Prevalence of high HbA1c levels in Brazilian adolescents: The Study of Cardiovascular Risk in Adolescents

Association of BMI and WC for insulin resistance and type 2 diabetes among Brazilian adolescents

OBJECTIVE

To investigate how body mass index (BMI) and waist circumference (WC) may be associated with insulin resistance and type 2 diabetes (T2DM) in Brazilian adolescents.

METHODS

Cross-sectional study using data from the Brazilian Study of Cardiovascular Risks in Adolescents (ERICA) including adolescents aged 12-17 years. The relationship between adiposity and T2DM was investigated using ordinal logistic regression models. To study the association between adiposity categories and the occurrence of insulin resistance, linear regression models were used.

RESULTS

The prevalence of T2DM for the same BMI category did not increase with the presence of high WC. Regarding insulin resistance, for the same BMI categories, having a high WC resulted in a higher prevalence of insulin resistance (HOMA-IR). The only groups significantly associated with prediabetes and T2DM were those with obesity by BMI with elevated WC (POR 1.68, 95 % CI 1.45; 1.94) and obesity with normal WC (POR 1.58, 95 % CI 1.01; 2.46). Similar findings were observed concerning insulin resistance, where the increased WC had its greatest effect when associated with obesity by BMI (β Coefficient 2.20, 95 % CI 1.89; 2.50).

CONCLUSION

The combination of BMI and WC is better for assessing adolescents at risk of developing T2DM.

Distribution and determinants of glycosylated hemoglobin in adolescents - Results from a nationwide population-based survey in Germany

The role of glycosylated hemoglobin (HbA1c) in youth is largely unclear. The aims of this study are to investigate the distribution and potential determinants of HbA1c among a population-based sample of adolescents. The German Health Interview and Examination Survey for Children and Adolescents (KiGGS) Wave 2 includes a nationwide representative sample of 0-17-year-old participants. For this evaluation, data from a randomly selected subgroup aged 14-17 years and without diagnosed diabetes was included (n = 857). Percentile-based HbA1c values (measured at laboratory in whole blood samples by high performance liquid chromatography) were calculated to examine HbA1c distribution. Multivariable linear regression analyses were performed to investigate factors (age, sex, parental socioeconomic status, body mass index (BMI), birth weight, smoking, alcohol consumption, healthy food diversity, sport activity, oral contraceptive use) associated with HbA1c. The mean HbA1c level was 5.2% (minimum: 3.9%, P10: 4.8%, P50: 5.1%, P90: 5.5%, maximum: 6.7%). Overall, 2.8% of adolescents had an HbA1c value in the prediabetic range (5.7-6.4%) and 0.1% had an undiagnosed diabetes (≥6.5%). Multivariable regression analysis showed an inverse association of age with HbA1c (17 vs. 14 years: ß: -1.18; 95% CI -2.05, -0.31). Higher HbA1c values were observed for higher BMI-standard deviation scores (SDS) (ß: 0.24; 95% CI -0.04, 0.52) and smoking (ß: 0.73; 95% CI -0.12, 1.57), but these tendencies were non-significant. In sex-stratified analysis, smoking and birth weight were significantly associated with HbA1c in boys. Among adolescents without diagnosed diabetes in Germany, HbA1c values ranged from 3.9% to 6.7%. To ensure health in adulthood, the influence of determinants on HbA1c levels in younger age should be further investigated.

Prevalence of type 2 diabetes among adolescents in Brazil: Findings from Study of Cardiovascular Risk in Adolescents (ERICA)

BACKGROUND

Type 2 diabetes mellitus (T2DM) in adolescents represents a clinical challenge related to lifestyle and obesity; however, only a few data are available in developing countries. Therefore, our aim was to investigate the prevalence of T2DM and prediabetes among Brazilian adolescents, as well as to describe the cardio-metabolic profile according to the diagnosis.

METHODS

This is a cross-sectional school-based multicenter study including youth aged 12 to 17 years from cities with more than 100 000 inhabitants in Brazil (n = 37 854 students). Fasting glucose, hemoglobin A1c (HbA1c) and other cardio-metabolic risk factors were measured. Prediabetes was defined by glucose levels 100 to 125 mg/dL or HbA1c 5.7% to 6.4%. T2DM was defined by self-report, glucose ≥126 mg/dL or HbA1c ≥ 6.5%. Multinomial logistic regression was used to estimate the odds ratio (OR) of prediabetes or T2DM according to covariates.

RESULTS

Prevalences of prediabetes and T2DM were 22.0% (95% confidence interval [CI] 20.6%-23.4%) and 3.3% (95% CI 2.9%-3.7%), respectively. This estimates represented 213 830 adolescents living with T2DM and 1.46 million adolescents with prediabetes in Brazil. Prevalences of cardio-metabolic risk factors were higher in adolescents with prediabetes and T2DM. In the multinomial logistic model, obesity (OR 1.59, 95% CI 1.20-2.11), high waist circumference (OR 1.51, 95% CI 1.13-2.01), and skipping breakfast (OR 1.48, 95% CI 1.21-1.81) were associated with an increased OR for T2DM, while studying at rural area (OR 0.56, 95% CI 0.41-0.78) was associated with a decreased OR for T2DM.

CONCLUSIONS

The prevalence of T2DM and prediabetes was high among Brazilian adolescents, which highlights that this disease became a public health challenge not only among adults in Brazil.