Validation of a new method to assess the long-term Hypothalamic-Pituitary-Adrenal Activity using hair glucocorticoids as biomarkers. - Studies on pigs and laboratory Sprague-Dawley Rats

The evaluation of chronic activity of the hypothalamic-pituitary-adrenal (HPA) axis is critical for determining the impact of chronic stressful situations. The potential use of hair glucocorticoids as a non-invasive, retrospective, biomarker of long term HPA activity is of great interest, and it is gaining acceptance in humans and animals. However, there are still no studies in literature examining hair cortisol concentration in pigs and corticosterone concentration in laboratory rodents. Therefore, we developed and validated, for the first time, a method for measuring hair glucocorticoids concentration in commercial sows and in Sprague-Dawley rats. Our preliminary data demonstrated: 1) a validated and specific washing protocol and extraction assay method with a good sensitivity in both species; 2) the effect of the reproductive phase, housing conditions and seasonality on hair cortisol concentration in sows; 3) similar hair corticosterone concentration in male and female rats; 4) elevated hair corticosterone concentration in response to chronic stress manipulations and chronic ACTH administration, demonstrating that hair provides a good direct index of HPA activity over long periods than other indirect parameters, such adrenal or thymus weight. From these results we believe that this new non-invasive tool needs to be applied to better characterize the overall impact in livestock animals and in laboratory rodents of chronic stressful situations that negatively affect animals welfare. Nevertheless, further studies are needed to improve this methodology and maybe to develop animal models for chronic stress of high interest and translational value in human medicine.

Hair: a tool to evaluate the HPA axis activity

Hair cortisol is a novel marker to measure long-term secretion cortisol free from many methodological caveats associated with other matrices such as plasma, saliva, urine, milk and faeces. For decades hair analysis has been successfully used in forensic science and toxicology to evaluate the exposure to exogenous substances and assess endogenous steroid hormones. Evaluation of cortisol in hair matrix began about a decade ago and have over the past five years had a remarkable development by advancing knowledge and affirming this method as a new and efficient way to study the hypothalamic-pituitary-adrenal (HPA) axis activity over a long time period. In farm animals, certain environmental or management conditions can potentially activate the HPA axis. Given the importance of cortisol in monitoring the HPA axis activity, a first approach has involved the study on the distribution of hair cortisol concentrations (HCC) in healthy dairy cows showing a physiological range of variation of this hormone. Moreover, HCC have been significantly influenced also by changes in environmental conditions and a significant positive correlation was detected between HCC and cows clinically or physiologically compromised suggesting that these cows were subjected to repeated HPA axis activation. Additionally, Crossbreed F1 heifers showed significantly lower HCC compared to pure animals and a breed influence has been seen also on the HPA axis activity stimulated by an environmental change showing thus a higher level of resilience and a better adaptability to the environment of certain genotypes. Hair proved to be an excellent matrix also in the study of the activation of the HPA axis during the perinatal period. The use of hair analysis in research holds great promise to significantly enhance current understanding on the role of HPA axis over a long period of time.

Correlation between insulin resistance and treatment-resistant acne

Physiologically during puberty and adolescence, when juvenile acne usually appears, the response to a glucose load is increased if compared to the one observed in adult and at pre-pubertal age, while insulin sensitivity is reduced. Insulin is a hormone that acts at different levels along the axis which controls the sex hormones. It increases the release of LH and FSH by pituitary gland, stimulates the synthesis of androgens in the gonads and stimulates the synthesis of androgenic precursors in adrenal glands. Finally, it acts in the liver by inhibiting the synthesis of Sex Hormone Binding Globulin (SHBG). Insulin is also able to act directly on the production of sebum and amplify the effects of Iinsulin Growth Factor-1 in the skin, inhibiting the synthesis of its binding protein (IGF Binding Protein-1). In female subjects with acne and Polycystic Ovary Syndrome (PCOS) insulin resistance is a well known pathogenetic factor, while the relationship between acne and insulin resistance has been poorly investigated in males so far. The purpose of this study is to investigate the correlation between insulin resistance and acne in young males who do not respond to common therapies. Clinical and biochemical parameters of glucose, lipid metabolism, androgens and IGF-1 were evaluated. Insulin resistance was estimated by Homeostasis Model assessment (HOMA-IR) and Oral Glucose Tolerance Test was also performed. We found that subjects with acne had higher Sistolic and Diastolic Blood Pressure, Waist/Hip Ratio, Waist Circumference, 120' OGTT serum insulin and serum IGF-1 and lower HDL-cholesterol than subjects of comparable age and gender without acne. The results thus obtained confirmed what other authors have recently reported about a metabolic imbalance in young males with acne. Furthermore, these results support the hypothesis that insulin resistance might play an important role in the pathogenesis of treatment-resistant acne in males.

Il craniofaringioma nel bambino e nell'adolescente. Luci ed ombre durante il follow-up

Introduction. Craniopharyngioma (CF) is a malformation of the hypothalamicpituitary region and it is the most common nonglial cerebral tumor in children with an high overall survival rate. In some case severe endocrinologic and metabolic sequelae may occur during follow up. 50% of patients (pts), in particular those with radical removal of suprasellar lesions, develop intractable hyperphagia and morbid obesity, with dyslypidemia and high cardiovascular risk. We studied the auxological and metabolic features of a series of 29 patients (18 males) treated at a mean age of 7,6 years, followed up in our Centre from 1973 to 2008 with a mean follow up of 8,3 years. Patients features at the onset. 62% of pts showed as first symptoms of disease visual impairment and neurological disturbancies (headache); 34% growth arrest; 24% signs of raised intracranial pressure and 7% diabetes insipidus. Diagnosis. Diagnosis of CF was reached finally by TC or MRI scans which showed endo-suprasellar lesion in 23 cases and endosellar tumour in 6 cases. Treatment and outcome. 25/29 pts underwent surgical removal of CF (19 by transcranial approach and 6 by endoscopic surgery); 4 pts underwent stereotactic surgery as first line therapy. 3 pts underwent local irradiation with yttrium-90, 5 pts post surgery radiotherapy. 45% of pts needed more than one treatment procedure. Results. After CF treatment all patients suffered from 3 or more pituitary hormone deficiencies and diabetes insipidus. They underwent promptly substitutive therapy with corticosteroids, l-thyroxine and desmopressin. In 28/29 pts we found growth hormone (GH) deficiency. 20/28 pts started GH substitutive therapy and 15 pts reached final height(FH) near target height(TH). 8 pts were not GH treated for good growth velocity, even without GH, or for tumour residual. They reached in 2 cases FH over TH showing the already known phenomenon of growth without GH. 38% of patients showed BMI SDS >2 SDS at last assessment, in particular pts not GH treated (BMI 2,5 SDS) are more obese than GH treated (BMI 1,2 SDS). Lipid panel of 16 examined pts showed significative differencies among GH treated (9 pts) and not treated (7 pts) with better profile in GH treated ones for Total Cholesterol/C-HDL and C-LDL/C-HDL. We examined intima media thickness of common carotid arteries in 11 pts. 3/4 not GH treated pts showed ultrasonographic abnormalities: calcifications in 2 and plaque in 1 case. Of them 1 pt was only 12,6 years old and already showed hypothalamic obesity with hyperphagia, high HOMA index and dyslipidemia. In the GH treated group (7) we found calcifications in 1 case and a plaque in another one. GH therapy was started in the young pt with carotid calcifications, with good improvement within 6 months of treatment. 5/29 pts showed hypothalamic obesity, related to hypothalamic damage (type of surgical treatment, endo-suprasellar primitive lesion, recurrences). 48% of patients recurred during follow up ( mean time from treatment: 3 years) and underwent, in some cases up to 4 transcranial surgical treatments. GH seems not to increase recurrence rate since 40% of GH treated recurred vs 66,6% of not GH treated pts. Discussion. Our data show the extereme difficulties that occur during follow up of craniopharyngioma treated patients. GH therapy should be offered to all patients even with good growth velocity after CF treatment, to avoid dislypidemia and reduce cardiovascular risk. The optimal therapy is not completely understood and whether gross tumor removal or partial surgery is the best option remains to be decided only on one patient tumour features and hypothalamic involvement. In conclusion the gold standard treatment of CF remains complete tumour removal, when feasible, or partial resection to preserve hypothalamic function in endosuprasellar large neoplasms.

The cardio-renal axis. Non ST-segment elevation myocardial infarction risk stratification according to renal dysfunction

Background: Chronic kidney disease (CKD) is one of the strongest risk factor for myocardial infarction (MI) and mortality. The aim of this study was to assess the association between renal dysfunction severity, short-term outcomes and the use of in-hospital evidence-based therapies among patients with non–ST-segment elevation myocardial infarction (NSTEMI). Methods: We examined data on 320 patients presenting with NSTEMI to Maggiore’s Emergency Department from 1st Jan 2010 to 31st December 2011. The study patients were classified into two groups according to their baseline glomerular filtration rate (GFR): renal dysfunction (RD) (GFR<60) and non-RD (GFR≥60 ml/min). Patients were then classified into four groups according to their CKD stage (GFR≥60, GFR 59-30, GFR 29-15, GFR <15). Results: Of the 320 patients, 155 (48,4%) had a GFR<60 ml/min at baseline. Compared with patients with a GFR≥60 ml/min, this group was, more likely to be female, to have hypertension, a previous myocardial infarction, stroke or TIA, had higher levels of uric acid and C-reactive protein. They were less likely to receive immediate (first 24 hours) evidence-based therapies. The GFR of RD patients treated appropriately increases on average by 5.5 ml/min/1.73 m2. The length of stay (mean, SD) increased with increasing CKD stage, respectively 5,3 (4,1), 7.0 (6.1), 7.8 (7.0), 9.2 (5.8) (global p <.0001). Females had on average a longer hospitalization than males, regardless of RD. In hospital mortality was higher in RD group (3,25%). Conclusions: The in-hospital mortality not was statically difference among the patients with a GFR value ≥60 ml/min, and patients with a GFR value <60 ml/min. The length of stay increased with increasing CKD stages. Despite patients with RD have more comorbidities then without RD less frequently receive guideline –recommended therapy. The GFR of RD patients treated appropriately improves during hospitalization, but not a level as we expected.