A high prevalence of periodontitis has been reported in rheumatoid arthritis (RA) patients, although the strength of this association, its temporal link and the possible relationship between the severity of periodontitis and RA disease activity remain unclear. The objective of this work was to investigate whether periodontitis is associated with RA and whether periodontitis severity is linked to RA disease activity. This case–control study included 187 patients diagnosed with RA and 157 control patients without inflammatory joint disease. RA disease activity and severity were evaluated by the Disease Activity Score 28, the Simplified Disease Activity Index, the Clinical Disease Activity Index, rheumatoid factor, anti-citrullinated protein antibody titers, the erythrocyte sedimentation rate, C-reactive protein, presence of extra-articular manifestations and type of RA therapy. Exposure severity was assessed by the following periodontal parameters: plaque index, bleeding on probing, probing pocket depth and clinical attachment levels. Sociodemographic variables and comorbidities were evaluated as confounding variables. Outcome and exposure variables were compared by both parametric and nonparametric tests, and possible associations were assessed through regression analysis with a calculation for the adjusted odds ratio (OR). A significant association was demonstrated between periodontitis and RA with an adjusted OR of 20.57 (95% CI 6.02–70.27, p < 0.001). Compared with controls, all parameters related to periodontal status (plaque index, bleeding on probing, probing pocket depth and clinical attachment levels) were significantly worse in RA patients (p < 0.001). Periodontitis severity was significantly associated with RA disease activity (p < 0.001), showing in an ordinal logistic regression model an association between periodontal severity and disease activity with an adjusted OR of 2.66 (95% CI 1.24–5.74, p = 0.012). A significant association was demonstrated between periodontitis and RA, independent of other confounders. This association was more evident in patients with pronounced periodontal disease and higher RA disease activity.

In semi-arid ecosystems, rainfall and temperature induce changes in the food chain and affect breeding conditions of raptors. We examined the influence of rainfall and temperature on the breeding success of the Eurasian Kestrel Falco tinnunculus inhabiting xerophytic scrub on Tenerife Island, Canary Archipelago. Reproductive performance was recorded during five years, and food availability (arthropods, lizards, mice and birds) was monitored monthly during a wet and a dry breeding season. We found that increased rainfall in the previous autumn was associated with an earlier laying date and a more prolonged breeding season. Mean clutch size showed a positive correlation with rainfall in the month prior to laying. Hatching and fledgling success did not vary significantly between a wet and a dry year. Temperature did not influence breeding parameters. Despite the advanced laying date and larger clutch size observed, high prey availability during egg formation in the wet year did not result in higher overall b...