The effect of puberty on fat oxidation rates during exercise in overweight and normal-weight girls

2014 ◽  
Vol 116 (1) ◽  
pp. 76-82 ◽  
Author(s):  
L. Chu ◽  
M. C. Riddell ◽  
J. E. Schneiderman ◽  
B. W. McCrindle ◽  
J. K. Hamilton
Keyword(s):  
Tanner Stage ◽  
Fat Oxidation ◽  
Tolerance Test ◽  
Cycle Ergometer ◽  
Normal Weight ◽  
Fat Free Mass ◽  
Oral Glucose ◽  
Model Assessment ◽  
Early Puberty ◽  
Oxidation Rates

Excess weight is often associated with insulin resistance (IR) and may disrupt fat oxidation during exercise. This effect is further modified by puberty. While studies have shown that maximal fat oxidation rates (FOR) during exercise decrease with puberty in normal-weight (NW) and overweight (OW) boys, the effect of puberty in NW and OW girls is unclear. Thirty-three NW and OW girls ages 8–18 yr old completed a peak aerobic capacity test on a cycle ergometer. FOR were calculated during progressive submaximal exercise. Body composition and Tanner stage were determined. For each participant, a best-fit polynomial curve was constructed using fat oxidation vs. exercise intensity to estimate max FOR. In a subset of the girls, IR derived from an oral glucose tolerance test ( n = 20), and leptin and adiponectin levels ( n = 11) were assessed in relation to FOR. NW pre-early pubertal girls had higher max FOR [6.9 ± 1.4 mg·kg fat free mass (FFM)−1·min−1] than NW mid-late pubertal girls (2.2 ± 0.9 mg·kg FFM−1·min−1) ( P = 0.002), OW pre-early pubertal girls (3.8 ± 2.1 mg·kg FFM−1·min−1), and OW mid-late pubertal girls (3.3 ± 0.9 mg·kg FFM−1·min−1) ( P < 0.05). Bivariable analyses showed positive associations between FOR with homeostatic model assessment of IR ( P = 0.001), leptin ( P < 0.001), and leptin-to-adiponectin ratio ( P = 0.001), independent of percent body fat. Max FOR decreased in NW girls during mid-late puberty; however, this decrease associated with puberty was blunted in OW girls due to lower FOR in pre-early puberty. The presence of IR due to obesity potentially masks the effect of puberty on FOR during exercise in girls.

scholarly journals Circulating obestatin levels and the ghrelin/obestatin ratio in obese women

2007 ◽  
Vol 157 (3) ◽  
pp. 295-301 ◽  
Author(s):  
Valentina Vicennati ◽  
Silvia Genghini ◽  
Rosaria De Iasio ◽  
Francesca Pasqui ◽  
Uberto Pagotto ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Tolerance Test ◽  
Normal Weight ◽  
Metabolic Parameters ◽  
Blood Levels ◽  
Oral Glucose ◽  
Sensitivity Index ◽  
Model Assessment ◽  
Obese Women ◽  
Glucose Levels

Objective: We measured blood levels of obestatin, total ghrelin, and the ghrelin/obestatin ratio and their relationship with anthropometric and metabolic parameters, adiponectin and insulin resistance, in overweight/obese and normal-weight women. Design: Outpatients Unit of Endocrinology of the S Orsola-Malpighi Hospital of Bologna, Italy. Methods: Fasting obestatin, ghrelin, adiponectin and lipid levels, fasting and glucose-stimulated oral glucose tolerance test insulin, and glucose levels were measured in 20 overweight/obese and 12 controls. The fasting ghrelin/obestatin ratio was calculated; the homeostasis model assessment-IR (HOMA-IR) and insulin sensitivity index (ISIcomposite) were calculated as indices of insulin resistance. Results: Obese women had higher obestatin and lower ghrelin blood levels, and a lower ghrelin/obestatin ratio compared with controls. In all subjects, obestatin was significantly and positively correlated with total cholesterol and triglycerides, but not with ghrelin, anthropometric, and metabolic parameters. In the obese women, however, obestatin and ghrelin concentrations were positively correlated. By contrast, the ghrelin/obestatin ratio was significantly and negatively correlated with body mass index, waist, waist-to-hip ratio, fasting insulin, and HOMA-IR, and positively with ISIcomposite but not with adiponectin. None of these parameters were correlated with the ghrelin/obestatin ratio in the obese. Conclusions: Increased obestatin, decreased ghrelin levels, and a decreased ghrelin/obestatin ratio characterize obesity in women. This supports the hypothesis that the imbalance of ghrelin and obestatin may have a role in the pathophysiology of obesity. On the other hand, some relevant differences between our data on circulating levels of obestatin and the ghrelin/obestatin ratio in obese subjects and those reported in the few studies published so far imply that further research is needed.

scholarly journals Insulin Resistance Diagnosed by HOMA-IR may be Overestimated in Adults with Greater Fat-Free Mass: The ELSA-Brasil Study

2020 ◽  
Author(s):  
Divanei Zaniqueli ◽  
Rafael de Oliveira Alvim ◽  
Rosane Harter Griep ◽  
Isabela Martins Benseñor ◽  
Sandhi Maria Barreto ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Fat ◽  
Bioelectrical Impedance ◽  
Tolerance Test ◽  
Fat Free Mass ◽  
Percent Body Fat ◽  
Oral Glucose ◽  
Model Assessment ◽  
Fasting Insulin ◽  
Cross Sectional

Abstract Background Conflicting results have been reported on the association of fat-free mass (FFM) and insulin resistance (IR). The way of indexing FFM may be a bias. This study sought to test the association of FFM and IR after indexing FFM to avoid collinearity. Methods This cross-sectional study comprised 11,284 volunteers, ages 38-79 years. Body composition was assessed by multi-frequency bioelectrical impedance. FFM indexed to body surface area (FFMbsa) was calculated. Excess body fat was assigned to individuals with percent body fat ≥ 85th percentile for age and sex. Fasting insulin and glucose, and 2h glucose in the oral glucose tolerance test were obtained. Homeostasis model assessment-insulin resistance (HOMA-IR) > 3.0 was set as the cut-off for IR.Results Percent body fat decreased from the 1st to the 5th quintile of FFMbsa in both women (Eta 2 = 0.166) and men (Eta 2 = 0.133). In women, fasting insulin (Eta 2 = 0.002), glucose (Eta 2 = 0.006), and HOMA-IR (Eta 2 = 0.007) increased slightly, whereas 2h glucose did not change towards the highest quintile of FFMbsa. In men, fasting insulin and HOMA-IR were similar across the quintiles of FFMbsa, whereas fasting glucose increased slightly (Eta 2 = 0.002) and 2h glucose decreased (Eta 2 = 0.005) towards the highest quintile of FFMbsa. Greater FFMbsa explained 1.8% of the odds of IR among women and 0.9% among men.Conclusion The lack of association of FFM and 2h glucose contrasted with greater odds of IR (by HOMA-IR) associated with greater FFM. The association of greater FFM and IR may be overestimated when the diagnosis is provided by HOMA-IR.

Substrate Oxidation Is Altered by Obesity During Submaximal Cycling in Prepubertal and Early Pubertal Children: A Quality Study

2020 ◽  
pp. 1-8
Author(s):  
Kerri Z. Delaney ◽  
Leandra Spatari ◽  
Mélanie Henderson ◽  
Sylvia Santosa ◽  
Marie-Eve Mathieu
Keyword(s):  
Lipid Oxidation ◽  
Tanner Stage ◽  
Substrate Oxidation ◽  
Cycle Ergometer ◽  
Gas Analysis ◽  
Fat Free Mass ◽  
Healthy Weight ◽  
Exercise Protocol ◽  
Early Puberty ◽  
Stage 1

Background: To examine substrate oxidation in prepubertal and early pubertal children as a function of body weight, body composition, and sex during an exhaustive cycling test. Methods: This study included 320 children in prepubertal and early puberty (Tanner stage 1 or 2; n = 188 males) who completed a minimum of 4 stages (2–5 min/stage) of an adapted version of the McMaster exhaustive exercise protocol on an upright cycle ergometer. Substrate utilization, relative to individual VO2peak, was determined using VO2 and VCO2 data, obtained with breath-by-breath gas analysis during exercise. Results: Both peak (mg/kg lean body mass·min) and submaximal lipid oxidation (mg/kg lean body mass·min) were highest (P < .01) in children with healthy weight (HW), then overweight, and lowest in obese (OB). Both females with HW (compared with males with HW) and females with OB (compared with males with OB) had higher (P < .01) peak and submaximal lipid oxidation. In children with OB, fat-free mass correlated positively (P < .01) with submaximal lipid oxidation (r = .50). In contrast, in children with HW and overweight, fat-free mass correlated positively (P < .01) with carbohydrate oxidation (r = .52 and r = .47, respectively). Conclusion: Obesity during childhood may alter substrate oxidation during exercise. These results may have implications in the implementation of exercise programs in prepubertal or early puberty to control adiposity.

The Entero-Insular Axis in Polycystic Ovarian Syndrome

1996 ◽  
Vol 33 (3) ◽  
pp. 190-195 ◽  
Author(s):  
R Garaa ◽  
F Norris ◽  
J Wright ◽  
L Morgan ◽  
S Hampton ◽  
...  
Keyword(s):  
Polycystic Ovarian Syndrome ◽  
Gastric Inhibitory Polypeptide ◽  
Tolerance Test ◽  
Normal Weight ◽  
Immunoreactive Insulin ◽  
Oral Glucose ◽  
Hepatic Extraction ◽  
C Peptide ◽  
Molar Ratios ◽  
Ovarian Syndrome

We investigated the contributions made by the entero-insular axis, proinsulin and the fractional hepatic extraction of insulin to the hyperinsulinaemia characteristic of polycystic ovarian syndrome (PCOS). We measured plasma glucose, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (7–36 amide) (GLP-17–36 amide), immunoreactive insulin (IRI), intact proinsulin (IPI), and C-peptide concentrations during a 75 g oral glucose tolerance test in seven normal weight women with PCOS and eight healthy women. Women with PCOS had higher fasting ( P = 0·05) and integrated ( P < 0·01) IRI concentrations than controls. Fasting C-peptide levels were similar in both groups but integrated C-peptide ( P < 0·05) concentrations were greater in PCOS subjects than controls. Fasting and integrated concentrations of glucose, GIP and GLP-17–36 amide were similar in subjects with PCOS and controls. Although fasting IPI concentrations were similar in both groups, integrated IPI concentrations were higher ( P = 0·05) in patients with PCOS. Women with PCOS had similar fasting but higher ( P <0·05) integrated IRI: C-peptide molar ratios than controls. Fasting and integrated IPI: IRI molar ratios were similar in both groups. These results confirm that lean women with PCOS have peripheral hyperinsulinaemia. The mild fasting hyperinsulinaemia is due to increased pancreatic secretion, whereas the stimulated hyperinsulinaemia is due to both pancreatic hypersecretion and reduced fractional hepatic extraction of insulin. Hyperproinsulinaemia is modest and appropriate in PCOS. GIP and GLP-17–36 amide do not contribute to the stimulated hyperinsulinaemia in PCOS.

Glucose tolerance and insulin action in healthy centenarians

1996 ◽  
Vol 270 (5) ◽  
pp. E890-E894 ◽  
Author(s):  
G. Paolisso ◽  
A. Gambardella ◽  
S. Ammendola ◽  
A. D'Amore ◽  
V. Balbi ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Plasma Glucose ◽  
Insulin Action ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Fat Free Mass ◽  
Whole Body ◽  
Glucose Disposal ◽  
Oral Glucose ◽  
Aged Subjects

Advancing age has been found to be associated with a decline in insulin action. Nevertheless, no study has been conducted in healthy centenarians. Our study investigates glucose tolerance and insulin action in centenarians. Fifty-two subjects were enrolled. The subjects were divided in three groups as follows: 1) adults (< 50 yr; n = 20);2) aged subjects (> 75 yr; n = 22); and 3) centenarians (> 100 yr; n = 14). Body composition was studied by bioimpedance analysis. In all subjects, an oral glucose tolerance test and euglycemic glucose clamp were performed. Centenarians have a lower fat-free mass (FFM) than aged subjects and adults, whereas fasting plasma glucose, triglycerides, free fatty acids, urea, and creatinine were not different in the groups studies. Centenarians had a 2-h plasma glucose concentration (6.0 +/- 0.2 mmol/l) that was lower than that in aged subjects (6.6 +/- 0.5 mmol/l, P < 0.05) but not different from adults [6.4 +/- 0.4 mmol/l, P = not significant (NS)]. During the clamp, plasma glucose and insulin concentrations were similar in the three groups. In these conditions, centenarians had a whole body glucose disposal (34.1 +/- 0.6 mumol.kg FFM-1.min 1) that was greater than that in aged subjects (23.3 +/- 0.5 mumol.kg FFM-1.min-1 P < 0.01) but not different from adults (34.6 +/- 0.5 mumol/kg x min, P = NS). In conclusion, our study demonstrates that centenarians compared with aged subjects had a preserved glucose tolerance and insulin action.

Leptin concentrations during oral glucose tolerance test (OGTT) in obese and normal weight women

1999 ◽  
Vol 23 (6) ◽  
pp. 625-628 ◽  
Author(s):  
M Bougoulia ◽  
T Tzotzas ◽  
H Efthymiou ◽  
G Koliakos ◽  
TH Konstantinidis ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Oral Glucose Tolerance Test ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Normal Weight ◽  
Oral Glucose ◽  
Oral Glucose Tolerance

scholarly journals Studies of insulin resistance in patients with clinical and subclinical hypothyroidism

2009 ◽  
Vol 160 (5) ◽  
pp. 785-790 ◽  
Author(s):  
Eirini Maratou ◽  
Dimitrios J Hadjidakis ◽  
Anastasios Kollias ◽  
Katerina Tsegka ◽  
Melpomeni Peppa ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Plasma Membrane ◽  
Glucose Transport ◽  
Subclinical Hypothyroidism ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Model Assessment ◽  
Increased Risk

ObjectiveAlthough clinical hypothyroidism (HO) is associated with insulin resistance, there is no information on insulin action in subclinical hypothyroidism (SHO).Design and methodsTo investigate this, we assessed the sensitivity of glucose metabolism to insulin both in vivo (by an oral glucose tolerance test) and in vitro (by measuring insulin-stimulated rates of glucose transport in isolated monocytes with flow cytometry) in 21 euthyroid subjects (EU), 12 patients with HO, and 13 patients with SHO.ResultsAll three groups had comparable plasma glucose levels, with the HO and SHO having higher plasma insulin than the EU (P<0.05). Homeostasis model assessment index was increased in HO (1.97±0.22) and SHO (1.99±0.13) versus EU (1.27±0.16, P<0.05), while Matsuda index was decreased in HO (3.89±0.36) and SHO (4.26±0.48) versus EU (7.76±0.87, P<0.001), suggesting insulin resistance in both fasting and post-glucose state. At 100 μU/ml insulin: i) GLUT4 levels on the monocyte plasma membrane were decreased in both HO (215±19 mean fluorescence intensity, MFI) and SHO (218±24 MFI) versus EU (270±25 MFI, P=0.03 and 0.04 respectively), and ii) glucose transport rates in monocytes from HO (481±30 MFI) and SHO (462±19 MFI) were decreased versus EU (571±15 MFI, P=0.04 and 0.004 respectively).ConclusionsIn patients with HO and SHO: i) insulin resistance was comparable; ii) insulin-stimulated rates of glucose transport in isolated monocytes were decreased due to impaired translocation of GLUT4 glucose transporters on the plasma membrane; iii) these findings could justify the increased risk for insulin resistance-associated disorders, such as cardiovascular disease, observed in patients with HO or SHO.

scholarly journals The effects of natural nano-sized clinoptilolite and Nigella sativa supplementation on serum bone markers in diabetic rats

Bioimpacts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 173-178
Author(s):  
Yalda Salari Lak ◽  
Sirous Khorram ◽  
Mehran Mesgari Abbasi ◽  
Mohammad Asghari-Jafarabadi ◽  
Ali Tarighat-Esfanjani ◽  
...  
Keyword(s):  
Bone Markers ◽  
Nigella Sativa ◽  
Bone Mineralization ◽  
Serum Levels ◽  
Study Groups ◽  
Tolerance Test ◽  
Diabetic Rats ◽  
Oral Glucose ◽  
Model Assessment ◽  
Beneficial Effects

Introduction: Many studies confirm that diabetes mellitus is associated with higher risks of bone fracture. The beneficial effects of Nigella sativa (NS) and clinoptilolite in preventing/reducing some diabetes-related disorders have been shown. This study was conducted to examine the effects of separate and concurrent supplementation of natural nano-sized clinoptilolite (NCLN) and NS on serum bone markers in rats with type 2 diabetes. Methods: A total of 42 (case=36 and control=6) adult male Wistar rats were divided into 2 groups: diabetic and non-diabetic. An oral glucose tolerance test and a homeostatic model assessment of insulin resistance (HOMA-IR) test were conducted to confirm diabetes. Then, the diabetic group was divided into 4 subgroups: [1] control (n=9), [2] NS 1%/food (n=9), [3] NCLN 2%/food (n=9), [4] NS 1%/food + NCLN 2%/food (n=9). After 7 weeks, serum levels of bone markers were determined using ELISA kits. Results: Analysis showed that serum levels of alkaline phosphatase (ALP) in the NCLN group (1318.6 ± 217.5 U/L) was significantly (P<0.05) higher than other intervented groups. On the other hand, serum levels of calcium in NCLN+NS group (10.8 ± 2.6 mg/dL) were higher (P=0.027) compared to all other study groups. However, rats in the NS group had higher (535.8 ± 49.3 pg/mL) PTH (P<0.0001) compared to other supplementation groups. There were no significant differences in vitamin D and osteoprotegerin. Conclusion: The results of the current study suggest that bone mineralization may be affected by concurrent use of NS and NCLN through influencing calcium circulation. Moreover, dietary NS administration is strongly related to an augmented level of PTH.

Nighttime snacking reduces whole body fat oxidation and increases LDL cholesterol in healthy young women

2013 ◽  
Vol 304 (2) ◽  
pp. R94-R101 ◽  
Author(s):  
Masanobu Hibi ◽  
Ayumi Masumoto ◽  
Yuri Naito ◽  
Kahori Kiuchi ◽  
Yayoi Yoshimoto ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Fat Oxidation ◽  
Tolerance Test ◽  
Whole Body ◽  
Oral Glucose ◽  
Night Time ◽  
Snack Consumption

The increase in obesity and lipid disorders in industrialized countries may be due to irregular eating patterns. Few studies have investigated the effects of nighttime snacking on energy metabolism. We examined the effects of nighttime snacking for 13 days on energy metabolism. Eleven healthy women (means ± SD; age: 23 ± 1 yr; body mass index: 20.6 ± 2.6 kg/m2) participated in this randomized crossover trial for a 13-day intervention period. Subjects consumed a specified snack (192.4 ± 18.3 kcal) either during the daytime (10:00) or the night time (23:00) for 13 days. On day 14, energy metabolism was measured in a respiratory chamber without snack consumption. An oral glucose tolerance test was performed on day 15. Relative to daytime snacking, nighttime snacking significantly decreased fat oxidation (daytime snacking: 52.0 ± 13.6 g/day; nighttime snacking: 45.8 ± 14.0 g/day; P = 0.02) and tended to increase the respiratory quotient (daytime snacking: 0.878 ± 0.022; nighttime snacking: 0.888 ± 0.021; P = 0.09). The frequency of snack intake and energy intake, body weight, and energy expenditure were not affected. Total and low-density lipoprotein (LDL) cholesterol significantly increased after nighttime snacking (152 ± 26 mg/dl and 161 ± 29 mg/dl; P = 0.03 and 76 ± 20 mg/dl and 83 ± 24 mg/dl; P = 0.01, respectively), but glucose and insulin levels after the glucose load were not affected. Nighttime snacking increased total and LDL cholesterol and reduced fat oxidation, suggesting that eating at night changes fat metabolism and increases the risk of obesity.

Successful treatment of pituitary gigantism

2021 ◽  
Vol 14 (12) ◽  
pp. e247989
Author(s):  
Clara Cunha ◽  
Catarina Saraiva ◽  
Conceição Canas Marques ◽  
João Sequeira Duarte
Keyword(s):  
Transsphenoidal Surgery ◽  
Glucose Tolerance Test ◽  
Tanner Stage ◽  
Treatment Delay ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Residual Tumour ◽  
Oral Glucose Tolerance ◽  
Excessive Secretion

Pituitary gigantism is extremely rare, resulting from excessive secretion of growth hormone (GH) before fusion of epiphysial growth plates. We report a case of a 13-year-old boy, who presented with increased statural growth and headaches since the age of 10 years. On physical examination, his height was 180.7 cm (+3.3 SD) and Tanner stage V. Investigation revealed increased levels of serum age-adjusted and sex-adjusted insulin-like growth factor 1 (IGF-1) and failure of GH suppression during an oral glucose tolerance test (OGTT). MRI of the sellar region revealed a pituitary macroadenoma. He underwent transsphenoidal surgery and histopathological evaluation revealed mammosomatotropic adenoma. Three months after surgery, IGF-1 normalised, nadir GH during OGTT was less than 1 ng/mL and no residual tumour was found on the MRI. Genetic testing identified a mutation in the AIP gene. This case emphasises the importance of early diagnosis of gigantism, as treatment delay increases long-term morbidity.

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