Photoperiod effects on body mass, body composition, growth hormone, and thyroid hormones in male collared lemmings (Dicrostonyx groenlandicus)

1994 ◽  
Vol 72 (10) ◽  
pp. 1726-1734 ◽  
Author(s):  
Tim R. Nagy ◽  
Barbara A. Gower ◽  
Milton H. Stetson

The purpose of this study was to examine the effect of photoperiod on serum levels of growth hormone (GH) and thyroid hormones (TH), body mass, and body composition in collared lemmings (Dicrostonyx groenlandicus). Collared lemmings undergo seasonal changes in body mass and body composition, being heavier, but relatively less fat, during the winter months. These physiological changes can be induced in the laboratory by exposure to short photoperiod. The present study tests the hypothesis that photoperiod-mediated changes in GH and TH occur simultaneously with, and therefore may regulate or be permissive to, changes in body mass and body composition. Juvenile (19 d of age) or adult (50 d of age) male collared lemmings reared in long photoperiod (LD), 22 h light (L): 2 h dark (D), either remained in LD or were transferred to short photoperiod (SD), 8 h L: 16 h D. After 1, 2, 3, and 4 weeks (juveniles) or 1 and 3 weeks (adults) of treatment, animals were sacrificed. Serum levels of GH, triiodothyronine, and thyroxine were determined. Carcasses were weighed and analyzed for absolute and relative (analysis of covariance) fat-free dry mass, fat, and water. Exposure to SD resulted in an increase in GH, a decrease in TH, an increase in body mass (due to an absolute increase in all body components), a relative decrease in fat mass, and a relative increase in body water. Results are compatible with the hypothesis that a SD-mediated increase in GH is involved in the greater body mass gain observed in SD animals. Decreases in TH resulting from SD exposure, if associated with a decrease in heat production, may be permissive to mass gain.

1985 ◽  
Vol 108 (2) ◽  
pp. 211-216 ◽  
Author(s):  
G. Benker ◽  
C. Splittstößer ◽  
H. Meinhold ◽  
Th. Olbricht ◽  
D. Reinwein

Abstract. Bovine TSH was administered iv to 10 normal volunteers in doses of 2.5, 7.5, 15 and 30 mU/kg. Brisk elevations of serum diiodotyrosine occurred already after the smallest dose (mean, + 183%) while larger doses had only slight additional effects. T3 rose much higher than T4 (+71% compared to +23% after 15 mU bTSH/kg), and free thyroid hormones exhibited changes similar to total T3 and total T4. The mean absolute increase in serum fT3 ranged from 2.03 to 9.04 pmol/l and proved to be an easily measurable parameter for the TSH effect. Dose-response effects were seen for the increases of fT4, fT3 and T3. TBG and rT3 did not change but the degradation product 3,3'-T2 showed large increments of serum levels. There was no correlation between the response of T3 and T4, fT3 and fT4, or diiodotyrosine and any of the other parameters of thyroid function. The interindividual differences in the magnitude of thyroid hormone response to TSH were considerable, and there was no relationship between this response and thyroid volume by ultrasound. We conclude that direct stimulation of the thyroid gland with bTSH in small doses leads to consistent increases of thyroid hormones, especially T3 and fT3, that the response varies between individuals, and that the precursor diiodotyrosine is released together with thyroid hormones.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Adriana Claudia Lopes Carvalho-Furtado ◽  
Cintia Ramari ◽  
Edgard Soares ◽  
Daniel R F Saint-Martin ◽  
Luiz Guilhemme Grossi Porto ◽  
...  

Abstract Objective: To compare health-related physical fitness (HRPF) in patients with severe adult growth hormone deficiency (AGHD) according to the deficiency onset phase, and to evaluate the effects of a six-months human growth hormone (rhGH) replacement therapy on HRPF, in a subgroup of patients. Methods: First arm: cross-sectional observational study at baseline of naive rhGH multiple pituitary hormonal deficiency (MPHD) hypopituitarism patients - adult-onset growth hormone deficiency (AO-GHD) versus child onset growth hormone deficiency (CO-GHD). Second arm: a 6-month intervention clinical trial in a selected group of a non-randomized, non-controlled cohort. HRPF was evaluated by measuring isokinetic and isometric torque stensor strength at the knee using an isokinetic dynamometer, handgrip strength and six-minute walk test. Body composition was assessed by DXA. Results: Patients who presented AO-GHD had higher BMI than CO-GHD (28.1±3.5 x 22.4±4.8; p=0.017), but body composition (lean body mass%:57.9±7.9 x 58.9±8.6;p=0.816/fatty body mass%:39.3±6.8 x 36.0±9.1;p=0.434), stensor peak torque/body weight at 60, 90 and 180deg/s (2.18±0.6 x 2.18±0.6; p=0.580/1.99±0.5 x 2.14±0.5;p=0.546/1.52±0.4 x 1.64±0.4;p=0.547), isometric torque/body weight at the knee (2.62±0.7 x 2.91±0.6;p=0.357) and six-minute walk test (570.2±76.0cm x 554.1±91.0cm;p= 0.703) did not differ between groups. Handgrip strength test also showed significant reduction in scores for age and gender in both groups of GHD patients. After six months of rhGH, no improvement in muscular strength tests was found. There was a significant worsening in the six-minute walk test (575.1±84cm x 545.4±90.6cm; p=0.033) despite the improvement in body composition (lean body mass%:59.7±8.6 x 63.6±11.1;p=0.005/fatty body mass%:35.7±9.2 x 32.9±10.0;p=0.003). Conclusion: Despite differences in BMI, there were no other differences in HRPF between AO-GHD and CO-GHD patients. The decrease of the six-minute walking test performance after rhGH replacement therapy supports the clinical evidence that the GH regulates bioenergetics in human skeletal muscle fibers. Although the treatment had a short period, GH might have stimulated the anaerobic and suppressed the aerobic energy system.


1998 ◽  
pp. 633-639 ◽  
Author(s):  
T Sugimoto ◽  
D Nakaoka ◽  
M Nasu ◽  
M Kanzawa ◽  
T Sugishita ◽  
...  

The present study was performed to investigate the age-dependent changes in body composition and the possible role of growth hormone (GH), insulin-like growth factor (IGF)-I and IGF-binding protein-3 (IGFBP-3) in these changes in postmenopausal Japanese women. A total of 161 Japanese women aged 45-88 years (mean 62) were enrolled in the cross-sectional study. Body composition (bone mineral content (BMC), lean body mass (LBM) and fat) was measured by dual-energy X-ray absorptiometry, and the percentage of BMC, LBM and fat was calculated by dividing each absolute value of body composition by total body mass. Urinary GH concentration divided by creatinine in nocturnal urine samples collected just after waking was used as an index of endogenous GH secretion. Serum levels of IGF-I and IGFBP-3 were measured by RIA. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 declined with age. BMC, %BMC and LBM also declined with age, while fat mass and %fat did not obviously change with age. Urinary GH levels as well as serum levels of IGF-I and IGFBP-3 correlated positively with BMC, even if age was taken into account. On the other hand, urinary GH correlated negatively with fat and %fat. In contrast, serum levels of IGF-I and IGFBP-3 correlated positively with fat and %fat. LBM did not correlate with either urinary GH or serum IGFBP-3 levels but exhibited a weakly positive correlation with serum IGF-I level. The present study suggests that the GH-IGF-I-IGFBP-3 axis positively regulates bone mass, and that GH and IGF-I-IGFBP-3 inversely regulate fat mass, i.e. GH negatively and IGF-I-IGFBP-3 positively regulates it.


2019 ◽  
Vol 23 (4) ◽  
pp. 173-180
Author(s):  
Soo Youn Kim ◽  
Jung Ho Cho ◽  
Ji Hyun Lee ◽  
Jae Hyun Jung

This study investigated changes in body composition, energy balance, and appetite-regulating hormones in professional female ballet dancers before and after 3 days of ballet performances. The subjects were 43 professional female ballet dancers in Korea. The mean age of the subjects was 25.9 ± 2.8 years, and they had over 13 years of ballet training on average. For body composition, the body mass index (BMI), percent body fat (%BF), lean body mass (LBM), and total body water (TBW) were evaluated. By way of blood analysis the serum levels of ghrelin, leptin, and insulin were examined. The calculations of energy intake (EI) and expenditure (EE) were based on journals that were self-recorded by the subjects for 14 days. For statistical analysis, the dependent sample t-test was applied (p < 0.05). The results showed no significant change in %BF, but the BMI, LBM, and TBW increased significantly in the post-performance measurement. Energy balance results demonstrated a significant increase in EI and decrease in EE. Both the ghrelin and leptin levels increased significantly. Although reported energy intake increased after performances, it remained below estimated energy requirements. Ballet dancers should be aware of the need to maintain energy balance in order to optimize their health and performance.


Author(s):  
Anna G W Rosenberg ◽  
Caroline De Gouveia Buff Passone ◽  
Karlijn Pellikaan ◽  
Durval Damiani ◽  
Aart J Van Der Lely ◽  
...  

Abstract Context Features of Prader-Willi syndrome (PWS) overlap with features of growth hormone (GH) deficiency, like small hands and feet, short stature, increased body fat and low muscle mass and strength. In children with PWS, GH treatment (GHt) improves physical health and cognition. GHt has become standard of care in PWS children, but in adults this is not yet the case. Objective To provide an overview of the current knowledge on GHt in PWS adults. Data source Medline, Embase and Cochrane Central Register of Controlled Trials databases. Study selection Randomized controlled trials (RCTs) and non-randomized (un)controlled trials (NRCTs) that reported data for adults with PWS, who received GHt for at least six months. Data extraction Data on body composition, body mass index (BMI), cardiovascular endpoints, bone, cognitive function, quality of life and safety were extracted. Data synthesis Nine RCTs and 20 NRCTs were included. Body composition improved during 12 months of GHt with an increase in mean (95% CI) lean body mass of 1.95 kg (0.04 – 3.87 kg), and a reduction of mean (95% CI) fat mass of -2.23% (-4.10% to -0.36%). BMI, low-density lipoprotein cholesterol levels, fasting glucose levels and bone mineral density did not change during GHt. There were no major safety issues. Conclusion GHt appears to be safe and improves body composition in adults with PWS. As poor body composition is closely linked to the observed high incidence of cardiovascular morbidity in adults with PWS, improving body composition might reduce cardiovascular complications in this vulnerable patient group.


1987 ◽  
Vol 65 (10) ◽  
pp. 2362-2368 ◽  
Author(s):  
David Crews ◽  
Mark Grassman ◽  
William R. Garstka ◽  
Andrew Halpert ◽  
Brian Camazine

Field and laboratory studies revealed that male and female Canadian red-sided garter snakes, Thamnophis sirtalis parietalis, differ in the pattern of body mass gain, nutrient storage, and nutrient availability following emergence from hibernation. In nature males fail to gain weight or store fat until 3 weeks after emergence from prolonged (7 months) winter hibernation. In the laboratory males also do not exhibit an increase in body mass following emergence from artificial hibernation (17 weeks) until mating behavior has ended, about 3 weeks after emergence; as in free-living males, fat stores do not increase until all mating behavior has ceased. In contrast, females in both field and laboratory populations gain weight steadily following emergence but exhibit a gradual decrease in the proportion of abdominal fat reserves to body mass. While females exhibit increased serum levels of protein, unchanged levels of glucose, and decreased levels of lipid, males exhibit unchanged levels of protein, increased levels of glucose, and decreased levels of lipid. Males display a greater resting oxygen consumption postemergence compared with females. Oxygen consumption was decreased in both sexes during the period coinciding with mating; at the end of breeding, oxygen consumption increased. These data are consistent with the marked differences in reproductive behaviors between the sexes following emergence from hibernation.


2018 ◽  
Vol 74 (12) ◽  
pp. 1973-1979
Author(s):  
Maria Theresa D Opina ◽  
Tina E Brinkley ◽  
Michelle Gordon ◽  
Mary F Lyles ◽  
Barbara J Nicklas

Abstract Background Adiposity-related ventilatory constraints in older adults can potentially contribute to greater risk of exercise intolerance and mobility disability. This study investigated whether ventilatory limitation, measured by breathing reserve (BR) at peak exercise, is associated with body composition and physical function in older adults with obesity. Methods This study was a cross-sectional analysis of data from a community-based cohort (N = 177) of older men and women (65–79 years) with obesity (body mass index = 30–45 kg/m2). All participants underwent cardiopulmonary exercise testing on a treadmill, dual-energy X-ray absorptiometry for body composition, and physical function assessments. We examined relationships between BR and body composition and physical function using multiple linear regression and compared a subset with (BR ≤ 30%; BR-low; n = 56) and without (BR ≥ 45%; BR-high, n = 48) ventilatory limitation using unpaired Student’s t test and analysis of covariance. Results BR was inversely related to total body mass, lean mass, fat mass, % body fat, and waist circumference (p < 0.05 for all). BR was positively related to 400 m walk time (p = .006) and inversely related to usual gait speed (p = .05) and VO2peak (p < .0001), indicative of worse physical function. BR-low had greater adiposity, but also greater lean mass, higher VO2peak, and faster 400 m walk time, compared to BR-high (p < .05, for all). Conclusions Older adults with obesity who also have ventilatory limitation have overall higher measures of adiposity, but do not have lower peak exercise capacity or physical function. Thus, ventilatory limitation does not appear to be a contributing factor to obesity-related decrements in exercise tolerance or mobility.


Sign in / Sign up

Export Citation Format

Share Document