CHAPTER 1
 INTRODUCTION

 Background

 Diabetes is a group of diseases characterized by high levels of blood glucose

resulting from defects in insulin production, insulin action, or both. Insulin is a hormone

that is needed to convert sugar, starches and other food into energy needed for daily life.

The cause of diabetes continues to be unknown, although both genetics and

environmental factors such as obesity and lack of exercise appear to play roles. There are

currently 18.2 million people in the United States, or 6.3% of the population, who have

diabetes [1]. While an estimated 13 million have been diagnosed, 5.2 million people (or

nearly 33%) are unaware that they have the disease [1, 2]. Systemic complications of

Diabetes Mellitus (DM) include retinopathy, nephropathy, neuropathy, increased

susceptibility to infection, increased risk of periodontal disease, and altered wound

healing.

 This paper will focus on the relationship of DM and oral complications, in

particular periodontal diseases. Previous studies have revealed an up-regulation of

insulin-like growth factor-i receptors (IGF-1) involved in the pathogenesis of DM in

various tissues, but until now no one has investigated gingival tissues. This study will

examine gingival tissue samples from self-reported diabetic patients and self-reported

non-diabetic controls to confirm the presence of the IGF-1 receptors and determine

whether there is an up-regulation in those patients with diabetes.