Abstract
Osteocalcin (OC) is a component of phenotypic characteristics, associated with carbohydrate and lipid metabolism. Of interest is the phenotype of type 2 diabetes mellitus (T2DM) without obesity, which may be associated with impaired levels of counter-insulin hormones.
87 patients with T2DM (age 40-78, females/males – 41/46) were examined. Anthropometric parameters and body composition were assessed by the bioelectrical impedance. OC, cortisol, dehydroepiandrosterone sulfate (DHEA-S) blood levels, and the ratio of cortisol/DHEA-S as indicator of the body stress resistance, were measured. Patients were divided into 4 quartiles, depending on the serum OC level, that were significantly different from each other.
Cortisol/DHEA-S ratio was significantly different between the first (lowest OC level) and the fourth quartiles (highest OC level) and between the second, third and fourth quartiles. Visceral fat level was the highest in the first OC quartile, and the lowest in the fourth quartile. When comparing the percentage of total fat between quartiles, no significant difference was found, which may indicate the importance of visceral fat in the formation of metabolic phenotypic changes in the presence of T2DM.
The lowest serum OC level was observed in patients with the greatest intensity of chronic endogenous stress, which is manifested by glucocorticoid function increase according to the cortisol/DHEA-S ratio. It is assumed, that local hypercorticism is the cause of stem cell differentiation into adipocytes, which leads to the formation of a diabetes phenotype with the accumulation of visceral fat without general obesity and the slowing of osteosynthesis with a decrease of the OC level.