Short-term variations in bone remodeling biochemical markers: cyclical etidronate and alendronate effects compared

Effects of a Functional Ice Cream Enriched with Milk Proteins on Bone Metabolism: A Feasibility Clinical Study and In Vitro Investigation

Background: Milk proteins (MPs) and their derivative whey proteins (WPs) are important components of human diet that might prevent bone loss. We aimed to investigate the effects of MP on the bones of postmenopausal women, along with the effects of WP on osteoblast cells. Methods: We conducted a feasibility controlled clinical study with 62 postmenopausal women who were asked to consume an MP-enriched ice cream. We also investigated the effect of WP on the ERK1/2 and AKT pathways, RUNX2, alkaline phosphatase, RANKL/OPG ratio, and COL1A of Saos-2. Results: After 12 weeks, we found a greater bone mineral density and bone alkaline phosphatase reduction in women who consumed the MP-enriched ice cream compared to the control group (p = 0.03 and p = 0.02, respectively). In Saos-2 cells, WP upregulated ERK1/2 and AKT pathways (p = 0.002 and p = 0.016), cell proliferation (p = 0.03), and osteoblast differentiation markers, along with downregulating RANKL/OPG (p < 0.001). Moreover, the inhibition of ERK1/2 by PD184253 reverted the effects on both the RUNX2 and ALP mRNA expression and cells proliferation (p = 0.028, p = 0.004, and p = 0.003, respectively) when treated with WP. Conclusions: WP upregulates cell proliferation, RUNX2, and alkaline phosphatase through the activation of the ERK1/2 pathways on Saos-2. These mechanisms probably contribute to preventing bone loss in postmenopausal women.

Circulating osteocalcin: A potential predictor of ketosis in type 2 diabetes

AIMS

Osteocalcin contributes to the regulation of endocrine system. However, the association between osteocalcin and ketosis has not been evaluated. We thus aimed to explore the relationship between total osteocalcin and risk of ketosis in type 2 diabetes (T2DM).

MATERIALS AND METHODS

We identified 6157 diabetes patients from Shanghai Tenth People's Hospital between 1 January 2011 and 1 March 2017. Six hundred eight subjects were enrolled in the retrospective cross-sectional study: 304 T2DM patients with ketosis whose age, gender, and body mass index were matched with 304 T2DM patients without ketosis. A further retrospective nested case-control study was conducted in 252 T2DM patients without ketosis for a mean duration of 21.58 ± 12.43 months to investigate the occurrence of ketosis.

RESULTS

Osteocalcin levels were negatively correlated with blood ketones (adjusted r = -0.263) and urine ketones (adjusted r = -0.183). The inverse dose-dependent relationship of osteocalcin and risk of ketosis was present across osteocalcin level quintiles (top quintile as the reference, adjusted odds ratio [95% CI] = 2.56 [0.80-8.17], 3.71 [0.90-15.29], 10.77 [2.63-44.15], 23.81 [4.32-131.17] per osteocalcin quintile, respectively). Ketosis occurred in 17 of the 252 T2DM patients during follow-up. The Cox regression analysis indicated that osteocalcin was an independent protective factor against development of ketosis (adjusted hazard ratio [95% CI]: 0.668 [0.460-0.971]).

CONCLUSIONS

Total osteocalcin can be used as a predictor of ketosis in T2DM.

Soluble Biomarkers of Osteoporosis and Osteoarthritis, from Pathway Mapping to Clinical Trials: An Update

Serum biomarkers of osteoarticular diseases have been in the limelight of current clinical research trends. Laboratory validation of defined and candidate biomarkers for both osteoarthritis and osteoporosis is of key importance for future decisional algorithms in the diagnosis, monitoring, and prognosis of these diseases. The current guidelines recommend the use of collagen degradation remnants, eg, CTX-I and CTX-II, in the complementary diagnosis of both osteoporosis and osteoarthritis. Besides the collagen degradation markers, enzymes that regulate bone and articular metabolism are useful in the clinical evaluation of osteoarticular pathologies. Along these, several other recommended and new nominee molecules have been recently studied. Wnts and Wnt-related molecules have a cardinal role in the bone-joint homeostasis, making them a promising target not only for pharmaceutical modulation, but also to be considered as soluble biomarkers. Sclerostin and dickkopf, two inhibitor molecules of the Wnt/β-catenin signaling, might have a dual role in the assessment of the clinical manifestations of the osteoarticular unit. In osteoarthritis, besides fragments of collagen type II many pathway-related molecules have been studied and proposed for biomarker validation. The most serious limitation is that a significant proportion of studies lack statistical power due to the reduced number of cases enrolled. Serum biomarkers of bone and joint turnover markers represent an encouraging possibility for the diagnosis and prognosis of osteoarticular diseases, although further studies and laboratory validations should be carried out as to solely rely on them.

Lycopene and bone: an in vitro investigation and a pilot prospective clinical study

Background

There are several effective therapies for osteoporosis but these agents might cause serious adverse events. Lycopene intake could prevent bone loss, however studies on its effects on bone are scarce. Our aim was to investigate the effects of lycopene on osteoblast cells as well as bone mineral density and bone turnover markers in postmenopausal women.

Methods

We investigated the effect of lycopene on the Wnt/β-catenin and ERK 1/2 pathways, RUNX2, alkaline phosphatase, RANKL and COL1A of Saos-2. We also carried out a pilot controlled clinical study to verify the feasibility of an approach for bone loss prevention through the intake of a lycopene-rich tomato sauce in 39 postmenopausal women.

Results

Lycopene 10 µM resulted in higher β-catenin and phERK1/2 protein Vs the vehicle (p = 0.04 and p = 0.006). RUNX2 and COL1A mRNA was induced by both 5 and 10 µM doses (p = 0.03; p = 0.03 and p = 0.03; p = 0.05) while RANKL mRNA was reduced (p < 0.05). A significant bone density loss was not detected in women taking the tomato sauce while the control group had bone loss (p = 0.002). Tomato sauce intake resulted in a greater bone alkaline phosphatase reduction than the control (18% vs 8.5%, p = 0.03).

Conclusions

Lycopene activates the WNT/β-catenin and ERK1/2 pathways, upregulates RUNX2, alkaline phosphatase, COL1A and downregulates RANKL Saos-2. These processes contributed to prevent bone loss in postmenopausal women.

Morning vs evening dosing of the cathepsin K inhibitor ONO-5334: effects on bone resorption in postmenopausal women in a randomized, phase 1 trial

The cathepsin K inhibitor, ONO-5334, improves bone mineral density in postmenopausal women with osteoporosis. The effects of morning versus evening administration of ONO-5334 were investigated by measuring bone turnover marker levels in healthy postmenopausal women. Morning administration of ONO-5334 showed a more consistent suppressive effect on bone resorption than evening administration.

INTRODUCTION

Bone turnover is thought to be subject to circadian variation, and the efficacy of osteoporosis treatments may be optimized by regulating the time of dosing. This study assessed whether evening administration of the cathepsin K inhibitor, ONO-5334, had a differential effect on the bone turnover marker, C-terminal telopeptide of type I collagen (CTX-I), compared with morning administration.

METHODS

This was a single-center, single blind crossover study. Fourteen healthy postmenopausal women were assigned to receive ONO-5334 150 mg once daily for 5 days in each period; they were randomized to receive either evening doses in the first period and morning doses in the second or vice versa. Serum and urinary levels of CTX-I were measured throughout the study.

RESULTS

Both regimens showed similar patterns of reduction in serum and urinary CTX-I; however, CTX-I suppression was more consistently >60% over 24 h following morning administration. Morning administration led to 6% greater suppression of 24-h serum CTX-I area under the effect curve (AUE; 69 vs 63%; P < .05) and 7% greater suppression of urinary CTX-I/creatinine AUE (93 vs 86%; P < .01) than evening administration. Higher plasma ONO-5334 concentrations were observed between 12 and 24 h postdose following morning administration, with mean trough concentrations for the morning and evening regimens at 9.4 and 4.0 ng/mL, respectively. There were no safety findings of concern.

CONCLUSION

Morning dosing of ONO-5334 is more efficacious at reducing markers of bone turnover in healthy postmenopausal women than evening dosing.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01384188 , registered on June 27, 2011 EudraCT: 2008-006284-37.

Bone turnover marker profile in relation to the menstrual cycle of premenopausal healthy women

OBJECTIVE

To explore the bone turnover marker profile during the menstrual cycle of premenopausal women.

DESIGN

This was a noninterventional study. Levels of bone turnover markers, including serum C-terminal telopeptide of type I collagen (sCTX), bone-specific alkaline phosphatase, osteocalcin, procollagen type 1 N propeptide, and urinary N-terminal telopeptide of type I collagen, were measured in blood and urine samples during one menstrual cycle. Levels were expressed as raw test results and percent change from serum luteinizing hormone peak. Differences in mean levels of bone turnover markers between menstrual phases and subphases were examined.

RESULTS

Fifty-five women comprised the per-protocol population. Mean sCTX values were 0.48 ng/mL during the follicular phase (FP), 0.47 ng/mL at serum luteinizing hormone peak, and 0.43 ng/mL during the luteal phase (LP). Additionally, the mean percent change from luteinizing hormone peak varied from +4.35% during the FP to -5.11% during the LP (P = 0.0014). Mean sCTX levels during the early and through mid FP were significantly higher than levels during the mid and late LP. The pattern for urinary N-terminal telopeptide of type I collagen was similar to that of sCTX but not statistically significant. There was a statistically significant tendency for procollagen type I N propeptide levels to be lower during the FP relative to the LP. Levels of osteocalcin and bone-specific alkaline phosphatase did not vary significantly during the menstrual cycle.

CONCLUSIONS

Levels of some bone turnover markers varied during the menstrual cycle. A statistically significant change in sCTX (9.46%) occurred between the FP and LP of the menstrual cycle.

Inhibitory Effect of Alendronate on Bone Resorption of Autogenous Free Bone Grafts in Rats

PURPOSE

This study was designed to investigate the effect of alendronate on the resorption of autogenous free bone grafts by biochemical and histopathologic methods. Alendronate is a potent inhibitor of osteoclast-mediated bone resorption with no adverse effect on the mineralization of bone.

MATERIALS AND METHODS

In this experimental study, 56 male Wistar rats were used. Autogenous free bone grafts were prepared with standard trephine bur in the right femur of each rat. The animals were then divided into 2 groups. In the first group, rats were treated with a daily subcutaneous injection of alendronate (0.25 mg/kg/day) for 2, 4, and 12 weeks, respectively. In the second group, rats were treated with saline solution injection for the same time periods. At the end of these periods, serum and overnight fasting urine samples were collected from all animals. In serum, the level of calcium, phosphate, parathyroid hormone, and 25 dihydroxyvitamin D were measured. In urine, pyridinoline, deoxypyridinoline, calcium, and creatinine were analyzed. The rats were sacrificed at 2, 4, and 12 weeks postsurgery. The number of osteoclasts and the number and size of resorptive lacunae were evaluated histopathologically.

RESULTS

Alendronate caused significant reduction in urinary pyridinoline, deoxypyridinoline levels biochemically, and the number of osteoclasts and resorptive lacunae histopathologically.

CONCLUSION

Suppression of the graft resorption occurred in the alendronate-treated group.

The effect of a low-carbohydrate diet on bone turnover

INTRODUCTION

Low-carbohydrate diets have become popular as weight loss techniques. These diets are high in protein, saturated fats, and omega-6 fatty acids. They also lead to a ketogenic state. These factors could lead to increased bone turnover. This study was designed to see whether a low-carbohydrate diet would lead to increased bone turnover in humans.

METHODS

Thirty patients (15 study subjects and 15 controls) were recruited for this 3-month study. The 15 patients on the diet were instructed to consume less than 20 g of carbohydrates per day for the 1st month and then less than 40 g per day for months 2 and 3. Control subjects had no restrictions on their diet. The primary end point was urinary N-telopeptide (UNTx) at 3 months. Secondary end points included UNTx at 1 month, bone-specific alkaline phosphatase (BSAP) at 1 month, bone turnover ratio (BSAP/UNTx) at 1 month, and weight loss.

RESULTS

The mean UNTx in the study subjects increased by 1.6 [95% confidence interval (CI) +/-22.8] compared with an increase of 1.9 (95% CI +/-17.6) in the controls at 3 months (p=0.86). The mean UNTx decreased by 2.2 (95% CI +/-27.2) and 3.1 (95% CI +/-17.6) at 1 month in the dieters and controls, respectively (p=0.36). The mean BSAP decreased by 0.53 (95% CI +/-2.96) in the dieters and increased by 0.34 (95% CI +/-2.92) in the controls at 1 month (p=0.27). The bone turnover ratio increased by 0.08 (95% CI +/-0.81) in the dieters and by 0.05 (95% CI +/- 0.27) in the controls at 1 month (p=0.78). The dieters lost 6.39 kg versus 1.05 kg for the controls at 3 months (p=0.0008).

CONCLUSIONS

Although the patients on the low-carbohydrate diet did lose significantly more weight than the controls did, the diet did not increase bone turnover markers compared with controls at any time point. Further, there was no significant change in the bone turnover ratio compared with controls.

Effect of menatetrenone on bone mineral density and incidence of vertebral fractures in postmenopausal women with osteoporosis: a comparison with the effect of etidronate

The purpose of the present study was to compare the effects of etidronate and menatetrenone on bone mineral density (BMD) and the incidence of vertebral fractures in postmenopausal women with osteoporosis. Seventy-two osteoporotic women, more than 5 years after menopause, 53-78 years of age, were randomly divided into three administration groups: E group; intermittent cyclical etidronate (200 mg/day, 14 days per 3 months; n = 25); M group; menatetrenone (45 mg/day, daily; n = 23); and C group (control); calcium lactate (2 g/day, daily; n = 24). Forearm BMD was measured by dual-energy X-ray absorptiometry at 0, 6, 12, 18, and 24 months after the treatment started. There were no significant differences in age, body mass index, years since menopause, and initial BMD among the three groups. One-way analysis of variance (ANOVA) with repeated measurements showed a significant decrease in BMD in the C group (P < 0.0001). Two-way ANOVA with repeated measurements showed a significant increase in BMD in the M group compared with that in the C group (P < 0.0001), and a significant increase in BMD in the E group compared with that in the C and M groups (P < 0.0001 and P < 0.01, respectively). The indices of new vertebral fractures/1000 patient-years in the E and M groups were significantly higher than that in the C group (chi(2) = 47.7; P < 0.0001 and chi(2) = 42.4; P < 0.0001, respectively), and did not differ significantly between the E and M groups. The present preliminary study provides evidence to suggest that, despite the lower increase in BMD produced by menatetrenone, this agent, as well as etidronate, may have the potential to reduce osteoporotic vertebral fractures in postmenopausal women with osteoporosis.

Alendronate: an update of its use in osteoporosis

Alendronate (alendronic acid) is a nitrogen-containing bisphosphonate which binds to bone surfaces and inhibits bone resorption by osteoclasts. Oral alendronate 5 or 10 mg/day produces sustained increases in bone mineral density (BMD) in postmenopausal women with or without osteoporosis, in men with primary osteoporosis and in both men and women with or without osteoporosis receiving systemic corticosteroid therapy. Histomorphometric analyses have found that alendronate does not appear to impair bone quality. Alendronate reduced the risk of radiographic vertebral fracture, clinical vertebral fracture or hip fracture by 47 to 56% in postmenopausal women who had > or = 1 existing vertebral fracture and in those with no existing vertebral fractures but who had osteoporosis. In a number of comparative trials in postmenopausal women with osteoporosis, alendronate 10 mg/day was found to be more effective at inducing sustained increases in BMD than intranasal calcitonin, and at least as effective as conjugated estrogens and raloxifene. Alendronate 70 mg administered once weekly and 35 mg twice weekly are as effective at increasing BMD as 10 mg/day in this patient group. In clinical trials, alendronate was generally well tolerated when taken as recommended. Adverse events tended to be transient and associated with the upper GI tract, most commonly including abdominal pain, nausea, dyspepsia, acid regurgitation and musculoskeletal pain. No statistically significant differences between alendronate 10 mg/day and placebo have been found in the incidence of upper GI adverse events in large clinical trials. However, postmarketing surveillance reported a low incidence of adverse events related to the oesophagus. Specific instructions aimed at reducing the risk of upper GI adverse events have been provided by the manufacturer.

CONCLUSIONS

Alendronate is effective and generally well tolerated in the treatment of women or men with primary (including postmenopausal) or corticosteroid-induced osteoporosis and in the prevention of osteoporosis in postmenopausal women. The drug has been associated with upper GI tract adverse events, although the extent to which alendronate is responsible for these events has not been clearly established. Alendronate should be considered a treatment of choice in postmenopausal women with osteoporosis. Alendronate is also a suitable treatment option for primary osteoporosis in men and for corticosteroid-induced osteoporosis in both men and women.

Bone markers in clinical practice

Although biologic indices of bone turnover are widely accepted as research tools in population-based studies, their clinical utility in the management of the individual patient remains controversial. Their main limitation for a routine clinical use is related to an important biologic variability, which means that large variations (ie, in response to therapy) are needed to consider a difference between two measurements as reflecting a significant biologic change. To date, the most valuable bone markers are serum osteocalcin, bone-specific alkaline phosphatase, and the N-terminal propeptide of type 1 procollagen for bone formation and urinary measurements of the phenazopyridine crosslinks and related telopeptides for bone resorption. New serum assays for both C-telopeptide and N-telopeptide of type 1 collagen seem promising but need extensive validation. Although bone markers provide little information in the diagnosis of osteoporosis, strong evidence now shows that they can predict, albeit imperfectly, the rate of bone loss in menopausal women and the response to some antiresorptive therapies. In some populations, increased bone turnover has been shown to be a strong predictor of fracture risk, independently and to the same extent as low bone density. Whether bone markers are used to monitor the efficacy of (or compliance with) a specific treatment or to identify patients at risk for osteoporosis and thus to target preventive therapy, cost-benefit analysis, and evaluation of the potential improvement in patient outcome are clearly needed before these parameters may be universally accepted as tools to optimize patient care.

Recurrence of vertebral fracture with cyclical etidronate therapy in osteoporosis: histomorphometry and X-Ray microanalysis evaluation

In an open prospective study, we evaluated differences between patients with (wRVF group) and without recurrence of vertebral fracture (woRVF group) during cyclical etidronate therapy for osteoporosis. Thirty-two patients (age 64 +/- 1.8 years) characterized by at least one osteoporotic VF were treated during 1 year. At baseline, body mass index was significantly lower (23.3 +/- 0.6 vs. 26.9 +/- 1.0 kg/m2, p< 0.05), the number of previous VFs was higher (4.0 +/- 0. 4 vs. 2.4 +/- 0.4, NS), and patients were older in the wRVF group as compared with the woRVF group (67.8 +/- 3 vs. 62.6+/- 2.2 year, NS). Trabecular bone volume (11.6 +/- 1.2 vs. 15 +/- 0.9%, p< 0.05) and trabecular number (1.06 +/- 0.08 vs. 1.27 +/- 0.05, p < 0.05) were significantly lower in the wRVF group. None of the baseline resorptive variables differed, whereas the bone formation rate (BFR) was 2-fold lower in the wRVF group (p< 0. 05). After 1 year of treatment, osteoclast number, active eroded surfaces, and resorption depth dramatically decreased in both groups (p< 0. 01). To a lesser extent, the mineral apposition rate and serum alkaline phosphatase level were significantly reduced (p< 0.05). No impaired mineralization was observed. Using X-ray microanalysis, we found no abnormality in bone mineral but a significant increase of the calcium/phosphorus ratio during treatment in the wRVF group. Our results demonstrate that recurrence of VFs within the first year of cyclical etidronate therapy was related neither to a lack of histologic response to the treatment nor induction of an abnormality of mineralization. VFs were more likely in the presence of a decreased BFR and lower trabecular connectivity, providing support for treating osteoporotic patients with etidronate early in the course of the disease.

Bisphosphonates and osteoporosis treatment in Italy

A treatment against osteoporosis can be considered efficacious only when its beneficial effects on bone remodeling, bone mass, and osteoporotic fracture incidence are proven. As for any treatment, proven efficacy must be combined with proven safety. This review analyzes published data on efficacy and safety of alendronate, clodronate and etidronate, the bisphosphonates currently marketed in Italy for osteoporosis treatment. Different studies have shown that alendronate, clodronate and etidronate reduce bone turnover, and increase bone mineral density in postmenopausal osteoporotic patients. Prospective, double blind, multicenter studies reported a reduction in osteoporotic fracture incidence for alendronate and etidronate. Fracture incidence reduction by clodronate, on the other hand, was shown only in an open label study. Finally, a reduction in fracture incidence by etidronate was shown in a large retrospective postmarketing study. Postmarketing surveillance evidenced that osteomalacia, a suspected side effect of etidronate treatment, does not occur at the currently used dose regimens. Postmarketing surveillance of alendronate has recently raised some concern regarding possible severe esophageal damage during alendronate treatment, especially when the drug is not taken according to the manufacturer's instructions.