Association between prediabetes diagnosis and body mass index trajectory of overweight and obese adolescents

Diabetes screening outcomes in youth presenting for paediatric weight management: A report of the Paediatric Obesity Weight Evaluation Registry

OBJECTIVE

Rising prevalence of obesity has led to increased rates of prediabetes and diabetes mellitus (DM) in children. This study compares rates of prediabetes and diabetes using two recommended screening tests (fasting plasma glucose [FPG] and haemoglobin A1c [HbA1c]).

STUDY DESIGN

Data were collected prospectively from 37 multi-component paediatric weight management programs in POWER (Paediatric Obesity Weight Evaluation Registry).

RESULTS

For this study, 3962 children with obesity without a known diagnosis of DM at presentation and for whom concurrent measurement of FPG and HbA1c were available were evaluated (median age 12.0 years [interquartile range, IQR 9.8, 14.6]; 48% males; median body mass index 95th percentile [%BMIp95] 134% [IQR 120, 151]). Notably, 10.7% had prediabetes based on FPG criteria (100-125 mg/dL), 18.6% had prediabetes based on HbA1c criteria (5.7%-6.4%), 0.9% had DM by FPG abnormality (≥126 mg/dL) and 1.1% had DM by HbA1c abnormality (≥6.5%). Discordance between the tests was observed for youth in both age groups (10-18 years [n = 2915] and age 2-9 years [n = 1047]).

CONCLUSION

There is discordance between FPG and HbA1c for the diagnosis of prediabetes and DM in youth with obesity. Further studies are needed to understand the predictive capability of these tests for development of DM (in those diagnosed with prediabetes) and cardiometabolic risk.

Prediabetes in children and adolescents: An updated review

Prediabetes, the precursor of type 2 diabetes mellitus, is an intermediate stage between normal glucose homeostasis and overt diabetes. This asymptomatic metabolic state is increasingly prevalent in pediatric population and is very difficult to detect without appropriate screening. Studies have shown that a certain proportion of children with prediabetes will develop diabetes in a few years. Even more alarming is the evidence that youth-onset diabetes has a more aggressive clinical course with progressive beta-cell decline and accelerated end-organ damage. Despite its importance, several aspects involving prediabetes in childhood are disputed or unknown. This review presents the latest insights into this challenging entity and outlines a simplified screening approach to aid clinical practice. In summary, childhood prediabetes is an important clinical condition indicating the need for proper screening and timely intervention.

Which Is the Most Appropriate Cut-Off of HbA1c for Prediabetes Screening in Caucasian Youths with Overweight or Obesity?

This cross-sectional study aimed to assess the best cut-off of HbA1c for detection of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), beta-cell impairment and cardiometabolic risk (CMR) profile in overweight or obese (OW/OB) Caucasian youths. Two-hour oral glucose tolerance test was available in 1549 youths, one-hour glucose (G₆₀) in 1430 youths and disposition index (DI) in 972 youths. Insulin resistance (IR) was calculated as Homeostatic Model Assessment for IR and insulin sensitivity (IS) as 1/fasting insulin. High G₆₀ was defined by a value ≥ 133 mg/dL. The best cut-off of HbA1c for IFG or IGT was 5.5%. The frequency of individuals with HbA1c ≥ 5.5% was 32.5%, compared to 16.3% with HbA1c ≥ 5.7% (as proposed by the American Diabetes Association). HbA1c ≥ 5.5% showed higher sensitivity and lower specificity with respect to HbA1c ≥ 5.7% for all the abnormalities examined (IFG, IGT, high G₆₀, IR, low IS, DI and CMR factors). In conclusion, this lower cut-off might represent a more appropriate screening marker of glucose dysmetabolism in youths with OW/OB. Prospective studies are needed to validate this cut-off for predicting prediabetes/diabetes in youths with OW/OB.

Phenotypes of prediabetes and metabolic risk in Caucasian youths with overweight or obesity

PURPOSE

To assess the prevalence of pre-diabetes phenotypes, i.e., impaired fasting glucose (IFG), impaired glucose tolerance (IGT), increased HbA1c (IA1c), and their association with metabolic profile and atherogenic lipid profile in youths with overweight/obesity (OW/OB).

METHODS

This cross-sectional study analyzed data of 1549 youths (5-18 years) with OW/OB followed in nine Italian centers between 2016 and 2020. Fasting and post-load measurements of glucose, insulin, and HbA1c were available. Insulin resistance (IR) was estimated by HOMA-IR and insulin sensitivity (IS) by reciprocal of fasting insulin. The atherogenic lipid profile was assessed by triglycerides-to-HDL ratio or cholesterol-to-HDL ratio. Insulinogenic index was available in 939 youths, in whom the disposition index was calculated.

RESULTS

The prevalence of overall pre-diabetes, IFG, IGT and IA1c was 27.6%, 10.2%, 8% and 16.3%, respectively. Analyzing each isolated phenotype, IGT exhibited two- to three-fold higher odds ratio of family history of diabetes, and worse metabolic and atherogenic lipid profile vs normoglycemic youths; IFG was associated only with IR, while IA1c showed a metabolic and atherogenic lipid profile intermediate between IGT and IFG.

CONCLUSION

Prevalence of pre-diabetes was high and IA1c was the most prevalent phenotype in Italian youths with OW/OB. The IGT phenotype showed the worst metabolic and atherogenic lipid profile, followed by IA1c. More studies are needed to assess whether HbA1c may help improving the prediction of diabetes.