Unique Meteorological Characteristics in Upper Gastrointestinal Bleeding by Different Etiologies in Beijing Area, China
Upper gastrointestinal bleeding (UGIB), defined as hemorrhage occurring from the mouth to the ligament of Treitz, is a critical medical condition influenced by various factors, including climatic conditions. Meteorological factors such as temperature, atmospheric pressure, humidity, and wind speed can impact physiological processes like blood pressure regulation and neuroendocrine function, potentially exacerbating bleeding episodes. However, the relationship between UGIB and weather patterns remains inconsistent across studies, possibly due to differences in geographic regions, underlying etiologies, and methodological approaches to analyzing temporal trends. This study investigates the influence of meteorological factors on UGIB occurrence in Beijing, a region characterized by a temperate monsoon climate with distinct seasonal variations, focusing on three etiological groups: non-steroidal anti-inflammatory drug (NSAID)-related peptic ulcers, non-NSAID-related peptic ulcers, and esophagogastric variceal (EGV) bleeding.
Study Design and Methodology
The retrospective analysis included 664 patients admitted to Beijing Chaoyang Hospital from 2014 to 2018. Cases were categorized into three groups: non-NSAID-related peptic ulcer bleeding (non-NSAID group, n=345), NSAID-related peptic ulcer bleeding (NSAID group, n=161), and EGV bleeding (EGV group, n=158). Diagnoses were confirmed via endoscopy and medication history. Meteorological data for Beijing during this period, including daily average temperature, atmospheric pressure, relative humidity, wind speed, and daily temperature range, were analyzed for stability across the five-year study period. No significant annual variations were observed, permitting aggregated analysis.
Temporal patterns in UGIB incidence were evaluated using three frameworks: traditional seasons (spring: March–May; summer: June–August; autumn: September–November; winter: December–February), 12-month cycles, and the 24 solar terms of the Chinese lunar calendar—a system dividing the year into 15-day intervals reflecting climatic and phenological changes. Statistical methods included chi-square tests for seasonal/monthly variations, circular distribution analysis for solar term patterns, Spearman correlation to assess associations between UGIB incidence and meteorological factors, and generalized additive models (GAMs) to model non-linear relationships between weather variables and bleeding risk.
Key Findings
Seasonal and Monthly Variations
Non-NSAID Group: Significant seasonal variations were observed (P=0.014), with the lowest incidence in summer (18.8%) and the highest in winter (31.3%). Monthly analysis revealed a peak in December (11.3% of annual cases) and troughs in July (5.8%) and August (6.1%) (P=0.004).
NSAID Group: No seasonal (P=0.484) or monthly (P=0.254) variations were detected, suggesting NSAID-related bleeding occurs independently of climatic fluctuations.
EGV Group: While seasonal differences were marginally insignificant (P=0.065), monthly analysis showed near-significant variation (P=0.054), with a trend toward higher incidence in colder months.
Solar Term Patterns
The 24 solar terms provided finer temporal resolution:
- Non-NSAID Group: Incidence peaked during Great Snow (November 22–December 6) and Waking of Insects (March 5–19) but lacked a centralized trend (Rayleigh’s Z=2.87, P>0.05).
- NSAID Group: No significant clustering (P=0.142).
- EGV Group: A distinct central tendency emerged (Rayleigh’s Z=6.64, P<0.05), with peak bleeding from Great Heat (July 22–August 6) of the previous year to Spring Equinox (March 20–April 3) of the current year.
Meteorological Correlations
Spearman correlation and GAMs revealed etiology-specific associations:
- Non-NSAID Group: A non-linear relationship with temperature was identified. Incidence peaked at an average solar term temperature of 10°C (Figure 1G). Below 10°C, bleeding risk rose by 3% per 1°C decrease.
- EGV Group: Lower temperatures (rs=−0.442, P=0.031) and higher atmospheric pressure (rs=0.490, P=0.015) correlated with increased incidence. GAMs indicated a 3% rise in EGV bleeding per 1°C temperature drop and a 1.3% increase per 1% rise in relative humidity.
- NSAID Group: No significant correlations with meteorological factors.
Mechanistic Insights
The differential impact of weather across etiologies may stem from distinct pathophysiological mechanisms:
- Non-NSAID Peptic Ulcers: Cold exposure reduces gastric mucus thickness, suppresses heat shock protein 70 (HSP70) expression, and increases gastric acid secretion, exacerbating mucosal injury. The observed peak during Great Snow (average temperature: −2°C to 5°C in Beijing) aligns with these mechanisms.
- NSAID-Related Ulcers: The absence of seasonal trends suggests that NSAIDs’ direct mucosal toxicity—mediated via cyclooxygenase inhibition and systemic effects—overrides climatic influences. Chronic NSAID use likely masks transient weather-related risks.
- EGV Bleeding: Portal hypertension, exacerbated by cold-induced vasoconstriction and increased cardiac output, drives seasonal patterns. The correlation with humidity may reflect baroreceptor-mediated splanchnic vasodilation during high humidity, elevating portal pressure.
Clinical and Public Health Implications
- Preventive Strategies: For non-NSAID ulcers, clinicians should emphasize prophylactic measures (e.g., acid suppression, Helicobacter pylori eradication) before winter. EGV patients may benefit from closer monitoring during high-pressure, low-temperature periods.
- Meteorological Forecasting: Integrating weather forecasts into clinical practice could enable preemptive interventions during high-risk periods.
- Solar Term Utility: The 24 solar terms, capturing rapid weather transitions (e.g., Great Heat to Spring Equinox for EGV), offer a culturally relevant framework for public health advisories in East Asian populations.
Limitations and Future Directions
- HP Infection: H. pylori status, a key ulcer risk factor, was not analyzed due to incomplete emergency department records. Future studies should incorporate HP testing.
- Regional Specificity: Findings may not generalize to non-temperate climates.
- Mechanistic Studies: Experimental models are needed to validate temperature-humidity interactions in EGV pathophysiology.
Conclusion
This study establishes that UGIB etiologies exhibit distinct meteorological associations in Beijing: non-NSAID ulcers peak in winter and transitional solar terms, EGV bleeding correlates with cold and humidity, and NSAID-related bleeding remains seasonally neutral. By integrating traditional solar terms with modern climatic data, these findings enhance risk stratification and prevention strategies tailored to local environmental conditions.
doi.org/10.1097/CM9.0000000000001156
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