Tag Archives: abstract

Low Sodium may be Risk Factor for Maintaining Calcium and Magnesium

Abstract

Positive correlation between dietary intake of sodium and balances of calcium and magnesium in young Japanese adults–low sodium intake is a risk factor for loss of calcium and magnesium–.

The content of calcium (Ca) and magnesium (Mg) in sweat during exercise is considerably higher during a relatively low intake of sodium (Na) of 100 mmol/d than with an intake of 170 mmol/d. For this reason and also because Ca and Mg have a negative balance with a Na intake of 100 mmol/d, we analyzed the relationship between Na intake and balances of Ca and Mg in data from 11 balance studies. From 1986 to 2000, 109 volunteers (23 males, 86 females) with an age range of 18 to 28 y took part in mineral balance studies. The balance periods ranged from 5 to 12 d. In a given experiment, the diet of each subject contained the same quantity of food, although this varied between experiments, and was supplied during the balance period without consideration of body weight. In the data of all the studies (n= 109), the balances of Ca and Mg did not correlate positively with Na intake. However, when the data of the highest Na study were excluded, the balances of Ca and Mg correlated positively with Na intake. The mean value for the regression equation between Na intake and Ca and Mg balances when the respective balance was equal to zero were, 63.308 mg Na/kg BW/d (Ca: n=96, r2=0.134) and 60.977 mg Na/kg BW/d (Mg: n=96, r2=0.268), respectively. These values are considerably higher than Na requirements estimated by inevitable Na loss. Low dietary Na may therefore be a risk factor for maintaining positive balances of Ca and Mg.

Nishimuta M, Kodama N, Morikuni E, Yoshioka YH…
J. Nutr. Sci. Vitaminol. Aug 2005
PMID: 16261999

High Sodium has an Insignificant Effect on Bone Density in Rats

Abstract

Sodium and calcium intakes and bone mass in rats revisited.

High sodium intake accompanied by insufficient dietary calcium may have detrimental effects on bone mass. Our study evaluated the effects of increased sodium and decreased calcium intakes on bone mineral density (BMD) and bone mineral content (BMC) in rats.
Four-month-old female Wistar rats were given deionized water or 1.8% solution of sodium chloride in deionized water and fed normal (1.2%) or marginal (0.33%) calcium in the diet for 2 mo. At the end of the experiment, BMD and BMC of the whole body and urinary sodium and calcium excretion were evaluated. All rats were killed and right femurs were removed to assess dry and ash weights. Two-way analysis of variance was used to evaluate effect of salt intake and effect of dietary calcium on these parameters.
Salt-loaded animals had greater water consumption during the entire 2-mo period and significantly lower body weight from week 5 of the experiment. High salt intake increased urine volume and urinary excretion of sodium and calcium. Urinary calcium was about five times higher in salt-loaded animals than in rats on deionized water irrespective of dietary calcium content. Calcium in diet itself had no significant effect on these parameters. High salt intake slightly, but not significantly, decreased BMD, BMC, and femur weights. Lower calcium in diet significantly decreased BMD, and its effect on femur ash weight almost reached a level of significance.
We confirmed the benefit of adequate calcium intake to BMD. Under our experimental condition, high salt intake in rats for 2 mo had no statistically significant effect on femur weights, BMD, or BMC even with marginal calcium in the diet.

Sarić M, Piasek M, Blanusa M, Kostial K…
Nutrition May 2005
PMID: 15850968

DASH Diet and Sodium Reduction Improve Bone in Adults

Abstract

The DASH diet and sodium reduction improve markers of bone turnover and calcium metabolism in adults.

Dietary strategies to prevent and treat osteoporosis focus on increased intake of calcium and vitamin D. Modification of whole dietary patterns and sodium reduction may also be effective. We examined the effects of two dietary patterns and three sodium levels on bone and calcium metabolism in a randomized feeding study. A total of 186 adults, aged 23-76 y, participated. After a 2-wk run-in period, participants were assigned randomly to diets containing three levels of sodium (50, 100 and 150 mmol/d) to be consumed for 30 d in random order. Serum osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX), fasting serum parathyroid hormone (PTH), urinary sodium, potassium, calcium and cAMP were measured at baseline and at the end of each sodium period. The Dietary Approaches to Stop Hypertension (DASH) diet reduced serum OC by 8-11% and CTX by 16-18% (both P < 0.001). Urinary calcium excretion did not differ between subjects that consumed the DASH and control diets. Reducing sodium from the high to the low level significantly decreased serum OC 0.6 microg/L in subjects that consumed the DASH diet, fasting serum PTH 2.66 ng/L in control subjects and urinary calcium 0.5 mmol/24 h in both groups. There were no consistent effects of the diets or sodium levels on urinary cAMP. In conclusion, the DASH diet significantly reduced bone turnover, which if sustained may improve bone mineral status. A reduced sodium intake reduced calcium excretion in both diet groups and serum OC in the DASH group. The DASH diet and reduced sodium intake may have complementary, beneficial effects on bone health.

Lin PH, Ginty F, Appel LJ, Aickin M…
J. Nutr. Oct 2003
PMID: 14519796 | Free Full Text

Low Sodium Causes Body to Rob Bones of Sodium, Calcium and Magnesium in Women

Abstract

Negative balance of calcium and magnesium under relatively low sodium intake in humans.

The balance of minerals (sodium [Na], potassium [K], calcium [Ca], and magnesium [Mg]) was measured in six female students for 10 d while under a relatively low Na intake (100 mmol/d or 2.2 g/d) with receiving adequate Ca (20 mmol/d or 800 mg/d) and Mg (12 mmol/d or 280 mg/d). Both the plasma renin activity (PRA) and aldosterone level were above the reference ranges throughout the experiment, which implied that the subjects were Na deficient. However, the urine Na excretion was about the same as that ingested, while there was no substantial reduction of sweat Na concentration observed during moderate physical exercise (13.2+/-2.6 mmol/L) (mean+/-SD). On the other hand, the urine Ca and Mg levels were high, but the apparent absorption of Ca and Mg was moderate (21 +/- 5%, 34 +/- 4%, respectively), which resulted in a negative balance of these two elements. It seems that the stored Na in the bone is eluted so as to compensate for the low dietary Na intake, while any excess Ca and Mg also inevitably flows into the blood stream with Na, which inhibited the intestinal absorption of both Ca and Mg and accelerates their excretion in urine.

Kodama N, Nishimuta M, Suzuki K
J. Nutr. Sci. Vitaminol. Jun 2003
PMID: 12953799

ACE Inhibitors, But Not ARBs, Marginally Increase Bone Loss in Men

Abstract

Does the use of ACE inhibitors or angiotensin receptor blockers affect bone loss in older men?

In a prospective cohort study of 5,995 older American men (MrOS), users of angiotensin-converting enzyme (ACE) inhibitors had a small but significant increase in bone loss at the hip over 4 years after adjustment for confounders. Use of angiotensin II AT1 receptor blockers (ARB) was not significantly associated with bone loss.
Experimental evidence suggests that angiotensin II promotes bone loss by its effects on osteoblasts. It is therefore plausible that ACE inhibitor and ARB may reduce rates of bone loss. The objective of this study is to examine the independent effects of ACE inhibitor and ARB on bone loss in older men.
Out of 5,995 American men (87.2%) aged ≥65 years, 5,229 were followed up for an average of 4.6 years in a prospective six-center cohort study-The Osteoporotic Fractures in Men Study (MrOS). Bone mineral densities (BMD) at total hip, femoral neck, and trochanter were measured by Hologic densitometer (QDR 4500) at baseline and year 4.
Out of 3,494 eligible subjects with complete data, 1,166 and 433 subjects reported use of ACE inhibitors and ARBs, respectively. When compared with nonusers, continuous use of ACE inhibitors was associated with a small (0.004 g/cm(2)) but significant increase in the average rate of BMD loss at total hip and trochanter over 4 years after adjustment for confounders. Use of ARB was not significantly associated with bone loss.
Use of ACE inhibitors but not ARB may marginally increase bone loss in older men.

Kwok T, Leung J, Zhang YF, Bauer D…
Osteoporos Int Aug 2012
PMID: 22080379

 

ACE Inhibitor Moexipril Doesn’t Harm Bones in Ovariectomized Rats

Abstract

Impact of antihypertensive therapy on postmenopausal osteoporosis: effects of the angiotensin converting enzyme inhibitor moexipril, 17beta-estradiol and their combination on the ovariectomy-induced cancellous bone loss in young rats.

No data are available on whether angiotensin converting enzyme (ACE) inhibition affects the skeleton, though this might be of clinical relevance when antihypertensive therapy is initiated, particularly in hypertensive women after menopause who typically suffer from a concomitant rapid onset of osteoporosis. In the present study we investigated the effects of the new ACE inhibitor moexipril, 17beta-estradiol and their combination on the bone turnover in ovariectomized Sprague-Dawley rats, an established animal model for studying human postmenopausal osteoporosis.
We studied 119 12-week-old virgin female Sprague-Dawley rats. Seven rats were killed on day 0 as basal controls. The remaining rats were divided into sham-ovariectomy or ovariectomy groups. Vehicle, moexipril at 10 mg/kg per day alone (orally), 17beta-estradiol at 10 mu g/kg per day alone (subcutaneously) or both were administered to both groups immediately after the operation for 14 (short-term effects) or 56 (long-term effects) days. A stereology computer program was used for measurements. Static histomorphometric measurements, using a stereology computer program, were taken on double-fluorescent labeled undecalcified proximal tibial metaphyseal (cancellous bone site) and tibial shaft (cortical bone site) sections.
Ovariectomy induced dramatically cancellous bone loss due to increased bone turnover, with resorption exceeding formation. Moexipril had no effect on the cancellous bone site in either ovariectomized or sham-operated rats. 17beta-Estradiol treatment added extra cancellous bone in the sham-operated rats and prevented cancellous bone loss in the ovariectomized rats by inhibiting bone resorption. The combination of moexipril and 17beta-estradiol gave similar results to those of 17beta-estradiol alone. Comparable results were observed in the cortical bone site.
The results of this study show that ACE inhibition by moexipril has no effect on the skeleton when given alone and that it does not hamper the osteoprotective effects of 17beta-estradiol. These findings are relevant for the use of antihypertensive therapy in postmenopausal women treated or not with hormone replacement therapy.

Stimpel M, Jee WS, Ma Y, Yamamoto N…
J. Hypertens. Dec 1995
PMID: 8903666

Clove Preserves Bone in Ovariectomised Rats

Abstract

Clove (Syzygium aromaticum Linn) extract rich in eugenol and eugenol derivatives shows bone-preserving efficacy.

This study examined the efficacy of hydroalcoholic extract of dried clove buds, which is rich in phenolic compounds namely eugenol and eugenol derivatives (precursors of flavones, isoflavones and flavonoids), on different primary and secondary osteoporotic marker changes in an ovariectomised (OVX) rat model of osteoporosis. Female Wistar rats were randomly divided into three groups: sham-operated control (A), OVX (B) and OVX plus 50% hydroalcoholic extract of dried clove buds for 4 weeks (C). Results indicated that, compared to control, serum alkaline phosphatase (AP; 48.25%, p < 0.01), serum tartrate-resistant acid phosphatase (TRAP; 63.48%, p < 0.01), urinary calcium (14.70%, p < 0.01), urinary phosphate (50.30%, p < 0.01) and urinary creatinine (122.44%, p < 0.01) were significantly altered in OVX rats. All these altered responses were significantly restored (AP: 27.53%, p < 0.01; TRAP: 33.51%, p < 0.01; calcium: 53.15%, p < 0.01; phosphate: 27.49%, p < 0.01; creatinine: 46.40%, p < 0.01) by supplementation with hydroalcoholic extract of dried clove buds. Results of bone density, bone mineral content, bone tensile strength and histological analysis also showed similar trend of results, which supported initial observations of this study. It is proposed that hydroalcoholic extract of dried clove buds has bone-preserving efficacy against hypogonadal osteoporosis.

Karmakar S, Choudhury M, Das AS, Maiti A…
Nat. Prod. Res. 2012
PMID: 21711176

Tongkat Ali Maintains Bone Calcium in Orchidectomised Rats

Abstract

The anti-osteoporotic effect of Eurycoma Longifolia in aged orchidectomised rat model.

Osteoporosis in elderly men is becoming an important health issue with the aging society. Elderly men with androgen deficiency are exposed to osteoporosis and can be treated with testosterone replacement. In this study, Eurycoma longifolia (EL), a plant with androgenic effects, was supplemented to an androgen-deficient osteoporotic aged rat as alternative to testosterone. Aged 12 months old Sprague-Dawley rats were divided into groups of normal control (NC), sham-operated (SO), orchidectomised-control (OrxC), orchidectomised and supplemented with EL (Orx + El) and orchidectomised and given testosterone (Orx + T). After 6 weeks of treatment, serum osteocalcin, serum terminal C-telopeptide Type 1 collagen (CTX) and the fourth lumbar bone calcium were measured. There were no significant differences in the osteocalcin levels before and after treatment in all the groups. The CTX levels were also similar for all the groups before treatment. However, after treatment, orchidectomy had caused significant elevation of CTX compared to normal control rats. Testosterone replacements in orchidectomised rats were able to prevent the rise of CTX. Orchidectomy had also reduced the bone calcium level compared to normal control rats. Both testosterone replacement and EL supplementation to orchidectomised rats were able to maintain the bone calcium level, with the former showing better effects. As a conclusion, EL prevented bone calcium loss in orchidectomised rats and therefore has the potential to be used as an alternative treatment for androgen deficient osteoporosis.

Shuid AN, Abu Bakar MF, Abdul Shukor TA, Muhammad N…
Aging Male Sep 2011
PMID: 20874437

Onobrychis Ebenoides Has SERM-Like Activity in Ovariectomized Rats

Abstract

Protective effect of plant extract from Onobrychis ebenoides on ovariectomy-induced bone loss in rats.

Certain plant extracts have been the object of recent studies due to their mild estrogenic action and their possible potential role in osteoporosis prevention and/or treatment. The present study was undertaken to investigate the possible protective effect of the aqueous solution of the plant Onobrychis ebenoides, with proven in vitro mild estrogenic action, on bone mass loss of the ovariectomized (Ovx) rat experimental model of osteoporosis.
Forty intact female mature (10-month-old) Wistar rats were separated into three groups: Ovx, Ovx plus plant extract (Ph) and sham-operated (control). Ph administration in the drinking water at a dose of 300 mg/kg body weight/day commenced immediately after Ovx. Bone mineral density (BMD) values, percentage change from the baseline measurement and histomorphometry of the tibia, as well as body and uterine weight, were examined and compared between groups.
Comparison of BMD absolute values of the whole tibia of Ovx + Ph and Ovx animals at both 3 and 6 months post-Ovx were highly significant (p < 0.0005), showing a protective effect on treated animals. The extract did not appear to have such a beneficial effect on BMD of the proximal tibia of the treated animals compared to the Ovx animals after 3 months; however, a significant protective effect was observed at 6 months post-Ovx in treated animals compared to the Ovx (p = 0.015). When the % changes from baseline measurement of the whole tibia of Ovx + Ph and controls were compared, there was no significant difference at 3 or 6 months, demonstrating a highly protective effect; the respective comparisons of proximal tibia % changes did not display such protection. Body and uterine weight comparisons showed no significant difference between Ovx and treated rats, whereas, the level of significance for each group compared to controls was p < 0.0005.
The Ph studied showed a highly significant protective effect on BMD of the whole tibia of Ovx rats after 3 and 6 months of treatment, compared to the non-treated animals. Its effect on the proximal tibia was less pronounced, but also statistically significant compared to non-treated rats after 6 months. The lack of significant effect on body and uterine weight is in favor of its selective estrogen receptor modulator-like activity, and merits further studies.

Dontas I, Halabalaki M, Moutsatsou P, Mitakou S…
Maturitas Jan 2006
PMID: 15979258

Whey Acidic Protein Fractions Increases Bone Density and Elasticity in Ovariectomised Rat

Abstract

The effect of whey acidic protein fractions on bone loss in the ovariectomised rat.

Bovine milk has been shown to contain bioactive components with bone-protective properties. Earlier studies on bovine milk whey protein showed that it suppressed bone resorption in the female ovariectomised rat. A new osteotropic component was subsequently identified in the whey basic protein fraction, but bone bioactivity may also be associated with other whey fractions. In the present study, we investigated whether acidic protein fractions isolated from bovine milk whey could prevent bone loss in mature ovariectomised female rats. Six-month-old female rats were ovariectomised (OVX) or left intact (sham). The OVX rats were randomised into four groups. One group remained the control (OVX), whereas three groups were fed various whey acidic protein fractions from milk whey as 3 g/kg diet for 4 months. Outcomes were bone mineral density, bone biomechanics and markers of bone turnover. Bone mineral density of the femurs indicated that one of the whey AF over time caused a recovery of bone lost from OVX. Plasma C-telopeptide of type I collagen decreased significantly in all groups except OVX control over time, indicating an anti-resorptive effect of whey acidic protein. Biomechanical data showed that the AF may affect bone architecture as elasticity was increased by one of the whey AF. The femurs of AF-supplemented rats all showed an increase in organic matter. This is the first report of an acidic whey protein fraction isolated from milk whey that may support the recovery of bone loss in vivo.

Kruger MC, Plimmer GG, Schollum LM, Haggarty N…
Br. J. Nutr. Aug 2005
PMID: 16115359