Oral Glucose Tolerance Test among Adolescents with Impaired Fasting Blood Glucose

Abstract

Background: Type 2 Diabetes Mellitus (DM) is emerging as a major health problem even amongst children and adolescents. The onset is usually preceded by period of impaired glucose metabolism known as Impaired Fasting Glucose (IFG) and or Impaired Glucose Tolerance (IGT). This study is aimed at determining the presence of impaired glucose tolerance in adolescents aged 10 to 19 years with impaired fasting glucose.

Methodology: Oral glucose tolerance test was done for a cohort of 68 adolescents aged 10 to 19 years with impaired fasting blood glucose detected at a school screening. Age, sex, anthropometric measures (height, weight, BMI and BMI percentiles were determined using appropriate methods. Blood pressure and family history of DM was determined. IGT was determined as a two hour post glucose load blood glucose value of> 7.8mmol/l and< 11.1mmol/l.

Result: The mean age of the subjects was 15.08 ± 2.03 years. There were 23 (33.8%) males and 45 (66.2%) females, giving a male to female ratio of 1:2. Thirteen (19.1%) were overweight/obese, 16 (23.5%) had family history of diabetes mellitus and 17(25%) had hypertension. Seven (10.3%) of the subjects had impaired glucose tolerance and no case of diabetes. The mean BMI and fasting blood glucose value was higher in subjects with impaired glucose tolerance compared to those without. There was no statistically significant difference in prevalence of hypertension, overweight/obesity and hypertension in group with or without impaired glucose tolerance.

Conclusion: There was no concordance in occurrence of IFG and IGT. Mean fasting blood glucose and mean BMI was higher in those with both IFG and IGT. Screening for only IGT will therefore miss subjects with IFG.

Keywords: Oral Glucose Tolerance Test; Impaired Fasting Blood Glucose; Adolescents; Nigeria