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Bone resorption responses to potassium-enriched high-calcium skim milk
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Abstracts
P 49
Bone Vol. 27, No. 4, Supplement October 2000:1S 54S
P 50
BONE RESORPTION RESPONSES TO POTASSIUM-ENRICHED HIGH-CALCIUM SKIM MILK J Hilary Green, Trevor Walmsley ~, Jill Richards, Richard Bunning, Milk and Health Research Centre, Institute of Food, Nutrition and Human Health, Massey University, Palmerston North. New Zealand, tCanterbu~' Health Laboratories, Christchurch. New Zealand
BONE RESORPTION RESPONSES TO MAGNESIUMENRICHED HIGH CALCIUM MILK IN POSTMENOPAUSAL WOMEN J Hilary Green, Jill Richards, Jeremy Madigan, Richard Bunmng, Milk and Health Research Centre, Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
It is well documented that bone mineral density is positively associated with the consumption of various nutrients, including calcium (Ca) and potassium (K). We investigated whether skim milk, high Ca skim milk or K-enriched high Ca skim milk impacts on bone resorption. We recruited 54 healthy men and women aged 54 ± 11 years (40-84 years), with adequate daily intakes of Ca (1.1± 0.5 g) and K (4.0 ± 1.1 g) and who were usually consuming 300 ± 365 ml liquid milk per day (means ± SD). The volunteers were divided into 3 groups, matched for age, weight and Ca and K intake, to test one of 3 milk formulas. These were skim milk (720 mg Ca, 885mg K), high Ca skim milk, (1075 mg Ca, 855 mg K) and K-enriched high Ca skim milk (1040 mg Ca, 1585 nag K, each per 2 serves) The volunteers replaced their usual liquid milk, ad lib, with 2 x 240 ml serves of the test milk for 28 days Urine was collected for approximately 24-h, once at the start and once at the end of the intervention. It was analysed for Ca, K. free deoxypyridinoline, N-telopeptides. Ctelopeptides and expressed as a ratio to creatinine. There was no difference between the groups in any of the urinal/variables (repeated measures ANOVA) This study suggests that 2 serves/da3. of skim milk. high Ca skim milk or K-enriched high Ca milk, consumed ad lib, has no impact on bone resorption in people whose diet is adequate in Ca and K.
We investigated whether Mg-enriched high calcium milk influences bone resorption in postmenopausal women. We recruited 35 healthy women, aged 61 ± 4 years (age at menopause, 51 • 4 years) who had not taken any drugs known to impact on bone metabolism in the last 3 years. The women had adequate daily intakes of Ca and M g This was a randomised controlled trial in which the volunteers replaced their usual liquid milk with 2 x 240 ml serves of the test milk for 28 days. One serve was consumed just before going to bed. 18 women consumed high Ca skim milk (control: 1134 mg Ca, 70 mg Mg), and 17 women consumed Mg-enriched high Ca skim milk (treatment; 1150 mg Ca, 230 mg Mg), each per 2 serves. There was no difference in age, age at menopause or Ca and Mg intakes between groups. Urine was collected overnight on 2 consecutive days before each intervention and again after 2 and 4 weeks. It was analysed for free deoxypyridinoline (DPD), N-telopeptides (NTx) and Ctelopeptides (CTx) and expressed as a ratio to creatinine (Cr). Data were log transformed and analysed by repeated measures ANOVA Baseline excretion rates of each marker were higher in the treatment group. The excretion rates ofDPD, NTx and CTx did not change in the control group. In the treatment group DPD decreased from 7.4 " 2.7 to 3 9 ± 1.5nmol/mmol Cr (p-0.01)01), NTx decreased from 75.9 ± 32 to 48.6 ± 18.7nmol/mmol Cr (p=0.0001) and CTx decreased from 13.9 ± 6.2 to 10.4 ± 4 7 nmol/mmol Cr (p<0.01), each at 4 weeks. These data suggest Mg-enriched high calcium milk reduces bone resorption in postmenopausal women. NEW ZEALAND MILK funded this work
P 51 DOES LONGTERM SWIMMING PARTICIPATION LEAD TO REDUCED BMD? K Greenway; 1 P Rich1; R Villania and P Ebeling 2 (IDept of Human Biology and Movement Science RMIT Victoria Australia; 2 Dept of Endocrinology, Royal Melbourne Hospital, Australia) Swimming is a particularly popular activity in Australian society with large numbers of women engaged in regular training and competition. However the weight supporting medium provided by water reduces the mechanical loading of the skeleton perhaps leading to bone loss. The purpose of the present study was to examine this possibility by measuring total and regional bone mass in pre-menopausal swimmers, compare the data with Australian norms and determine what relationships might exist between bone mass and swimming history. Twenty five swimmers recruited from AUSSI Masters Swimming Inc., (mean age 42yr) provided data for this report. Menstrual, and swimming history were determined by interview and questionnaire Total, Spine (L2-L4), Femoral Neck (left total) and Radius (left ultradistal) bone density were determined by DEXA (Lunar DPX-IQ) All participants had regular menses and normal onset. Lifetime annual swimming hours (Lifetime Sw) averaged 70 (SD 60 ) while annual hours swum prior to age 20 (Pre20) averaged 102 (SD 80). T and Z scores for bone mass measurements (Australian data base) were 1.3, 1.2; .8, .9; .4, 6; -.3, -.2 for Total, Spine, Femoral Neck and Forearm respectively. Z scores for Total, and Forearm correlated negatively with Lifetime Sw (r - -.27, -.32 respectively) as did Total, Spine and Femur with Pre20 (r = -.25, -.13, -.28 respectively). However, none reached significance (p > 0.05). On the basis of this preliminary data, we conclude that swimming has not compromised the skeletons of these women though there is evidence for a negative effect on the forearm. Furthermore, the negative relationships detected, warrant further study in a larger cohort. (Grant: Shepherd Foundation)
P 52 THE USE OF MULTIVARIATE ANALYSIS OF MARKERS OF BONE TURNOVER T O DEMONSTRATE THE EFFECT OF NUTRITIONAL INTERVENTION ON BONE HEALTH. B Kuhn-Shedock l, LM Schollum 1, S Garlesh2, 1Milk & Health Research Centre, 2Institute of Information Sciences and Technology (Statistics), Massey University, Palmerston North, New Zealand. There is conflicting information on the relative value o f different markers of bone turnover in evaluating the effect of nutritional supplements on bone health. We performed different mulfivarfiate analyses (MANOVA, canonical discriminant and principle components analysis) on a set of data obtained for a rat trial specifically designed to evaluate the relative value of different markers to separate different dietary groups. Male Sprague-Dawley rats (2 months of age) were allocated to one of four dietary treatments (n=8 per treatment) as follows: 0.1% calcium, 0.5% calcium, 0.5% calcium plus alendronate (10mg/kg/d), and 0.5% calcium plus 0.03mg/g/d zinc. During the 6-week treatment period, blood and urine samples were collected every 2 weeks (i.e. at weeks 0, 2, 4, and 6), and the long bones of all four extremities were harvested at the end o f the treatment period. Parameters were measured as follows: rat (live weight, humerus weight, bone mineral density), blood (tartrate-resistant acid phosphatase, alkaline phosphatase, total protein, albumin), urine (creafinine, calcium, hydroxyproline, D-pyridinium), bone extracts (tartrate-resistant acid phosphatase, alkaline phosphatase, total protein), bone hydrolysates (hydroxyproline, D-pyridiniurn). A highly significant effect of dietary treatment on the parameters of bone turnover (P<0.001) can be demonstrated using MANOVA (multivariate analysis of variance). Results from canonical discriminant analysis indicate that two dimensions are sufficient to account for most o f the between group variation (95%). The impact of the four dietary- interventions on parameters of bone turnover measured can easily be demonstrated in a 2-dimensional plot.
Abstracts
P 49
Bone Vol. 27, No. 4, Supplement October 2000:1S 54S
P 50
BONE RESORPTION RESPONSES TO POTASSIUM-ENRICHED HIGH-CALCIUM SKIM MILK J Hilary Green, Trevor Walmsley ~, Jill Richards, Richard Bunning, Milk and Health Research Centre, Institute of Food, Nutrition and Human Health, Massey University, Palmerston North. New Zealand, tCanterbu~' Health Laboratories, Christchurch. New Zealand
BONE RESORPTION RESPONSES TO MAGNESIUMENRICHED HIGH CALCIUM MILK IN POSTMENOPAUSAL WOMEN J Hilary Green, Jill Richards, Jeremy Madigan, Richard Bunmng, Milk and Health Research Centre, Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
It is well documented that bone mineral density is positively associated with the consumption of various nutrients, including calcium (Ca) and potassium (K). We investigated whether skim milk, high Ca skim milk or K-enriched high Ca skim milk impacts on bone resorption. We recruited 54 healthy men and women aged 54 ± 11 years (40-84 years), with adequate daily intakes of Ca (1.1± 0.5 g) and K (4.0 ± 1.1 g) and who were usually consuming 300 ± 365 ml liquid milk per day (means ± SD). The volunteers were divided into 3 groups, matched for age, weight and Ca and K intake, to test one of 3 milk formulas. These were skim milk (720 mg Ca, 885mg K), high Ca skim milk, (1075 mg Ca, 855 mg K) and K-enriched high Ca skim milk (1040 mg Ca, 1585 nag K, each per 2 serves) The volunteers replaced their usual liquid milk, ad lib, with 2 x 240 ml serves of the test milk for 28 days Urine was collected for approximately 24-h, once at the start and once at the end of the intervention. It was analysed for Ca, K. free deoxypyridinoline, N-telopeptides. Ctelopeptides and expressed as a ratio to creatinine. There was no difference between the groups in any of the urinal/variables (repeated measures ANOVA) This study suggests that 2 serves/da3. of skim milk. high Ca skim milk or K-enriched high Ca milk, consumed ad lib, has no impact on bone resorption in people whose diet is adequate in Ca and K.
We investigated whether Mg-enriched high calcium milk influences bone resorption in postmenopausal women. We recruited 35 healthy women, aged 61 ± 4 years (age at menopause, 51 • 4 years) who had not taken any drugs known to impact on bone metabolism in the last 3 years. The women had adequate daily intakes of Ca and M g This was a randomised controlled trial in which the volunteers replaced their usual liquid milk with 2 x 240 ml serves of the test milk for 28 days. One serve was consumed just before going to bed. 18 women consumed high Ca skim milk (control: 1134 mg Ca, 70 mg Mg), and 17 women consumed Mg-enriched high Ca skim milk (treatment; 1150 mg Ca, 230 mg Mg), each per 2 serves. There was no difference in age, age at menopause or Ca and Mg intakes between groups. Urine was collected overnight on 2 consecutive days before each intervention and again after 2 and 4 weeks. It was analysed for free deoxypyridinoline (DPD), N-telopeptides (NTx) and Ctelopeptides (CTx) and expressed as a ratio to creatinine (Cr). Data were log transformed and analysed by repeated measures ANOVA Baseline excretion rates of each marker were higher in the treatment group. The excretion rates ofDPD, NTx and CTx did not change in the control group. In the treatment group DPD decreased from 7.4 " 2.7 to 3 9 ± 1.5nmol/mmol Cr (p-0.01)01), NTx decreased from 75.9 ± 32 to 48.6 ± 18.7nmol/mmol Cr (p=0.0001) and CTx decreased from 13.9 ± 6.2 to 10.4 ± 4 7 nmol/mmol Cr (p<0.01), each at 4 weeks. These data suggest Mg-enriched high calcium milk reduces bone resorption in postmenopausal women. NEW ZEALAND MILK funded this work
P 51 DOES LONGTERM SWIMMING PARTICIPATION LEAD TO REDUCED BMD? K Greenway; 1 P Rich1; R Villania and P Ebeling 2 (IDept of Human Biology and Movement Science RMIT Victoria Australia; 2 Dept of Endocrinology, Royal Melbourne Hospital, Australia) Swimming is a particularly popular activity in Australian society with large numbers of women engaged in regular training and competition. However the weight supporting medium provided by water reduces the mechanical loading of the skeleton perhaps leading to bone loss. The purpose of the present study was to examine this possibility by measuring total and regional bone mass in pre-menopausal swimmers, compare the data with Australian norms and determine what relationships might exist between bone mass and swimming history. Twenty five swimmers recruited from AUSSI Masters Swimming Inc., (mean age 42yr) provided data for this report. Menstrual, and swimming history were determined by interview and questionnaire Total, Spine (L2-L4), Femoral Neck (left total) and Radius (left ultradistal) bone density were determined by DEXA (Lunar DPX-IQ) All participants had regular menses and normal onset. Lifetime annual swimming hours (Lifetime Sw) averaged 70 (SD 60 ) while annual hours swum prior to age 20 (Pre20) averaged 102 (SD 80). T and Z scores for bone mass measurements (Australian data base) were 1.3, 1.2; .8, .9; .4, 6; -.3, -.2 for Total, Spine, Femoral Neck and Forearm respectively. Z scores for Total, and Forearm correlated negatively with Lifetime Sw (r - -.27, -.32 respectively) as did Total, Spine and Femur with Pre20 (r = -.25, -.13, -.28 respectively). However, none reached significance (p > 0.05). On the basis of this preliminary data, we conclude that swimming has not compromised the skeletons of these women though there is evidence for a negative effect on the forearm. Furthermore, the negative relationships detected, warrant further study in a larger cohort. (Grant: Shepherd Foundation)
P 52 THE USE OF MULTIVARIATE ANALYSIS OF MARKERS OF BONE TURNOVER T O DEMONSTRATE THE EFFECT OF NUTRITIONAL INTERVENTION ON BONE HEALTH. B Kuhn-Shedock l, LM Schollum 1, S Garlesh2, 1Milk & Health Research Centre, 2Institute of Information Sciences and Technology (Statistics), Massey University, Palmerston North, New Zealand. There is conflicting information on the relative value o f different markers of bone turnover in evaluating the effect of nutritional supplements on bone health. We performed different mulfivarfiate analyses (MANOVA, canonical discriminant and principle components analysis) on a set of data obtained for a rat trial specifically designed to evaluate the relative value of different markers to separate different dietary groups. Male Sprague-Dawley rats (2 months of age) were allocated to one of four dietary treatments (n=8 per treatment) as follows: 0.1% calcium, 0.5% calcium, 0.5% calcium plus alendronate (10mg/kg/d), and 0.5% calcium plus 0.03mg/g/d zinc. During the 6-week treatment period, blood and urine samples were collected every 2 weeks (i.e. at weeks 0, 2, 4, and 6), and the long bones of all four extremities were harvested at the end o f the treatment period. Parameters were measured as follows: rat (live weight, humerus weight, bone mineral density), blood (tartrate-resistant acid phosphatase, alkaline phosphatase, total protein, albumin), urine (creafinine, calcium, hydroxyproline, D-pyridinium), bone extracts (tartrate-resistant acid phosphatase, alkaline phosphatase, total protein), bone hydrolysates (hydroxyproline, D-pyridiniurn). A highly significant effect of dietary treatment on the parameters of bone turnover (P<0.001) can be demonstrated using MANOVA (multivariate analysis of variance). Results from canonical discriminant analysis indicate that two dimensions are sufficient to account for most o f the between group variation (95%). The impact of the four dietary- interventions on parameters of bone turnover measured can easily be demonstrated in a 2-dimensional plot.