Clinical Significance and Prognostic Value of Systemic Immune Inflammation Index and Systemic Inflammation Response Index in Obesity and Associated Metabolic Complications
Overview
- Phase
- Not Applicable
- Status
- Not yet recruiting
- Sponsor
- University of Rijeka
- Enrollment
- 200
- Primary Endpoint
- Diagnostic and prognostic value of SII and SIRI
Overview
Brief Summary
This observational study aims to evaluate the diagnostic and prognostic value of the systemic immune-inflammatory index (SII) and the systemic inflammation response index (SIRI) in individuals with overweight or obesity. The study will assess their association with obesity status, metabolic complications, lifestyle patterns, dietary indices, and established inflammatory biomarkers. Participants will undergo anthropometric assessment, laboratory testing, dietary evaluation, and follow-up for response to different obesity treatment modalities over 3 years. The study intends to determine whether SII and SIRI can serve as clinically useful predictors of metabolic risk and treatment outcomes of obesity.
Detailed Description
Obesity is a complex chronic disease associated with systemic low-grade inflammation, metabolic dysfunction, and increased risk of comorbidities such as type 2 diabetes, dyslipidemia, nonalcoholic fatty liver disease, and cardiovascular disease. Adipose tissue acts as an active endocrine organ, influencing immune regulation and inflammatory signalling. Although numerous inflammatory biomarkers have been evaluated in obesity, the diagnostic performance of novel composite systemic immune-inflammatory indices, particularly the systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI), remains inadequately characterised. SII and SIRI, derived from peripheral blood counts, have shown prognostic potential in various clinical settings but have not been systematically evaluated in predicting metabolic complications or treatment response in obesity. This study seeks to expand their application in patients with overweight and obesity by 1) evaluating the cross-sectional associations between SII/SIRI and obesity severity, inflammatory biomarkers, metabolic disorders, and dietary patterns; and 2) determining the prognostic value of SII/SIRI for predicting metabolic complications and clinical response to behavopural and lifestyle modification, pharmacotherapy, and bariatric surgery over a 1-year follow-up.
Participants will complete anthropometric measurements, comprehensive biochemical profiling, inflammatory cytokine assessment, dietary evaluation, and structured follow-up at 12 and 24 weeks, with continued monitoring of treatment response and metabolic outcomes over 1 year.
STUDY PROCEDURES (Structured per visit) Visit 1 - Baseline (Week 1)
- Informed consent
- Anthropometrics (height, weight, waist circumference, hip circumference, BIA)
- Venous blood sampling: complete blood count (CBC) and differential blood count (DBC), fasting glucose, HbA1c, lipid profile (cholesterol, LDL, HDL, triglycerides), thyroid panel (TSH, FT4, FT3), liver panel, renal panel, CRP, cortisol, bilirubin, iron status parameters, vitamins/minerals (Ca, P, Mg, vitamin D)
- Biobanking: 3 frozen aliquots for hs-CRP, adiponectin, IL-6, TNF-α
- Lifestyle and dietary questionnaires (socio-demographics, physical activity, smoking, sleep, stress, medication use; 24 h dietary recall + FFQ)
- Motivational and educational counselling (diet, activity, pharmacotherapy options)
Visit 2 - Week 12
- Anthropometrics + BIA
- Laboratory testing (repeated, as above)
- Assessment of dietary and lifestyle adherence
- Motivational counselling (in person or telephone)
Visit 3 - Week 24
- Anthropometrics + BIA
- Full biochemical panel
- Dietary questionnaires (24 h recall+MEDAS+Short Diet Screener)
- Evaluation of treatment response to lifestyle intervention, pharmacotherapy, or bariatric surgery
- Motivational counselling
LONG-TERM FOLLOW-UP (Year 1)
- Monitoring metabolic outcomes
- Evaluation of obesity treatment response
- Prognostic assessment of SII/SIRI
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Age ≥ 18 years
- •BMI 25.0-29.9 kg/m² (overweight) or BMI ≥ 30 kg/m² (obesity)
- •Ability to attend scheduled clinical visits
- •Willingness to provide informed consent
Exclusion Criteria
- •Pregnancy or breastfeeding
- •Use of immunosuppressive therapy
- •Active infection
- •Inflammatory disease
- •Malignancy
- •Acute illness affecting immune parameters
- •Conditions interfering with study participation (as assessed by the investigator)
- •Known hematologic disorders affecting leukocyte or platelet counts
- •Chronic inflammatory diseases requiring systemic therapy
- •Recent major surgery (within the last 3 months)
Arms & Interventions
Overweight and obesity cohort
Adults with overweight or obesity presenting to outpatient obesity clinics. Participants aged ≥18 years with BMI ≥25 kg/m² undergoing clinical evaluation for obesity. All participants will follow the same assessment and follow-up schedule; variation occurs only in the type of treatment chosen (lifestyle, pharmacotherapy, bariatric surgery).
Intervention: Nutritional counselling (Behavioral)
Outcomes
Primary Outcomes
Diagnostic and prognostic value of SII and SIRI
Time Frame: baseline, 24 weeks and at study completion, an average of 1 year
The diagnostic and prognostic value of systemic inflammation indices (SII and SIRI) will be assessed using ROC curve analysis, including sensitivity, specificity, and AUC calculations.
Secondary Outcomes
- Association of SII and SIRI with Metabolic Complications(baseline, 24 weeks and at study completion, an average of 1 year)
- Association of SII and SIRI with Dietary Patterns(baseline, 24 weeks and at study completion, an average of 1 year)
- Identification of Prognostic Markers of Metabolic Comorbidities(baseline, 12 weeks, 24 weeks, and at study completion, an average of 1 year)
- Changes in SII and SIRI During Treatment(baseline, 12 weeks, 24 weeks, and at study completion, an average of 1 year)
- Relationship Between SII/SIRI and Inflammatory Biomarkers(baseline, 12 weeks, 24 weeks, and at study completion, an average of 1 year)
Investigators
Gordana Kenđel Jovanović
Assistant Professor
University of Rijeka