Deiodinating activity in the brown adipose tissue of rats following short cold exposure after strenuous exercise

Exercise and/or Cold Exposure Alters the Gene Expression Profile in the Fat Body and Changes the Heart Function in Drosophila

The major reason of human morbidity and mortality is obesity and related diseases. Brown adipose tissue (BAT) is associated with low total adipose tissue content and a lower risk of type 2 diabetes mellitus. Studies have shown that exercise and cold expose may induce browning. In this study, we verified (1) whether exercise and/or cold exposure can improve the expression level of ucp4c, serca, ampkα, camkII, sirt1, octβ3r, and hamlet; (2) if these interventions can save cardiac dysfunction induced by a high-fat diet (HFD) in Drosophila. w1118 (wild-type) virgin female flies collected within 8 h after eclosion were divided into eight groups: the normal feed control group (NFD-C), the normal feed exercise group (NFD-E), the normal feed cold exposure group (NFD-CA), the normal feed exercise/cold exposure group (NFD-EC), the HFD control group (HFD-C), the HFD exercise group (HFD-E), the HFD cold exposure group (HFD-CA), and the HFD exercise/cold exposure group (HFD-EC). After exercise and/or cold exposure for 7 days, the mRNA expression levels of ucp4c, serca, ampkα, camk II, sirt1, octβ3r, and hamlet were tested by qRT-PCR, and m-mode was used to assess cardiac function. In addition, we assessed the triacylglycerol (TAG) levels, motor ability, fat mass (by Oil Red O [ORO] staining), and morphological features. The results of TAG, ORO staining, and morphological features all indicate that after interventions, body size of Drosophila was smaller compared with the control group, irrespective of the feeding patterns. The mRNA expression levels of ucp4c, serca, octβ3r, hamlet, ampkα, camkII, and sirt1 were changed to varying degrees under different intervention states (exercise and/or cold exposure). Cold exposure and exercise/cold exposure partly improved cardiac function and the normal fruit flies' cardiac function and exercise ability. However, after exercise intervention, exercise ability and heart function were improved in both HFD and normal-fat diet (NFD) fruit flies. In conclusion, different intervention states (exercise and/or cold exposure) can change the mRNA expression levels of ucp4c, serca, octβ3r, hamlet, ampkα, camkII, and sirt1. Exercise is the most effective way to restore HFD-induced cardiac dysfunction.

The effect of concurrent aerobic-resistance training on thyroid hormones, blood glucose hemostasis, and blood lipid indices in overweight girls with hypothyroidism

Background

The present study aimed to explore the effect of 8 weeks of concurrent aerobic-resistance training on thyroid stimulating hormone (TSH), thyroxine (T4), blood lipid profile, and blood glucose hemostasis in adolescent girls with hypothyroidism.

Materials and methods

In this clinical trial, 20 adolescent girls with hypothyroidism [age: 12.10 ± 1.94 years; body mass index (BMI): 25.25 ± 2.91 kg/m2] were selected and randomly assigned to experimental and control groups. The experimental group was treated with 8 weeks of concurrent aerobic [60–80% heart rate reserve (HHR)] and resistance (40–65% of 1RM) training. Blood was sampled before and after training. Data were analyzed using a pairwise t-test and an independent t-test (α < 0.05).

Results

Within-group comparison revealed significant decline of body index, BMI, fat percentage, fasting blood sugar, and homeostatic model assessment (HOMA) in the experimental group (p = 0.002, p = 0.001, p = 0.001, p = 0.03, and p = 0.02, respectively). Also, inter-group comparisons indicated significant differences in weight, BMI, fat percentage and HOMA (p = 0.001). But, no significant difference was observed in the blood sugar index (p > 0.05).

Conclusion

A short-term period of concurrent aerobic-resistance training may improve blood glucose hemostasis and body composition of adolescent girls with hypothyroidism. However, further research is necessary.

Effect of acute aerobic exercise on arterial stiffness and thyroid-stimulating hormone in subclinical hypothyroidism

Acute exercise has been reported to increase thyroid hormone levels and decrease arterial stiffness in healthy young subjects. However, the effect of acute aerobic exercise on circulating thyroid hormone levels and arterial stiffness in patients with subclinical hypothyroidism remains unclear. The aim of this study was to investigate the effects of acute aerobic exercise on arterial stiffness and thyroid hormone levels, and any relationship between these endpoints, in patients with subclinical hypothyroidism. We studied patients with untreated subclinical hypothyroidism (n = 53, 65 ± 12 years old) compared with euthyroid subjects (n = 55, 64 ± 10 years old). Exercise analysis was performed with a ramp cycle ergometer test. Arterial stiffness (cardio-ankle vascular index, CAVI) was measured at baseline and 5 min after exercise. We collected participant blood samples for serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4) measurements before and 5 min after exercise. The CAVI and serum TSH levels significantly decreased after exercise in the subclinical hypothyroidism group (CAVI; 8.1 ± 1.6 vs. 8.5 ± 1.5, p < 0.001, TSH; 6.7 ± 1.4 vs. 7.6 ± 1.2 μIU/ml, p < 0.001) and euthyroid group (CAVI; 7.6 ± 1.0 vs. 8.3 ± 0.9, p < 0.001, TSH; 2.2 ± 1.1 vs. 2.4 ± 1.2 μIU/ml, p = 0.005). The changes in CAVI from baseline compared with after exercise were lower, in absolute values, in the subclinical hypothyroidism group than in the euthyroid group (subclinical hypothyroidism group vs euthyroid group; ΔCAVI: - 0.4 ± 0.6 vs. - 0.7 ± 0.7, p = 0.012). The changes in serum TSH from baseline to after exercise were higher, in absolute values, in the subclinical hypothyroidism group than in the euthyroid group (subclinical hypothyroidism group vs euthyroid group; Δ serum TSH: - 1.3 ± 1.4 vs. - 0.3 ± 0.5, p < 0.001). The changes in CAVI from baseline to after exercise were negatively correlated with changes in TSH (r = - 0.32, p = 0.038) in the subclinical hypothyroidism group. In conclusion, acute aerobic exercise decreased both arterial stiffness and serum TSH levels in patients with subclinical hypothyroidism and euthyroid subjects. While the absolute change in arterial stiffness decreased, the absolute change in serum TSH levels increased in patients with subclinical hypothyroidism compared with euthyroid subjects. These data suggest that subclinical hypothyroidism reduces CAVI during acute aerobic exercise. Further changes in absolute levels of serum TSH in subclinical hypothyroidism may result in reduced CAVI improvement by acute aerobic exercise.

Effects of aerobic exercise on thyroid hormonal change responses among adolescents with intellectual disabilities

Objective

We aimed to investigate the impact of a 16-week aerobic exercise programme on the changes in the plasma level concentration of thyroid hormones in adolescents with intellectual disabilities.

Methodology

Using purposive sampling, a total of 36 adolescents with intellectual disabilities were selected to participate in the study. The training programme consisted of 16 weeks of moderate-intensity aerobic exercises at an intensity of 45–75 hours. These exercises were performed in three sessions a week, and each session took 30–45 min: 10 min warm-up, 15–30 min main aerobic workout and 5 min cool-down exercises. The plasma levels of triiodothyronine (T3) and tetraiodothyronine (T4) and of thyroid stimulating hormone were measured before and after 16 weeks of aerobic exercise intervention.

Results

After 16 weeks of intervention, a significant change was observed in the plasma level concentration of thyroid (T3 and T4) and thyroid stimulating hormones (p<0.05) in the group treated with aerobic exercise.

Conclusion

We concluded that aerobic exercise had an impact on the change in the plasma level concentration of thyroid and thyroid stimulating hormones in adolescents with intellectual disabilities.

Voluntary exercise adapts the hypothalamus-pituitary-thyroid axis in male rats

The hypothalamic-pituitary thyroid (HPT) axis modulates energy homeostasis. Its activity decreases in conditions of negative energy balance but the effects of chronic exercise on the axis are controversial and unknown at hypothalamic level. Wistar male rats were exposed for up to 14 days to voluntary wheel running (WR), or pair-feeding (PF; 18% food restriction), or to repeated restraint (RR), a mild stressor. WR and RR diminished food intake; body weight gain decreased in the 3 experimental groups, but WAT mass and serum leptin more intensely in the WR group. WR, but not RR, produced a delayed inhibition of central markers of HPT axis activity. At day 14, in WR rats paraventricular nucleus-pro-TRH mRNA and serum TSH levels decreased, anterior pituitary TRH-receptor 1 mRNA levels increased, but serum thyroid hormone levels were unaltered, which is consistent with decreased secretion of TRH and clearance of thyroid hormones. A similar pattern was observed if WR animals were euthanized during their activity phase. In contrast, in PF animals the profound drop of HPT axis activity included decreased serum T3 levels and hepatic deiodinase 1 activity; these changes were correlated with an intense increase in serum corticosterone levels. WR effects on HPT axis were not associated with changes in the activity of the hypothalamic-pituitary adrenal axis, but correlated positively with serum leptin levels. These data demonstrate that voluntary WR adapts the status of the HPT axis, through pathways that are distinct from those observed during food restriction or repeated stress.