The influence of cigarette smoke inhalation on bone density. A radiographic study in rats.

The aim of this study was to evaluate the influence of cigarette smoke inhalation (CSI) and its cessation on tibiae bone quality. Forty-one male Wistar rats were randomly assigned to one of the following groups: Group 1--control (n = 14), Group 2--3 months of CSI and 2 months without exposure to CSI (n = 12), and Group 3--5 months of CSI (n = 15). At the end of the experimental period, the animals were sacrificed, the tibiae removed and immediately radiographed for photodensitometric analysis. The results showed that continuous exposure to cigarette smoke promoted a significantly reduced bone density (p < 0.05) (3.22 mm Al eq +/- 0.58; 2.93 mm Al eq +/- 0.45; 1.86 mm Al eq +/- 0.35; for groups 1, 2 and 3, respectively). Similar levels of bone density were observed for the control and cessation groups (groups 1 and 2 - p > 0.05). Thus, within the limits of the present study, it can be concluded that CSI may affect tibiae bone quality, and CSI cessation results in a return towards the level of the control group.