Age-related determinants of the metabolic syndrome in women of reproductive age of the main ethnic groups of the Baikal Region

The aim of the study. To determine the age limit of the initial manifestations of the metabolic syndrome in women of reproductive age of the Caucasian and Asian ethnic groups. Materials and methods. The study included women of reproductive age of the Russian and Buryat ethnic groups (n = 1231). We carried out general clinical examination, studied glycemia levels and lipid metabolism indicators. The analysis of the components of the metabolic syndrome was performed taking into account age characteristics and ethnicity. Threshold values for the age of metabolic disorders manifestation were determined. Results. It was found that the main components of the metabolic syndrome in women of reproductive age of the Russian and Buryat ethnic groups were a decrease in  high-density lipoprotein (HDL), an increase in waist circumference, and an increase in blood pressure. The age-related determinants of the metabolic syndrome in the  population of women of reproductive age in the Baikal region were determined. It was shown that the age-related determinants of the metabolic syndrome in Caucasian and Asian women do not differ significantly and amount to 33.5 years (95% confidence interval (95% CI): 32.5; 38.5) and 36.5 years (95% CI: 27.5; 52.5), respectively. A universal critical age value was determined as 34.5 years (95% CI: 32.5; 38.5), which is associated with a significant increase in the prevalence of the metabolic syndrome in accordance with the ATP  III criteria. The ranking of metabolic syndrome criteria in the studied groups revealed the following order of their occurrence: the decrease in HDL index prevailed, followed by the increase in waist circumference, blood pressure, glucose and triglycerides; no dependence on the ethnicity was found. Conclusion. When assessing the age-related determinants of the metabolic syndrome in the mixed Caucasoid-Asian group, it is advisable to use universal approaches, taking into account the cut-off point of age, which is 34.5 years. The determination of age criteria for the correct classification of patients with respect to the manifestations of the metabolic syndrome is necessary to analyze the contribution of the age factor to the implementation of various metabolic syndrome predictors, to  develop prognostic models, and to  use effective age-determined markers of metabolic disorders

The experience in the development and validation of method for testosterone measurement in blood serum of premenopausal women using HPLC-MS/MS

Testosterone assessment is essential for detecting biochemical hyperandrogenism, one of the important diagnostic criteria of polycystic ovary syndrome (PCOS) both in clinical practice and in epidemiological studies. Currently, tandem liquid chromatography-mass spectrometry (LC-MS/MS) is the most preferred technique to measure testosterone level in women. Its validation is important to reproducibility of androgen tests results for clinical practice and for epidemiological studies of the prevalence PCOS.The aim of the study. To develop and validate a method for determining total testosterone in blood serum using highly efficient LC-MS/MS to assess androgenemia in the epidemiological study of the prevalence of PCOS and its phenotypes in Eastern Siberia (ESPEP STUDY).Materials and methods. We determined a total testosterone level in serum blood using triple quadrupole mass spectrometer LCMS-8060 (Shimadzu, Japan). The protocol of technique was developed using self-prepared purified human testosteronefree serum with a known concentration of analyzed compound. We used the serum samples of women of reproductive age to test the developed method.Results. Optimum chromatographic conditions were obtained with a Kromasil 100-2.5-C18 column (2.1 mm × 100 mm; AkzoNobel, Netherlands), and an isocratic elution mode using a mobile phase consisting of acetonitrile and 0.1 % aqueous solution of formic acid. The total flow rate was 0.35 ml/min. The lower limit of quantification was 5 ng/dl with an average accuracy of 100.2 %. During the approbation of the method in a test population sample of 1138 premenopausal women (mean age – 34.3 ± 6.3 years), the median testosterone concentration was 26.9 ng/dl.Conclusion. It was found that the proposed method for determining testosterone in blood serum has acceptable linearity and reproducibility and meets the requirements for bioanalytical methods under the regulatory documentation. This method can be used for clinical practice and epidemiological study of the prevalence of PCOS