Impact of type 2 diabetes and periodontal disease on oral status of Sudanese adults. Clinical, microbial and immune-inflammatory aspects

Abstract

Diabetes is a major global public health challenge, afflicting 380 million people worldwide. The onset is insidious and progression is associated with irreversible medical complications, including oral diseases. Little is known about the oral health of patients with diabetes in developing countries such as The Sudan, which is currently experiencing an alarming increase in diabetes cases. The overall aim of this thesis was to evaluate oral health indicators in Sudanese adults with type 2 diabetes (T2D) and to investigate the impact of T2D and chronic periodontitis on biomarkers of inflammation and glucose regulation in gingival crevicular fluid (GCF) and saliva. The subjects comprised 157 T2D cases and 304 controls without diabetes, 461 in all. Participants were interviewed using a structured questionnaire on socio-demographics, lifestyle and oral health related quality of life (OHRQoL). The clinical examination comprised full mouth probing depths, bleeding on probing, dental plaque index, tooth mobility index, furcation involvement and coronal and root caries. In GCF samples, the levels of 10 glucoregulatory molecules and 27 inflammatory molecules were measured by bead-based multiplex assays. MMP-8, MMP-9, OPG and RANKL in whole saliva samples were quantified by ELISA. Subgingival plaque samples were analysed by conventional polymerase chain reaction (PCR), to assess the prevalence of six periodontal pathogens. T2D patients had poorer periodontal parameters, more missing teeth and poorer OHRQoL than individuals without diabetes. Chronic periodontitis was associated with disturbed GCF levels of biomarkers related to the onset and medical complications of T2D. On the other hand, T2D was associated with a high Th-2/Th-1 cytokines ratio and disturbed levels of molecules involved in the anti-inflammatory and healing processes. T2D had no significant effect on either the prevalence of the investigated periodontal pathogens or the levels of salivary MMP-8, MMP-9 and OPG. Further research is warranted to identify disease markers which could form the basis of a test to alert the dentist to patients with undiagnosed T2D, or those at risk of developing the disease.