Acta Pædiatrica ISSN 0803-5253
REGULAR ARTICLE
Shape of glucose curve can be used as a predictor for screening prediabetes in obese children ChunYan Yin, Hongai Zhang, YanFeng Xiao ([email protected]), WeiHua Liu The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, ShangXi, China
Keywords Abnormal glucose tolerance, Glucagon, Glucose, Insulin, Obese children Correspondence YanFeng Xiao, Department of pediatrics, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, ShangXi 710049, China. Tel: +86-029-87679543 | Fax: +86-029-8767542 | Email: [email protected] Received 15 September 2013; revised 2 December 2013; accepted 20 January 2014. DOI:10.1111/apa.12572
ABSTRACT Aim: We attempted to classify obese children with glucose abnormalities into different categories based on the plasma glucose (PG) at 0, 60, 120 and 180 min and extract the metabolic information from the shape of the PG curve. Methods: We recruited 1205 obese children and 325 nonobese children. Their body weight, blood pressure, waist and hip circumferences were measured. An oral glucose tolerance test (OGTT) was carried out, and glucose, insulin and glucagon levels were tested. Results: There were six forms of abnormal glucose tolerance (AGT) curves in obese children in addition to normal glucose tolerance (NGT). 58.3% of obese children had AGT. BMI, waist circumference, waist-to-hip ratio and systolic blood pressure of each obese group were much higher than in nonobese children (p < 0.05). HOMA-IR increased significantly in obese children with high fasting PG and obese children with high fasting and 3-h PG (p < 0.05), and HOMA-b cell increased significantly in obese children with high 1- and 2-h but low 3-h PG (p < 0.05). Conclusion: Abnormal glucose tolerance was highly prevalent when concerning with glucose values at 60 and 180 min. The shape of PG which contains a net of metabolic information can be a predictor for screening prediabetes.
INTRODUCTION The epidemic of childhood obesity over the last decade has resulted in an unprecedented rise in the incidence of type 2 diabetes mellitus (1). Even more worrisome is the recent observation that 22–25% of children and adolescents with severe obesity are prediabetic (2). The course of type 2 diabetes is slow, and most prediabetic individuals (perhaps up to 60%) will eventually develop diabetes in the subsequent five to 10 years (3). However, with appropriate changes in lifestyle, progression from impaired glucose tolerance to frank diabetes can be delayed or prevented (4). Thus, early detection and treatment for abnormal glucose tolerance (AGT) are very important for preventing the progression to diabetes. The cut-off points or diagnostic threshold used to differentiate prediabetes and diabetes have been revised over the years (5,6). Recently, the American Diabetes Association lowered the threshold for impaired fasting glucose (IFG) from 6.1 to 5.6 mmol/L in order to detect a higher proportion of those with prediabetes (7), but identification of individuals with prediabetes (impaired fasting glucose and/or impaired glucose tolerance) is still based on the plasma glucose (PG) concentration at 0 and 2 h, and the information provided at different times during the oral glucose tolerance test (OGTT) seems to attract little attention in obese children. Also, the shape of the
glucose concentration curve, which is determined by the rate of change in the appearance and disappearance of glucose, may reflect metabolic information about insulin and glucagon secretion (8). The shape of the PG concentration curve may be influenced by prediabetes, but the diagnostic function of changes in PG in obese children with prediabetes is not widely appreciated. In this study, we classified obese children with glucose abnormalities into different categories based on the glucose measurements at 0, 60, 120 and 180 min. We attempted to extract metabolic information about the secretion of insulin and glucagon from the shape of the PG concentration curve.
Key notes
©2014 Foundation Acta Pædiatrica. Published by John Wiley & Sons Ltd 2014 103, pp. e199–e205
The diagnostic function of the shape of plasma glucose (PG) in obese children is unknown. We find that there are six forms of AGT in obese children in addition to the NGT and the shape of PG curve contains a net of metabolic information. This can assist in early detection and treatment of patients when they first develop impaired glucose tolerance.
e199
Characteristics of abnormal glucose tolerance in obese children
Yin et al.
PATIENTS AND METHODS Subjects We enrolled 1205 obese children (485 girls and 720 boys; mean age, 12.04 2.90 years; mean BMI, 29.57 5.53) and 325 nonobese children (150 girls and 175 boys, mean age, 11.07 2.10 years; mean BMI, 19.50 3.51). The children were recruited in 2008–2010 from those visiting the second Affiliated Hospital of Xi’an Jiao Tong University. The subjects’ body weight, height, blood pressure, waist and hip circumferences were measured using standardised techniques. BMI was calculated as weight (in kilograms) divided by height (in meters) squared. All subjects with a BMI above the 95th percentile for age and gender were classified as obese. Parents provided informed consent, and children provided informed assent, before enrolment. OGTT After a 12-h overnight fast, glucose (1.75 g per kg body weight, maximum 75 g) was given orally, and blood samples were obtained at 0, 60, 120 and 180 min for determination of PG, insulin and glucagon. The glucose was measured by the glucose oxidase method. Insulin was measured with a radioimmunoassay (Linco; St. Charles, MO, USA). Glucagon was determined by an enzymelinked immunosorbent assay (American, RD). The HOMAIR was calculated as fasting insulin (lU/mL) 9 fasting glucose (mmol/L)/22.5. HOMA b-cell was calculated as 20 9 fasting insulin (lU/mL)/fasting glucose (mmol/ 1) 3.5 (9). Diagnosis and classification The American Diabetes Association defines normal glucose tolerance (NGT) as fasting PG (FPG)
REGULAR ARTICLE
Shape of glucose curve can be used as a predictor for screening prediabetes in obese children ChunYan Yin, Hongai Zhang, YanFeng Xiao ([email protected]), WeiHua Liu The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, ShangXi, China
Keywords Abnormal glucose tolerance, Glucagon, Glucose, Insulin, Obese children Correspondence YanFeng Xiao, Department of pediatrics, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, ShangXi 710049, China. Tel: +86-029-87679543 | Fax: +86-029-8767542 | Email: [email protected] Received 15 September 2013; revised 2 December 2013; accepted 20 January 2014. DOI:10.1111/apa.12572
ABSTRACT Aim: We attempted to classify obese children with glucose abnormalities into different categories based on the plasma glucose (PG) at 0, 60, 120 and 180 min and extract the metabolic information from the shape of the PG curve. Methods: We recruited 1205 obese children and 325 nonobese children. Their body weight, blood pressure, waist and hip circumferences were measured. An oral glucose tolerance test (OGTT) was carried out, and glucose, insulin and glucagon levels were tested. Results: There were six forms of abnormal glucose tolerance (AGT) curves in obese children in addition to normal glucose tolerance (NGT). 58.3% of obese children had AGT. BMI, waist circumference, waist-to-hip ratio and systolic blood pressure of each obese group were much higher than in nonobese children (p < 0.05). HOMA-IR increased significantly in obese children with high fasting PG and obese children with high fasting and 3-h PG (p < 0.05), and HOMA-b cell increased significantly in obese children with high 1- and 2-h but low 3-h PG (p < 0.05). Conclusion: Abnormal glucose tolerance was highly prevalent when concerning with glucose values at 60 and 180 min. The shape of PG which contains a net of metabolic information can be a predictor for screening prediabetes.
INTRODUCTION The epidemic of childhood obesity over the last decade has resulted in an unprecedented rise in the incidence of type 2 diabetes mellitus (1). Even more worrisome is the recent observation that 22–25% of children and adolescents with severe obesity are prediabetic (2). The course of type 2 diabetes is slow, and most prediabetic individuals (perhaps up to 60%) will eventually develop diabetes in the subsequent five to 10 years (3). However, with appropriate changes in lifestyle, progression from impaired glucose tolerance to frank diabetes can be delayed or prevented (4). Thus, early detection and treatment for abnormal glucose tolerance (AGT) are very important for preventing the progression to diabetes. The cut-off points or diagnostic threshold used to differentiate prediabetes and diabetes have been revised over the years (5,6). Recently, the American Diabetes Association lowered the threshold for impaired fasting glucose (IFG) from 6.1 to 5.6 mmol/L in order to detect a higher proportion of those with prediabetes (7), but identification of individuals with prediabetes (impaired fasting glucose and/or impaired glucose tolerance) is still based on the plasma glucose (PG) concentration at 0 and 2 h, and the information provided at different times during the oral glucose tolerance test (OGTT) seems to attract little attention in obese children. Also, the shape of the
glucose concentration curve, which is determined by the rate of change in the appearance and disappearance of glucose, may reflect metabolic information about insulin and glucagon secretion (8). The shape of the PG concentration curve may be influenced by prediabetes, but the diagnostic function of changes in PG in obese children with prediabetes is not widely appreciated. In this study, we classified obese children with glucose abnormalities into different categories based on the glucose measurements at 0, 60, 120 and 180 min. We attempted to extract metabolic information about the secretion of insulin and glucagon from the shape of the PG concentration curve.
Key notes
©2014 Foundation Acta Pædiatrica. Published by John Wiley & Sons Ltd 2014 103, pp. e199–e205
The diagnostic function of the shape of plasma glucose (PG) in obese children is unknown. We find that there are six forms of AGT in obese children in addition to the NGT and the shape of PG curve contains a net of metabolic information. This can assist in early detection and treatment of patients when they first develop impaired glucose tolerance.
e199
Characteristics of abnormal glucose tolerance in obese children
Yin et al.
PATIENTS AND METHODS Subjects We enrolled 1205 obese children (485 girls and 720 boys; mean age, 12.04 2.90 years; mean BMI, 29.57 5.53) and 325 nonobese children (150 girls and 175 boys, mean age, 11.07 2.10 years; mean BMI, 19.50 3.51). The children were recruited in 2008–2010 from those visiting the second Affiliated Hospital of Xi’an Jiao Tong University. The subjects’ body weight, height, blood pressure, waist and hip circumferences were measured using standardised techniques. BMI was calculated as weight (in kilograms) divided by height (in meters) squared. All subjects with a BMI above the 95th percentile for age and gender were classified as obese. Parents provided informed consent, and children provided informed assent, before enrolment. OGTT After a 12-h overnight fast, glucose (1.75 g per kg body weight, maximum 75 g) was given orally, and blood samples were obtained at 0, 60, 120 and 180 min for determination of PG, insulin and glucagon. The glucose was measured by the glucose oxidase method. Insulin was measured with a radioimmunoassay (Linco; St. Charles, MO, USA). Glucagon was determined by an enzymelinked immunosorbent assay (American, RD). The HOMAIR was calculated as fasting insulin (lU/mL) 9 fasting glucose (mmol/L)/22.5. HOMA b-cell was calculated as 20 9 fasting insulin (lU/mL)/fasting glucose (mmol/ 1) 3.5 (9). Diagnosis and classification The American Diabetes Association defines normal glucose tolerance (NGT) as fasting PG (FPG)
