Assessment of disturbed glucose metabolism and surrogate measures of insulin sensitivity in obese children and adolescents

Effects of COVID-19 time on the development of pre-impaired glucose tolerance state in children and adolescents with overweight and obesity

OBJECTIVES

We aimed to characterize the effects of COVID-19 Pandemic on 2 h plasma glucose (2 h PG) values after an OGTT postulating a correlation between 2 h PG spectrum and the decline of β-cell function. Particularly, we tried to evaluate the effects on the risk of showing 2 h plasma glucose values in the highest range of normal values in children and adolescent with obesity during COVID-19 Pandemic compared to those evaluated during the 13 years before.

SUBJECTS/METHODS

Data from 532 children and adolescents with obesity and overweight (before COVID-19 Pandemic, 209M/262F, 2008-2019; during COVID-19 Pandemic, 40M/21F, 2020-2021) who had undergone a complete evaluation and had performed an OGTT were analyzed. The two groups were further divided into three sub-groups based on the 2 h PG, group 1 (2 h PG < 5.55 mmol/L), group 2 (5.56 < 2 h PG < 6.60 mmol/L), group 3 (6.61 < 2h PG < 7.72 mmol/L), respectively. The prevalence of 2 h PG values distribution in children was evaluated between before and during COVID-19 Pandemic period and the main differences between the two groups 3 of each period were analyzed.

RESULTS

A significant difference (P = 0.01) in terms of distribution of the prevalence of 2h PG values was documented between the group before COVID-19 (35.6%, 45.9% and 18.5%) and the group during COVID-19 Pandemic (31.1%, 31.1% and 37.8%). A roughly doble higher prevalence of subjects with pre-IGT was documented in the COVID-19 group. In addition, group 3 of COVID-19 time showed significantly higher values for waist circumference (WC), Waist/Height ratio (WtHR), fasting glucose and HOMA-IR compared to the group 3 of the period before COVID-19 Pandemic (all P < 0.05).

CONCLUSIONS

During COVID-19 time a higher percentage of children are in the highest range of normal 2 h PG values which is known to be associated with a significant impairment of β-cell function and insulin sensitivity and have higher risk of developing IGT.

Longitudinal study of ICET-A on glucose tolerance, insulin sensitivity and β-cell secretion in eleven β-thalassemia major patients with mild iron overload

BACKGROUND

Iron chelation therapy (ICT) is the gold standard for treating patients with iron overload, though its long-term effects are still under evaluation. According to current recommendations regarding  transfusion-dependent  (TD)  β-thalassemia major (β-TM) patients, their serum ferritin (SF) levels should be maintained below 1,000 ng/mL and ICT should be discontinued when the levels are <500 ng/mL in two successive tests. Alternatively, the dose of chelator could be considerably reduced to maintain a balance between iron input and output of  frequent transfusions.

STUDY DESIGN

Due to the paucity of information on long-term effects of ICT  in β-TM with low SF levels on glucose homeostasis, the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescence Medicine (ICET-A) promoted a retrospective and an ongoing prospective observational study with the primary aim to address the long-term effects of ICT on glucose tolerance and metabolism (β-cell function and peripheral insulin sensitivity) in adult β-TM patients with persistent SF level below 800 ng/mL.

PATIENTS AND METHODS

11 β-TM patients (mean age: 35.5 ± 5.5 years; SF range: 345-777 ng/mL) with normal glucose tolerance test (OGTT) or abnormal glucose tolerance (AGT) for a median of 5.3(1.1-8.3) years.

RESULTS

Abnormal glucose tolerance (AGT) was observed in 7 patients (63.6%) at first observation and ) persisted in 6 patients (54.5%) at last observation. None of them developed diabetes mellitus. AGT was reversed in two patients. One patient with NGT developed early glucose intolerance (1-h PG ≥155 and 2-h PG <140 mg/dL). Three out of  5 patients with isolated impaired glucose tolerance presented a variation of  ATG. Stabilization of low indices for β-cell function and insulin sensitivity/resistance was observed. One patient developed hypogonadotrophic hypogonadism. Three out of 6 patients with SF below 500 ng/dL had hypercalciuria.

CONCLUSION

Despite low SF level, the burden of endocrine complications remains a challenge in β-TM patients. The ability to keep iron at near "normal" level with acceptable risks of toxicity remains to be established.

The bad rainbow of COVID-19 time: effects on glucose metabolism in children and adolescents with obesity and overweight

BACKGROUND

COVID-19 restriction measurements have enhanced the obesity status in the pediatric population which might further contribute to obesity-related glucose-insulin metabolism alterations. Therefore, we retrospectively compared anthropometric and OGTT data on children with obesity during the 13 years before and during the COVID-19 pandemic.

SUBJECTS/METHODS

Data from 741 children with obesity and overweight were retrieved and clustered into seven groups starting from year 2008-2009 until 2020-2021. Differences in anthropometric measurements and glucose/insulin metabolism were evaluated between the different groups.

RESULTS

Children with overweight and obesity in the COVID-19 restriction group did not present increased values of SDS-Body Mass Index (BMI). Significantly higher values for Waist Circumference (WC), SDS-WC, Waist/Height ratio (WHtR), and body mass fat were detected in these children (all P < 0.01). Fasting glycaemia, glucose, and insulin excursions were significantly higher compared to pre- pandemic children (all P < 0.01). Insulin resistance was higher while insulin secretion was lower (all P < 0.01) determining a significantly higher percentage of impaired glucose tolerance in the COVID-19 restriction group (P < 0.002). Furthermore, High-Density Lipoprotein (HDL) cholesterol was significantly lower (P < 0.01) and SDS for systolic and diastolic blood pressure values were significantly higher (P = 0.03 and P = 0.02, respectively).

CONCLUSIONS

COVID-19 restriction measurements determined profound alterations in glucose and insulin metabolism in children with obesity and overweight. Urgent strategies are needed in order to reverse COVID-19 restriction measures' effects on glucose and insulin metabolism.

The role of hyperinsulinaemia in screening for prediabetes in the adolescent population: A systematic literature review

BACKGROUND/AIMS

Present screening methods for Type 2 diabetes (T2DM) fall short of detecting prediabetes. This paper summarises the literature on the utility of insulin measurements (hyperinsulinemia) in detecting prediabetes in adolescents.

METHODS

A systematic literature review was conducted using EMBASE and Medline. Relevant data on hyperinsulinemia in the adolescent population is narrated.

RESULTS

The database search identified 174 potential articles; 106 underwent a full-paper review, and 36 were included.

CONCLUSION

Elevated fasting insulin is a marker of impaired insulin resistance and pending beta-cell dysfunction in at-risk adolescents and can be an early indicator of prediabetes.

Difference in Insulin Resistance Assessment between European Union and Non-European Union Obesity Treatment Centers (ESPE Obesity Working Group Insulin Resistance Project)

INTRODUCTION

The obesity epidemic has become one of the most important public health issues of modern times. Impaired insulin sensitivity seems to be the cornerstone of multiple obesity related comorbidities. However, there is no accepted definition of impaired insulin sensitivity.

OBJECTIVE

We hypothesize that assessment of insulin resistance differs between centers.

METHODS

The ESPE Obesity Working Group (ESPE ObWG) Scientific Committee developed a questionnaire with a focus on the routine practices of assessment of hyperinsulinemia and insulin resistance, which was distributed through Google Docs platform to the clinicians and researchers from the current ESPE ObWG database (n = 73). Sixty-one complete responses (84% response rate) from clinicians and researchers were analyzed: 32 from European Union (EU) centers (representatives of 14 countries) and 29 from Non-EU centers (representatives from 10 countries). Standard statistics were used for the data analysis.

RESULTS

The majority of respondents considered insulin resistance (IR) as a clinical tool (85.2%) rather than a research instrument. For the purpose of IR assessment EU specialists prefer analysis of the oral glucose tolerance test (OGTT) results, whereas non-EU ones mainly use Homeostatic Model Assessment of Insulin Resistance (HOMA-IR; p = 0.032). There was no exact cutoff for the HOMA-IR in either EU or non-EU centers. A variety of OGTT time points and substances measured per local protocol were reported. Clinicians normally analyzed blood glucose (88.52% of centers) and insulin (67.21%, mainly in EU centers, p = 0.0051). Furthermore, most participants (70.5%) considered OGTT insulin levels as a more sensitive parameter of IR than glucose. Meanwhile, approximately two-thirds (63.9%) of the centers did not use any cutoffs for the insulin response to the glucose load.

CONCLUSIONS

Since there is no standard for the IR evaluation and uniform accepted indication of performing, an OGTT the assessment of insulin sensitivity varies between EU and non-EU centers. A widely accepted standardized protocol is needed to allow comparison between centers.

Obesity, putative biological mediators, and cognitive function in a national sample of children and adolescents

Childhood obesity has reached epidemic rates nationwide and may be associated with impaired cognitive function. A growing body of evidence suggests that poorer academic performance for children with obesity and overweight is related to declines in executive function skills. This study aimed to identify biological mediators between obesity and overweight and cognitive function among children and adolescents. A total of 3323 children aged 6-16 years from the Third National Health and Nutrition Examination Survey between 1988 and 1994 (NHANES III) was used to measure associations between measures of obesity and overweight, cognitive function (IQ test batteries), iron deficiency, inflammation (c-reactive protein), and glucose metabolism (glycosylated hemoglobin) using multiple mediation models. Approximately 15% of the children were overweight and 11% were obese. Results showed lower scores for children who were obese or overweight than children of normal weight on several IQ subtest batteries. Obesity and overweight were also associated with biological mediators such as iron deficiency, elevated c-reactive protein and glycosylated hemoglobin. Several biomarkers of iron status were also related to measures of cognitive function. Early declines in cognitive function are associated with biomarkers of iron deficiency and inflammation in children and adolescents, and while some biological linkages between obesity and overweight and cognitive function are identified herein, further study is needed to identify additional biological mediators between obesity and overweight and cognitive function in pediatric populations.

Obesity and impairment of pancreatic β-cell function in early adulthood, independent of obesity age of onset: The Santiago Longitudinal Study

AIM

We investigated the relation of time of onset and length of obesity with biomarkers of β-cell function in early adulthood in an infancy cohort.

MATERIAL AND METHODS

In 1039 23-year-olds, body-mass index (BMI) was measured at multiple time-points from enrollment. BMI trajectories were interpolated with cubic polynomials. Fasting glucose, insulin and adiponectin were measured at 23 years. Homeostatic model assessment-insulin resistance (HOMA-IR), HOMA-S, HOMA-β, HOMA-adiponectin (AD) and disposition index (DI) were estimated. IR and non-alcoholic fatty liver (NAFL) were diagnosed. According to the BMI trajectory, five groups were defined: participants who were never obese (NOB); participants with obesity starting in adolescence and remained obese into adulthood (recent-onset obesity, ROB); participants who were obese in early childhood but transitioned to non-obesity as preadolescents (former obesity, FOB); participants who were obese in early childhood and remained obese into adulthood (persistent obesity, POB); participants with obesity starting in preadolescence and transitioned to non-obesity as adolescents (transient obesity; TOB).

RESULTS

Obesity was present in 47% of participants during at least one time-point. ROBs and POBs had higher insulin, HOMA-IR and HOMA-β, lower HOMA-S and DI, and higher prevalence of IR and NAFL at 23 years than NOBs, TOBs and FOBs. No differences were found in the β-cell functionality of NOBs, TOBs and FOBs.

CONCLUSIONS

Persistent and recent obesity are both related to IR, NAFL and a decline of β-cell function in emerging adulthood. Defeating obesity in childhood or adolescence allows reaching emerging adulthood with β-cell functioning similar to that of subjects who were NOB.

A Review of Recent Evidence from Meal-Based Diet Interventions and Clinical Biomarkers for Improvement of Glucose Regulation

In recent decades, the prevalence of diabetes has rapidly increased worldwide. Medical nutrition therapy has been identified as a major therapeutic support for diabetic patients, while preventive strategies in prediabetic or high-risk individuals have mainly focused on supplementation with bioactive compounds. Recently, meal-based interventions have been investigated as novel and safe long-term strategies for improving glucose regulation. However, evaluation of meal-based interventions is difficult since it requires analysis of sensitive markers. Biomarkers can also be used to identify individuals at risk for diabetes, which is important for disease prevention. In this review, we summarize current evidence from meal-based intervention studies conducted with the aim of improving glucose homeostasis in individuals at risk of diabetes using clinical biomarkers currently used to assess diabetic risk. Very low-calorie diets have significantly improved glucose regulation in obese adults and in adults with type 2 diabetes mellitus. In particular, changing the ratios of macronutrients through calorie restriction reduces fasting glucose level and hemoglobin A1c levels in patients with diabetes mellitus. However, this effect is limited in both obese and healthy adults. To date, multiple glucose-related markers have been identified as clinical biomarkers of diabetes. Additional clinical biomarkers include cholesterol levels, hematological markers, and inflammatory markers. Taken together, the evidence presented in this review may help for selection of clinical biomarkers for meal-based preventive approaches for non- or pre-diabetic individuals to prevent onset of diabetes.