Seasonal Variations of the Incidence of Ruptured Abdominal Aortic Aneurysm at the Territory of the South Serbia

Climatic influence on the risk of abdominal aortic aneurysm rupture

Our aim is to examine the effects of climatic conditions on the incidence of ruptured abdominal aortic aneurysms (rAAA) in Catalonia, Spain. We combined clinical data from the Public Health official registries in Catalonia, Spain (HD-MBDS) of all rAAA with local climatic data obtained from the closest meteorological station (69 stations, National Meteorological Service: MeteoCat) from 2008 to 2017. We analyzed the median, maximum, minimum, and variability of atmospheric pressure (hPa) and air temperature (°C), solar irradiation (MJ/m²), humidity (%), accumulated precipitation (mm), median wind, and maximum flaw direction and velocity (°, m/s), recorded on the days of events, the previous day, and mean results for 3, 7, and 30 days before, as well as seasonality. Seventy-five control days were randomly selected in a 1-year period around every rAAA day at the same meteorological station, and compared. A total of 717 days and locations with rAAA were identified, and 53,775 controls were randomly selected. For the rAAA days, there were significantly lower temperatures, lower solar global irradiation, and higher mean humidity levels in all time periods (p < 0.001, p < 0.001, p < 0.05); higher atmospheric pressure variability during 1 week and 1 month before (p = 0.011, p = 0.007); and they often occurred during autumn/winter (57.6%, p < 0.001). Logistic regression identified low mean temperatures on the days of ruptures and high mean humidity the week before as independent rupture predictors. In conclusion, low median temperatures the same day and high humidity during 1 week before were identified as independent predictors of rAAA occurrence. The role of climate on pathophysiologic mechanisms may require further investigation.

Forecasting aortic aneurysm rupture: A systematic review of seasonal and atmospheric associations

BACKGROUND

Abdominal aortic aneurysms (AAAs) represent a significant burden of disease worldwide, and their rupture, without treatment, has an invariably high mortality rate. Whereas some risk factors for ruptured AAAs (rAAAs) are well established, such as hypertension, smoking, and female sex, the impact of seasonal and meteorologic variables is less clear. We systematically reviewed the literature to determine whether these variables are associated with rAAA.

METHODS

Review methods were according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We calculated pooled proportions and incidence rate ratios (IRRs) for the different months and seasons. Funnel plots were constructed to assess for publication bias. Given the poor methodologic quality of included studies, a sensitivity analysis was performed on better-quality studies, which scored 6 and above of 9 in the author-modified Newcastle-Ottawa Scale.

RESULTS

The pooled proportion of rAAA was highest in the autumn season (incidence rate, 26.6%; 95% confidence interval [CI], 25.6%-27.7%; I² = 15.4%), followed by winter (incidence rate, 26.2%; 95% CI, 24.1%-28.2%; I² = 72.4%), and lowest in summer (incidence rate, 21.1%; 95% CI, 19.3%-23.0%; I² = 70.4%). The IRRs of rAAA were -6.9% (95% CI, -9.8% to -3.9%), -19.5% (95% CI, -22% to -16.8%), +10.5% (95% CI, 7.2%-13.9%), and +18.1% (95% CI, 15%-22%) in spring, summer, autumn, and winter compared with the remaining seasons, respectively (all P < .0001), thus affirming existence of seasonal variation. The pooled proportion of rAAA was highest in December (incidence rate, 8.9%; 95% CI, 7.1%-10.9%; I² = 54.5%) but lowest in July (incidence rate, 5.7%; 95% CI, 4.2%-7.3%; I² = 54.5%). The IRR was significantly the highest in January (IRR, 1.14; 95% CI, 1.01-1.29; P = .031) but lowest in July (IRR, 0.75; 95% CI, 0.65-0.87; P < .0001). There is also some evidence for a possible association with atmospheric pressure. Associations with temperature and daylight hours, however, are at best speculative.

CONCLUSIONS

Autumn and winter are significantly associated with a higher incidence of rAAAs, and autumn is associated with the highest rupture incidence of all the seasons. However, the inability to appropriately control for other confounding factors known to increase the risk of AAA rupture precludes any additional recommendations to alter current provision of vascular services on the basis of these data.