Age-Related Dynamics of the Indicators of Protein, Lipid, Carbohydrate, and Purin Metabolism and the Level of Pituitary Hormones in the Blood of Healthy, 22- to 55-Year-Old Men

Abstract

The levels of total protein, glucose, cholesterol and its fractions, triglycerides, uric acid, and hormones of the anterior pituitary gland (prolactin, luteinizing hormone, follicle-stimulating hormone, growth hormone, and thyroid-stimulating hormone) were analyzed in the serum of 60 healthy men aged 22–55 years. The blood pressure was measured, and the body-mass index (BMI) was calculated for each participant. To assess the age-related dynamics of the parameters, groups of young (up to 35 years old) and middle-aged (over 35 years old) participants were formed according to the classification adopted at the International Symposium on Age Periodization in 1965. A correlation analysis of the biochemical parameters, level of pituitary hormones, age, BMI, and level of mean blood pressure found a (p < 0.05) in the total blood protein level (within the normal range), a tendency towards a decrease in prolactin levels, and an increase (p < 0.05) in total cholesterol and LDL cholesterol in the middle-aged group as compared with the young group. The HDL-cholesterol levels did not differ between the groups; this demonstrates the constancy of antiatherogenic protection over many decades. The slight decrease in the total protein concentration in the blood and the tendency towards a decrease in the prolactin level, which were associated with negative correlations between a low prolactin level and age (r = –0.20; p = 0.01) and total protein and age (r = –0.35; p = 0.01) confirm the participation of prolactin in the protein metabolism and also indirectly indicate changes in the regulatory effect of dopamine on prolactin synthesis and secretion.