Keshan disease is a severe cardiomyopathy caused by a deficiency of selenium, an essential trace mineral critical for antioxidant defense and immune function. Named after Keshan County in China, where it was first identified, this disease is prevalent in regions with selenium-deficient soils, such as parts of China, Africa, and certain areas in Europe and Asia. In these regions, the dietary intake of selenium is often insufficient, making the population vulnerable to this life-threatening condition.
The symptoms of Keshan disease vary depending on its classification into acute, subacute, chronic, or latent forms. Acute Keshan disease manifests as a sudden onset of severe cardiogenic shock, acute heart failure, and fatal arrhythmias. Early warning signs include nausea, dizziness, chills, shortness of breath, and a marked loss of appetite. Subacute Keshan disease typically presents with congestive heart failure, cardiogenic shock, and significant heart enlargement, which often progresses rapidly.
Chronic Keshan disease develops over time and is characterized by persistent symptoms, including palpitations, dyspnea (difficulty breathing), productive cough sometimes accompanied by hemoptysis (coughing up blood), pain in the right upper abdominal quadrant, peripheral edema, and progressive cardiomegaly (heart enlargement). These symptoms indicate long-term damage to the heart muscle, severely affecting its ability to pump blood efficiently.
Latent Keshan disease exhibits milder symptoms such as fatigue, dizziness, minor palpitations, and slight heart enlargement. While less dramatic than acute or chronic forms, latent Keshan disease poses significant risks if selenium deficiency persists, potentially escalating to more severe stages.
The pathogenesis of Keshan disease is linked to a combination of selenium deficiency and the presence of coxsackievirus infections, which exacerbate oxidative stress and myocardial damage. Selenium plays a vital role in the function of glutathione peroxidase, an enzyme that protects cells from oxidative damage. Without adequate selenium, the heart muscle becomes vulnerable to free radical injury, leading to structural and functional impairments.
Preventing and managing Keshan disease involves ensuring sufficient selenium intake through dietary sources like nuts, seafood, and organ meats, or supplementation where necessary. Public health interventions, such as soil enrichment programs and targeted supplementation campaigns, have significantly reduced the prevalence of Keshan disease in affected regions, underscoring the importance of addressing micronutrient deficiencies in global health initiatives.
Clinical Manifestations and Pathogenesis of Keshan Disease
