Serum Fetuin-A and Insulin Levels in Classic Congenital Adrenal Hyperplasia

Evaluation of the pathophysiological role of Fetuin A levels in adolescents with polycystic ovary syndrome

OBJECTIVES

Polycystic ovary syndrome (PCOS) is an endocrinopathy, in which hyperandrogenism and hyperinsulinism have both occurred. Fetuin-A, a natural inhibitor of tyrosine kinase, leads to insulin resistance. The aim was to evaluate the relationship between fetuin-A and hyperandrogenism and hyperinsulinism and the role of fetuin-A in the pathophysiology of PCOS.

METHODS

Thirty-eight cases with PCOS and 40 healthy adolescents were included in the study. PCOS and controls were divided into obese/non-obese subgroups. LH, FSH, total and free testosterone (TT, FT), SHBG, androstenedione, DHEAS were measured in patients with PCOS. Fasting glucose, insulin, lipid profile, AST, ALT, HsCRP, and fetuin levels of PCOS patients and healthy controls were also measured.

RESULTS

Fetuin-A levels were higher in PCOS patients than in controls. In the obese-PCOS group, when compared to non-obese PCOS patients; the levels of SHBG and HDL were low while cholesterol, LDL, triglyceride, HOMA-IR, FT, FAI, and HSCRP levels were high, but Fetuin-A levels were similar. In the obese-PCOS group, fetuin-A levels were higher than in obese-controls. HOMA-IR and fetuin-A levels were higher in non-obese PCOS patients than in non-obese controls. In the PCOS group, fetuin-A was positively correlated with TT, FT, FAI and androstenedione and negatively correlated with SHBG. Regression analysis demonstrated that FT, SHBG, and androstenedione significantly predicted fetuin-A levels (R2=54%). In non-obese PCOS patients and controls, fetuin-A was positively correlated with insulin and HOMA-IR.

CONCLUSIONS

These results suggest a relationship between androgen levels and fetuin-A in PCOS cases, independent of insulin resistance, and may shed light on further studies.

Clinical outcomes in 21-hydroxylase deficiency

PURPOSE OF REVIEW

The introduction of synthetic glucocorticoids 70 years ago made survival possible in classic 21-hydroxylase deficiency (21OHD). The currently used glucocorticoid therapy may lead to unphysiological dosing with negative consequencies on health in addition to the problems that may arise due to androgen over-exposure.

RECENT FINDINGS

Fertility in females with 21OHD seemed to be impaired, especially in the salt-wasting (SW) phenotype but when pregnancies did occur there was a higher risk for gestational diabetes and cesearean section. Increased fat mass, body mass index, insulin resistance and frequency of autoimmune disorders as well as impaired echocardiographic parameters and lower bone mineral density were found in 21OHD compared to controls. Negative effects on cognitive functions have been identified. Adrenal tumors, especially myelolipomas, were prevalent. Increased knowledge on steroid metabolism in 21OHD and urine steroid profiling may improve assessment of treatment efficacy. Nevanimibe, abiraterone acetate and anastrozole may have a place in the future management of 21OHD. Long-acting glucocorticoids may be a less favorable, especially dexamethasone.

SUMMARY

The various clinical outcomes need regular monitoring. Negative consequencies are to large extent the result of the unphysiological glucocorticoid replacement. Modern management with improved follow-up and future addition of new drugs may improve outcomes.

Role of insulin and insulin resistance in androgen excess disorders

Insulin has complex effects on cell growth, metabolism and differentiation, and these effects are mediated by a cell-surface bound receptor and eventually a cascade of intracellular signaling events. Among the several metabolic and growth-promoting effects of insulin, insulin resistance is defined as an attenuated effect of insulin on glucose metabolism, primarily the limited export of blood glucose into skeletal muscle and adipose tissue. On the other hand, not all the signaling pathways and insulin-responsive tissues are equally affected, and some effects other than the metabolic actions of insulin are overexpressed. Ovaries and the adrenal glands are two examples of tissues remaining sensitive to insulin actions where insulin may contribute to increased androgen secretion. Polycystic ovary syndrome (PCOS) is the most common form of androgen excess disorder (AED), and its pathogenesis is closely associated with insulin resistance. Patients with idiopathic hirsutism also exhibit insulin resistance, albeit lower than patients with PCOS. Although it is not as evident as in PCOS, patients with congenital adrenal hyperplasia may have insulin resistance, which may be further exacerbated with glucocorticoid overtreatment and obesity. Among patients with severe insulin resistance syndromes, irrespective of the type of disease, hyperinsulinemia promotes ovarian androgen synthesis independently of gonadotropins. It is highly debated in whom and how insulin resistance should be diagnosed and treated among patients with AEDs, including PCOS. It is not suitable to administer an insulin sensitizer relying on only some mathematical models used for estimating insulin resistance. Instead, the treatment decision should be based on the constellation of the signs, symptoms and presence of obesity; acanthosis nigricans; and some laboratory abnormalities such as impaired glucose tolerance and impaired fasting glucose.