Prevalence of impaired fasting glucose and its relationship with cardiovascular disease risk factors in US adolescents, 1999-2000

Objective. Several studies have reported increases in the occurrence of type 2 diabetes in youths. People with prediabetic states such as impaired fasting glucose (IFG) are at increased risk for developing diabetes and cardiovascular disease (CVD). The objective of this study was to examine the prevalence of IFG and its relationship with overweight and CVD risk factors in a nationally representative sample of US adolescents who were aged 12 to 19 years. Methods. We used data from the 1999 - 2000 National Health and Nutrition Examination Survey ( NHANES). Adolescents who had fasted for 8 hours or more were included in the study (n = 915). IFG was defined as a fasting glucose of 100 to 125 mg/dL. Participants were classified as overweight when their age- and gender-specific BMI was >= 95th percentile and as at-risk for overweight when their BMI was >= 85th and < 95th percentile. Results. In 1999 - 2000, the prevalence of IFG in US adolescents was 7.0% and was higher in boys than in girls (10.0% vs 4.0%). Prevalence of IFG was higher in overweight adolescents (17.8%) but was similar in those with normal weight and those who were at risk for overweight (5.4% vs 2.8%). The prevalence of IFG was significantly different across racial/ethnic groups (13.0%, 4.2%, and 7% in Mexican Americans, non-Hispanic black individuals, and non-Hispanic white individuals, respectively). Adolescents with IFG had significantly higher mean hemoglobin A1c, fasting insulin, total and low-density lipoprotein cholesterol, triglycerides, and systolic blood pressure and lower high-density lipoprotein cholesterol than those with normal fasting glucose concentrations. Conclusions. These data, representing 27 million US adolescents, reveal a very high prevalence of IFG ( 1 in 10 boys and 1 in 25 girls) among adolescents; the condition affects 1 in every 6 overweight adolescents. Adolescents with IFG have features of insulin resistance and worsened CVD risk factors. Evidence for prevention is still forthcoming in this age group.