RESUMO
Growth hormone deficiency (GHD) is an endocrine disorder, which may be either isolated or associated with other pituitary hormone deficiencies. In children, short stature is a useful clinical marker for GHD. In contrast, symptomatology is not always so obvious in adults, and the existing methods of testing might be inaccurate and imprecise, especially in the lack of a suggestive clinical profile. Since the quality of life of patients diagnosed with GHD could also be significantly affected, in both children and adults, a correct and accurate diagnosis is therefore tremendously important to select those patients that can benefit from the GH treatment. In general, the endocrine diseases are challenging in terms of diagnosis, the simple measurement of the basal level of hormones is not sufficient for distinguishing between the physiological and pathological conditions. Traditionally, several stimulation tests have been considered by professional clinical guidelines, such as insulin tolerance test (ITT), GHRH-arginine stimulation test and the glucagon stimulation test, and all of them have both advantages and limitations. More recently (December 2017), FDA approved a growth hormone secretagogue receptor agonist, macimorelin, for the diagnosis of adults with GHD. The obvious advantage for macimorelin is the simple oral administration and the high level of agreement with the insulin tolerance test for those patients with organic disease and low levels of insulin-like growth factor (IGF-I). However, the safety profile and the diagnostic value was not yet established for the pediatric population and for those adults with extreme or morbid obesity. In addition, administration of macimorelin with drugs that prolong QT interval and CYP3A4 inducers should be avoided. Genetic screening could obviously bring a great insight in the GHD pathology. However, it remains an open question if it would be also cost effective to include it in the routine evaluation of the patients with GHD. Although major progresses have been made in this area, genetic testing continues to be difficult to access, mostly because of its high costs, especially in the low-income and middle-income countries.
RESUMO
Type 2 diabetes mellitus represents a major public health challenge, due to the continuously growing prevalence and the complexity of the diabetic complications. Hyperglycemia seems to be the main mechanism for the disease progression. During erythrocyte's long life span, erythrocyte membranes are affected by the chronic exposure to glucose, which triggers several biochemical modifications that lead to both structural and functional disruption, which are further involved in the physiopathology of diabetes and its complications. Non-enzymatic protein glycation of red blood cell membrane proteins occur in two phases: early glycation, characterized by Schiff bases and Amadouri compounds formation, and advanced glycation, characterized by advanced glycation end products (AGEs). These products could be valuable tools for early diagnosis or biomarkers for disease progression, depending on how advanced they are in the glycation process. Advanced glycated end products were linked with diabetic complications. Also, lipid peroxidation and decreased activity of the enzyme pumps occur in the erythrocyte membrane of the diabetic patients. The investigation of lipid rafts and erythrocyte membrane fatty acids are a valuable tool for long-term monitoring of metabolic status. Further investigation of the erythrocyte membrane could provide novel biomarkers for monitoring of diabetes and its complications.
