Altered Serum Amino Acid and Acylcarnitine Profiles in Hyperinsulinemic Hypoglycemia and Ketotic Hypoglycemia.

Background: In addition to inborn metabolic disorders, altered metabolic profiles were reported to be associated with the risk and prognosis of some non-metabolic diseases, while as a rare metabolic disease, the overall secondary metabolic spectrum in congenital hyperinsulinemic hypoglycemia (HH) is largely undetermined. Therefore, we investigated metabolic profiles in HH patients and used ketotic hypoglycemia (KH) patients as a control cohort to unveil their distinct metabolic features. Methods: A total of 97 hypoglycemia children, including 74 with hyperinsulinemic hypoglycemia and 23 with ketotic hypoglycemia, and 170 euglycemia control subjects were studied retrospectively. Clinical and biochemical data were collected. The normoglycemic spectra of amino acids and acylcarnitines were determined by liquid chromatography tandem mass spectrometry. The serum insulin and fatty acid concentrations during standardized fasting tests in hypoglycemia patients were also collected. Receiver operating characteristic curve analysis was performed to screen potential biomarkers. Results: Among the normoglycemic spectra of amino acids, blood valine (p < 0.001), arginine (p < 0.001), threonine (p = 0.001), glutamate (p = 0.002), methionine (p = 0.005), ornithine (p = 0.008), leucine (p = 0.014), alanine (p = 0.017), proline (p = 0.031), citrulline (p = 0.042), aspartate (p = 0.046), and glycine (p = 0.048) levels differed significantly among the three groups. Significantly decreased levels of long- (C14:1, p < 0.001; C18, p < 0.001), medium- (C8, p < 0.001; C10, p < 0.001; C10:1, p < 0.001), and short-chain (C4-OH, p < 0.001; C5OH, p < 0.001) acylcarnitines were found in the hyperinsulinemic hypoglycemia group. Hyperinsulinemic hypoglycemia children with focal lesions and diffuse lesions had similar amino acid and acylcarnitine spectra. C10:1 < 0.09 µmol/L, threonine > 35 µmol/L, and threonine/C10:1 > 440 showed sensitivities of 81.1, 66.2, and 81.1% and specificities of 72.7, 78.3, and 81.8%, respectively, in distinguishing HH from KH. Conclusions: We found significantly different altered serum amino acid and acylcarnitine profiles at normoglycemia, especially decreased C10:1 and increased threonine levels, between HH and KH children, which may reflect the insulin ketogenesis inhibition effect in HH patients; however, the detailed mechanisms and physiological roles remain to be studied in the future.

Clinical characteristics and beta-cell function of Chinese children and adolescents with type 2 diabetes from 2009 to 2018.

BACKGROUND: The limited available studies have unveiled different natural histories and prognosis associated with pediatric type 2 diabetes (T2D) and adult T2D. To date, data on the clinical features, metabolic profiles and beta-cell function characteristics are still limited in the Chinese pediatric T2D population. METHODS: A total of 56 children with T2D, 31 with prediabetes and 159 with obesity were recruited. Clinical characteristics, metabolic profiles, beta-cell function and insulin resistance were analyzed. RESULTS: The mean onset age of T2D was 12.35 ± 1.99 (7.9-17.8) years, and 7% of children were younger than 10 years; 55% of them were male, 57% had a family history of diabetes and 64% had classic symptoms, and 25% had a low or high birth weight. 89% of T2D patients were obese or overweight. A total of 58% of the patients with prediabetes were male. The fast serum C-peptide level was highest in the obesity group (P < 0.001), and there was no significant difference between the T2D and prediabetes groups. The mean homeostatic model of assessment of beta-cell function was the highest in the obesity group and was lowest in the T2D group (P < 0.001). The T2D group had the most serious lipid metabolism disorder, with the highest levels of total triglycerides, total cholesterol, and low density lipoprotein and the lowest high density lipoprotein level among the three groups. CONCLUSIONS: A younger onset age and greater male susceptibility were found in Chinese pediatric T2D patients, and there was a stepwise deterioration trend in beta-cell function among patients with obesity, prediabetes and T2D. Based on our results, together with the SEARCH study results, an early screening and intervention program for T2D is recommended in high-risk or obese Chinese pediatric populations starting at 7 years.

Uncovering the molecular pathogenesis of congenital hyperinsulinism by panel gene sequencing in 32 Chinese patients.

Congenital hyperinsulinism (CHI) has been mostly associated with mutations in seven major genes. We retrospectively reviewed a cohort of 32 patients with CHI. Extensive mutational analysis (ABCC8,KCNJ11,GCK,GLUD1,HADH,HNF4A, and UCP2) was performed on Ion torrent platform, which could analyze hundreds of genes simultaneously with ultrahigh-multiplex PCR using up to 6144 primer pairs in a single primer pool and address time-sensitive samples with single-day assays, from samples to annotated variants, to identify the genetic etiology of this disease. Thirty-seven sequence changes were identified, including in ABCC8/KCNJ11 (n = 25, 65.7%), GCK (n = 2), HNF4A (n = 3), GLUD1 (n = 2), HADH (n = 4), and UCP2 (n = 1); these mutations included 14 disease-causing mutations, eight rare SNPs, 14 common SNPs, and one novel mutation. Mutations were identified in 21 of 32 patients (65.6%). Among the patients with an identified mutation, 14 had mutations in ABCC8, one of which was combined with a GLUD1 mutation. Four patients had mutations in KCNJ11, 1 had a GCK mutation, 1 had a mutation in HADH, and two had a mutation in HNF4A. Among the 32 patients, the age at the onset of hyperinsulinemia ranged from the neonatal period to 1 year of age; five patients underwent a pancreatectomy due to intractable hyperinsulinemia. This study describes novel and previously identified mutations in patients with CHI. The spectrum of mutations in CHI patients represents an important tool for the diagnosis and prognosis of CHI patients in the Chinese population as well as for the genetic counseling of CHI families.