Biomedical subjects

R Mikulová

Publications and source records attributed to R Mikulová.

5 recordsLinked to original sources

PubMed2002

Serum cortisol and sex hormone binding globulin (SHBG) levels, body fat distribution and the role of genetic factors in obese females.

Fasting plasma levels of both cortisol and sex hormone binding globulin (SHBG) in obese women were significantly inversely related to anthropometric characteristics of body fat distribution. It means that a central accumulation of body fat might be partly mediated by cortisol and SHBG levels. Significant within-pair resemblance observed in plasma cortisol level in obese female monozygotic twins suggests an important role of genetic factors in determination of cortisol secretion. However, no within-pair similarities revealed in plasma SHBG concentrations favour a major role of environmental factors in the regulation of plasma SHBG level. On the other hand the twin study supported the role of genetic determinants in changes of both cortisol and SHBG levels in response to energy deficit induced by very low calorie diet (VLCD). The mechanisms controlling baseline levels of cortisol and SHBG apparently differ from those controlling their responses to energy restriction.

Adipose Tissue↗

PubMed2002

Adipose tissue distribution in obese females. Relationship to androgens, cortisol, growth hormone and leptin.

Adipose tissue distribution predicts development of obesity complications better than total adipose tissue content. The aim of the study was to evaluate the role of the hormonal factors contributing to the adipose tissue distribution in obese females. The cohort examined consisted of 94 women in the range of overweight to obesity, aged 44.2 +/- 11.2 years (21-67), weight 100.1 +/- 17.5 kg (65.8-148), BMI 37.13 +/- 5.72 kg/m2 (26.4-50.7). Adipose tissue (AT) distribution was examined by CT at level L4/5 and intraabdominal adipose tissue and the subcutaneous abdominal adipose tissue area (IAAT and SAAT, respectively) were determined. Growth hormone (GH), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), cortisol, testosterone, androstene-dione, SHBG, total thyroxine, total triiodothyronine (T3), TSH and leptin were assessed by routine methods by RIA and CLIA. GH, DHEA and DHEA-S correlated significantly negatively with IAAT (r = -0.24, p < 0.05, r = -0.30, p < 0.01, r = -0.34, p < 0.005, respectively). A borderline significant negative correlation of T3 with IAAT was shown (r = -0.20, p = 0.054). A significant positive correlation of SAAT with total testosterone and serum leptin was found (r = 0.27, p < 0.01, r = 0.64, p < 0.001, respectively). When comparing the difference of individual hormone levels between the 1st and 5th quintile of IAAT, no significant difference between the groups was found after adjustment for weight and age. In contrast, when comparing the 1st and 5th quintile according to the SAAT a significantly lower total testosterone and leptin in the 1st quintile of SAAT was found. Only in leptin the difference remained significant after adjustment for adipose tissue content. In conclusion, the results suggest that the relationship of individual hormones examined in this study to the central adipose tissue distribution are mostly mediated by age and adipose tissue content; they do not seem to be in a causal connection with the intraabdominal adipose tissue content. The only exception concerns leptin, which is significantly related to the subcutaneous abdominal adipose tissue area.

Adipose Tissue↗

PubMed2001

[Uncoupling proteins].

Uncoupling proteins are located in the inner mitochondria membrane. Their name is derived from their function: they uncouple oxidative procesess of the respiratory chain from ATP synthesis. Hitherto several members of the family have been described, the best known being UCP1. UCP1 can be expressed exclusively in brown adipose tissue and it is responsible for the heat production. In humans the brown fat disappears during the early childhood. In adults another members of the UCP family can be found--UCP2 and UCP3. It is widely accepted that these proteins affect lipid metabolism and energy expenditure. They are intensively studied owing to their possible use in the therapy of obesity. However, their physiological function has not been yet fully established.

Adipose Tissue, Brown↗

PubMed2001

The within-pair resemblance in serum levels of androgens, sex-hormone binding globulin and cortisol in female obese identical twins - effect of negative energy balance induced by very low-calorie diet.

The first aim of the present study was to evaluate the changes in serum levels of cortisol, testosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEA-S) and sex hormone-binding globulin (SHBG) in response to weight loss induced by one month of treatment with a very low-calorie diet (VLCD) in twelve pairs of female obese monozygotic twins. The second aim of the study was to investigate any within-pair resemblance in serum levels of steroids and SHBG before and after a negative balance protocol, as well as the resemblance in changes in response to therapeutic weight loss. VLCD-induced weight loss of 8.7+2.9 kg was associated with significant increases in serum testosterone (p<0.05) and SHBG (p<0.001) levels, whereas no significant changes in serum levels of cortisol, DHEA and DHEA-S were observed. Significant within-pair resemblances for both pre-treatment and post-treatment concentrations were revealed for DHEA-S (pre-treatment ICC = 0.795, p < 0.01, post-treatment ICC = 0.712, p < 0.01) and for testosterone (pre-treatment ICC = 0.594, p <0.05, post-treatment ICC = 0.735, p < 0.01). The baseline within-twin-pair resemblance in serum cortisol level at 7 a.m. (ICC=0.747, p < 0.05) was lost with VLCD treatment, while its concentration at 9 p.m. developed a within-pair similarity with weight loss (ICC = 0.824, p < 0.001). Similarly, VLCD treatment led to a significant within-pair resemblance in post-treatment level of DHEA (ICC = 0.755, p < 0.01), while no within-twin-pair resemblance was shown for either pre-treatment or post-treatment SHBG levels. None of the hormones measured exhibited any within-pair resemblance in response to VLCD-induced energy deficit, except for serum cortisol levels. A significant within-twin-pair resemblance in the changes in serum cortisol levels at 7 a. m. (ICC = 0.789, F = 8.5, p < 0.001), at 1 p.m. (ICC = 0.660, F = 4.9, p <0.01) and at 9 p.m. (ICC = 0.795, F = 8.8, p <0.001) were demonstrated even after adjustment for fat mass loss. An absence of any within-pair similarity was observed in both pretreatment and post-treatment levels of SHBG, while a significant within-pair resemblance in SHBG response to VLCD treatment (ICC = 0.658, p < 0.05) was recorded. We conclude that the significant within-twin-pair resemblance demonstrated for androgens and cortisol might suggest an important role for genetic factors in the regulation of their serum levels. Our results also suggest that the mechanisms controlling baseline levels of cortisol and SHBG differ from those influencing their responses to energy deficit induced by VLCD.

Adipose Tissue↗

PubMed2000

Respiratory quotient in obesity: its association with an ability to retain weight loss and with parental obesity.

A high fasting respiratory quotient (RQ) was observed during the treatment by very low calorie diet (VLCD) in obese patients who regained weight at two-year follow-up (weight regainers) or in those who exhibited repeated cycles of weight loss with a subsequent weight regain (weight cyclers). In contrast obese patients who succeeded to retain the weight loss achieved initially by the VLCD at 2-yr follow-up (weight losers) or those who did not exhibit weight fluctuations (weight noncyclers) were characterized by a significantly lower RQ. Therefore a high fasting RQ during the VLCD treatment should be considered predictive of body weight gain. Resting metabolic rate (RMR) expressed per kg fat free mass (FFM) did not influence body weight changes. A high RQ revealed in obese subjects reporting parental obesity and a low fasting RQ observed in those obese without family history of obesity suggest a role of hereditary factors in the ability to oxidize fat in severely obese subjects. In contrast, parental history of obesity did not affect RMR in severely obese individuals.

Adult↗