Background: The selenium content in foods varies widely, with foods high in protein and low in fat, such as fish, lean meats, legumes, cereals and dairy products being its best nutritional sources. Selenium is a component of type 1 deiodinase, the enzyme converting T4 to T3 peripherally. Treatment of obesity with hypocaloric diets causes changes in thyroid function consisting of a decrease in total T4 and total and free T3 with a corresponding increase in reverse (r)T3. Aim: To evaluate the effect of selenium in combination with a balanced mild hypocaloric diet on thyroid function and body composition in euthyroid overweight/obese women. Patients and methods: Twenty-one euthyroid overweight/obese women (BMI median value 31(26-42) kg/m2), with age range 19-49 yrs, were consecutively recruited. Fifteen age and BMI-matched women served as control group. Anthropometric parameters, TSH, FT3, and FT4 levels and FT3/FT4 ratio , as an index of deiodination, were evaluated. The intake of selenium was evaluated with a 3- Days Food Diary and then calculated with software WinFood Light 1.0. A balanced mild hypocaloric diet (57% CHO, 28% fat, 15% protein) with Kcal median values 1435(1280-1580) was associated with a supplementation of 400 mg/die of L-selenomethionine, (Syrel® 400 mg) for 6 months. Body composition was evaluated by bioimpedance analysis (single-frequency 50 kHz BIA 101 RJL, Akern) and biavector analysis (BIVA software [Piccoli A, Pastori G (2002)]. Results: After 6 months BMI and waist circumference were reduced in both patients (BMI: 31(26-42) vs 28(24-41) kg/m2, p<0.001; waist circumference: 95(79-126) vs 91(72-122) cm, p<0.001) and controls (BMI: 33(28-44) vs 29(26-42) kg/m2, p=0.02; waist circumference: 99(84-133) vs 96(81-123) cm, p=0.02). Percentage of fat-free mass increased in patients (56%(27-69) vs 62%(50-71), p=0.05), while decreased in controls (58%(39-76) vs 53%(31-69), p=0.04). In patients, TSH, FT3 and FT4 levels did not change significantly, but FT3/FT4 ratio increased significantly (2.2(0.9-3.2) vs 2.6(1.1-3.3), p=0.05), whereas in control group FT3 levels (1.4(0.8-2) vs 1.0(0.7-1.5) pg/ml, p<0.001) and FT3/FT4 ratio (2.3(1.9-2.6) vs 1.8(1.7-2.3), p=0.05) were significantly reduced. Conclusions: Our data suggest that the supplementation with selenium associated with a balanced mild hypocaloric diet in euthyroid overweight/obese women might contribute to preserve thyroid function and to counteract some of the adaptive mechanisms implicated in weight regain after weight loss.
EFFECTS OF SELENIUM SUPPLEMENTATION ON THYROID FUNCTION IN OVERWEIGHT-OBESE WOMEN AFTER A BALANCED MILD HYPOCALORIC DIET.
Barrea L;
2013-01-01
Abstract
Background: The selenium content in foods varies widely, with foods high in protein and low in fat, such as fish, lean meats, legumes, cereals and dairy products being its best nutritional sources. Selenium is a component of type 1 deiodinase, the enzyme converting T4 to T3 peripherally. Treatment of obesity with hypocaloric diets causes changes in thyroid function consisting of a decrease in total T4 and total and free T3 with a corresponding increase in reverse (r)T3. Aim: To evaluate the effect of selenium in combination with a balanced mild hypocaloric diet on thyroid function and body composition in euthyroid overweight/obese women. Patients and methods: Twenty-one euthyroid overweight/obese women (BMI median value 31(26-42) kg/m2), with age range 19-49 yrs, were consecutively recruited. Fifteen age and BMI-matched women served as control group. Anthropometric parameters, TSH, FT3, and FT4 levels and FT3/FT4 ratio , as an index of deiodination, were evaluated. The intake of selenium was evaluated with a 3- Days Food Diary and then calculated with software WinFood Light 1.0. A balanced mild hypocaloric diet (57% CHO, 28% fat, 15% protein) with Kcal median values 1435(1280-1580) was associated with a supplementation of 400 mg/die of L-selenomethionine, (Syrel® 400 mg) for 6 months. Body composition was evaluated by bioimpedance analysis (single-frequency 50 kHz BIA 101 RJL, Akern) and biavector analysis (BIVA software [Piccoli A, Pastori G (2002)]. Results: After 6 months BMI and waist circumference were reduced in both patients (BMI: 31(26-42) vs 28(24-41) kg/m2, p<0.001; waist circumference: 95(79-126) vs 91(72-122) cm, p<0.001) and controls (BMI: 33(28-44) vs 29(26-42) kg/m2, p=0.02; waist circumference: 99(84-133) vs 96(81-123) cm, p=0.02). Percentage of fat-free mass increased in patients (56%(27-69) vs 62%(50-71), p=0.05), while decreased in controls (58%(39-76) vs 53%(31-69), p=0.04). In patients, TSH, FT3 and FT4 levels did not change significantly, but FT3/FT4 ratio increased significantly (2.2(0.9-3.2) vs 2.6(1.1-3.3), p=0.05), whereas in control group FT3 levels (1.4(0.8-2) vs 1.0(0.7-1.5) pg/ml, p<0.001) and FT3/FT4 ratio (2.3(1.9-2.6) vs 1.8(1.7-2.3), p=0.05) were significantly reduced. Conclusions: Our data suggest that the supplementation with selenium associated with a balanced mild hypocaloric diet in euthyroid overweight/obese women might contribute to preserve thyroid function and to counteract some of the adaptive mechanisms implicated in weight regain after weight loss.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
