41 Duhok Medical Journal Volume 14, Issue 2, 2020 * Assis. Lecturer, Dep. of Medical Physiology and Pharmacology, College of Medicine, University of Duhok, Kurdistan Region, Iraq. ** Professor, Dep. of Medical Physiology and Pharmacology, University of Duhok, Kurdistan Region, Iraq. *** Professor, Dep. of Medical Physiology and Pharmacology, University of Duhok, Kurdistan Region, Iraq. Corresponding author: Raed S. Al-Naemi Email: raed.salim@uod.ac, Mobil +964 750 411 5262 VALUES OF SERUM C-REACTIVE PROTEIN AND SALIVARY IMMUNOGLOBULIN IGA IN DIABETIC PATIENTS: RELATION TO THE SEVERITY OF PERIODONTAL DISEASE NAZDAR MOHAMMED OMER, BDS, MSC (ORAL PHYSIOLOGY)* QASIM H. ABDULLAH, MBCHB, MSC, PHD (CLINICAL PHYSIOLOGY)** RAED S. AL-NAEMI, BVM, MSC, PHD (MEDICAL PHYSIOLOGY)*** Submitted 12 April 2020; accepted 23 July 2020 ABSTRACT Background: Altered immune response and improper neutrophils chemotaxis, phagocytosis, and adhesion might be the principal causative factor for increased susceptibility to periodontal pathogens and oral complications in diabetic patients. This study aimed to determine the relationship between C-reactive protein and salivary IgA with periodontal disease and the severity of dental caries with the glycemic control state of patients with diabetes mellitus. Patients and Methods: This study was carried out on 91 subjects, 61 patients with diabetes mellitus, and 30 apparently healthy subjects (as a control group). The patient groups were regularly attended Duhok Diabetes Center, Duhok City, Kurdistan Region (Iraq) for diabetes management. The healthy controls were recruited from the staff and sub staff of Azadi Teaching Hospital. Fasting plasma glucose, HbA1c, and serum high sensitivity C-reactive protein (Hs-CRP) were measured. The whole saliva collection was performed by an unstimulated method for five minutes in a graduated test tube to recognize the salivary secretion rate and then stored at -20 0 C for IgA estimation. Periodontal Index was used to determine the periodontal disease status. Each tooth was scored according to the condition of the surrounding tissues. Results: Significantly higher Hs-CRP (9.2 vs 3.3 μg/ml), fasting plasma glucose (215.4 vs 98.9 mg/dl) and HbA1c (8.5 vs 4.9 %), ( P < 0.001 for all parameters, together with lower hemoglobin (13.6 vs 14.5 gm/dl, P=0.03) levels were found in diabetic patients compared to control group, A significantly higher mean salivary IgA level in diabetic patients compared to controls (312.4 vs 177.3 mg/dl, P<0.001), associated with a significant high periodontal index (1.68 vs 0.81, P = 0.003). Conclusion: Elevated serum Hs-CRP and salivary IgA in patients with diabetes mellitus as inflammatory response sequences raise inflammation potential in the periodontium. Further, the results confirm that periodontal index was associated with poor glycemic control. Duhok Med J 2020; 14 (2): 40-50 Keywords: Hs-CRP, IgA, Periodontal disease, Periodontal index pidemiological data support microvascular changes in diabetes mellitus (DM) 1 . The microvascular changes lead to reduced tissue blood flow, decreased oxygen diffusion, and a better environment for the growth of anaerobic bacteria and susceptibility to infection 2 . The possible association between oral and systemic health has been highlighted; evidence suggested a bi-directional relationship between systemic and periodontal disease. Oral manifestations in DM include high dental caries, xerostomia, glossitis, oral candidiasis, burning mouth, and gingival and periodontal disease 3,4 . The altered immune response and improper neutrophils E