Dental and craniofacial features associated with GNAS loss of function mutations.

BACKGROUND: Pseudohypoparathyroidism (PHP, OMIM #103580) is a very rare disease (incidence 0.3-1/100,000). Heterozygous inactivating mutations involving the maternal GNAS exons 1-13 that encodes the alpha subunit of the stimulatory G protein (Gsα) cause inactivating parathyroid hormone (PTH)/PTHrP signalling disorder type 2 (iPPSD2 or PHP type 1A), which is characterized by Albright hereditary osteodystrophy and resistance to multiple hormones that act through the Gsα signalling pathway (including PTH, thyroid-stimulating hormone, and α-melanocyte-stimulating hormone). To date, little information is available on craniofacial features in patients with PHP. The small number of patients studied in previous reports as well as the lack of molecular characterization of the patients may have precluded the detection of specific orofacial manifestations in the different PHP subtypes. MATERIALS/METHODS: We conducted a systematic analysis of dental and craniofacial features in 19 patients with iPPSD2 and maternal GNAS inactivating mutations to assess the frequency and specificity of the anomalies. RESULTS: Facial examinations showed reduced vertical, sagittal, and transverse development of the mid-facial structures. Intraoral and radiographic examinations revealed that 89 per cent of the patients had at least one dental anomaly, including tooth submergence leading to severe infraocclusion in 83 per cent of cases. Craniofacial analysis of lateral cephalometric radiographs also showed a significant alteration in the development of the cranial base and maxillary and mandibular structures in these patients. CONCLUSIONS: Patients with iPPSD2 and maternal GNAS mutations had specific craniofacial alterations and dental abnormalities. These specific defects should be assessed in order to provide appropriate dental and orthodontic care to these patients. (clinical trial registration: 1920371 v 0, French Nationale Data Processing and Liberties Commission - CNIL).

Association between quality of life of adolescents with type 1 diabetes and parents' illness perception as evaluated by adolescents.

Children and adolescents account for half of all cases of type 1 diabetes, which is one of the most common pediatric chronic diseases. The disease's effects and the treatment/disease-management protocols patients must follow can lead to a marked deterioration in quality of life, especially for adolescents. Patients' illness perceptions have been shown to impact their quality of life, but do other people's illness perceptions also have an effect? The present study addressed this question by investigating possible links between the quality of life of adolescent patients with type 1 diabetes and illness perceptions, measured in terms of the adolescents' self-perceptions, parents' self-perceptions, and the adolescents' evaluations of their parents' perceptions. We asked 41 adolescents (M = 13.9 years; SD = 1.9) who had been undergoing treatment for type 1 diabetes for at least a year (M = 6.6 years; SD = 3.7) to complete the Diabetes Quality of Life for Youth Questionnaire-Short Form (DQOLY-SF) and the Illness Perception Questionnaire-Revised (IPQ-R). They completed the IPQ-R twice, once to state their own opinions (self-report) and once to give their evaluations of their parents' perceptions. At the same time, but in a different room, their parents (N = 47) completed the IPQ-R (self-report). Quality of life was predicted by gender (p < .05) and by the parents' emotional representations (p < .01) and perceptions of consequences (p < .01) as evaluated by the adolescents. This new approach provides new insights into the impact of parents' perceptions on the quality of life of adolescents with type 1 diabetes.

[The contribution of social networks using the example of type 1 diabetes]. / Apport des réseaux sociaux à partir de l'exemple du diabète de type 1.

Type 1 diabetes has an impact not only on physical health, but also on social life, family life and psychological balance. Social networks play a decisive role, alongside associations, in helping patients to adopt the "other pace of life" implied by the disease. Beyond health, the skills needed to enable patients to achieve personal fulfillment are beyond the scope of healthcare professionals. Peer communities are an invaluable contribution to building this life with diabetes.

Ovarian Hyperandrogenism and Response to Gonadotropin-releasing Hormone Analogues in Primary Severe Insulin Resistance.

CONTEXT: Insulin resistance (IR) is associated with polycystic ovaries and hyperandrogenism, but underpinning mechanisms are poorly understood and therapeutic options are limited. OBJECTIVE: To characterize hyperandrogenemia and ovarian pathology in primary severe IR (SIR), using IR of defined molecular etiology to interrogate disease mechanism. To extend evaluation of gonadotropin-releasing hormone (GnRH) analogue therapy in SIR. METHODS: Retrospective case note review in 2 SIR national referral centers. Female patients with SIR with documented serum total testosterone (TT) concentration. RESULTS: Among 185 patients with lipodystrophy, 65 with primary insulin signaling disorders, and 29 with idiopathic SIR, serum TT ranged from undetectable to 1562 ng/dL (54.2 nmol/L; median 40.3 ng/dL [1.40 nmol/L]; n = 279) and free testosterone (FT) from undetectable to 18.0 ng/dL (0.625 nmol/L; median 0.705 ng/dL [0.0244 nmol/L]; n = 233). Higher TT but not FT in the insulin signaling subgroup was attributable to higher serum sex hormone-binding globulin (SHBG) concentration. Insulin correlated positively with SHBG in the insulin signaling subgroup, but negatively in lipodystrophy. In 8/9 patients with available ovarian tissue, histology was consistent with polycystic ovary syndrome (PCOS). In 6/6 patients treated with GnRH analogue therapy, gonadotropin suppression improved hyperandrogenic symptoms and reduced serum TT irrespective of SIR etiology. CONCLUSION: SIR causes severe hyperandrogenemia and PCOS-like ovarian changes whether due to proximal insulin signaling or adipose development defects. A distinct relationship between IR and FT between the groups is mediated by SHBG. GnRH analogues are beneficial in a range of SIR subphenotypes.

Presenting features and molecular genetics of primary hyperparathyroidism in the paediatric population.

AIM: To describe the presenting features and molecular genetics of primary hyperparathyroidism (PHPT) in the paediatric population. METHODS: Retrospective study of 63 children diagnosed with primary PHPT from 1998 to 2018. RESULTS: Compared to older children, infants were often asymptomatic (54% vs 15%, P = 0.002) with a milder form of PHPT. When symptomatic, children and adolescents mostly presented with non-specific complaints such as asthenia, depression, weight loss, vomiting or abdominal pain. A genetic cause of PHPT was identified in about half of this cohort (52%). The infancy period was almost exclusively associated with mutation in genes involved in the calcium-sensing receptor (CaSR) signalling pathway (i.e. CaSR and AP2S1 genes, 'CaSR group'; 94% of infants with mutations) whereas childhood and adolescence were associated with mutation in genes involved in parathyroid cell proliferation (i.e. MEN1, CDC73, CDKN1B and RET genes, 'cell proliferation group'; 69% of children and adolescents with mutations). Although serum calcium levels did not differ between the two groups (P = 0.785), serum PTH levels and the urinary calcium/creatinine ratio were significantly higher in 'cell proliferation group' patients compared to those in the 'CaSR group' (P = 0.001 and 0.028, respectively). CONCLUSION: Although far less common than in adults, PHPT can develop in children and is associated with significant morbidity. Consequently, this diagnosis should be considered in children with non-specific complaints and lead to monitoring of mineral homeostasis parameters. A genetic cause of PHPT can be identified in about half of these patients.

High Diagnostic Yield of Targeted Next-Generation Sequencing in a Cohort of Patients With Congenital Hypothyroidism Due to Dyshormonogenesis.

Objective: To elucidate the molecular cause in a well-characterized cohort of patients with Congenital Hypothyroidism (CH) and Dyshormonogenesis (DH) by using targeted next-generation sequencing (TNGS). Study design: We studied 19 well-characterized patients diagnosed with CH and DH by targeted NGS including genes involved in thyroid hormone production. The pathogenicity of novel mutations was assessed based on in silico prediction tool results, functional studies when possible, variant location in important protein domains, and a review of the recent literature. Results: TNGS with variant prioritization and detailed assessment identified likely disease-causing mutations in 10 patients (53%). Monogenic defects most often involved TG, followed by DUOXA2, DUOX2, and NIS and were usually homozygous or compound heterozygous. Our review shows the importance of the detailed phenotypic description of patients and accurate analysis of variants to provide a molecular diagnosis. Conclusions: In a clinically well-characterized cohort, TNGS had a diagnostic yield of 53%, in accordance with previous studies using a similar strategy. TG mutations were the most common genetic defect. TNGS identified gene mutations causing DH, thereby providing a rapid and cost-effective genetic diagnosis in patients with CH due to DH.

Loss of constitutive activity of the growth hormone secretagogue receptor in familial short stature.

The growth hormone (GH) secretagogue receptor (GHSR) was cloned as the target of a family of synthetic molecules endowed with GH release properties. As shown recently through in vitro means, this receptor displays a constitutive activity whose clinical relevance is unknown. Although pharmacological studies have demonstrated that its endogenous ligand--ghrelin--stimulates, through the GHSR, GH secretion and appetite, the physiological importance of the GHSR-dependent pathways remains an open question that gives rise to much controversy. We report the identification of a GHSR missense mutation that segregates with short stature within 2 unrelated families. This mutation, which results in decreased cell-surface expression of the receptor, selectively impairs the constitutive activity of the GHSR, while preserving its ability to respond to ghrelin. This first description, to our knowledge, of a functionally significant GHSR mutation, which unveils the critical importance of the GHSR-associated constitutive activity, discloses an unusual pathogenic mechanism of growth failure in humans.

Should 45,X/46,XY boys with no or mild anomaly of external genitalia be investigated and followed up?

OBJECTIVE: Few studies of patients with a 45,X/46,XY mosaicism have considered those with normal male phenotype. The purpose of this study was to evaluate the clinical outcome of 45,X/46,XY boys born with normal or minor abnormalities of external genitalia, notably in terms of growth and pubertal development. METHODS: Retrospective longitudinal study of 40 patients followed between 1982 and 2017 in France. RESULTS: Twenty patients had a prenatal diagnosis, whereas 20 patients had a postnatal diagnosis, mainly for short stature. Most patients had stunted growth, with abnormal growth spurt during puberty and a mean adult height of 158 ± 7.6 cm, i.e. -2.3 DS with correction for target height. Seventy percent of patients presented Turner-like syndrome features including cardiac (6/23 patients investigated) and renal malformations (3/19 patients investigated). Twenty-two patients had minor abnormalities of external genitalia. One patient developed a testicular embryonic carcinoma, suggesting evidence of partial gonadal dysgenesis. Moreover, puberty occurred spontaneously in 93% of patients but 71% (n = 5) of those evaluated at the end of puberty presented signs of declined Sertoli cell function (low inhibin B levels and increased FSH levels). CONCLUSION: This study emphasizes the need to identify and follow-up 45,X/46,XY patients born with normal male phenotype until adulthood, as they present similar prognosis than those born with severe genital anomalies. Currently, most patients are diagnosed in adulthood with azoospermia, consistent with our observations of decreased testicular function at the end of puberty. Early management of these patients may lead to fertility preservation strategies.

Neuropsychological dysfunction and developmental defects associated with genetic changes in infants with neonatal diabetes mellitus: a prospective cohort study [corrected].

BACKGROUND: Neonatal diabetes mellitus is a rare genetic form of pancreatic ß-cell dysfunction. We compared phenotypic features and clinical outcomes according to genetic subtypes in a cohort of patients diagnosed with neonatal diabetes mellitus before age 1 year, without ß-cell autoimmunity and with normal pancreas morphology. METHODS: We prospectively investigated patients from 20 countries referred to the French Neonatal Diabetes Mellitus Study Group from 1995 to 2010. Patients with hyperglycaemia requiring treatment with insulin before age 1 year were eligible, provided that they had normal pancreatic morphology as assessed by ultrasonography and negative tests for ß-cell autoimmunity. We assessed changes in the 6q24 locus, KATP-channel subunit genes (ABCC8 and KCNJ11), and preproinsulin gene (INS) and investigated associations between genotype and phenotype, with special attention to extra-pancreatic abnormalities. FINDINGS: We tested 174 index patients, of whom 47 (27%) had no detectable genetic defect. Of the remaining 127 index patients, 40 (31%) had 6q24 abnormalities, 43 (34%) had mutations in KCNJ11, 31 (24%) had mutations in ABCC8, and 13 (10%) had mutations in INS. We reported developmental delay with or without epilepsy in 13 index patients (18% of participants with mutations in genes encoding KATP channel subunits). In-depth neuropsychomotor investigations were done at median age 7 years (IQR 1-15) in 27 index patients with mutations in KATP channel subunit genes who did not have developmental delay or epilepsy. Developmental coordination disorder (particularly visual-spatial dyspraxia) or attention deficits were recorded in all index patients who had this testing. Compared with index patients who had mutations in KATP channel subunit genes, those with 6q24 abnormalities had specific features: developmental defects involving the heart, kidneys, or urinary tract (8/36 [22%] vs 2/71 [3%]; p=0·002), intrauterine growth restriction (34/37 [92%] vs 34/70 [48%]; p<0·0001), and early diagnosis (median age 5·0 days, IQR 1·0-14·5 vs 45·5 days, IQR 27·2-95·0; p<0·0001). Remission of neonatal diabetes mellitus occurred in 89 (51%) index patients at a median age of 17 weeks (IQR 9·5-39·0; median follow-up 4·7 years, IQR 1·5-12·8). Recurrence was common, with no difference between the groups who had 6q24 abnormalities versus mutations in KATP channel subunit genes (82% vs 86%; p=0·36). INTERPRETATION: Neonatal diabetes mellitus is often associated with neuropsychological dysfunction and developmental defects that are specific to the underlying genetic abnormality. A multidisciplinary assessment is therefore essential when patients are diagnosed. Features of neuropsychological dysfunction and developmental defects should be tested for in adults with a history of neonatal diabetes mellitus. FUNDING: Agence Nationale de la Recherche-Maladies Rares Research Program Grant, the Transnational European Research Grant on Rare Diseases, the Société Francophone du Diabète-Association Française du Diabète, the Association Française du Diabète, Aide aux Jeunes Diabétiques, a CIFRE grant from the French Government, HRA-Pharma, the French Ministry of Education and Research, and the Société Française de Pédiatrie.

Impaired puberty, fertility, and final stature in 45,X/46,XY mixed gonadal dysgenetic patients raised as boys.

CONTEXT: Gender assignment followed by surgery and hormonal therapy is a difficult decision in the management of 45,X/46,XY patients with abnormal external genitalia at birth considering the paucity of studies evaluating pubertal development and fertility outcome, most notably for patients raised as boys. OBJECTIVE: The purpose of this study was to describe the pubertal course of 20 45,X/46,XY patients born with ambiguous genitalia and raised as boys. METHODS: This is a multicenter retrospective study. RESULTS: Mean age at study was 25.6±2.4 years. Eighty-five percent of the patients presented a 'classical' mixed gonadal dysgenetic phenotype at birth. Puberty was initially spontaneous in all but three boys, although in six other patients, testosterone therapy was subsequently necessary for completion of puberty. Sixty-seven percent of the remaining patients presented signs of declined testicular function at the end of puberty (increased levels of FSH and low levels of testosterone and/or inhibin B). Moreover, an abnormal structure of the Y chromosome, known to alter fertility, was found in 10 out of 16 (63%) patients. Two patients developed testicular cancer. Half of the patients have adult penile length of <80 mm. Mean adult height is 156.9±2 cm, regardless of GH treatment. CONCLUSIONS: In summary, 45,X/46,XY children born with ambiguous genitalia and raised as boys have an altered pubertal course and impaired fertility associated with adult short stature, which should, therefore, be taken into consideration for the management of these patients.

Markers of recurrence and long-term morbidity in craniopharyngioma: a systematic analysis of 171 patients.

CONTEXT: Craniopharyngiomas are often associated with an unfavorable prognosis, but data on their long-term consequences are sparse. OBJECTIVE: The aim of the study was to identify markers of recurrence and factors associated with compromised social rehabilitation and altered quality of life in a large cohort of patients with either childhood-onset (CO) or adult-onset craniopharyngioma. METHODS: Retrospective analysis was performed for 171 patients treated for craniopharyngioma in two academic centers in France between 1972 and 2009. For each subject, data were collected concerning clinical presentation, imaging features, visual sequelae, endocrine and metabolic impact, treatment modalities (surgery, radiotherapy), recurrence-free survival rate, and social insertion, as well as answers to the WHO-QOL BREF questionnaire. RESULTS: A total of 65 CO and 106 adult-onset patients were reviewed. If CO was diagnosed before the age of 10 yr, this was associated with a higher incidence of obesity, blindness, and panhypopituitarism, and only 40.7% of subjects had adequate work or school attendance compared to 72.4% of patients with later disease onset. Initial symptoms of intracranial hypertension (SIHT), pterional surgery, and multiple surgery were associated with obesity and poorer social insertion. No determinant of quality of life was identified. In the subgroup of patients treated in the 1990s and later, the progression rate was 59.4% in patients with residual tumor on magnetic resonance imaging compared with a 19.8% recurrence rate in the group with apparently complete resection. Recurrence/progression correlates significantly with male gender, early onset (before 10 yr), and SIHT, but only SIHT at presentation remained a significant predictor with multivariate analysis. CONCLUSIONS: Craniopharyngioma continues to be associated with severe outcomes. Higher morbidity rates are found in patients with early-onset disease (before 10 yr), initial SIHT, or in whom pterional surgery was required. Markers of recurrence are difficult to identify, with SIHT being the most powerful predictor.

Phenotypical, biological, and molecular heterogeneity of 5α-reductase deficiency: an extensive international experience of 55 patients.

CONTEXT: In 46,XY disorders of sex development, 5α-reductase deficiency is rare and is not usually the first-intention diagnosis in newborn ambiguous genitalia, contrary to partial androgen insensitivity syndrome. Yet the cause of ambiguous genitalia may guide sex assignment, and rapid, precise diagnosis of 5α-reductase deficiency is essential. OBJECTIVE: The aim of the study was to describe relevant data for clinical diagnosis, biological investigation, and molecular determination from 55 patients with srd5A2 mutations identified in our laboratory over 20 yr to improve early diagnosis. SETTING: The study was performed at Montpellier University Hospital. PATIENTS: We studied a cohort of 55 patients with srd5A2 gene mutations. MAIN OUTCOME MEASURE(S): Genetic analysis of srd5A2 was conducted. RESULTS: Clitoromegaly (49.1%) and microphallus with various degrees of hypospadias (32.7%) were frequent phenotypes. Female external genitalia (7.3%) and isolated micropenis (3.6%) were rare. Seventy-two percent of patients were initially assigned to female gender; five of them (12.5%) switched to male sex in peripuberty. Over 72% of patients were considered for 5α-reductase deficiency diagnosis when the testosterone/dihydrotestosterone cutoff was 10. In 55 patients (with 20 having a history of consanguinity), we identified 33 different mutations. Five have never been reported: p.G32S, p.Y91H, p.G104E, p.F223S, and c.461delT. Homozygous mutations were present in 69.1% of cases, compound heterozygous mutations in 25.5%, and compound heterozygous mutations alone with the V89L polymorphism in 5.4%. Exons 1 and 4 were most affected, with 35.8 and 21.7% mutant alleles per exon, respectively. CONCLUSIONS: In the largest cohort to date, we demonstrate a wide spectrum of phenotypes and biological profiles in patients with 5α-reductase deficiency, whatever their geographical or ethnic origins.

Resistance to leptin-replacement therapy in Berardinelli-Seip congenital lipodystrophy: an immunological origin.

CONTEXT: Recently, in a 4-month proof-of-concept trial, beneficial metabolic effects were reported in non-diabetic children with Berardinelli-Seip congenital lipodystrophy (BSCL); this information prompted us to hypothesize that long-term leptin-replacement therapy might improve or reverse the early complications of the disease in these patients. PATIENTS AND METHODS: A 28-month trial was implemented in eight patients. Efficacy assessment was based on a decrease in serum triglyceride concentrations, and/or a decrease in liver volume and/or an increase in insulin sensitivity of at least 30% respectively. The response was defined as follows: total (3/3 positive criteria), partial (1 or 2/3), or negative (0/3). Anti-leptin antibodies were measured with a radiobinding assay, and a neutralizing effect was assessed in primary cultures of embryonic neurons incubated with an apoptotic agent (N-methyl-D-aspartate) and the patient serum, with or without leptin. RESULTS: A negative or partial response to treatment was observed in five of eight patients even when leptin dosages were increased. A displaceable leptin binding was detectable in all patients after 2 months of treatment. At 28 months, binding was higher in the patients with a negative response than in the total responders, and it paralleled both the increase in leptin dosage and serum leptin concentrations. Co-incubation of embryonic neurons with serum from two patients with a negative response inhibited the neuroprotective effect of leptin. CONCLUSION: Under leptin therapy, patients with BSCL may develop a resistance to leptin, which could be partly of immunological origin, blunting the previously reported beneficial effects.

Heterozygous missense mutations in the insulin gene are linked to permanent diabetes appearing in the neonatal period or in early infancy: a report from the French ND (Neonatal Diabetes) Study Group.

OBJECTIVE: Permanent neonatal diabetes (PND) is defined by chronic hyperglycemia due to severe nonautoimmune insulin deficiency diagnosed in the first months of life. Several genes, including KCNJ11 and ABCC8, which encode the two subunits of the ATP-sensitive K(+) channel (K(ATP) channel) can cause PND. Mutations in the insulin (INS) gene have been recently described in families with neonatal diabetes. Our study aimed to investigate the genetic anomalies and clinical heterogeneity in PND patients who are negative for a K(ATP) channel mutation. RESEARCH DESIGN AND METHODS: We screened the INS gene by direct sequencing in 38 PND patients and in one child with nonautoimmune early-infancy diabetes, where no mutation in GCK, KCNJ11, and ABCC8 was identified. A detailed clinical phenotyping of the patients was carried out to specify the diabetes features in those found with an INS mutation. RESULTS: We identified three missense mutations in the INS gene in four probands. Two of four mutations were inherited in a dominant manner, and the familial description evidenced a marked variability in age of diagnosis and disease progression. In our cohort, the INS mutations may represent approximately 10% of all permanent neonatal diabetes cases, having a later presentation of diabetes and no associated symptoms compared with cases with K(ATP) channel mutations. CONCLUSIONS; Heterozygous INS gene mutations can cause isolated permanent early-infancy diabetes and should be assessed in neonatal as well as in childhood diabetes appearing like type 1, when autoimmune markers are absent. New pharmacogenomic strategies may be applicable, since residual beta-cell function is still present in some patients.

Metabolic correction induced by leptin replacement treatment in young children with Berardinelli-Seip congenital lipoatrophy.

OBJECTIVE: Berardinelli-Seip syndrome is a rare congenital lipoatrophy with a severe prognosis and no efficient therapy. Children present with low leptin levels and severe metabolic complications (insulin resistance, elevated triglyceride levels, and hepatic steatosis). The objective of this study was to test safety and efficacy of recombinant-methionyl-human leptin replacement in children with Berardinelli-Seip syndrome before development of severe metabolic disease METHODS: As part of an open trial, recombinant-methionyl-human leptin was given daily for 4 months to children who did not have diabetes and had Berardinelli-Seip congenital lipoatrophy and metabolic complications at a dosage that was meant to achieve physiologic levels. Six boys and 1 girl (age: 2.4-13.6 years), with a mean fasting insulin level of >15 mIU/L and hypertriglyceridemia, were included. RESULTS: At the end of the recombinant-methionyl-human leptin treatment, a 63% reduction of fasting triglycerides level was achieved. A simultaneous 30% increase in insulin sensitivity was seen, and liver volume was reduced by 20.3%. More remarkable, values of insulin sensitivity and triglyceride level were in the reference range in 4 patients. CONCLUSIONS: Leptin replacement is able to reverse metabolic complications in the majority of children with Berardinelli-Seip congenital lipoatrophy and with insulin resistance or dyslipidemia before the development of overt diabetes.

Normal physical working capacity in prepubertal children with type 1 diabetes compared with healthy controls.

BACKGROUND: Exercise testing has become a valuable help for the physician to examine the influence of recommended exercise training on physical fitness. However, the question as to how diabetic prepubertal children differ from their non-diabetic peers in their performance capacity has only partial and sometimes conflicting answers in the literature. AIM AND METHODS: The aim of the current study was thus to evaluate aerobic fitness during an incremental submaximal test (measure of the Physical Working Capacity 170 (PWC170)) in 17 well-controlled prepubertal insulin-dependent diabetic boys aged 8.5-13 y. Eighteen healthy prepubertal boys matched for age, body size and physical activity served as controls. Part of the method was to check capillary blood glucose level in the diabetic patients and in nine of the healthy subjects throughout the exercise. RESULTS: From this experiment it appeared that the level of physical fitness was similar in diabetic and healthy boys (PWC170 2.28+/-0.09 vs 2.37+/-0.13 W x kg(-1)). While glucose homeostasis was well maintained in the healthy group, diabetic children showed a marked fall in blood glucose during the exercise. In addition, the PWC170 level correlated significantly with the estimate of energy expenditure attributed to vigorous activities in the diabetic boys. CONCLUSION: By studying the responses to incremental exercise there is growing evidence that normal physical fitness is preserved in diabetic prepubertal boys given appropriate involvement in physical activity.