Danuta Rosołowska-Huszcz

Leptin, Thyrotropin, and Thyroid Hormones in Obese/Overweight Women Before and After Two Levels of Energy Deficit

The aim of our study was to compare serum concentration of leptin and pituitary-thyroid axis hormones in obese/overweight women before and after two levels of energy deficit with those parameters in lean women on adequate energy intake. Additionally, we attempted to elucidate if the effect of weight reduction could be related to anthropometric and hormonal parameters before treatment. Anthropometric and hormonal parameters—serum leptin, TSH, T4, fT4, T3 and leptin to fat mass (Lep/fm), T3/T4, fT4/T4, T4/TSH, fT4/TSH—were compared in two groups of women (n=18 each)—lean women (C: BMI 22.0±1.2) and overweight/obese (Ov/Ob: BMI 29.9±3.3). Ov/Ob women were subjected to weight-reducing treatment consisting of energy intake equal to 80% of calculated total energy expenditure for the first 4 wk and to 50% for subsequent 4 wk. All baseline hormone concentrations, Lep/fm, and fT4/T4 were higher in overweight/obese group. After 20% energy deficit decrease in BMI, percent body fat (fm%), leptin, T3, and TSH serum concentrations as well as in Lep/fm and T3/T4 was observed; T4/TSH increased, fT4, fT4/T4 and fT4/TSH did not change significantly. Increase in energy deficit from 20% to 50% resulted in normalization of Lep/fm, on the other hand, it provoked greater decline in thyroid hormone plasma concentration, which could hinder further mass reduction. Leptin and TSH levels were positively correlated after 50% energy deficit treatment. Changes in fm% were directly related to baseline T4/TSH, fT4/TSH, and log TSH. In conclusion, TSH serum concentration and its ratio to T4 and fT4 before weight reduction could be a good predictor of successful weight loss.

Influence of low protein diet on nonthyroidal illness syndrome in chronic renal failure.

Renal failure causes alterations in thyroid hormone metabolism known as nonthyroidal illness syndrome. In the present study we have examined the effect of a low protein diet (LPD) on circulating levels of hormones of the pituitary-thyroid axis, and tumor necrosis factor alpha (TNF-alpha) in patients with chronic renal failure. Seventeen subjects with conservatively treated chronic renal failure (estimated creatinine clearance 39.5±11.1 mL/min) were studied before and after 8 wk of dietary intervention (0.6 g/kg of ideal body mass protein, 30% of calories derived from fat, 62% of calories derived from carbohydrates, and 10 mg/kg of phosphorus). Body fat and fat-free mass remained unchanged. Urea and TNF-alpha serum concentrations significantly decreased, whereas T3 and total and free T4 serum concentrations increased significantly. Triiodothyronine level after treatment correlated negatively with baseline urea level. Changes in T3, T4, and fT4 serum concentrations as well as calculated peripheral deiodinase activity correlated negatively with their baseline values. Alterations in TNF-alpha correlated positively with protein intake, whereas changes in T4 and T4/TSH were inversely related to vegetal protein intake. In conclusion, low protein, low phosphorus diet, which is often prescribed to patients with moderate impairment of renal function, exerts a beneficial effect on low T3 syndrome coexisting with renal failure. The effect of low protein diet on the pituitary-thyroid axis is dependent on the degree of renal functional impairment and LPD-induced decrease in TNF-alpha may also contribute to the observed effects of dietary treatment.

Low protein diet causes a decrease in serum concentrations of leptin and tumour necrosis factor-alpha in patients with conservatively treated chronic renal failure.

Background:  Chronic renal failure (CRF) provokes derangement in various hormonal regulations of food intake and energy expenditure. In the present study, we have examined the effect of a low protein, low phosphorus diet on circulating levels of leptin, tumour necrosis factor (TNF)‐alpha, and insulin in patients with CRF.

Adiponectin, resistin and leptin response to dietary intervention in diabetic nephropathy.

OBJECTIVE Adipokines play an important role in metabolic regulations. Obesity, diabetes, and renal disturbances affect adipokine profile by influencing their complex effects on metabolism. Our objective was to assess the effect of low-energy diet intervention on serum adiponectin, leptin, and resistin levels in diabetic nephropathy. METHODS Seventeen subjects with diabetes type 2 and nephropathy participated in the study. After estimation of individual resting metabolic rates by indirect calorimetry, diets introducing 20% energy deficit were applied. At baseline and after 2 months of dieting, the following parameters were measured: body composition by dual x-ray spectrometry and serum adiponectin (Adp), leptin (Lep), resistin (Res), insulin, urea, creatinine, glucose, glycosylated hemoglobin, C-reactive protein, and tumor necrosis factor-alpha concentrations. Homeostatic model assessment (HOMA) was used to quantify insulin resistance. RESULTS Total energy, protein, and fat intakes diminished significantly with intentional dieting. Significant decreases in total body fat mass (FM) and its percentage in body mass (FM%) and trunk and gynoid fat mass, as well as in serum resistin and tumor necrosis factor-alpha levels, were also observed. Responses of adipokines to dietary treatment varied individually. Generally, they were affected by FM. Alterations in Lep concentrations correlated negatively with baseline FM, FM%, and android and gynoid fat mass and positively with changes in intake of protein, carbohydrates, and total energy of the consumed diet. Changes in Adp were inversely related to FM after therapy. Alterations in Res concentrations correlated positively with android fat mass before therapy and initial Lep levels. Adiponectin was inversely related to HOMA index before and after treatment. CONCLUSIONS Low-energy diet applied in diabetic nephropathy may decrease serum resistin levels and inflammation. In addition, responses of all adipokines to dieting appear to be affected by body fat mass, especially android fat mass.

The State of Knowledge about Nutrition Sources of Vitamin D, Its Role in the Human Body, and Necessity of Supplementation among Parents in Central Poland

The percentage of children with vitamin D deficiency in Poland is alarming. The aim of the study was to assess the knowledge about sources of food and the function of vitamin D, as well as the frequency of its supplementation. A survey was conducted among the parents of children from Central Poland attending primary schools, and a questionnaire containing mainly open-ended questions was used to collect the data. Most mothers knew at least one of the functions of vitamin D in the body but had a low level of knowledge about its dietary sources. Only a small group of respondents supplemented themselves and their children with vitamin D. Statistically significant influences on the level of knowledge about the functions and sources of vitamin D were place of residence (i.e., better knowledge in the countryside) and mothers’ level of education (i.e., the better educated, the greater knowledge). In the case of monthly income level, such impact was observed only in relation to the knowledge of vitamin D functions. Concerning the frequency of supplementation, only maternal level of education had a statistically significant effect (i.e., the higher the education level, the higher the frequency of supplementation). In addition, mothers who were aware of functions of vitamin D and nutritional sources, significantly more frequently supplemented vitamin D.

Effects of Dietary Protein on Thyroid Axis Activity

Thyroid hormones (TH) are essential for the normal development and function of every vertebrate. The hypothalamic-pituitary-thyroid (HPT) axis is regulated to maintain euthyroid status. One of the most influential environmental factors that determines HPT axis activity is nutrition. Both food availability and substrate diversity affect thyroid hormone economy. The present paper aims to summarize literature data concerning the influence of the amount and the type of protein on thyroid axis activity. This review sheds light on the contribution of a low-protein diet or insufficient intake of essential amino acids to TH abnormalities. We believe that the knowledge of these dependencies could improve the results of nutritional interventions in thyroid axis disorders and enhance the efficiency of animal breeding.