment to see if treatment, itself, had a significant effect. While a similar trend to Table III was obtained, differences both in systolic BP and diastolic BP between subjects with and without periodontitis were slightly decreased throughout the unadjusted, adjusted 1 and adjusted 2 analyses. Consequently, the observed result appears to be contrary to Bautista's conjectures.

2. We do not feel that our study design should be classified as longitudinal, since measurements were performed only twice, at baseline and at 1‐year follow‐up.

3. Periodontitis is a chronic inflammatory process that may last for years. It is, however, unknown whether BP gradually increases with persistent periodontitis. If it does, the presence of periodontitis likely would slowly affect BP, and increases over a short observation period should be minimal. To examine this hypothesis, a longer observation period than we undertook would be required. Moreover, subjects with periodontitis at baseline generally are counseled to treat this disease early, though this precise information sometimes is unavailable. Such treatment of periodontitis might dilute the association between BP and periodontitis at follow‐up. Nevertheless, we found a positive association at follow‐up as well as at baseline. This would support the persistent association between periodontitis and BP.

We agree with Bautista's comment that a longer period of observation is warranted and necessary to confirm the long‐term association between BP and periodontitis. We wish to thank him sincerely for his thoughtful and practical comments.