Relationship between Hemoglobin A1c Levels and Metabolic Syndrome using Data Collected during a Medical Check-ups Program

ABSTRACT

BACKGROUND: Hemoglobin A1c (HbA1c) level is an indicator of the average blood glucose concentration of the past 2 to 3 months. Studies on the association of HbA1c levels with cardiovascular disease have reported inconsistent findings groups stratified by gender, age, and race. Therefore we conducted this study to determine the relationship between HbA1c levels and metabolic syndrome in a Korean population participating in medical check-up programs. METHODS: The study population comprised 7,301 nondiabetic Korean subjects (3,384 men and 3,917 women) who had enrolled for a medical check-up program. All subjects were divided into 5 groups on the basis of their HbA1c levels. Age, blood pressure, abdominal obesity, fasting glucose levels, lipid profile and high sensitivity C-reactive protein (hsCRP) levels were compared among the groups. In addition, we also investigated the association of HbA1c levels with cardiovascular risk factors and metabolic syndrome. RESULTS: Age, waist circumference, body mass index, blood pressure, hsCRP levels, lipid profile and fasting glucose levels differed significantly among the 5 HbA1c groups, both in men and women. The possibility of the occurrence of metabolic syndrome increased as HbA1c levels increased, both in men and women. Abdominal obesity was the most common component of metabolic syndrome and more prominently occurred in women. CONCLUSIONS: HbA1c levels were significantly correlated to metabolic syndrome among these Korean subjects and abdominal obesity was the most frequently observed component of metabolic syndrome. Thus, abdominal obesity should be treated when high HbA1c levels are detected, particularly in women, even though the patient is not diabetic.