Dr. Nouh Baqar: Obesity Causes Respiratory Diseases
Dr. Wala’a Hafiz: Obesity is one of the most prominent global health challenges due to its direct and indirect impacts on various body systems, particularly the respiratory system. Increased body mass index does not merely cause mechanical changes in the structure of the chest and lungs; it also triggers inflammatory and hormonal disturbances that may increase the likelihood of developing a wide range of respiratory diseases and conditions. In this context, we spoke with Dr. Noha Baqer, Consultant of Internal Medicine and Respiratory Diseases, Pulmonary Hypertension, and Head of the Respiratory Unit at Mubarak Al-Kabeer Hospital, who outlined the key aspects of the relationship between obesity and respiratory diseases, highlighting their complications and impacts on several conditions, including asthma, gastroesophageal reflux, pulmonary embolism, pulmonary arterial hypertension, sleep apnea, and lung cancer.
Dr. Baqer told Al-Qabas, “Obesity is not just a general risk factor, but a complex pathological condition that affects various levels of the respiratory system, from respiratory mechanics to inflammation, immunity, coagulation, and ultimately lung cancer.” He emphasized that understanding the link between obesity and respiratory diseases is a crucial step toward improving diagnosis, treatment, and reducing complications, especially in the daily clinical practice of pulmonologists.
**First: Obesity and Asthma**
Dr. Baqer clarified that numerous studies have shown obesity increases the risk of developing asthma and exacerbates its severity through several mechanisms:
1. **Mechanical Effects**
• Increased fat around the chest wall and abdomen reduces the lungs’ ability to expand.
• Obesity leads to reduced lung volume, which may cause small airway narrowing and make breathing more difficult.
2. **Inflammatory Effects**
• Adipose tissue releases inflammatory substances, causing chronic inflammation that increases airway sensitivity and narrowing.
• Reduced response to conventional treatments such as inhaled steroids, due to the different nature of inflammation compared to allergic asthma.
3. **Hormonal Effects**
• Insulin resistance and leptin (a hormone secreted by fat cells, playing a key role in regulating appetite and energy balance) may influence the immune response of the airways.
**Second: Obesity, Gastroesophageal Reflux, and Respiratory Infections**
Dr. Baqer noted that gastroesophageal reflux is more common among obese patients and is a direct cause of several respiratory problems, including:
1. **Increased Incidence of Reflux**
• Increased intra-abdominal pressure leads to relaxation of the lower esophageal sphincter.
• Fat accumulation around the stomach facilitates the transfer of acid into the esophagus.
2. **Impacts on the Respiratory System**
• Micro-aspiration of stomach acid and esophageal contents may lead to:
• Chronic airway inflammation.
• Chronic cough.
• Exacerbation of asthma.
• Chemical or bacterial pneumonia.
3. **High-Risk Pattern in Some Patients**
• Recurrent reflux may lead to reflux-associated pulmonary fibrosis or worsen pre-existing fibrosis.
**Third: Obesity and Pulmonary Artery Thrombosis**
Dr. Baqer confirmed that obesity is clearly associated with an increased risk of deep vein thrombosis and pulmonary embolism, as follows:
1. **Contributing Factors**
• Chronic inflammatory state promotes hypercoagulability.
• Physical inactivity, especially in severe obesity or post-surgery.
• Insulin resistance and metabolic syndrome increase coagulation factor activity.
2. **Higher Risk of Complications**
• Diagnosis may be delayed due to overlapping symptoms (shortness of breath, fatigue).
• Technical difficulties in imaging pulmonary arteries or performing ultrasound on limbs.
3. **Risk of Chronic Pulmonary Hypertension from Thromboembolism**
• Some studies suggest obesity may increase the likelihood of chronic pulmonary arterial hypertension following pulmonary embolism.
**Fourth: Obesity and Pulmonary Hypertension**
Dr. Baqer explained that the relationship between obesity and pulmonary hypertension involves several factors, most notably sleep-disordered breathing, the impact of obesity on the heart and blood vessels, and the difficulty in diagnosing and assessing the condition’s severity.
1. **Sleep-Disordered Breathing and Hypoxia**
• Obesity is linked to sleep-disordered breathing, particularly obstructive sleep apnea and obesity hypoventilation syndrome.
• Recurrent oxygen desaturation during sleep may cause pulmonary vasoconstriction, raising pulmonary blood pressure over time.
2. **Impact of Obesity on the Heart**
• Obesity may be associated with heart failure with preserved ejection fraction, increasing pressure in the left side of the heart.
• This pressure can transmit to pulmonary blood vessels, leading to pulmonary hypertension.
3. **Chronic Inflammation and Vascular Effects**
• Obesity causes a chronic inflammatory state that may affect blood vessel endothelium and function, potentially impacting pulmonary vessels and contributing to pulmonary hypertension.
4. **Diagnostic and Assessment Challenges**
• Dr. Baqer pointed out that obesity may make measuring pulmonary blood pressure using echocardiography more difficult and sometimes less accurate due to poor image quality.
• When strong suspicion exists, the physician may require right heart catheterization, the most accurate test for measuring pressure within pulmonary vessels and confirming the diagnosis.
**Fifth: Obesity and Obstructive Sleep Apnea**
Dr. Baqer emphasized that obstructive sleep apnea is one of the most prominent respiratory problems associated with obesity.
1. **How It Occurs**
• Fat accumulation around the neck and pharynx narrows the airway.
• Throat muscles relax during sleep, facilitating airway obstruction.
2. **Key Symptoms and Complications**
• Severe daytime sleepiness.
• Headaches upon waking.
• High blood pressure, especially when difficult to control with medication.
• Increased risk of certain heart disorders, such as atrial fibrillation.
3. **Relationship with Other Diseases**
• May worsen asthma severity.
• May increase the risk of pulmonary hypertension.
• May make controlling chronic obstructive pulmonary disease (COPD) more difficult in patients with overlap syndrome.
**Sixth: Obesity and Lung Cancer**
Dr. Baqer mentioned that although the relationship is less direct compared to previous diseases, data indicate increasing impacts:
1. **Chronic Inflammation**
• Obesity creates an environment rich in cytokines (inflammatory substances) that promote cancer.
2. **Hormonal Changes**
• Elevated insulin and IGF-1 (a hormone contributing to cell growth and tissue regeneration) increase cellular susceptibility to transformation.
3. **Diagnostic Challenges**
• Symptoms may be delayed or attributed to weight.
• Imaging tests or biopsies may be technically more complex.
4. **Impact of Obesity on Treatment**
• Dr. Baqer noted that obesity is not just a risk factor but may affect the treatment course, particularly in:
• Pre-surgical rehabilitation.
• Response to immunotherapy.
• Tolerance to chemotherapy.
**Recommendation**
Dr. Baqer recommended treating obesity as a disease rather than a symptom, emphasizing that this is a fundamental step toward improving diagnosis, treatment, and reducing complications, especially in the daily clinical practice of pulmonologists.
