Kathleen Laborde

Long-Term Outcome of Patients with Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency

Aims: Conflicting results exist regarding bone mineral density (BMD), metabolism and reproductive function of adult patients with congenital adrenal hyperplasia (CAH). We evaluated the long-term outcome and the impact of chronic glucocorticoid replacement in these patients. Methods: Physical characteristics, serum hormone concentrations, BMD and metabolism were studied in 45 consecutive CAH adult patients. Results: Among the 36 women, only 14 (39%) had regular menses. Among the 27 women with classical CAH, the mean number of surgical reconstructions of virilized genitalia was 2.1 ± 0.2. Twenty of them (74%) were sexually active. Three men presented with testicular adrenal rest tumors. Twenty-five patients (55%) had decreased BMD at the femoral neck and/or at the lumbar spine. BMI was correlated with the BMD T-score at the femoral neck (p < 0.001) and at the lumbar spine (p < 0.01). Hydrocortisone dose was negatively correlated with the BMD T-score at the femoral neck (p = 0.04). Subjects with osteopenia had a significantly lower BMI and received higher hydrocortisone dose than those with normal BMD. Overweight was found in 21 patients (47%). There was a significantly positive correlation between HOMA and BMI (p < 0.001), and between HOMA and 17-OHP levels (p = 0.016). Conclusions: Adult patients with CAH treated with long-term glucocorticoids are at risk for decreased BMD, increased BMI, and disturbed reproductive function.

Glucose Metabolism in 105 Children and Adolescents After Pancreatectomy for Congenital Hyperinsulinism

OBJECTIVE To describe the long-term metabolic outcome of children with congenital hyperinsulinism after near-total or partial elective pancreatectomy. RESEARCH DESIGN AND METHODS Patients (n = 105: 58 diffuse and 47 focal congenital hyperinsulinism) received operations between 1984 and 2006. Follow-up consisted of periodic measurements of pre- and postprandial plasma glucose over 24 h, OGTT, and IVGTT. Cumulative incidence of hypo- or hyperglycemia/insulin treatment was estimated by Kaplan-Meier analysis. RESULTS After near-total pancreatectomy, 59% of children with diffuse congenital hyperinsulinism still presented mild or asymptomatic hypoglycemia that responded to medical treatments and disappeared within 5 years. One-third of the patients had both preprandial hypoglycemia and postprandial hyperglycemia. Hyperglycemia was found in 53% of the patients immediately after surgery; its incidence increased regularly to 100% at 13 years. The cumulative incidence of insulin-treated patients was 42% at 8 years and reached 91% at 14 years, but the progression to insulin dependence was very variable among the patients. Plasma insulin responses to IVGTT and OGTT correlated well with glycemic alterations. In focal congenital hyperinsulinism, hypoglycemia or hyperglycemia were rare, mild, and transient. CONCLUSIONS Patients with focal congenital hyperinsulinism are cured of hypoglycemia after limited surgery, while the outcome of diffuse congenital hyperinsulinism is very variable after near-total pancreatectomy. The incidence of insulin-dependent diabetes is very high in early adolescence.

Association of Prenatal and Postnatal Exposure to Lopinavir-Ritonavir and Adrenal Dysfunction Among Uninfected Infants of HIV-Infected Mothers

CONTEXT Lopinavir-ritonavir is a human immunodeficiency virus 1 (HIV-1) protease inhibitor boosted by ritonavir, a cytochrome p450 inhibitor. A warning about its tolerance in premature newborns was recently released, and transient elevation of 17-hydroxyprogesterone (17OHP) was noted in 2 newborns treated with lopinavir-ritonavir in France. OBJECTIVE To evaluate adrenal function in newborns postnatally treated with lopinavir-ritonavir. DESIGN, SETTING, AND PARTICIPANTS Retrospective cross-sectional analysis of the database from the national screening for congenital adrenal hyperplasia (CAH) and the French Perinatal Cohort. Comparison of HIV-1-uninfected newborns postnatally treated with lopinavir-ritonavir and controls treated with standard zidovudine. MAIN OUTCOME MEASURES Plasma 17OHP and dehydroepiandrosterone-sulfate (DHEA-S) concentrations during the first week of treatment. Clinical and biological symptoms compatible with adrenal deficiency. RESULTS Of 50 HIV-1-uninfected newborns who received lopinavir-ritonavir at birth for a median of 30 days (interquartile range [IQR], 25-33), 7 (14%) had elevated 17OHP levels greater than 16.5 ng/mL for term infants (>23.1 ng/mL for preterm) on days 1 to 6 vs 0 of 108 controls having elevated levels. The median 17OHP concentration for 42 term newborns treated with lopinavir-ritonavir was 9.9 ng/mL (IQR, 3.9-14.1 ng/mL) vs 3.7 ng/mL (IQR, 2.6-5.3 ng/mL) for 93 term controls (P < .001). The difference observed in median 17OHP values between treated newborns and controls was higher in children also exposed in utero (11.5 ng/mL vs 3.7 ng/mL; P < .001) than not exposed in utero (6.9 ng/mL vs 3.3 ng/mL; P = .03). The median DHEA-S concentration among 18 term newborns treated with lopinavir-ritonavir was 9242 ng/mL (IQR, 1347-25,986 ng/mL) compared with 484 ng/mL (IQR, 218-1308 ng/mL) among 17 term controls (P < .001). The 17OHP and DHEA-S concentrations were positively correlated (r = 0.53; P = .001). All term newborns treated with lopinavir-ritonavir were asymptomatic, although 3 premature newborns experienced life-threatening symptoms compatible with adrenal insufficiency, including hyponatremia and hyperkalemia with, in 1 case, cardiogenic shock. All symptoms resolved following completion of the lopinavir-ritonavir treatment. CONCLUSION Among newborn children of HIV-1-infected mothers exposed in utero to lopinavir-ritonavir, postnatal treatment with a lopinavir-ritonavir-based regimen, compared with a zidovudine-based regimen, was associated with transient adrenal dysfunction.

Nephrogenesis and angiotensin II receptor subtypes gene expression in the fetal lamb

To investigate the role of angiotensin II (ANG II) in nephrogenesis, a developmental study of renal AT1 and AT2 receptor mRNA expression was performed in parallel with the quantitative and qualitative analysis of metanephros development in fetal lamb from 60 to 140 days of gestation. Both ANG II receptor subtypes were expressed early during nephrogenesis but displayed specific spatial and temporal distribution during gestation. High-AT2 mRNA expression took place in the outermost nephrogenic area and in the undifferentiated mesenchymal cells surrounding the ampulla; level of AT2 expression in this localization followed closely glomeruli proliferation rate and disappeared after nephrogenesis completion (>120 days). AT2 mRNA was also detected in the differentiated epithelial cells of macula densa of maturing glomeruli. Although most of AT1 mRNA labeling was found in the mesangial cells of maturing glomeruli, where it persisted after nephrogenesis completion, additional labeling was found in undifferentiated cells, in cells invading the inferior cleft of S-shaped bodies (80 days), and in medullar cells between tubules (120 days). Our results suggest that each receptor subtype has a specific role in renal morphogenesis, i.e., AT2 in mesenchymal proliferation or apoptosis and AT1 in vascular smooth muscle cells differentiation.

High prevalence of hirsutism and menstrual disorders in obese adolescent girls and adolescent girls with type 1 diabetes mellitus despite different hormonal profiles

OBJECTIVES To compare the pubertal development, the hormonal profiles and the prevalence of hirsutism and menstrual disorders in obese adolescent girls and adolescent girls with type 1 diabetes mellitus (T1DM). METHODS Data were collected from 96 obese adolescent girls and 78 adolescent girls with T1DM at Tanner stage IV or V, whose ages ranged between 11.9 and 17.9 years. RESULTS High prevalence of hirsutism and menstrual disorder was found in the obese adolescent girls (36.5 and 42% respectively) and the adolescent girls with T1DM (21 and 44% respectively). The obese girls were significantly younger at pubarche, thelarche and menarche than the girls with T1DM. Hirsutism in the obese girls and those with T1DM was associated with hyperandrogenaemia and a raised free androgen index (FAI). When the cause of the raised FAI was investigated in both the groups of girls with hirsutism, the raised FAI in the obese girls was due to low serum sex hormone-binding globulin (SHBG) levels. In contrast, the raised FAI of the girls with T1DM and hirsutism was due to hyperandrogenaemia. Menstrual disorders in the T1DM girls were associated also with hyperandrogenaemia unlike obese girls. CONCLUSIONS Hirsutism and menstrual disorders are common in obese adolescent girls and adolescent girls with T1DM. Although hyperandrogenaemia is present in both groups of girls, the androgenic profiles of the two groups differ. The hyperandrogenaemia in the obese girls is primarily due to their decreased serum SHBG levels, whereas the hyperandrogenaemia in the girls with T1DM is due to their increased androgen production.

Protein kinase C activation causes inhibition of Na/K-ATPase activity in Madin-Darby canine kidney epithelial (MDCK) cells

To evaluate the influence of protein kinase C (PKC) activation on Na/K-ATPase activity in MDCK cells, we studied the effect of phorbol myristate acetate (PMA) and two diacylglycerol analogues, oleoylacetylglycerol and dioctanoylglycerol, on the enzyme activity. Na/K-ATPase activity was determined by cytochemistry. PMA induced a time- and dose-dependent inhibition of Na/K-ATPase activity and at 100 ng/ml decreased the enzyme activity by 55% of the initial value. These effects were mimicked by oleoylacetylglycerol and dioctanoylglycerol, and were abolished by two inhibitors of PKC, 1-(5-isoquinolinylsulphonyl)-2-methylpiperazine (H7) and sphingosine. A phorbol ester that does not activate PKC, 4α-phorbol 12, 13-didecanoate, did not inhibit Na/ K-ATPase activity. PMA inhibition persisted in the presence of cycloheximide and actinomycin D but not in the presence of amiloride. Dopamine (10 μM) inhibition of Na/K-ATPase activity was abolished in a dose-dependent manner by sphingosine. Results suggest that in MDCK cells Na/K-ATPase is an effector protein for PKC and that dopamine inhibition of its activity may be mediated by PKC.

Prevalence of Pituitary Dysfunction After Severe Traumatic Brain Injury in Children and Adolescents: A Large Prospective Study

CONTEXT Traumatic brain injury (TBI) in childhood is a major public health issue. OBJECTIVE We sought to determine the prevalence of pituitary dysfunction in children and adolescents after severe TBI and to identify any potential predictive factors. DESIGN This was a prospective longitudinal study. SETTING The study was conducted at a university hospital. PATIENTS Patients, hospitalized for severe accidental or inflicted TBI, were included. The endocrine assessment was performed between 6 and 18 months after the injury. MAIN OUTCOME MEASURES Basal and dynamic tests of pituitary function were performed in all patients and GH dynamic testing was repeated in patients with low stimulated GH peak (<7 ng/mL). The diagnosis of proven severe GH deficiency (GHD) was based on the association of two GH peaks less than 5 ng/mL on both occasions of testing and IGF-I levels below -2 SD score. Initial cranial tomography or magnetic resonance imaging was analyzed retrospectively. RESULTS We studied 87 children and adolescents [60 males, median age 6.7 y (range 0.8-15.2)] 9.5 ± 3.4 months after the TBI (73 accidental, 14 inflicted). The second GH peak, assessed 4.9 ± 0.1 months after the first evaluation, remained low in 27 children and adolescents. Fifteen patients had a GH peak less than 5 ng/mL (mean IGF-I SD score -1.3 ± 1.5) and five (5.7%) strict criteria for severe GHD. Two children had mild central hypothyroidism and one had ACTH deficiency. We did not find any predictive factors associated with existence of GHD (demographic characteristics, growth velocity, trauma severity, and radiological parameters). CONCLUSION At 1 year after the severe TBI, pituitary dysfunction was found in 8% of our study sample. We recommend systematic hormonal assessment in children and adolescents 12 months after a severe TBI and prolonged clinical endocrine follow-up.

Mechanisms of dopamine effects on Na-K-ATPase activity in Madin-Darby canine kidney (MDCK) epithelial cells.

Dopamine decreases tubular sodium reabsorption, attributed in part to Na-K-ATPase inhibition in the proximal convoluted tubule (PCT). Because the final regulation of sodium excretion occurs in the collecting duct, where specific dopamine DA1 binding sites have been demonstrated, we examined the effects of dopamine, as well as of DA1 and DA2 receptor agonists on Na-K-ATPase activity and on the number of units in Madin-Darby canine kidney (MDCK) cells, which retain differentiated properties of the renal cortical collecting tubule epithelium. Dopamine (10−5 M) inhibited pump activity (by 50%) and reduced the number of units. This effect was reproduced by the DA1 agonist SKF 38393, which inhibited pump activity in a dose- and time-dependent manner (maximum, 10−5 M). The DA2 agonist quinpirole hydrochloride was without effect, either alone or in combination with SKF 38393. Inhibition of pump activity by dopamine was totally abolished by H7 (100 μM), an inhibitor of protein kinase (PK), but partially by 2′, 5′-dideoxyadenosine (DDA) and H4, respective inhibitors of cAMP production and PKA, which suggests that the dopamine effect on Na-K-ATPase activity may be linked to activation of both PKC and PKA. In these cells, amiloride addition during preincubation did not alter the effect of dopamine on Na-K-ATPase activity; in contrast, furosemide increased further the inhibitory effect of dopamine on the enzyme activity. Monensin addition (10−3 M) reversed the inhibitory effect of dopamine after a 30-min preincubation. These results indicate that dopamine inhibits Na-K-ATPase activity in MDCK cells and that this inhibition is mediated by activation of the DA1 receptor, they also suggest that PKC and PKA activation inhibits apical sodium entry.

Effects of prolactin on Na-K-ATPase activity along the rat nephron.

To test prolactin (PRL) action on osmoregulation in mammals, we evaluated in the rat the effect of this hormone on a major enzyme in renal regulation of water and electrolyte: renal Na−K-ATPase. Enzyme activity was determined by cytochemistry in medullary ascending limb (MAL) and distal convoluted tubule (DCT) from rats treated either by bromocriptine, or by PRL. Three hours after a bromocriptine injection (0.1 mg/100 g IP) a significant decrease of Na−K-ATPase activity is observed in both MAL (80% of control values,p<0.001) and DCT (78%,p<0.01). Reciprocally, a significant (p<0.001) increase in enzyme activity is induced 3 h after a single PRL injection (140 μg/100 g IM), in both segments (MAL: 165%, DCT: 172% of control activities) and persists 6 h after the injection (MAL: 130%, DCT: 118%). Na−K-ATPase activity was correlated to plasma PRL levels (r=0.78 in DCT,r=0.89 in MAL). A direct effect of PRL on the tubule is suggested by results from experiments in which PRL, at various concentrations, is added in vitro on renal slices before Na−K-ATPase activity measurements. The increase in Na−K-ATPase activity exhibits a log-dose dependency with PRL concentration (p<0.01) and is still observed when AVP antagonist is added before PRL incubation, ruling out the possible role of AVP contamination of PRL. These results suggest a direct effect of PRL on renal Na−K-ATPase in MAL and DCT.

Persisting Glomerular Hyperfiltration in Short-term Diabetic Children without Microalbuminuria

ABSTRACT. The renal function in a group of diabetic children (n=29; age: 4–17 yr; IDDM duration: 1.5–13 yr) was studied with a 3 year interval. At the first evaluation glomerular filtration rate (GFR) as assessed by inulin clearance was significantly increased compared to control values (167±32 vs. 124±18 ml/min/1.73 m2; p≤0.01). Eighteen out of 29 children exhibited a glomerular hyperfiltration (GFR ≥ 160). Three years later mean GFR was identical (169±25 ml/min/1.73 m2) and 16 children were hyperfiltrating. Among them, 11 have had a persisting glomerular hyperfiltration over the 3‐year period. Renal plasma flow (RPF) was positively correlated to GFR (r=0.7; p≤0.01) and remained elevated at both evaluations (794±163 and 812±157 ml/min/1.73 m2, p≤0.01 vs. control values). When the children were separated into 3 groups according to IDDM duration no significant differences were observed in the results for GFR and RPF. Mean urinary albumin excretion was comparable at the 3‐year interval, and not significantly different from the control values (5.2±3.7 and 8.2±6.6 respectively vs. 8.65±4 |ig/min). None of the children demonstrated a persistent microalbuminuria. This study reveals a high proportion of diabetic children with a persisting glomerular hyperfiltration, without any other symmptom of incipiens nephropathy. If elevated GFR plays an important role in the development of diabetic nephropathy, this study emphasizes the value of regular evaluation of renal function in diabetic children.