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Abbreviations: HSV-1, herpes simplex virus type 1 ; IgG, immunoglobulin G.
Although the primary cause of type 2 diabetes is unknown, two breakthroughs have been made regarding its development (1). First, insulin resistance in muscle is the earliest detectable defect in people in whom type 2 diabetes will later develop. Second, β-cell function has to be abnormal before hyperglycemia develops. One of the risk factors for diabetes development might be virus infection (2). Preexisting hepatitis C virus infection may increase the risk for type 2 diabetes (3,4).
Herpes simplex virus type 1 (HSV-1) has been recognized as a potential pathogen of cardiovascular diseases. The presence of antibodies to HSV-1 is reported to be associated with an increase in the risk ol incident myocardial infarction and coronary heart death (5,6). Type 2 diabetes is a major risk factor for cardiovascular morbidity and mortality (7) and is recorded as a coronary artery disease risk equivalent (8). In this study, we attempted to investigate the potential relationship between HSV-1 infection and type 2 diabetes.
RESARCH DESIGN AND METHODS- All subjects were consecutive inpatients at Beijing Fu Wai Heart Hospital. Diabetes was diagnosed as follows (9): patients who had overnight fasting plasma glucose ≥7.0 mmol/l (126 mg/dl) or were taking antidiabetic medication. Patients not meeting these criteria were not considered to have diabetes. Subjects taking insulin alone (type 1 diabetes) were excluded from the analyses, ensuring that all patients with the diagnosis of diabetes had type 2 diabetes. The local ethics committee approved the study, and informed consent was obtained from all patients. The following potential risk factors for diabetes were analyzed in this study: age, cigarette smoking, physical inactivity, BMI, hypertension, dyslipidemia, coronary artery disease, and immunoglobulin G (IgG) seropositive status to HSV-1.
Serum samples were collected and frozen at -80°C until analysis. Each serum sample was tested for specific antiHSV-1 IgG antibody by enzyme-linked immunosorbent assay with a commercially available kit (Virus Institute, Chinese Academy of Prevention Medical Sciences, Beijing, China). Cellular filtrates obtained by ultrasonic destruction of Vero cells infected with the standard HSV-1 strain were used as the specific HSV-1-coated antigen to detect the specific HSV-1 IgG. Presence or absence of anti-HSV-1 IgG was determined by comparing the absorbency value of the sample to...