Objective: To study the relationship between Ca 2+ intake,Ca 2+ absorption and Ca 2+ retention. Methods; Thirty-six weaning rats were firstly fed with Ca-poor diet for a 3-week Ca 2+ depletion period,and ...Objective: To study the relationship between Ca 2+ intake,Ca 2+ absorption and Ca 2+ retention. Methods; Thirty-six weaning rats were firstly fed with Ca-poor diet for a 3-week Ca 2+ depletion period,and then randomly divided into 3 groups to receive diet with low,adequate and high Ca 2+ contents.The experiment lasted 12 weeks,with a 3-day metabolism experiment conducted in the 5th week. Results:Supplement with adequate amount of Ca 2+ increased bone Ca 2+,bone mineral density(BMD),bone mineral content(BMC)and the weight of femur(P<0.05).Higher doses of Ca 2+ failed to further improve the efficiency.Analysis showed that Ca 2+ intake was positively correlated to bone Ca 2+,BND and BMC,and negatively correlated to the rates of Ca 2+ absorption and retention.Dose-effect study revealed that the Ca 2+ absorption rate()was a hyperbola function of Ca 2+ intake(X),i.e.=e 6.8068×X -0.8821+20(F=47.3154,P<0.0001).It was found from the results that bone Ca 2+ content(determined by atom absorption spectrophotometer)had a linear correlation to BMC(determined with uni-photon bone mineral densitometer). Conclusion:The rate of Ca 2+ absorption is a hyperbola function of Ca 2+ intake.The increment of Ca 2+ absorption will be minimal when Ca 2+ intake exceeds 3d 250 mg in rats.BMC,better than BMD,may substitute for the ideal bone Ca 2+ content as the index to assess the efficacy of Ca 2+ supplement.展开更多
Objective To investigate the effect of calcium supplementation on bone mineral density （BMD） in Chinese women with different Fokl vitamin D receptor （VDR） genotypes （FF, Ff, and ff） after weaning or resumption o...Objective To investigate the effect of calcium supplementation on bone mineral density （BMD） in Chinese women with different Fokl vitamin D receptor （VDR） genotypes （FF, Ff, and ff） after weaning or resumption of menstruation during lactation. Methods A total of 40 subjects with the same Fokl VDR genotype were randomly divided into two groups： one received calcium tablet （600 mg once daily as CaCO3） and the other placebo tablet once daily for 1 year. At baseline, BMD was measured by dual-energy X-ray absorptiometry at lumbar spine （L2-L4） and at left hip whereas serum PICP, serum OC, and urinary CTX, serum 25（OH）VitD3, and serum estradiol were measured at weaning and I year thereafter. Results After the intervention, BMD at lumbar spine and at left hip increased significantly in all these women with a trend among different Fokl VDR genotypes such as FF 〉 Ff 〉 ff （P〈O.05, 〈0.01, and 〈0.001, respectively）. BMD at lumbar spine in women with FF VDR genotype increased much more rapidly than in those with ff VDR genotype （P〈0.05）. Compared with the control group women with the FF genotype regained more BMD after calcium supplementation （P〈0.05）. Conclusion Daily calcium 600 mg supplementation has beneficial effect on the bone health of women with FF VDR genotype.展开更多
Therapy based on androgenic deprivation is one of the standard treatments that many prostate cancer patients receive. Moreover, its use is increasing owing to a clear expansion of the indications for this therapy in p...Therapy based on androgenic deprivation is one of the standard treatments that many prostate cancer patients receive. Moreover, its use is increasing owing to a clear expansion of the indications for this therapy in patients with localized prostate cancer. Despite classically being considered to be well tolerated, androgenic deprivation has adverse effects. Of these, the loss of mineral bone mass is particularly notable and can lead to osteoporosis, as well as an increased risk of bone fracture. Some fractures, such as hip fractures, may have serious consequences. Useful procedures such as bone densitometry can aid in the diagnosis of these conditions. Once diagnosed, decreases in mineral bone mass can be managed by dietary recommendations, general changes in lifestyle or medication. We review the most important randomized controlled trials evaluating different drugs （bisphosphonates, denosumab and toremifene） in the prevention of bone loss and in the reduction in fracture risk in prostate cancer patients treated with androgen-deprivation therapy. Following the applicable recommendations, urologists must carefully monitor the bone health of prostate cancer patients subjected to androgenic deprivation to obtain an early diagnosis and apply the appropriate general and/or therapeutic measures if necessary.展开更多
文摘Objective: To study the relationship between Ca 2+ intake,Ca 2+ absorption and Ca 2+ retention. Methods; Thirty-six weaning rats were firstly fed with Ca-poor diet for a 3-week Ca 2+ depletion period,and then randomly divided into 3 groups to receive diet with low,adequate and high Ca 2+ contents.The experiment lasted 12 weeks,with a 3-day metabolism experiment conducted in the 5th week. Results:Supplement with adequate amount of Ca 2+ increased bone Ca 2+,bone mineral density(BMD),bone mineral content(BMC)and the weight of femur(P<0.05).Higher doses of Ca 2+ failed to further improve the efficiency.Analysis showed that Ca 2+ intake was positively correlated to bone Ca 2+,BND and BMC,and negatively correlated to the rates of Ca 2+ absorption and retention.Dose-effect study revealed that the Ca 2+ absorption rate()was a hyperbola function of Ca 2+ intake(X),i.e.=e 6.8068×X -0.8821+20(F=47.3154,P<0.0001).It was found from the results that bone Ca 2+ content(determined by atom absorption spectrophotometer)had a linear correlation to BMC(determined with uni-photon bone mineral densitometer). Conclusion:The rate of Ca 2+ absorption is a hyperbola function of Ca 2+ intake.The increment of Ca 2+ absorption will be minimal when Ca 2+ intake exceeds 3d 250 mg in rats.BMC,better than BMD,may substitute for the ideal bone Ca 2+ content as the index to assess the efficacy of Ca 2+ supplement.
基金supported by the Ministry of Health and Ministry of Science and Technology (2008BAI58B02)National Nature Science Foundation (30571573)
文摘Objective To investigate the effect of calcium supplementation on bone mineral density （BMD） in Chinese women with different Fokl vitamin D receptor （VDR） genotypes （FF, Ff, and ff） after weaning or resumption of menstruation during lactation. Methods A total of 40 subjects with the same Fokl VDR genotype were randomly divided into two groups： one received calcium tablet （600 mg once daily as CaCO3） and the other placebo tablet once daily for 1 year. At baseline, BMD was measured by dual-energy X-ray absorptiometry at lumbar spine （L2-L4） and at left hip whereas serum PICP, serum OC, and urinary CTX, serum 25（OH）VitD3, and serum estradiol were measured at weaning and I year thereafter. Results After the intervention, BMD at lumbar spine and at left hip increased significantly in all these women with a trend among different Fokl VDR genotypes such as FF 〉 Ff 〉 ff （P〈O.05, 〈0.01, and 〈0.001, respectively）. BMD at lumbar spine in women with FF VDR genotype increased much more rapidly than in those with ff VDR genotype （P〈0.05）. Compared with the control group women with the FF genotype regained more BMD after calcium supplementation （P〈0.05）. Conclusion Daily calcium 600 mg supplementation has beneficial effect on the bone health of women with FF VDR genotype.
文摘Therapy based on androgenic deprivation is one of the standard treatments that many prostate cancer patients receive. Moreover, its use is increasing owing to a clear expansion of the indications for this therapy in patients with localized prostate cancer. Despite classically being considered to be well tolerated, androgenic deprivation has adverse effects. Of these, the loss of mineral bone mass is particularly notable and can lead to osteoporosis, as well as an increased risk of bone fracture. Some fractures, such as hip fractures, may have serious consequences. Useful procedures such as bone densitometry can aid in the diagnosis of these conditions. Once diagnosed, decreases in mineral bone mass can be managed by dietary recommendations, general changes in lifestyle or medication. We review the most important randomized controlled trials evaluating different drugs （bisphosphonates, denosumab and toremifene） in the prevention of bone loss and in the reduction in fracture risk in prostate cancer patients treated with androgen-deprivation therapy. Following the applicable recommendations, urologists must carefully monitor the bone health of prostate cancer patients subjected to androgenic deprivation to obtain an early diagnosis and apply the appropriate general and/or therapeutic measures if necessary.
