Effect of phosphate supplementation on metabolic and neuroendocrine responses to exercise and oral glucose load in obese women during weight reduction.
Thirty six obese women (BMI 29.5 to 44.0 kg m-2, aged 27 to 45 yrs) participated in the 4- week weight reducing program. All of them have prescribed low fat diet of approx. 4.2 MJ (1000 kcal per day) with high viscous fibre capsules as a basic supplement. In addition 18 women (group 1) received Redusan mineral tablets containing mainly calcium and potassium phosphates while the remaining subjects (group 2) were given Placebo instead of mineral tablets. Before energy restriction and after 4 weeks on the diet, half of the women from each group performed 30 min--bicycle ergometer exercise (30-50 W; HR approx. 110 beats.min-1). The remaining subjects were submitted to oral glucose (75 g) tolerance test (OGTT). Weight loss during energy restriction was not affected by phosphate supplementation (4.6 +/- 0.4 and 5.2 +/- 0.5 kg in group 1 and 2, respectively). Phosphates caused a significant increase (p < 0.05) in the resting metabolic rate (RMR). Net energy cost of work, resting and post-exercise blood glucose, lactate, plasma FFA, adrenalin, cortisol, growth hormone, insulin and testosterone did not differ between the groups receiving phosphates and placebo while respiratory exchange ratio was slightly higher (p < 0.05), and the plasma beta-hydroxybutyrate concentration lower (p < 0.05) than without phosphate supplementation. Post-exercise plasma noradrenaline was significantly lowered after 4 weeks of energy restriction in group 2 (on Placebo). Neither blood glucose, plasma insulin and noradrenaline responses to oral glucose ingestion nor the glucose induced thermogenesis were significantly affected by phosphate supplementation, whilst blood pressure increases following glucose load were reduced (p < 0.05). In conclusion, the present study confirmed a potential usefulness of phosphate supplementation during energy restriction in obese patients due to its effect on resting metabolic rate. The results did not, however, reveal any major alterations in the metabolic and hormonal responses to exercise or to glucose ingestion in comparison with placebo treatment.
Kaciuba-Uściłko
H
H
Department of Applied Physiology, Polish Academy of Sciences, Warsaw.
Nazar
K
K
Chwalbińska-Moneta
J
J
Ziemba
A
A
Kruk
B
B
Szczepanik
J
J
Titow-Stupnicka
E
E
Bicz
B
B
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D005951:Glucose Tolerance Test; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007328:Insulin / Q000097:blood; D009765:Obesity / Q000097:blood / Q000178:diet therapy / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010710:Phosphates / Q000494:pharmacology*; D015431:Weight Loss / Q000502:physiology*
D001786:Blood Glucose; D002395:Catecholamines; D007328:Insulin; D010710:Phosphates; D005947:Glucose