Cerebral salt wasting in a postoperative period

Cerebral salt wasting syndrome (CSW-cerebral salt wasting) was first described in 1950 by Peters. This syndrome can occur in patients who have sustained damage to the central nervous system (e.g. patients with subarachnoid bleeding, bacterial meningitis or after neurosurgery). Patients present with excessive natriuresis and hyponatremic dehydration. Differentiating this syndrome with the syndrome of inappropriate antidiuretic hormone secretion (SIADH-syndrome of inappropriate antidiuretic hormone secretion), which may occur in the same group of patients, is necessary in order to administer the correct treatment which consists of fluid restriction and sodium replacement in SIADH and fluid and sodium replacement as well as occasional mineralocorticoid therapy in CSW.

FGF23 contributes to insulin sensitivity in obese adolescents - preliminary results

Fibroblast growth factor-23 (FGF23) is a hormonal regulator of circulating phosphate and vitamin D levels. Recent investigations revealed that besides a key role in the pathogenesis of calcium-phosphorus disorders, in some patients FGF23 may be an indicator of cardiovascular complications. As a 'hormone-like' factor, it may also be involved in some metabolic processes, especially in the metabolism of glucose and fat. Its potential contribution to metabolic syndrome (MS) development has not been confirmed yet.

OBJECTIVE

The study was to examine the possible correlations between FGF23 serum levels and body composition, blood pressure and selected parameters of glucose, insulin and fat metabolism in adolescents with simple obesity.

PATIENTS AND DESIGN

In 68 (35 female) adolescents (mean age 13·9 years) with simple obesity [mean BMI SDS 4·9 (95% CI 4·4-5·4)], the levels of FGF23, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides were measured. Standard oral glucose tolerance tests were performed with the assessment of fasting and after 120' postload glucose and insulin levels; the insulin resistance index HOMA-IR was calculated.

RESULTS

Regardless of gender, there was a significant inverse correlation between FGF23 and fasting insulin level (r = -0·3), as well as HOMA-IR (r = -0·29). Multiple regression model showed the independent association between FGF23 and HOMA-IR.

CONCLUSION

FGF23 seems to be a novel factor contributing to insulin sensitivity. Further investigations are needed to define its role in the development of MS.

A decrease in fasting FGF19 levels is associated with the development of non-alcoholic fatty liver disease in obese adolescents

AIM

Fibroblast growth factor 19 (FGF19) is a hormone released from the small intestine; recently, it has emerged as an endocrine regulator of glucose and lipid metabolism. The aim of this study was to investigate the role of FGF19 in the development of nonalcoholic fatty liver disease (NAFLD).

PATIENTS

This study included 23 (17 boys) obese adolescents (mean age of 14.1 years) with NAFLD. The control group consisted of 34 (13 boys) obese peers with normal ultrasonographic imaging and normal liver function tests.

METHODS

The definition of NAFLD was based on clinical criteria: elevated alanine aminotransferase (>35 U/L) and liver steatosis features on ultrasound imaging. Serum FGF19 levels were measured in a fasting blood sample. The definition of insulin resistance was based on the homeostasis model assessment (HOMA) threshold: >2.5.

RESULTS

There was a significant difference between mean FGF19 levels in patients with NAFLD and controls (142.2 vs. 206 pg/mL, p=0.04). Mean fasting FGF19 levels were decreased in insulin-resistant patients in comparison with the non-insulin-resistant group (155.0 vs. 221.0 pg/mL, p=0.05). There was an inverse correlation between FGF19 and alanine aminotransferase levels (R=-0.3, p<0.05) and triglycerides (R=-0.27, p<0.05).

CONCLUSION

A decrease in fasting FGF19 is associated with the development of NAFLD in obese adolescents. A decrease in fasting FGF19 levels may be a new important risk factor for NAFLD and the metabolic syndrome in adolescents. Further studies are needed to explain whether exogenous delivery of FGF19 might be therapeutically beneficial.

The association of FGF23 levels in obese adolescents with insulin sensitivity

BACKGROUND

The fibroblast growth factor 23 (FGF23) is the most important hormonal regulator of circulating phosphate levels. Apart from this essential role, it may also act as a 'hormone-like' factor involved in glucose and lipid metabolism. It is believed to have a potential role in the development of insulin resistance.

AIM

The aim of the study was to compare FGF23 levels between two groups of obese adolescents: insulin resistant and non-insulin resistant.

PATIENTS

The study included 36 obese, insulin-resistant adolescents (21 boys and 15 girls) of pubertal age (mean age, 13.95 years; Tanner stage IV or V). The control group consisted of 21 obese peers with normal HOMA-IR values.

METHODS

FGF23 levels were measured in a fasting blood sample by Human Intact FGF-23 ELISA Kit (Immunotopics Inc., San Clemente, CA, USA). A standard oral glucose tolerance test was performed, which assessed fasting and 120 min postload plasma glucose and serum insulin levels; the insulin resistance index HOMA-IR was calculated. The definition of insulin resistance was based on a HOMA-IR threshold set for adolescents (> or = 3.16).

RESULTS

There was a significant inverse correlation between FGF23 levels and HOMA-IR (R = -0.26, p < 0.05) in the study group. FGF23 levels were also significantly lower in the study group (9.8 vs. 11.9 pg/mL, p = 0.026).

CONCLUSIONS

In adolescents with simple obesity and insulin resistance, FGF23 levels are lower compared with obese adolescents with normal HOMA-IR.

Causes and consequences of abandoning one-stage bilateral adrenalectomy recommended in primary pigmented nodular adrenocortical disease--case presentation

We present a 7-year-old girl with a 2-year history of decelerated growth rate and cushingoidal obesity, upon admission presenting with fixed hypertension. Cyclic hypercortisolemia with inhibited baseline and post-CRH stimulation ACTH level pointed to primary adrenal hypercortisolemia. Ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) showed normal adrenal glands. 131J-labeled cholesterol scintiscan showed a weak but slightly more expressed tracer uptake in the left adrenal gland. Cushing syndrome concomitant with isolated primary pigmented nodular adrenocortical disease (PPNAD) was diagnosed. After hypotensive pretreatment, a left adrenalectomy was performed, resulting in normalization of corticoadrenal function, blood pressure, Cushing features and growth rate. Histopathology confirmed PPNAD. In the course of infection, corticoadrenal function showed absence of adrenal reserve, and adrenal crisis. Hydrocortisone (HC) therapy, followed by HC supplementation was introduced. Four years later, a contralateral adrenalectomy was performed and total HC supplementation was introduced. Causes and consequences of abandoning one-stage bilateral adrenalectomy recommended in PPNAD are reviewed.