[The role of glucose and insulin in the metabolic regulation of growth hormone secretion].

The exact physiological basis for the suppression of growth hormone secretion by oral glucose intake remains unknown, despite the widespread use of the oral glucose tolerance test in endocrinology. Lack of growth hormone suppression by glucose occurs in about a third of patients with acromegaly, as well as in other disorders. It is currently known that the secretion of growth hormone is affected by various factors, such as age, gender, body mass index, and the redistribution of adipose tissue. There is also evidence of the impact of overeating as well as being overweight on the secretion of growth hormone. It is known that both of these conditions are associated with hyperinsulinemia, which determines the possibility of its predominant role in suppressing the secretion of growth hormone. The purpose of this review is to discuss the accumulated data on the isolated effects of hyperglycemia and hyperinsulinemia on growth hormone secretion, as well as other metabolic regulators and conditions affecting its signaling. Understanding of the pathophysiological basis of these mechanisms is essential for further research of the role of glucose and insulin in the metabolic regulation of growth hormone secretion. However, the studies in animal models are complicated by interspecific differences in the response of growth hormone to glucose loading, and the only possible available model in healthy people may be the hyperinsulinemic euglycemic clamp.

[Familial partial lipodystrophy (Dunnigan syndrome) due to LMNA gene mutation: The first description of its clinical case in Russia].

Hereditary lipodystrophies (HLD) are a heterogeneous group of rare diseases characterized by a complete or partial loss of subcutaneous fat and by the development of metabolic disturbances: diabetes mellitus with obvious insulin resistance and acanthosis nigricans, dyslipidemia, hepatic steatosis, hypertension, and polycystic ovary syndrome. The laminopathy variant familial partial lipodystrophy type 2 or Dunnigan syndrome (FPLD2) is the most common cause of partial LD. The paper describes a family (3 clinical cases) with FPLD2 caused by heterozygous R482W missense mutations in the gene encoding the protein lamin A/C (LMNA; 150330). This observation demonstrates that specialists should be more aware of this disease and make a timely diagnose in cases of concurrent severe metabolic disturbances at a young age, which contributes to more effective treatment of patients and to medical genetic counseling of their families.