Sex hormone levels are not associated with progression of renal disease in male patients with T2DM.

BACKGROUND: Greater renal function decline (RFD) in type 2 diabetes (T2DM) has been suggested in men compared with women, and imbalances in estrogen/androgen levels have been associated with cardiovascular disease mortality in elderly men, but it remains unclear whether sex hormone disequilibrium is related to diabetic nephropathy (DN) in men with T2DM. OBJECTIVE: This study examined the relationship between sex steroid concentrations and renal outcomes in male T2DM patients. POPULATION AND METHODS: Total testosterone (T), total estradiol (E2), sex hormone-binding globulin (SHBG), and total and calculated free (cf) E2/T ratios were compared in 735 male T2DM patients with (n=513) and without (n=222) DN, using a cross-sectional approach. Also, in a pilot complementary prospective nested case-control cohort, total E2/total T and cfE2/cfT were evaluated according to a hard renal outcome (HRO): end-stage renal disease/doubling of baseline serum creatinine (36 HRO cases, 72 HRO controls) and rate of eGFR decline (68 rapid vs 68 slow RFD). RESULT: With the cross-sectional approach, E2 and cfE2 were higher in DN cases vs DN controls (95.5 vs 86.8pmol/L [P=0.0246] and 2.59 vs 2.36pmol/L [P=0.005], respectively). The difference in E2 persisted on multivariate analysis. In the prospective approach, E2 and T concentrations, and total E2/total T and cfE2/cfT2 ratios did not differ in HRO cases vs controls or in patients with rapid vs slow RFD. CONCLUSION: Although positively related to DN in the cross-sectional analysis, progression of renal disease in male patients with T2DM was not related to either sex hormone levels or aromatase index as reflected by E2/T ratio.

Genetic analysis of GHR should contain sequencing of all coding exons and specific intron sequences, and screening for exon deletions.

BACKGROUND: The work-up of patients with clinical and/or biochemical features of growth hormone insensitivity (GHI) usually contains genetic analysis of the growth hormone receptor (GHR) gene, and if negative, of STAT5B, IGFALS and IGF1. In a previous report we described 2 siblings presenting with short stature, low IGF-1 levels, elevated GH secretion and no increase of IGF-1 after 1 week of GH administration. Repeated analysis of the GHR showed no abnormalities; however, further testing revealed a heterozygous STAT5B defect in both siblings. SUBJECTS AND METHODS: Two boys of Surinam-Hindustan origin showed growth failure up to the age of 6-7 years, followed by partial catch-up growth associated with increasing body mass index. Reanalysis of GHR including published intronic sequences was performed on the patients' DNA collected 7 years earlier. RESULTS: The heterozygous STAT5B variant proved to be functionally benign. A homozygous intronic mutation of the GHR, c.618+792A>G (IVS6+792A>G), was subsequently found, resulting in the activation of pseudoexon 6ψ, and explaining the GHI phenotype of the patients. CONCLUSION: An intronic GHR mutation should be considered in all patients with signs of GHI and no coding exon mutations, even if the phenotype is mild and even if other genetic variants have been found.

Genetic analysis of short children with apparent growth hormone insensitivity.

BACKGROUND/AIMS: In short children, a low IGF-I and normal GH secretion may be associated with various monogenic causes, but their prevalence is unknown. We aimed at testing GH1, GHR, STAT5B, IGF1, and IGFALS in children with GH insensitivity. SUBJECTS AND METHODS: Patients were divided into three groups: group 1 (height SDS <-2.5, IGF-I <-2 SDS, n = 9), group 2 (height SDS -2.5 to -1.9, IGF-I <-2 SDS, n = 6) and group 3 (height SDS <-1.9, IGF-I -2 to 0 SDS, n = 21). An IGF-I generation test was performed in 11 patients. Genomic DNA was used for direct sequencing, multiplex ligation-dependent probe amplification and whole-genome SNP array analysis. RESULTS: Three patients in group 1 had two novel heterozygous STAT5B mutations, in two combined with novel IGFALS variants. In groups 2 and 3 the association between genetic variants and short stature was uncertain. The IGF-I generation test was not predictive for the growth response to GH treatment. CONCLUSION: In severely short children with IGF-I deficiency, genetic assessment is advised. Heterozygous STAT5B mutations, with or without heterozygous IGFALS defects, may be associated with GH insensitivity. In children with less severe short stature or IGF-I deficiency, functional variants are rare.

Endocrine disorders in children with Prader-Willi syndrome--data from 142 children of the French database.

AIM: The first results from the French National Prader-Willi pediatric database in a cohort of 142 children aged 0.2-18.8 years are reported. This database gathers information about the endocrine dysfunctions traditionally described in Prader-Willi patients. METHODS: Questionnaires were filled in by the patients' practitioners. The coordination team of the reference center performed the statistical analysis. RESULTS: Median BMI Z-score was +1.3 for a median age of 7.1 years, and 40% of the population were overweight or obese (International Obesity Task Force 2000 criteria). Growth hormone deficiency was present in 80% of patients and 86.7% were treated, with a height gain of +1 SD and a BMI reduction of -0.8 Z-score achieved in the first year of treatment. Hypogonadism was present in 49% of patients, and hypothyroidism in 24.4%. Glucose intolerance was found in 4% of patients, but no diabetes mellitus was detected in the 74 patients explored. CONCLUSION: Our report gives an overview of endocrine dysfunctions recorded in a large registry database of French children and adolescents with Prader-Willi syndrome. The database, which now encompasses six southern regions of France, will be further extended to the whole country and to adult patients.

Aetiological heterogeneity of asymptomatic hyperglycaemia in children and adolescents.

INTRODUCTION: Randomly estimated fasting hyperglycaemia in an asymptomatic individual may represent the first sign of pancreatic beta-cell dysfunction. OBJECTIVE: We aimed at specifying the genetic aetiology of asymptomatic hyperglycaemia in a cohort of children and adolescents. SUBJECTS AND METHODS: We analysed the aetiological diagnosis in 82 non-obese paediatric subjects (38 males) aged 0.2-18.5 years (median: 13.1) who were referred for elucidation of a randomly found blood glucose level above 5.5 mmol/l. In addition to fasting glycaemia and circulating levels of insulin and C-peptide, the subjects were tested by an oral glucose tolerance test and an intravenous glucose tolerance test and screened for mutations in the genes encoding glucokinase (GCK), HNF-1alpha (TCF1), Kir6.2 (KCNJ11) (if aged <2 years) and HNF-4alpha (HNF4A) (those with a positive family history of diabetes). RESULTS AND DISCUSSION: We identified 35 carriers of GCK mutations causing MODY2, two carriers of TCF1 mutations causing MODY3, one carrier of a HNF4A mutation causing MODY1 and one carrier of a KCNJ11 mutation causing permanent neonatal diabetes mellitus. Of the remaining patients, 11 progressed to type 1 diabetes mellitus (T1DM) and 9 had impaired glucose tolerance or diabetes mellitus of unknown origin. In 23 subjects, an impairment of blood glucose levels was not confirmed. We conclude that 39 of 82 paediatric patients (48%) with randomly found fasting hyperglycaemia suffered from single gene defect conditions, MODY2 being the most prevalent. An additional 11 patients (13%) progressed to overt T1DM. The aetiological diagnosis in asymptomatic hyperglycaemic children and adolescents is a clue to introducing an early and effective therapy or, in MODY2, to preventing any future extensive re-investigations.