Metabolic Syndrome Associated Diet

Pro-İnflammatory Diet as a Modifying Factor in Periodontal Tissue Destruction Associated With Metabolic Syndrome

The goal of this observational study is to examine the relationship between metabolic syndrome (MetS) and periodontitis, and to evaluate the role of the Dietary Inflammatory Index (DII) in this association.

The main question it aims to answer is:

Does a pro-inflammatory diet, as measured by the DII, increase the risk or severity of periodontitis in individuals with metabolic syndrome?

Participants will include adults who meet the diagnostic criteria for metabolic syndrome. Their periodontal health will be assessed through standard clinical parameters, and dietary data will be collected using a validated food frequency questionnaire to calculate individual DII scores. The study will observe and analyze these factors to explore potential links between diet-induced inflammation, systemic metabolic health, and periodontal outcomes.

Study Overview

• Status: Not yet recruiting
• Conditions: Periodontitis; Diet, Food and Nutrition; Metabolic Syndrome (MetS)

Detailed Description

This study aims to investigate the potential relationship between metabolic syndrome (MetS) and periodontitis, and to evaluate this association through the Dietary Inflammatory Index (DII), which reflects the inflammatory potential of diet. Periodontal status will be assessed using clinical parameters (plaque index, probing pocket depth, clinical attachment loss, and gingival bleeding). MetS diagnosis will be based on criteria such as waist circumference, fasting glucose level, serum triglycerides, HDL cholesterol, and blood pressure. Dietary habits of participants will be analyzed using a validated food frequency questionnaire, and individual DII scores will be calculated. The data obtained will be used to evaluate the effects of dietary inflammatory load on systemic metabolic parameters and periodontal health. This study will aim to provide scientific evidence on the role of anti-inflammatory dietary strategies in periodontal and metabolic health.

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Oguz KOSE, Professor Dr.; Phone Number: +90 541 348 64 65; Email: oguz.kose@erdogan.edu.tr

Study Locations

• Turkey (Türkiye)
  • Rize Province
    • Rize, Rize Province, Turkey (Türkiye), 53200
      • Department of Periodontology of the Faculty of Dentistry of Recep Tayyip Erdogan University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients diagnosed with metabolic syndrome who come to the Periodontology Clinic of Recep Tayyip Erdoğan University Faculty of Dentistry for routine periodontal treatment

Description

Inclusion Criteria:

• Being between 18 and 65 years of age
• Presence of at least three of the following parameters: (For MetS diagnosis) Waist circumference: ≥ 94 cm for men, ≥ 88 cm for women Blood pressure ≥ 130/85 mmHg or taking antihypertensive medication Fasting blood glucose ≥ 100 mg/dl or diagnosed with Type 2 Diabetes Triglycerides ≥ 1.7 mmol/L HDL < 1.29 mmol/L
• Having at least 20 teeth
• Not having received periodontal therapy in the last 6 months
• Not having taken antibiotics, steroids, and/or nonsteroidal anti-inflammatory drugs in the last 3 weeks
• Not having any autoimmune disease, osteoporosis, or cancer
• Not taking immunosuppressive medications, oral contraceptives, Not taking bisphosphonates
• Not being pregnant
• Not having an active infectious disease (acute hepatitis, tuberculosis, AIDS)
• Not taking chronic medications that affect periodontal tissues (cyclosporine A, phenytoin)
• Not taking antioxidant supplements in the last 6 months

Exclusion Criteria:

• Patients with an active infectious disease,
• Those taking medications that could affect periodontal tissues,
• History of endocarditis,
• Recent antibiotic use (within 4 months),
• Alcohol/drug use,
• Psychological disorders,
• Eating disorders,
• Dementia,
• Pregnancy and breastfeeding,
• Patients who did not sign the informed consent form

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Patients diagnosed with metabolic syndrome; Metabolic syndrome is diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP III) criteria. Diagnosis is made by meeting three of the following five criteria: waist circumference: ≥ 94 cm in men and ≥ 88 cm in women, blood pressure ≥ 130/85 mmHg or use of antihypertensive medication, fasting blood glucose ≥ 100 mg/dL or diagnosed type 2 diabetes, triglycerides ≥ 1.7 mmol/L, and HDL < 1.29 mmol/L.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dietary Inflammatory Index	The Dietary Inflammatory Index (DII) provides a score that measures the potential for a person's diet to cause inflammation in the body. This index is based on the pro- or anti-inflammatory effects of consumed foods and nutrients. Participants' 3-day food intake records will be entered into the system, and average daily energy intake, macronutrients, and micronutrients will be calculated. Based on the food records, average daily intake of 36 nutrients will be determined, and DII scores will be derived from these nutrient parameters. A lower score indicates a more anti-inflammatory diet, while a higher score indicates a more pro-inflammatory diet.	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical Periodontal Parameters (Plaque Index)	Plaque Index (PI) (Silness and Löe, 1964) This index is used to evaluate the amount of dental plaque accumulation on tooth surfaces. Each tooth's four surfaces (buccal, lingual, mesial, distal) are examined using a probe or visually. Each surface is scored from 0 to 3. The average score is calculated for each tooth. The overall plaque index is obtained by averaging the scores from all examined teeth. Score Description 0 No plaque.; No visible plaque, but a slight film of plaque is detected when a probe is run along the gingival margin.; Visible plaque along the gingival margin, forming a continuous band.; Abundant plaque covering the gingival area and extending toward the middle of the tooth surface, including the interproximal spaces.	Day 1
Clinical Periodontal Parameters (Gingival Index)	The Gingival Index is used to assess the presence and severity of gingival inflammation (gingivitis). Four surfaces of each tooth (buccal, lingual, mesial, distal) are examined visually and with a periodontal probe. The evaluation considers color changes, edema (swelling), tissue consistency, and bleeding on probing. Each surface is scored from 0 to 3. The average score per tooth is calculated, and then the overall average is used to determine the individual's GI score. Score Description 0 Healthy gingiva: normal color and texture, no bleeding; Mild inflammation: slight color change and swelling, no bleeding on probing; Moderate inflammation: redness, edema, soft tissue, bleeding on probing; Severe inflammation: marked redness and swelling, ulceration, possible spontaneous bleeding	Day 1
Periodontal Clinical Parametres (Bleeding on Probing Index)	This index is used to assess the presence and severity of gingival inflammation by observing bleeding after gentle pressure is applied to the gingival sulcus using a periodontal probe. A thin periodontal probe is gently inserted into the gingival sulcus with light pressure (approximately 20-25 grams). Bleeding occurring within 10-30 seconds is observed. Each measurement site is recorded as either "bleeding present" or "bleeding absent." Presence of bleeding is an early and sensitive indicator of gingival inflammation. Score Description: 0 No bleeding 1 Bleeding present (mild or severe)	Day 1
Periodontal Clinical Parametres (Probing Pocket Depth)	Using a Williams periodontal probe, the distance between the gingival margin and the base of the periodontal pocket is measured in millimeters at six sites per tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. All teeth are measured. The values obtained from each site are summed and then divided by the total number of sites measured. This gives the average probing depth for the individual. Measurement Interpretation 1-3 mm Healthy sulcus 4-5 mm Shallow to moderate pocket ≥6 mm Deep periodontal pocket (advanced disease)	Day 1
Periodontal Clinical Parametres (Clinical Attachment Loss)	Using a Williams periodontal probe, the distance between the enamel-cementum junction and the base of the periodontal pocket is measured in millimeters at six sites per tooth: mesiobuccal, midbuccal, distobuccal, mesiolingual, midlingual, and distolingual. All teeth are measured. The values obtained from each site are summed and then divided by the total number of sites measured. This gives the average probing depth for the individual. CAL Value Interpretation 0-1 mm Healthy / minimal loss 2-3 mm Mild attachment loss 4-5 mm Moderate attachment loss ≥6 mm Severe attachment loss	Day 1

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Glycated Hemoglobin A1c	HbA1c (Glycated Hemoglobin A1c): A stable complex formed by the non-enzymatic covalent binding of glucose to the β-chain of hemoglobin, reflecting the average blood glucose level over the lifespan of erythrocytes (approximately 120 days). It is considered a gold standard indicator of long-term glycemic control.	Day 1
Triglyceride	Triglyceride: A neutral lipid composed of three fatty acids esterified to a glycerol backbone. It is primarily transported in plasma by VLDL and chylomicrons and serves as a biomarker of dyslipidemia and cardiometabolic risk.	Day 1
Height	Height: a measure of vertical distance, vertical dimension, or vertical position.	Day 1
Weight	Weight is the gravitational force exerted on an object.	Day 1
Waist Circumference	Waist Circumference: The individual stands upright. A tape measure is taken horizontally at the narrowest point of the waist (usually between the bottom of the ribs and the top of the hipbone). It is expressed in cm.	Day 1
Fasting Blood Glucose	Fasting Blood Glucose: The plasma glucose concentration measured after at least 8 hours of caloric restriction. It is a fundamental biochemical parameter for assessing glycemic status and diagnosing diabetes.	Day 1
High-Density Lipoprotein	HDL (High-Density Lipoprotein): Lipoprotein particles of high density that play a central role in reverse cholesterol transport, shuttling cholesterol from peripheral tissues to the liver for excretion. They exhibit anti-atherogenic, anti-inflammatory, and antioxidant properties.	Day 1
High-Sensitivity C-Reactive Protein	hsCRP (High-Sensitivity C-Reactive Protein): The low-level concentrations of the liver-derived acute-phase reactant CRP, measured by high-sensitivity immunoturbidimetric or nephelometric assays. It serves as a biomarker of subclinical inflammation and cardiovascular risk.	Day 1

Collaborators and Investigators

• Sponsor: Recep Tayyip Erdogan University Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 23, 2026
• Primary Completion (Estimated): September 21, 2026
• Study Completion (Estimated): November 23, 2026

Study Registration Dates

• First Submitted: March 4, 2026
• First Submitted That Met QC Criteria: March 4, 2026
• First Posted (Actual): March 10, 2026

Study Record Updates

• Last Update Posted (Actual): March 10, 2026
• Last Update Submitted That Met QC Criteria: March 4, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: inflammation; diet; periodontitis; metabolic syndrome
• Additional Relevant MeSH Terms: Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Pathologic Processes; Metabolic Diseases; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Periodontitis; Metabolic Syndrome; Inflammation
• Other Study ID Numbers: MetSDiet08/25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No