Biomarkers in Oral and Systemic Health in Obese and Hyperglycemic Children and Adolescents

Abstract

Introduction Certain salivary and serum biomarkers are predictive of diseases associated with obesity such as intermediate hyperglycemia and sleep-disordered breathing (SDB). Furthermore, permanent teeth eruption is largely under genetic control; however, factors such as obesity and DNA methylation can alter calcified tissues of the body, which can lead to changes in tooth eruption patterns. Thus, the aim of this study was to identify salivary and serum biomarkers and assess their predictive value for obesity, intermediated hyperglycemia, and symptoms of sleep-disordered breathing in adolescents. Furthermore, we conducted this study to examine tooth eruption patterns in obesity and the presence of m1A in a large homogenous cohort of Kuwaiti children. Methods We used data from the Kuwait Healthy Lifestyle Study (KHLS) which longitudinally collected data over a seven-year period. Body mass index z-score (BMIz) was measured at 10, 12, and 17 years of age. Salivary analysis was collected during all three visits. Serum analysis was collected only during the third visit. Levels of interleukin (IL)-6, IL-8, IL-10, leptin, C-reactive protein (CRP), insulin, vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1) were measured in the saliva and serum. Additionally, fasting blood plasma glucose levels were recorded. Six questions on symptoms associated with SDB, such as snoring and sleep fragmentation, were answered by the participants. Results Longitudinal analyses of biomarkers showed that with each one unit increase in salivary CRP and insulin levels, there was a 3.5 kg/m2 and 3.2 kg/m2 increase in BMIz, respectively over a seven-year period. Compared to serum CRP and insulin, high salivary CRP and insulin levels (OR 4.94 [95% CI: 1.66, 14.90], OR 2.64 [95% CI: 1.09, 6.38], respectively) were predictive of hyperglycemia and obesity (OR 4.53 [95% CI: 2.40, 8.50], OR 3.29 [95% CI: 1.82, 5.97], respectively). Additionally, tooth eruption was significantly higher for obese children than normal-weight children (IRR: 1.11; 95% CI:1.10-1.13). Further, with every one-unit increase in BMIz, the rate of tooth eruption significantly increased (IRR:1.01; 95% CI: 1.01-1.01). Finally, individuals with high leptin levels had a 3.93 odds (95% CI: 1.61, 9.62) of developing all the six symptoms associated with SDB after adjusting for BMIz. Conclusions Our findings demonstrated the predictive value of salivary biomarkers for hyperglycemia, obesity, and possibly diabetes in adolescents. Thus, saliva analysis is a non-invasive approach with a significant value for disease risk assessment and prevention. Our findings demonstrated that leptin was significantly associated with individuals who experienced both snoring and sleep fragmentation together. As more dentists are screening their patients for symptoms of SDB, patients who experience symptoms of both snoring and sleep fragmentation should be referred to a somnologist or their primary care physician for further evaluation. Finally, these data suggest that changes in calcified tissues, including a higher number of permanent teeth and greater height (particularly in female subjects) that occurred with the development of obesity, may be related to an acceleration of puberty.