cholecalciferol and deoxypyridinoline

The Mediterranean diet (MD) is widely recommended for the prevention of chronic disease, but evidence for a beneficial effect on bone health is lacking.. The aim of this study was to examine the effect of a Mediterranean-like dietary pattern [NU-AGE (New Dietary Strategies Addressing the Specific Needs of the Elderly Population for Healthy Aging in Europe)] on indexes of inflammation with a number of secondary endpoints, including bone mineral density (BMD) and biomarkers of bone and collagen degradation in a 1-y multicenter randomized controlled trial (RCT; NU-AGE) in elderly Europeans.. An RCT was undertaken across 5 European centers. Subjects in the intervention group consumed the NU-AGE diet for 1 y by receiving individually tailored dietary advice, coupled with supplies of foods including whole-grain pasta, olive oil, and a vitamin D3 supplement (10 µg/d). Participants in the control group were provided with leaflets on healthy eating available in their country.. A total of 1294 participants (mean ± SD age: 70.9 ±4.0 y; 44% male) were recruited to the study and 1142 completed the 1-y trial. The Mediterranean-like dietary pattern had no effect on BMD (site-specific or whole-body); the inclusion of compliance to the intervention in the statistical model did not change the findings. There was also no effect of the intervention on the urinary biomarkers free pyridinoline or free deoxypyridinoline. Serum 25-hydroxyvitamin D significantly increased and parathyroid hormone decreased (P < 0.001) in the MD compared with the control group. Subgroup analysis of individuals with osteoporosis at baseline (site-specific BMD T-score ≤ -2.5 SDs) showed that the MD attenuated the expected decline in femoral neck BMD (n = 24 and 30 in MD and control groups, respectively; P = 0.04) but had no effect on lumbar spine or whole-body BMD.. A 1-y intervention of the Mediterranean-like diet together with vitamin D3 supplements (10 µg/d) had no effect on BMD in the normal age-related range, but it significantly reduced the rate of loss of bone at the femoral neck in individuals with osteoporosis. The NU-AGE trial is registered at clinicaltrials.gov as NCT01754012.

Topics: Aged; Amino Acids; Biomarkers; Bone and Bones; Bone Density; Cholecalciferol; Collagen; Diet, Mediterranean; Dietary Supplements; Europe; Female; Femur Neck; Humans; Male; Olive Oil; Osteoporosis; Parathyroid Hormone; Vitamin D; Whole Grains

Severe vitamin D deficiency is common among Muslim immigrants. The dose necessary to correct the deficiency and its consequence for bone health are not known for immigrants. The aim was to assess the effect of relatively low dosages of supplemental vitamin D on vitamin D and bone status in Pakistani immigrants. This 1-year-long randomised double-blinded placebo-controlled intervention with vitamin D3 (10 and 20 microg/d) included girls (10.1-14.7 years), women (18.1-52.7 years) and men (17.9-63.5 years) of Pakistani origin living in Denmark. The main endpoints were serum 25-hydroxyvitamin D (S-25OHD), parathyroid hormone, bone turnover markers and bone mass. The study showed that supplementation with 10 and 20 microg vitamin D3 per d increased S-25OHD concentrations similarly in vitamin D-deficient Pakistani women (4-fold), and that 10 microg increased S-25OHD concentrations 2-fold and 20 microg 3-fold in Pakistani men. S-25OHD concentrations increased at 6 months and were stable thereafter. Baseline S-25OHD concentrations tended to be lower in girls and women than in men; females achieved about 46 nmol/l and men 55 nmol/l after supplementation. Serum intact parathyroid hormone concentrations decreased at 6 months, but there was no significant effect of the intervention on bone turnover markers and dual-energy X-ray absorptiometry measurements of the whole body and lumbar spine.

Topics: Adolescent; Adult; Age Factors; Amino Acids; Bone and Bones; Bone Density; Child; Cholecalciferol; Denmark; Dose-Response Relationship, Drug; Double-Blind Method; Emigrants and Immigrants; Female; Humans; Male; Middle Aged; Osteocalcin; Pakistan; Parathyroid Hormone; Sex Factors; Vitamin D; Vitamin D Deficiency; Young Adult

We examined the serum level of undercarboxylated osteocalcin (uc OC), which is a sensitive marker of vitamin K status, and levels of bone turnover markers in early postmenopausal women receiving vitamin K2 treatment with or without vitamin D3.. Thirty-four postmenopausal women with a mean age of 53 years whose bone mineral density (BMD) was less than 0.809 g/cm2 (osteopenia and osteoporosis) were treated with vitamin K2 or with a combination of vitamin K2 and vitamin D3. Seventeen women received daily oral administration of 45 mg vitamin K2 and 17 women received daily oral administration of 45 mg vitamin K2 plus 0.75 microg 1alpha-hydroxyvitamin D3. Serum levels of uc OC, intact osteocalcin (OC) and bone alkaline phosphatase (BAP), urinary deoxypyridinoline (DPD) levels and BMD at the lumbar spine were measured before and at 1 and 2 years after the start of treatment.. Serum uc OC levels in women treated with vitamin K2 alone and with both vitamin K2 and vitamin D3 decreased significantly (p < 0.05). Serum levels of intact OC and BAP in women treated with vitamin K2 did not show significant changes, while those in women who received the combined treatment decreased significantly (p < 0.05). On the other hand, urinary DPD level in women treated with vitamin K2 did not change, while that in women who received the combined treatment tended to decrease (p < 0.1).. Serum uc OC levels in early postmenopausal women who received vitamin K2 decreased due to carboxylation of uc OC. Combined treatment with vitamin K2 and vitamin D3 may be effective for sustaining BMD in early postmenopausal women whose bone turnovers are highly activated.

Topics: Alkaline Phosphatase; Amino Acids; Bone Density; Bone Density Conservation Agents; Bone Diseases, Metabolic; Cholecalciferol; Drug Therapy, Combination; Female; Humans; Middle Aged; Osteocalcin; Osteoporosis, Postmenopausal; Postmenopause; Vitamin K 2

Bone metabolism follows a seasonal pattern with high bone turnover and bone loss during the winter. In a randomized, open-label 2-year sequential follow-up study of 55 healthy adults, we found that supplementation with oral vitamin D3 and calcium during winter abolished seasonal changes in calciotropic hormones and markers of bone turnover and led to an increase in BMD. Supplementation with oral vitamin D3 and calcium during the winter months seems to counteract the effects of seasonal changes in vitamin D and thus may be beneficial as a primary prevention strategy for age-related bone loss.. Bone metabolism follows a seasonal pattern characterized by high bone turnover and bone loss during winter. We investigated whether wintertime supplementation with oral vitamin D3 and calcium had beneficial effects on the circannual changes in bone turnover and bone mass.. This prospective study comprised an initial observation period of 12 months ("year 1"), followed by an intervention during parts of year 2. Fifty-five healthy subjects living in southwestern Germany (latitude, 49.5 degrees N) were randomized into two groups: 30 subjects were assigned to the treatment group and received oral cholecalciferol (500 IU/day) and calcium (500 mg/day) during the winter months of year 2 (October-April), while 25 subjects assigned to the control group obtained no supplements. Primary endpoints were changes in calciotropic hormones [serum 25(OH)D, 1,25(OH)2D, and parathyroid hormone], markers of bone formation (serum bone-specific alkaline phosphatase) and of bone resorption (urinary pyridinoline and deoxypyridinoline), and changes in lumbar spine and femoral neck BMD.. Forty-three subjects completed the study. During year 1, calciotropic hormones, markers of bone turnover, and BMD varied by season in both groups. During the winter months of year 1, bone turnover was significantly accelerated, and lumbar spine and femoral BMD declined by 0.3-0.9%. In year 2, seasonal changes in calciotropic hormones and markers of bone turnover were either reversed or abolished in the intervention group while unchanged in the control cohort. In the subjects receiving oral vitamin D3 and calcium, lumbar and femoral BMD increased significantly (lumbar spine: +0.8%, p = 0.04 versus year 1; femoral neck: +0.1%, p = 0.05 versus year 1), whereas controls continued to lose bone (intervention group versus control group: lumbar spine, p = 0.03; femoral neck, p = 0.05).. Supplementation with oral vitamin D3 and calcium during winter prevents seasonal changes in bone turnover and bone loss in healthy adults. It seems conceivable that annually recurring cycles of low vitamin D and mild secondary hyperparathyroidism during the winter months contributes, at least in part and over many years, to age-related bone loss. Supplementation with low-dose oral vitamin D3 and calcium during winter may be an efficient and inexpensive strategy for the primary prevention of bone loss in northern latitudes.

Topics: Absorptiometry, Photon; Adult; Aged; Alkaline Phosphatase; Amino Acids; Bone and Bones; Bone Density; Bone Resorption; Calcium; Cholecalciferol; Dietary Supplements; Female; Femur Neck; Humans; Lumbar Vertebrae; Male; Middle Aged; Osteoporosis; Parathyroid Hormone; Prospective Studies; Seasons; Treatment Outcome; Vitamin D

Today, androgen deprivation therapy is a cornerstone of treatment for advanced prostate cancer, although it presents important complications such as osteoporosis. Neridronate, a relatively new bisphosphonate, is able to prevent bone loss in patients with prostate cancer during androgen ablation.. Androgen-deprivation therapy (ADT) is a cornerstone of treatment for advanced prostate cancer. This therapy has iatrogenic complications, such as osteoporosis. The aim of our study was to evaluate the efficacy of neridronate, a relatively new bisphosphonate, to prevent bone loss during androgen ablation.. Forty-eight osteoporotic patients with prostate cancer, treated with 3-month depot triptorelina, were enrolled and randomly assigned to two different treatment groups: group A (n = 24) was treated with a daily calcium and cholecalciferol supplement (500 mg of elemental calcium and 400 IU cholecalciferol), and group B (n = 24) received in addition to the same daily calcium and cholecalciferol supplement, 25 mg of neridronate given intramuscularly every month. All patients also received bicalutamide for 4 weeks. Lumbar and femoral BMD was evaluated by DXA at baseline and after 1 year of therapy; moreover, deoxypyridinoline (DPD) and bone alkaline phosphatase (BALP) were determined at the beginning, midway through, and at the end of the study.. After 6 and 12 months, whereas patients treated only with calcium and cholecalciferol (group A) showed a marked bone loss, with increased levels of DPD and BALP compared with baseline values, patients treated also with neridronate (group B) had substantially unchanged levels of these markers. After 1 year of treatment, lumbar and total hip BMD decreased significantly in patients treated only with calcium and cholecalciferol (group A), whereas it did not change significantly at any skeletal site in patients treated also with neridronate (group B). No relevant side effects were recorded during our study.. Neridronate is an effective treatment in preventing bone loss in the hip and lumbar spine in men receiving ADT for prostate cancer.

Topics: Absorptiometry, Photon; Aged; Alkaline Phosphatase; Amino Acids; Androgen Antagonists; Androgens; Antineoplastic Agents, Hormonal; Bone and Bones; Bone Density; Calcium; Cholecalciferol; Diphosphonates; Humans; Male; Osteoporosis; Prostatic Neoplasms; Time Factors; Triptorelin Pamoate

Although there have been some case reports suggesting that bone in patients with pseudohypoparathyroidism (PHP) might respond to parathyroid hormone (PTH), no information is available as to whether serum PTH concentration is related to bone metabolic markers or to bone mineral density (BMD) in PHP.. To address these relationships, by comparing intact serum PTH, bone metabolic markers and BMD in patients with PHP with those in patients with idiopathic hypoparathyroidism (IHP) and postoperative hypoparathyroidism (OHP).. Intact serum PTH, bone metabolic markers (osteocalcin, tartrate-resistant acid phosphatase, pyridinoline, deoxypyridinoline) and BMD by dual-energy X-ray absorptiometry or single-photon absorptiometry were measured in patients with PHP Ia (n=2) and PHP Ib (n=8). The results were compared with those in patients with IHP (n=5) and OHP (n=14).. All bone metabolic markers measured were present in significantly greater amounts in patients with PHP Ib than in those with IHP+OHP. The Z score (standard deviation of average BMD at each age) of the BMD of femoral neck was significantly lower in patients with PHP Ib than in those with IHP+OHP. The Z scores of BMD of lumbar spine and radius were also lower in patients with PHP Ib than in those with IHP+OHP, but the difference was not significant. Moreover, the intact serum PTH concentrations were significantly and positively related to bone metabolic marker levels in all patients, and the intact serum PTH concentrations were significantly and negatively related to BMD of lumbar spine in PHP patients.. These results suggest that PTH stimulates bone turnover in PHP Ib patients, resulting in a relatively lower BMD in PHP Ib patients than in IHP+OHP patients. The present study indicates that bones of most cases of PHP could respond to PTH.

Topics: Acid Phosphatase; Adult; Aged; Amino Acids; Biomarkers; Bone Density; Cholecalciferol; Creatinine; Cyclic AMP; Erythrocyte Membrane; Female; GTP-Binding Protein alpha Subunits, Gs; Humans; Hypoparathyroidism; Isoenzymes; Kidney; Male; Middle Aged; Osteocalcin; Parathyroid Hormone; Phosphates; Postoperative Complications; Pseudohypoparathyroidism; Tartrate-Resistant Acid Phosphatase

The aim of this study was to determine the bone mineral density (BMD) and the factors leading to reduction in BMD in children diagnosed with meningomyelocele.. A total of 31 patients with meningomyelocele (mean (SD) age, 8.5 (3.9) years; 51.6%were females) and 22 healthy children were included. BMD of femoral neck and spinal L1– L4 levels and markers for bone metabolism were recorded.. BMD of femoral neck (p=0.001) and spinal L1–L4 (p = 0.01), serum calcium (p = 0.031), and urinary deoxypyridinoline (p=0.015) levels were significantly lower in patients than in controls. Mobilization was significantly reduced in lumbar (p=0.001) and thoracic (p=0.002) level meningomyelocele compared to controls, while a significant positive correlation was noted between BMD of spinal L1–L4 and mobility (r=0.58, p=0.015).. Our findings suggest a decrease in BMD in meningomyelocele patients being associated with osteoporosis rather than nutritional and hormonal factors and the negative impact of higher levels of lesion on the mobility.

Topics: Absorptiometry, Photon; Adolescent; Adrenocorticotropic Hormone; Amino Acids; Anthropometry; Blood Chemical Analysis; Body Weight; Bone Density; Calcium; Case-Control Studies; Chi-Square Distribution; Child; Child, Preschool; Cholecalciferol; Female; Follicle Stimulating Hormone; Humans; Male; Meningomyelocele; Statistics as Topic

Time-dependent differences in adverse reactions and efficacy by a repeated administration of 1,25(OH)2 vitamin D3 (vit D, 0.3 microg/Kg/day for 12 weeks) were examined in 5/6 nephrectomized rats under a condition of 12-hour light-dark cycle. The 5/6 nephrectomy increased serum concentrations of phosphate, osteocalcin and PTH, and urinary excretions of phosphate and deoxypyridinoline (DPD) while the maneuver reduced serum Ca concentration and its urinary excretion. Animals with a dosing of the drug at 2 hours after light on (HALO) had more grade of hypercalcemia and hyperphosphatemia than those at 14 HALO. Reduction of serum intact PTH and increase of serum vit D were observed in both groups with a similar extent. Increase of osteocalcin by the drug was greater in 14 HALO trial. Urinary excretion of DPD was not influenced by the treatment. The increase in bone density of femur was greater in 14 HALO than in 2 HALO trials. These results suggest that adverse reactions of vit D were ameliorated and its efficacy was enhanced after the repeated dosing of the drug at 14 HALO. Time-dependent variation in the sensitivity of the drug to osteoblast was involved in the mechanism of these events, while the roles of pharmacokinetic alteration and renal response were small, if any.

Topics: Amino Acids; Animals; Biomarkers; Body Weight; Bone Density; Calcium; Cholecalciferol; Creatinine; Male; Nephrectomy; Osteocalcin; Parathyroid Hormone; Phosphorus; Rats; Rats, Wistar; Time Factors

The chronotherapeutic effects of 1-alpha-(OH) vitamin D3, a pro-drug of 1,25(OH)2 vitamin D3 (1,25(OH)2D3), were evaluated by repeated dosing of the drug in aged stroke-prone spontaneously hypertensive male rats, a model of osteoporosis. Animals (7 months old) were kept in rooms with a 12-h light/dark cycle. Drug (0.5 microg/kg) or vehicle was given once daily at 2 or 14 h after lights on for 3 months. The severity of adverse effects such as body weight loss, hypercalcemia and hyperphosphatemia was significantly less when the drug was given at 14 h after lights on (14 HALO). Serum 1,25(OH)2 vitamin D3 concentrations of 2 h after lights on (2 HALO) group and 14 HALO group did not differ significantly after dosing. The decrease in parathyroid hormone (PTH) level 12 weeks after the start of the study was greater in the 14 HALO group than in the 2 HALO group. Urinary excretion of inorganic Ca and P in the 2 HALO group was greater than that in the 14 HALO group. Urinary excretion of deoxypyridiniline, an index of the bone resorption capacity of osteoclasts, was much suppressed in the 14 HALO group, suggesting that the efficacy of vitamin D3 for suppressing bone resorption might vary with the dosing time. The increase in bone density of both femurs, determined by dual-energy X-ray absorption at the end of the study, was greater in the 14 HALO group than in the 2 HALO group. This is the first study to show the dosing time-dependent efficacy and toxicity of active vitamin D3 in an animal model of osteoporosis. These results indicate that a chronopharmacological approach is beneficial for establishing a more effective and/or safer regimen of active vitamin D3 for the treatment of osteoporosis.

Topics: Aging; Amino Acids; Animals; Body Weight; Bone Density; Calcium; Cholecalciferol; Chronotherapy; Disease Models, Animal; Hypercalcemia; Hypertension; Male; Osteoporosis; Parathyroid Hormone; Phosphates; Rats; Rats, Inbred SHR; Steroid Hydroxylases; Time Factors; Weight Loss

Topics: Alkaline Phosphatase; Amino Acids; Biomarkers; Bone Resorption; Cholecalciferol; Collagen; Collagen Type I; Diphosphonates; Enzyme-Linked Immunosorbent Assay; Hormone Replacement Therapy; Humans; Osteoporosis; Peptides

Tibolone is a synthetic steroid with tissue-specific estrogenic, progestogenic, and androgenic properties. The therapeutic effects of tibolone on bone mass and strength, bone metabolic markers, and indices of histomorphometry were investigated in ovariectomized (ovx) rats on a low (0.1%)-calcium diet in comparison with 17alpha-ethynylestradiol (EE) or 1alpha-hydroxyvitamin D3 [1alpha(OH)D3]. Tibolone (0.1-3 mg/kg/day), EE (0.1 mg/kg/day), or 1alpha(OH)D3 (0.5 microg/kg/day) was administered orally once a day for 16 weeks, starting 12 weeks after ovariectomy, when the bone mineral density (BMD) of lumbar vertebrae (L4-5) and femur (global, proximal, and distal regions) had already been decreased by the combination of ovariectomy and low dietary calcium. The BMD of the lumbar vertebrae and the femur were higher in the groups treated with tibolone, EE, or 1alpha(OH)D3 than in the ovx control group. The BMD of the mid-diaphysial regions of femur and tibia, which consist mainly of cortical bone, were decreased 28 weeks after ovariectomy in the ovx control group. The BMD of the mid-diaphysial femur was higher in the groups treated with 1alpha-(OH)D3, and the BMD of mid-diaphysial tibia was higher in the groups treated with tibolone or 1alpha(OH)D3 than in the ovx control group. Like BMD, the compressive strength of the vertebral body of L2, corrected for the volume of each individual vertebra tested, was higher in the groups treated with tibolone, EE, or 1alpha(OH)D3 than in the ovx control group. Trabecular bone volume and trabecular number were reduced 12 and 28 weeks after ovariectomy but there was no change in trabecular thickness. These reduced indices were increased in the groups treated with tibolone, EE, or 1alpha(OH)D3 when compared with the ovx control group. Tibolone or EE decreased serum levels of osteocalcin and bone alkaline phosphatase and urinary levels of deoxypyridinoline and pyridinoline compared with the ovx control group. Furthermore, tibolone or EE decreased the mineralizing surface and bone formation rate as well as the osteoclast surface and osteoclast numbers. 1Alpha(OH)D3, however, did not affect these serum and urinary parameters. These data suggest that tibolone suppresses the accelerated bone turnover induced by a combination of ovariectomy and low dietary calcium, and indicate that tibolone may be a potentially useful drug for the treatment of postmenopausal osteoporosis.

Topics: Absorptiometry, Photon; Alkaline Phosphatase; Amino Acids; Anabolic Agents; Animals; Bone and Bones; Bone Density; Bone Diseases, Metabolic; Calcium; Calcium, Dietary; Cholecalciferol; Ethinyl Estradiol; Female; Norpregnenes; Osteocalcin; Ovariectomy; Rats; Rats, Sprague-Dawley; Weight-Bearing

Further studies of mimosine toxicity in broiler chicks were done to clarify a possibility of osteopathy. The mineral content and density of femur and the strength, ductility, and toughness for the index of mechanical properties significantly decreased in the 1% mimosine group, compared with those in the control and restricted groups. The stiffness had a decreasing tendency in the 1% mimosine group. Consequently, it was concluded that chicks fed ad libitum a 1% mimosine diet for 12 days developed osteopathy. The bone mineral density and the strength of the restricted group were lower than those of the control group, and those of the 1% mimosine group were still lower than those of the restricted group. Contents of pyridinoline and deoxypyridinoline in the excrement were significantly higher in the restricted group than those in the control group, but the contents in the 1% mimosine group were significantly lowest among the groups. Osteopathy in chicks fed mimosine, therefore, seemed to be done by loss of appetite and changing to a low turnover of bone caused by mimosine.

Topics: Amino Acids; Animal Feed; Animals; Body Weight; Bone Density; Calcifediol; Calcium; Chickens; Cholecalciferol; Corticosterone; Fabaceae; Femur; Iron; Magnesium; Male; Mimosine; Organ Size; Osteoporosis; Plant Poisoning; Plants, Medicinal; Zinc

Adequate calcium intake is essential for skeletal integrity, particularly during the period of peak bone mass acquisition from 9 to 17 y of age. Currently, the calcium intake of many adolescent girls is below the recommended dietary allowance. The purpose of this study was to evaluate the ability of girls to respond to acute periods of inadequate dietary calcium intake. Calcium absorption was evaluated in 11 girls aged 11.6 +/- 2.4 y after 10 d on both a low-calcium (7.05 +/- 2.03 mmol/d) and a high-calcium (35.30 +/- 2.28 mmol/d) diet. Fractional calcium absorption was determined by using oral (46Ca) and intravenous (42Ca) stable isotopes of calcium. During a low calcium intake, fractional calcium absorption was significantly greater (0.582 +/- 0.087 compared with 0.260 +/- 0.068, P < 0.0001) and urinary calcium excretion was significantly lower (1.30 +/- 0.83 compared with 3.08 +/- 1.98 mmol/d, P < 0.004) than values obtained during a high calcium intake. Concentrations of 1,25-dihydroxyvitamin D (combination of cholecalciferol and ergocalciferol) were greater during the low calcium intake, although the difference was not significant (108.7 +/- 30.6 compared with 90.0 +/- 25.1 pmol/L, P < 0.1; n = 9). Excretion of N-telopeptide was significantly greater during the low calcium intake (761 +/- 508 compared with 413 +/- 341 nmol bone collagen equivalent (BCM)/mmol creatinine, P < 0.02; n = 9), indicating that bone resorption was increased. These results suggest that during short periods of inadequate calcium intake, girls are able to significantly increase the efficiency of calcium absorption and decrease urinary calcium losses to conserve calcium required for bone mineral acquisition.

Topics: Absorption; Adolescent; Amino Acids; Bone Density; Calcium; Calcium Isotopes; Calcium, Dietary; Child; Cholecalciferol; Collagen; Collagen Type I; Female; Humans; Osteocalcin; Parathyroid Hormone; Peptides; Time Factors

The measurement of urinary deoxypyridinoline (DPD) constitutes a specific and sensitive marker of bone resorption. Total and free forms of DPD are determined by chromatographic method (HPLC) after or without hydrolysis of urine, respectively. Pyrilinks-D, a new immunoassay, allows to assess directly the free forms and needs an appropriate hydrolysis step for measuring the total form. We have compared the values of free (F), total (T) and conjugated (NF) forms of DPD determined by HPLC and Pyrilinks-D, in elderly women (n = 21, mean age: 83.5 +/- 1.5 years) with vitamin D insufficiency (25 OH D < 6 ng/mL) and Ca insufficiency responsible for a secondary hyperparathyroidism (iPTH = 45.3 +/- 22.7 pg/mL) and in healthy elderly women (n = 25, mean age: 76.6 +/- 3.1 years) with a normal vit D status (25 OH D > 10 ng/mL) as control group. We have also measured DPD during the course of vit D and Ca supplementation. At baseline, the HPLC and Pyrilinks-D values of DPD/Cr are highly correlated (DPD-T: r = 0.92, p < 0.001 and DPD-F: r = 0.76, p < 0.001), DPD-F and -NF values are correlated with those of DPD-T, while DPD-F and -NF are not correlated between themselves. In elderly with vit D insufficiency, the values obtained with Pyrilinks-D as compared to control subjects, show a significant increase of urinary excretion of DPD-F (8.5 +/- 3.1 vs 5.7 +/- 1.9 nmol/mmol, Cr, p < 0.0001), DPD-T (16.8 +/- 10.2 vs 9.9 +/- 3.5 nmol/mmol, Cr; p < 0.001) and DPD-NF (8.3 +/- 9.0 vs 4.5 +/- 3.3 nmol/mmol, Cr, p < 0.05). The administration of 800 IU of vit D and 1 g of elemental Ca during a course of 6 months normalize the iPTH values (24.4 +/- 11.8 and 30.9 +/- 14.6 pg/mL at 3 and 6 months). Simultaneously, the urinary excretion at 3 and 6 months of DPD-T (12.9 +/- 6.0 and 13.6 +/- 6.5 nmol/mmol, Cr) and of DPD-NF (4.5 +/- 3.3 and 5.5 +/- 4.8 nmol/mmol Cr) assessed by Pyrilinks-D as well as by HPLC decreased significantly, while no change was seen with DPD-F assessed by both methods. The decreases expressed as percent of baseline values were about 20% for DPD-T and more than 30% for DPD-NF, while DPD-F levels remain unchanged. We conclude that the Pyrilinks-D immunoassay presents reliable characteristics and allows to assess either free or total forms of DPD, like the HPLC technique. It constitutes an excellent reflection of bone resorption in elderly with vit D insufficiency. However its application to monitor therapy like vit D and Ca supplementation, needs a hydrolysis step

Topics: Aged; Aged, 80 and over; Amino Acids; Analysis of Variance; Calcifediol; Cholecalciferol; Chromatography, High Pressure Liquid; Creatinine; Enzyme-Linked Immunosorbent Assay; Female; Humans; Hyperparathyroidism, Secondary; Parathyroid Hormone; Vitamin D Deficiency