Recurrent Respiratory Tract Infections

Recurrent upper respiratory tract infections (RURTIs) are a significant public health burden, often resulting in frequent illnesses, increased healthcare utilization, and diminished quality of life. The immune system's efficiency is influenced by a variety of nutritional and environmental factors, notably essential micronutrients and exposure to toxic metals. This hospital-based case-control study aims to explore the interplay between deficiencies in trace elements (such as selenium, zinc, copper) and vitamins (A, D, E, C, B6, B12), and exposure to toxic metals (lead, cadmium, arsenic, mercury), and how these affect oxidative stress and inflammatory markers in adults aged 18–65 years.

The study will enroll 335 cases (patients with 3 or more RURTI episodes within 1 year) and 335 matched controls with no recent RURTI history. Blood and urine samples will be collected to assess micronutrient and metal levels, as well as biomarkers such as malondialdehyde, 8-OHdG, catalase, and C-reactive protein. Questionnaires will gather lifestyle and demographic information.

We hypothesize that patients with RURTIs will exhibit significantly lower levels of protective nutrients and higher levels of toxic metals, contributing to increased oxidative stress and impaired immune function. Additionally, the study will assess the potential role of micronutrient and vitamin supplementation in reducing infection risks.

Expected outcomes include: (1) improved understanding of how nutritional deficiencies and metal exposure contribute to immune dysfunction, (2) evidence supporting micronutrient supplementation and environmental interventions, and (3) direct contributions to public health policy in alignment with the Saudi 2030 Vision. Findings will inform clinical guidelines and preventive strategies for RURTIs, providing a cost-effective, evidence-based approach to enhance population health.