Can Brain Natriuretic Peptides and Osteoprotegerin Serve As Biochemical Markers for the Detection of Aortic Pathology in Children and Adolescents with Turner Syndrome?

Inverse Regulation of Serum Osteoprotegerin and B-Type Natriuretic Peptide Concentrations by Free Fatty Acids Elevation in Young Healthy Humans

Osteoprotegerin (OPG) and B-type natriuretic peptide (BNP) are cardiovascular risk factors, interrelated with each other, with possible associations with insulin sensitivity and glucose homeostasis. The aim of this study was to assess association between OPG and BNP concentrations in a young healthy population, their relation to insulin sensitivity and obesity and their regulation by hyperinsulinemia and serum free fatty acids (FFA) elevation. The study group consisted of 59 male volunteers, 30 of whom were of a normal weight (BMI < 25 kg/m²), and 29 were overweight/obese (BMI > 25 kg/m²). Insulin sensitivity was assessed with the 2-h hyperinsulinemic-euglycemic clamp (HEC). In the subgroup of 20 subjects, the clamp was prolonged to 6 h. After one week, another 6-h clamp, with concurrent Intralipid/heparin infusion, was performed. Serum OPG was positively associated with insulin sensitivity (p = 0.002) and negatively with BMI (p = 0.019) and serum BNP (p = 0.025). In response to 6-h hyperinsulinemia, circulating BNP decreased (p < 0.001). In response to HEC with Intralipid/heparin infusion, OPG decreased (p < 0.001) and BNP increased (p < 0.001). Our data show that OPG and BNP are differentially regulated by FFA, which suggests their association with lipid-induced insulin resistance. The assessment of these cardiovascular risk factors should take into account both long-term and short-term effects associated with insulin resistance.

A Synopsis of Current Practice in the Diagnosis and Management of Patients with Turner Syndrome in Turkey: A Survey of 18 Pediatric Endocrinology Centers

OBJECTIVE

A comprehensive survey was conducted to evaluate the shortcomings of clinical care in patients with Turner syndrome (TS) in Turkey.

METHODS

A structured questionnaire prepared by the Turner study group in Turkey, which covered relevant aspects of patient care in TS was sent to 44 pediatric endocrinology centers.

RESULTS

Eighteen centers (41%) responded to the questionnaire. In the majority of the centers, diagnostic genetic testing, screening for Y chromosomal material, protocols regarding the timing and posology of growth hormone (GH) and estrogen, thrombophilia screening, fertility information and screening for glucose intolerance, thyroid, and coeliac diseases in patients with TS were in line with the current consensus. Thirteen centers (72.2%) performed GH stimulation tests. Only four centers (22.2%) used oxandrolone in patients with TS with very short stature. The majority of the centers relied on bone age and breast development to assess estrogen adequacy, though together with variable combinations of oestrogen surrogates. Two centers (11.1%) reported performing serum estradiol measurements. Eight centers (44.4%) routinely conducted cardiac/thoracic aorta magnetic resonance imaging. Screening for hearing, dental and ophthalmologic problems were performed by thirteen (72.2%), six (33.3%) and ten (55.6%) centers, respectively. Psychiatric assessments were made by four centers (22.2%) at diagnosis, with only one center (5.6%) requiring annual reassessments.

CONCLUSION

Although we found some conformity between the current consensus and practice of the participating centers in Turkey regarding TS, further improvements are mandatory in the multi-disciplinary approach to address co-morbidities, which if unrecognized, may be associated with reduced quality of life and even mortality.

Determinants of Increased Aortic Diameters in Young Normotensive Patients With Turner Syndrome Without Structural Heart Disease

Factors associated with aortic dilation and dissection in patients with Turner syndrome (TS) remain unclear. We assessed magnetic resonance imaging-based aortic diameters at nine predefined anatomic positions and examined associations of increased aortic diameters with B-type natriuretic peptide (BNP), A-type NP (ANP), growth hormone treatment, insulin-like growth factor 1 (IGF1), and estrogen status. Forty-seven patients with TS aged 7.3-21 years and 34 healthy peers were enrolled in this study. Aortic diameters were higher in patients with TS at three positions than in controls (p < 0.05). History of GH treatment, pubertal status, and serum estradiol levels were not associated with increased aortic diameters. Patients with TS had higher plasma BNP and ANP levels than controls. BNP and IGF1 were independently associated with the increase in aortic diameters in TS at three positions of the ascending aorta (R² = 0.361-0.458, p < 0.05 for all). At two positions of the descending aorta, only BNP emerged as an independent variable (R² = 0.130-0.139, p < 0.05). We conclude that young, normotensive patients with TS had greater aortic diameters at several positions than healthy controls. BNP and IGF1 were independently associated with increased aortic diameters in TS.