HbA(1c) levels in non-diabetic Dutch children aged 8-9 years: the PIAMA birth cohort study

Distribution of glycated haemoglobin and its determinants in Korean youth and young adults: a nationwide population-based study

The present study aimed to describe the distribution of and to investigate the factors associated with glycated haemoglobin (HbA1c) values in Korean youth (10–19 years old) and young adults (20–29 years old). Data from the Korea Health and Nutrition Examination Survey (2011–2015) were used. A total of 6,418 participants (male 3,140 [53.2%]) aged 10–29 years were included in the analysis. Percentiles of HbA1c were calculated and HbA1c values were compared according to age, sex, and associated factors. The mean HbA1c values (% [mmol/mol]) were 5.42 ± 0.01 (35.7 ± 0.1) for youths and 5.32 ± 0.01 (34.7 ± 0.1) for young adults (P < 0.001). Male participants showed significantly higher HbA1c level than females (P < 0.001). When age was grouped into 5-year intervals, HbA1c was the highest in those aged 10–14 years and the lowest in those aged 20–24 years. After controlling for confounding variables, the HbA1c values of youths and male participants were significantly higher than those of young adults and female participants. The present study provides nationally representative data on the distribution of HbA1c values in Korean youth and young adults. There were significant differences in the level of HbA1c according to age and sex.

Change in HbA1c levels between the age of 8 years and the age of 12 years in Dutch children without diabetes: the PIAMA birth cohort study

OBJECTIVE

HbA1c is associated with cardiovascular risk in persons without diabetes and cardiovascular risk accumulates over the life course. Therefore, insight in factors determining HbA1c from childhood onwards is important. We investigated (lifestyle) determinants of HbA1c at age 12 years and the effects of growth on change in HbA1c and the tracking of HbA1c between the age of 8 and 12 years.

STUDY DESIGN AND METHODS

Anthropometric measurements were taken and HbA1c levels were assessed in 955 children without diabetes aged around 12 years participating in the PIAMA birth cohort study. In 363 of these children HbA1c was also measured at age 8 years. Data on parents and children were collected prospectively by questionnaires.

RESULTS

We found no significant association between known risk factors for diabetes and HbA1c at age 12 years. Mean(SD) change in HbA1c between ages 8 and 12 years was 0.6(0.7) mmol/mol per year (or 0.1(0.1) %/yr). Anthropometric measures at age 8 and their change between age 8 and 12 years were not associated with the change in HbA1c. 68.9% of the children remained in the same quintile or had an HbA1c one quintile higher or lower at age 8 years compared to age 12 years.

CONCLUSION

The lack of association between known risk factors for diabetes and HbA1c suggest that HbA1c in children without diabetes is relatively unaffected by factors associated with glycaemia. HbA1c at age 8 years is by far the most important predictor of HbA1c at age 12. Therefore, the ranking of HbA1c levels appear to be fairly stable over time.

Bilirubin is an independent factor inversely associated with glycated hemoglobin level in pediatric patients with type 1 diabetes

OBJECTIVE

Bilirubin is a potent antioxidant, and serum total bilirubin (STB) concentrations correlate negatively with cardiovascular risk. In adult diabetic patients and in healthy adults, a negative correlation between STB and glycated hemoglobin (HbA1c) has been reported. We investigated whether there is such an association in children and adolescents with type 1 diabetes mellitus.

METHODS

The study group included 224 patients with type 1 diabetes duration of more than 12 months. Patients with suspected or confirmed hemolytic anemia or liver dysfunction were excluded.

RESULTS

A statistically significant negative correlation was found between STB and HbA1c (R = -0.15; p = 0.024), which retained its significance in multivariate analysis (β = -0.18, p = 0.005). Patients' age and daily insulin dose were positively correlated with HbA1c levels, whereas other variables included in the multivariate analysis [sex, diabetes duration, insulin regimen, C-peptide, hemoglobin, mean corpuscular hemoglobin concentration (MCHC), alanine transaminase (ALT), and aspartate transaminase (AST)] did not correlate with HbA1c. The mean HbA1c level in patients with STB >1.2 mg/dL (>21 µmol/L; the threshold for clinical diagnosis of Gilbert's syndrome) was lower than in patients with STB ≤1.2 mg/dL (≤21 µmol/L), and the mean difference was 0.63% (6.9 mmol/mol; 95% CI: 0.11-1.16%).

CONCLUSIONS

These results show that in young patients with type 1 diabetes, STB concentration is an independent factor inversely associated with HbA1c level. Further studies should investigate the background and long-term effects of this association.

Divergence between HbA1c and fasting glucose through childhood: implications for diagnosis of impaired fasting glucose (Early Bird 52)

OBJECTIVE

An HbA1c threshold of ≥ 6.5% has recently been adopted for the diagnosis of diabetes in adults, and of ≥ 5.7% to identify adults at risk. Little,however, is known of HbA1c's behaviour or diagnostic value in youth. Our aim was to describe the course of HbA1c during childhood, and its association with fasting glucose.

RESEARCH DESIGN AND METHODS

HbA1c and glucose were measured every year in a cohort of 326 healthy children (162 boys) from 5 to 15 years. Mixed effects modelling was used to establish the determinants of HbA1c and its development over time. ROC analysis was used to determine the diagnostic value of HbA1c in the 55 individuals who showed impaired fasting glucose(IFG – glucose ≥ 5.6 mmol/L).

RESULTS

Glucose rose progressively from 4.3 mmol/L at 5 years to 5.1 mmol/Lat 15 years, and although there were positive associations between HbA1c and glucose, from 10 to 13 years, HbA1c fell while glucose continued to rise. IFG developed in 55 children, but HbA1c exceeded 5.7% in only 16 of them. The maximum area under the ROC curve was 0.71 at the age of 14 (p<0.001), and the sensitivity and specificity were optimal at 50 and 80% respectively,corresponding to HbA1c of 5.4%.

CONCLUSIONS

Although HbA1c retains a positive association with glucose throughout childhood, it is weak, and their trends diverge from 10 years,suggesting that factors other than glycaemia systematically influence the variance of HbA1c in youth. These findings therefore limit the interpretation of HbA1c for the diagnosis of IFG during childhood.

Is glycosylated haemoglobin associated with psychosocial stress in non-diabetic 6-year-olds?

AIM

Glycosylated haemoglobin (HbA1c), a marker of diabetic glycemic control, is associated with chronic psychosocial stress in non-diabetic adults. This study aimed to determine whether HbA1c also acts as a biomarker of psychosocial stress in healthy 6-year-olds.

DESIGN AND PARTICIPANTS

Eligible participants were 326 children recruited from 6 socio-economically diverse areas in Melbourne, Australia, who took part in an earlier randomised trial for sleep problems at age 7 months. At 6 years, they participated in a follow-up assessment.

OUTCOME

 HbA1c collected by finger-prick. Exposures (collected simultaneously): proxy measures of child stress including: (i) child mental health; (ii) maternal mental health (depression, anxiety, stress), negative life events in the preceding year, life stresses and coping; and (iii) family socioeconomic status and financial stress.

ANALYSES

linear regressions, adjusted for original randomisation status and clustering.

RESULTS

Sixty percent (134/225) of children retained at 6 years provided HbA1c data, which ranged from 3.9%-5.8% (SD 0.3%). No child or family variable was associated with HbA1c. Of the maternal variables, only anxiety predicted HbA1c (adjusted difference per point increase: -0.01, 95% CI: -0.003 to 0.02, P = 0.01); this association was in the opposite direction to that hypothesised and clinically insignificant.

CONCLUSION

HbA1c was not associated with psychosocial stress in healthy 6-year-olds. This suggests that any link between HbA1c and psychosocial stress emerges after this age, and that HbA1c is unlikely to be a reliable biomarker for stress in early childhood or over the transition to school.

Use of HbA(1C) testing to diagnose pre-diabetes in high risk African American children: a comparison with fasting glucose and HOMA-IR

OBJECTIVE

This study aimed to compare the discriminating power of HbA(1C) with other pre-diabetes diagnostic tests specifically in high-risk African American children.

RESEARCH DESIGN AND METHODS

A cross-sectional analysis was performed on a sample of 172 children (70 boys and 102 girls) aged 9-11 years with BMI's above the 85th percentile. Fasting glucose, insulin and HbA(1C) were analyzed from the plasma samples.

RESULTS

Of the 172 participants included in this analysis, 21 (12.2%) had HbA(1C) concentrations above the cutoff of 5.7 used to identify pre-diabetes. None (0%) of these 21 participants, however, were observed to have a glucose concentration above the pre-diabetes cutoff of 110 mg/dl, and only 13 of 21 participants had HOMA-IR above the pre-diabetes cutoff of 2.5. When compared to the previously identified glucose cutoff of 110 mg/dl and HOMA-IR cutoff of 2.5 for pre-diabetes, HbA(1C) showed high specificity (88 and 93%, respectively) but very low sensitivity (0 and 21%, respectively). Glucose, insulin and HOMA-IR were significantly interrelated, but HbA(1C) was not significantly correlated with these biochemical prediabetes assessment variables, nor with anthropometric (BMIz, WC) risk factors.

CONCLUSION

Our results suggest that HbA(1C) had poor discrimination power to identify prediabetes in overweight and obese 9- to 11-year-old African American children. Future studies are recommended to compare the feasibility, sensitivity and predictive power of different screening tests currently recommended to avoid inadequacy when screening for prediabetes and diabetes.

Usefulness of HbA1c to diagnose diabetes among Japanese children detected by a urine glucose screening program in the Tokyo Metropolitan Area

We examined the correlation between plasma glucose (PG) and hemoglobin A1c (HbA1c) to evaluate the usefulness and limitations of applying the new diagnostic criteria for diabetes to Japanese pediatric patients. Data were collected from 298 school children who took an oral glucose tolerance test (OGTT) at a school-based urinary glucose screening program in the Tokyo Metropolitan Area between 1988 and 2009. Mean (SD) age of the children was 11.9 (2.5) years. Male-to-female ratio was 1:1.1. Children were diagnosed with renal glucosuria (n=146), diabetes mellitus (n=133), or the Japan Diabetes Society (JDS) "borderline type" (n=19). Median (range) values of fasting plasma glucose (FPG), 2-h plasma glucose in an OGTT (OGTT-2h), and HbA1c were 101 (76-378) mg/dL, 146.5 (57-563) mg/dL, and 6.05 (4.7-14.1) %. The correlation between PG and HbA1c was analyzed using least squares regression, and HbA1c was found to highly correlate with PG. From estimated regression equations, mean values of FPG and OGTT-2h corresponding to an HbA1c of 6.5% were calculated to be 111.4 mg/dL and 170.4 mg/dL. The mean values of HbA1c corresponding to an FPG of 126 mg/dL and OGTT-2h of 200 mg/dL were calculated to be 7.5% and 7.8%. The mean values of PG corresponding to HbA1c of 6.5% were lower than found in adults as analyzed by JDS. The mean values of HbA1c corresponding to diabetic type PG were higher than found in adults.

HbA1c in nondiabetic Dutch infants aged 8-12 months: the GECKO-Drenthe birth cohort study

OBJECTIVE

An international committee of experts recommended using HbA(1c) for diagnostic testing for diabetes. Little is known about normal values of HbA(1c) in infants. The aim of this study is to describe the distribution of HbA(1c) in 8- to 12-month-old nondiabetic infants.

RESEARCH DESIGN AND METHODS

HbA(1c) was measured in 86 infants participating in the Groningen Expert Center for Kids with Obesity (GECKO)-Drenthe birth cohort study. Anthropometric measurements were performed at Well Baby Clinics. Data on parents and children were collected prospectively using questionnaires.

RESULTS

HbA(1c) was normally distributed with a mean (SD) HbA(1c) level of 5.38% (0.24), range 4.8-6.0% or 35.29 mmol/mol (2.65), range 29.1-42.1 mmol/mol. Age, sex, birth weight, duration of breastfeeding, anthropometric measurements, and maternal BMI were not associated with HbA(1c).

CONCLUSIONS

We found a normal distribution of HbA(1c) with a relatively high mean HbA(1c) of 5.38%. No significant association between risk factors for type 2 diabetes and HbA(1c) levels was found.

Ability among adolescents for the metabolic syndrome to predict elevations in factors associated with type 2 diabetes and cardiovascular disease: data from the national health and nutrition examination survey 1999-2006

OBJECTIVE

The aim of this study was to compare currently proposed sets of pediatric metabolic syndrome criteria for the ability to predict elevations in "surrogate" factors that are associated with metabolic syndrome and with future cardiovascular disease and type 2 diabetes mellitus. These surrogate factors were fasting insulin, hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein (hsCRP), and uric acid.

METHODS

Waist circumference (WC), blood pressure, triglycerides, high-density lipoprotein cholesterol (HDL-C), fasting glucose, fasting insulin, HbA1c, hsCRP, and uric acid measurements were obtained from 2,624 adolescent (12-18 years old) participants of the 1999-2006 National Health and Nutrition Examination Surveys. We identified children with metabolic syndrome as defined by six commonly used sets of pediatric metabolic syndrome criteria. We then defined elevations in the surrogate factors as values in the top 5% for the cohort and calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each set of metabolic syndrome criteria and for each surrogate factor.

RESULTS

Current pediatric metabolic syndrome criteria exhibited variable sensitivity and specificity for surrogate predictions. Metabolic syndrome criteria had the highest sensitivity for predicting fasting insulin (40-70%), followed by uric acid (31-54%), hsCRP (13-31%), and HbA1c (7-21%). The criteria of de Ferranti (which includes children with WC >75(th) percentile, compared to all other sets including children with WC >90(th) percentile) exhibited the highest sensitivity for predicting each of the surrogates, with only modest decrease in specificity compared to the other sets of criteria. However, the de Ferranti criteria also exhibited the lowest PPV values. Conversely, the pediatric International Diabetes Federation criteria exhibited the lowest sensitivity and the highest specificity.

CONCLUSIONS

Pediatric metabolic syndrome criteria exhibit moderate sensitivity for detecting elevations in surrogate factors associated with metabolic syndrome and with risk for future disease. Inclusion of children with more modestly elevated WC improved sensitivity.