Challenges and pitfalls of youth-onset type 2 diabetes

The incidence and prevalence of youth-onset type 2 diabetes mellitus(T2DM)are increasing.The rise in frequency and severity of childhood obesity,inclination to sedentary lifestyle,and epigenetic risks related to prenatal hyperglycemia exposure are important drivers of the youth-onset T2DM epidemic and might as well be responsible for the early onset of diabetes complications.Indeed,youth-onset T2DM has a more extreme metabolic phenotype than adult-onset T2DM,with greater insulin resistance and more rapid deterioration of beta cell function.Therefore,intermediate complications such as microalbuminuria develop in late childhood or early adulthood,while end-stage complications develop in mid-life.Due to the lack of efficacy and safety data,several drugs available for the treatment of adults with T2DM have not been approved in youth,reducing the pharmacological treatment options.In this mini review,we will try to address the present challenges and pitfalls related to youth-onset T2DM and summarize the available interventions to mitigate the risk of microvascular and macrovascular complications.

Association between cardiorespiratory fitness level and insulin resistance in adolescents with various obesity categories

BACKGROUND An association between cardiorespiratory fitness(CRF)and insulin resistance in obese adolescents,especially in those with various obesity categories,has not been systematically studied.There is a lack of knowledge about the effects of CRF on insulin resistance in severely obese adolescents,despite their continuous rise.AIM To investigate the association between CRF and insulin resistance in obese adolescents,with special emphasis on severely obese adolescents.METHODS We performed a prospective,cross-sectional study that included 200 pubertal adolescents,10 years to 18 years of age,who were referred to a tertiary care center due to obesity.According to body mass index(BMI),adolescents were classified as mildly obese(BMI 100% to 120% of the 95^(th)percentile for age and sex)or severely obese(BMI≥120% of the 95^(th)percentile for age and sex or≥35 kg/m^(2),whichever was lower).Participant body composition was assessed by bioelectrical impedance analysis.A homeostatic model assessment of insulin resistance(HOMA-IR)was calculated.Maximal oxygen uptake(VO_(2)max)was determined from submaximal treadmill exercise test.CRF was expressed as VO_(2)max scaled by total body weight(TBW)(mL/min/kg TBW)or by fat free mass(FFM)(mL/min/kg FFM),and then categorized as poor,intermediate,or good,according to VO_(2)max terciles.Data were analyzed by statistical software package SPSS(IBM SPSS Statistics for Windows,Version 24.0).P<0.05 was considered statistically significant.RESULTS A weak negative correlation between CRF and HOMA-IR was found[Spearman’s rank correlation coefficient(rs)=-0.28,P<0.01 for CRF_(TBW);(r_(s))=-0.21,P<0.01 for CRF_(FFM)].One-way analysis of variance(ANOVA)revealed a significant main effect of CRF on HOMA-IR[F(2200)=6.840,P=0.001 for CRF_(TBW);F_((2200))=3.883,P=0.022 for CRF_(FFM)].Subsequent analyses showed that obese adolescents with poor CRF had higher HOMA-IR than obese adolescents with good CRF(P=0.001 for CRF_(TBW);P=0.018 for CRF_(FFM)).Two-way ANOVA with Bonferroni correction confirmed significant effect of interaction of CRF level and obesity category on HOMA-IR[F_((2200))=3.292,P=0.039 for CRF_(TBW)].Severely obese adolescents had higher HOMA-IR than those who were mildly obese,with either good or poor CRF.However,HOMA-IR did not differ between severely obese adolescents with good and mildly obese adolescents with poor CRF.CONCLUSION CRF is an important determinant of insulin resistance in obese adolescents,regardless of obesity category.Therefore,CRF assessment should be a part of diagnostic procedure,and its improvement should be a therapeutic goal.

Chronotropic incompetence is more frequent in obese adolescents and relates to systemic inflammation and exercise intolerance

Background:Adults with obesity may display disturbed cardiac chronotropic responses during cardiopulmonary exercise testing,which relates to poor cardiometabolic health and an increased risk for adverse cardiovascular events.It is unknown whether cardiac chronotropic incompetence(CI)during maximal exercise is already present in obese adolescents and,if so,how that relates to cardiometabolic health.Methods:Sixty-nine obese adolescents(body mass index standard deviation score=2.23±0.32,age=14.1±1.2 years;mean±SD)and 29lean adolescents(body mass index standard deviation score=-0.16±0.84,age=14.0±1.5 years)performed a maximal cardiopulmonary exercise testing from which indicators for peak performance were determined.The resting heart rate and peak heart rate were used to calculate the maximal chronotropic response index.Biochemistry(lipid profile,glycemic control,inflammation,and leptin)was studied in fasted blood samples and during an oral glucose tolerance test within obese adolescents.Regression analyses were applied to examine associations between the presence of CI and blood or exercise capacity parameters,respectively,within obese adolescents.Results:CI was prevalent in 32 out of 69 obese adolescents(46%)and 3 out of 29 lean adolescents(10%).C-reactive protein was significantly higher in obese adolescents with CI compared to obese adolescents without CI(p=0.012).Furthermore,peak oxygen uptake and peak cycling power output were significantly reduced(p<0.05)in obese adolescents with CI vs.obese adolescents without CI.The chronotropic index was independently related to blood total cholesterol(standardized coefficientβ=-0.332;p=0.012)and C-reactive protein concentration(standardized coefficientβ=-0.269;p=0.039).Conclusion:CI is more common in the current cohort of obese adolescents,and is related to systemic inflammation and exercise intolerance.

Differential diagnosis in patients with suspected bile acid synthesis defects

AIM: To investigate the clinical presentations associated with bile acid synthesis defects and to describe identification of individual disorders and diagnostic pitfalls. METHODS: We describe semiquantitative determination of 16 urinary bile acid metabolites by electrospray ionization-tandem mass spectrometry. Sample preparation was performed by solid-phase extraction. The total analysis time was 2 min per sample. We determined bile acid metabolites in 363 patients with suspected defects in bile acid metabolism. RESULTS: Abnormal bile acid metabolites were found in 36 patients. Two patients had bile acid synthesis defects but presented with atypical presentations. In 2 other patients who were later shown to be affected by biliary atresia and cystic fibrosis the profile of bile acid metabolites was initially suggestive of a bile acid synthesis defect. Three adult patients suffered from cerebrotendinous xanthomatosis. Nineteen patients had peroxisomal disorders, and 10 patients had cholestatic hepatopathy of other cause. CONCLUSION: Screening for urinary cholanoids should be done in every infant with cholestatic hepatopathy as well as in children with progressive neurological disease to provide specific therapy.