phosphate and metabolic rate

Doug Skrecky (oberon@vcn.bc.ca)
Tue, 19 Jan 1999 00:32:45 -0800 (PST)

Citations: 1-4
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Authors
Nazar K. Kaciuba-Uscilko H. Szczepanik J. Zemba AW. Kruk B. Chwalbinska-Moneta J. Titow-Stupnicka E. Bicz B. Krotkiewski M. Institution
Department of Applied Physiology, Polish Academy of Sciences, Warsaw, Poland. Title
Phosphate supplementation prevents a decrease of triiodothyronine and increases resting metabolic rate during low energy diet. Source
Journal of Physiology & Pharmacology. 47(2):373-83, 1996 Jun. Abstract
Thirty overweight women participated in 8 week slimming program consisting of a self-controlled low-energy diet (4.2 MJ/day) supplemented with highly viscous fibres and mineral tablets containing calcium, potassium and sodium phosphates (Redusan Combi, Biokraft Pharma AB, Sweden). Half of the patients received in double blind manner mineral tablets during first 4 weeks and placebo (without phosphates) during next 4 weeks (group 1) while the remaining patients were treated (cross-over) with placebo first and mineral tablets in the final period (group 2). The rate of weight loss was similar in groups 1 and 2 (4.7 vs 5.2 kg during the first 4 weeks and 2.7 vs 3.0 kg in the further 4 weeks). During periods of phosphate supplementation, the resting metabolic rate (RMR) increased by approx. 12% (p < 0.05) in group 1 and 19% (p < 0.05) in group 2. Phosphate supplementation ameliorated also a decrease in plasma triiodothyronine level and a decrease in thyroxine to triiodothyronine ratio. There were no differences between groups in the plasma insulin, catecholamine, growth hormone, cortisol and testosterone levels. Phosphate supplementation did not affect plasma lipids or blood glucose concentration. It is concluded that phosphate supplementation in obese patients on a low-energy diet enhances RMR irrespectively of the rate of weight loss. This effect seems to be, at least partly, due to an influence of phosphates on peripheral metabolism of thyroid hormones.

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Authors
Jaedig S. Lindgarde F. Arborelius M. Institution
Department of Medicine, Lund University, Malmo General Hospital, Sweden. Title
Increased postprandial energy expenditure in obese women after peroral K- and Mg-phosphate.
Source
Mineral & Electrolyte Metabolism. 20(3):147-52, 1994. Abstract
Energy expenditure (EE) was studied in 15 obese (BMI > 27.5, median 29.2) and 15 lean (BMI < 22.9, median 21.7) healthy, postmenopausal women before and after peroral orange juice with or without K- and Mg-phosphate supplementation. The women, 56-58 years old, were studied in a double-blind, crossover experiment on two separate days. They received 100 ml of orange juice (10 g of carbohydrates) with or without a supplement of K+ (35 mmol), Mg2+ (17 mmol) and HPO4(2-) (39 mmol). Measurements were made before and 30 and 60 min after the stimuli. Intake of juice only had no effect on EE in either the lean or the obese subjects. When the minerals were added, EE (+6.3%; p < 0.001) increased significantly in the obese group with in a maximum 30 min after stimulus, while no such increase was seen in the lean group. The difference between the groups was significant (p < 0.05) and so was the difference in the obese group with or without minerals (p < 0.01). We conclude that an addition of potassium/magnesium-phosphate to glucose increases the postprandial thermogenesis in obese postmenopausal women, but not in lean ones.

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Authors
Lind L. Lithell H. Hvarfner A. Pollare T. Ljunghall S. Institution
Department of Internal Medicine, University Hospital, Uppsala, Sweden. Title
On the relationships between mineral metabolism, obesity and fat distribution.
Source
European Journal of Clinical Investigation. 23(5):307-10, 1993 May. Abstract
Alterations in calcium metabolism have been associated with cardiovascular risk factors. An altered binding of calcium to plasma proteins and raised levels of parathyroid hormone (PTH) have been described in morbid obesity. In the present study, indices of mineral metabolism were related to obesity (body mass index, BMI) and fat distribution (waist to hip ratio, w/h) in 194 subjects with a wide range of BMI and w/h. The ratio of total serum calcium to plasma ionized calcium (Ca2+) was found to be significantly correlated to both BMI (r = 0.20, P < 0.02) and w/h (r = 0.22, P < 0.005). Serum phosphate was also correlated to both of the indices of obesity in an inverse way (r = -0.24, P < 0.0008 for BMI and r = -0.33, P < 0.0001 for w/h). These relationships were still significant when the influences of age, sex and serum creatinine were included in the multiple regression analysis. This kind of analysis also disclosed that w/h was superior to BMI as a determinant of serum phosphate and the total calcium/Ca2+ ratio in serum. PTH was not significantly correlated to any of the indices of obesity. In conclusion, fat distribution rather than obesity per se was found to be associated with an altered mineral metabolism.

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Authors
Jaedig S. Henningsen NC.
Institution
Department of Medicine, Lund University, Malmo General Hospital, Sweden. Title
Increased metabolic rate in obese women after ingestion of potassium, magnesium- and phosphate-enriched orange juice or injection of ephedrine. Source
International Journal of Obesity. 15(6):429-36, 1991 Jun. Abstract
Thirty-six obese, pre-menopausal women were studied after an overnight fast and randomized to four different regimens of metabolic stimuli: group I (n = 12), 100 ml orange juice with dissolved K- and Mg-phosphates (K, 40 mmol; Mg, 17.5 mmol; HPO4, 35 mmol); group II (n = 8), 100 ml of water with electrolytes as in group I; group III (n = 8), 100 ml of orange juice; group IV (n = 8), injection of ephedrine intravenously, 0.25 mg/kg body weight. The women in groups I, II and III were further stimulated with ephedrine as in group IV and new measurements made. Thirty minutes after the first stimulus VO2, VCO2 and energy expenditure (EE) rose significantly (13.1-16.5 per cent) in groups I and IV only. In groups I and III the blood concentrations of glucose, insulin, and C-peptide rose significantly. After the second stimulus (ephedrine i.v.) no further increase in VO2, VCO2 and EE occurred in group I, but the increases from basal values became significant in group III. In all women at baseline, whole-body potassium was significantly correlated to VO2. Serum-magnesium was negatively correlated to A/I weight (actual/ideal weight). We conclude that the addition of K- and Mg-phosphates to glucose increases the postprandial thermogenesis in obese patients.