DefinePK

Research Objective

To study the effect of high altitude on haemoglobin concentration with coronary artery disease.

Methodology

Prospective longitudinal study conducted at Combined Military Hospital, Skardu, Pakistan, from January to December 2018. Included individuals working at high altitudes (≥ 8000 feet) diagnosed with coronary artery disease (CAD). Excluded individuals with a previous history of CAD or newly diagnosed CAD at a height less than 8000 feet. Haemoglobin concentration was measured using a complete blood picture. CAD was diagnosed by ECG and cardiac enzymes (CK MB and Trop T). Height was categorized into three groups: 8000-13000 feet, 13001-18000 feet, and > 18000 feet. Data was analyzed using SPSS version 20.0.

Methodology Flowchart

                        graph TD
    A["Study Initiation"] --> B["Define Inclusion/Exclusion Criteria"];
    B --> C["Recruit Participants at High Altitude with CAD"];
    C --> D["Measure Haemoglobin Concentration"];
    D --> E["Diagnose CAD via ECG & Cardiac Enzymes"];
    E --> F["Categorize Participants by Altitude"];
    F --> G["Collect and Analyze Data"];
    G --> H["Interpret Results"];
    H --> I["Formulate Conclusion"];                    

Discussion

High altitude hypoxia leads to increased erythropoietin production and secondary polycythemia, potentially increasing blood viscosity and the risk of thromboembolic events. While increased haemoglobin can compensate for low oxygen tension, it may also contribute to adverse events. The study found a linear relationship between altitude and haemoglobin concentration but did not establish a positive linear correlation between increasing height and CAD. The debate on whether altitude is protective or harmful for CAD continues, with contradictory literature.

Key Findings

A total of 34 male patients diagnosed with CAD were included. 47% were evacuated from 8000-13000 feet, 47% from 13001-18000 feet, and 6% from > 18000 feet. Mean haemoglobin levels increased with altitude: 15.7±1.4 gm/dl (8000-13000 ft), 16.3±1.5 gm/dl (13001-18000 ft), and 18.3±1.2 gm/dl (> 18000 ft). A statistically significant increase in haemoglobin concentration was observed with increasing height (p < 0.05). However, most CAD patients had haemoglobin concentrations below 18 gm/dl.

Conclusion

This study observed an association between altitude and haemoglobin concentration. However, increasing haemoglobin concentration at high altitudes alone could not be solely responsible for coronary artery disease in deployed individuals.

Fact Check

1. Study Duration: The study was conducted from January to December 2018. (Confirmed in Methodology)
2. Number of Patients: 34 patients were diagnosed with coronary artery disease. (Confirmed in Results)
3. Haemoglobin at Highest Altitude: The mean haemoglobin for patients evacuated from > 18000 feet was 18.3±1.2 gm/dl. (Confirmed in Results)

Mind Map