Increased risk factors associated with lower BMD in antiretroviral-therapy-naïve HIV-infected adult male.

BACKGROUND: Low BMD (bone mineral density) has been described as a non-AIDS (Acquired Immune Deficiency Syndrome)-related event in HIV (human immunodeficiency virus)-patients but it is poorly studied in young HIV-infected men who have received no previous antiretroviral therapy. METHODS: A cross-sectional study of 245 naïve-HIV-infected men over 21 and under 50 years old who voluntary attended the Infectious Disease Division appointment in Hospital Fundación Jimenez Díaz in Madrid, from January 1st, 2014 to September 30th, 2017. All subjects underwent a baseline DXA scan (dual energy x-ray absorptiometry) performed prior to start antiretroviral treatment. Further, all patients who started treatment between May 1st and September 30th, 2017 were invited to participate in a substudy on bone mineral metabolism. All the information was collected through clinical history and complementary questionnaire. RESULTS: The mean age was 36.4 years, been 68% Caucasian, 29.3% Latin American and 2.7% African race. At the time of diagnosis, 91% of patients had stage-A (median CD4+ T-cell 481cells/µL, IQR, 320-659). 10% had a count below 200 CD4 cells/µL, and 40% had a CD4/CD8 cell-count-ratio below 0.4. Regarding lifestyle and risk factors, 14.1% presented underweight, 36.1% were not engage in any regular exercise, 51.9% were active smokers and 35.3% reported drug use. Low levels of vitamin D were seen in 87.6% of the study participants. Low BMD (Z-score <- 2.0) was found in 22.8% of the patients. It was only observed a significant association of Z-score in lumbar spine (LS) with CD8 and the CD4/CD8 ratio, and with alcohol for femoral neck (FN) measurement. CONCLUSIONS: We find prevalence of increased bone involvement among naïve HIV-infected men under 50 years old. Further studies are necessary to evaluate if changes in actual guidelines are needed to assess BMD measurements in HIV-infected adult male patients under 50.

Vitamin K and Bone Health: A Review on the Effects of Vitamin K Deficiency and Supplementation and the Effect of Non-Vitamin K Antagonist Oral Anticoagulants on Different Bone Parameters.

Although known for its importance in the coagulation cascade, vitamin K has other functions. It is an essential vitamin for bone health, taking part in the carboxylation of many bone-related proteins, regulating genetic transcription of osteoblastic markers, and regulating bone reabsorption. Vitamin K deficiency is not uncommon, as deposits are scarce and dependent upon dietary supplementation and absorption. Vitamin K antagonist oral anticoagulants, which are prescribed to many patients, also induce vitamin K deficiency. Most studies find that low serum K1 concentrations, high levels of undercarboxylated osteocalcin (ucOC), and low dietary intake of both K1 and K2 are associated with a higher risk of fracture and lower BMD. Studies exploring the relationship between vitamin K supplementation and fracture risk also find that the risk of fracture is reduced with supplements, but high quality studies designed to evaluate fracture as its primary endpoint are needed. The reduction in risk of fracture with the use of non-vitamin K antagonist oral anticoagulants instead of warfarin is also of interest although once again, the available evidence offers disparate results. The scarce and limited evidence, including low quality studies reaching disparate conclusions, makes it impossible to extract solid conclusions on this topic, especially concerning the use of vitamin K supplements.

Effects of PTH (1-84) on bone quality in a validated model of osteoporosis due to androgenic deprivation.

AIM: The purpose of this study was to evaluate the effect of parathyroid hormone (PTH) (1-84) in a model of male osteoporosis induced by orchidectomy in rats. METHODS: Six-month-old Wistar rats were used as follows: SHAM (simulated orchidectomy), orchidectomized (ORX), ORX + PTH1 (ORX and treated with 10 µg/Kg/d of PTH 1-84) and ORX + PTH2 (ORX and treated with 50 µg/Kg/d of PTH 1-84) over 3 months, with treatment beginning three months after orchidectomy. RESULTS: Orchidectomy resulted in a decreased of femoral and lumbar bone mineral density (BMD), a worsening of trabecular and cortical microarchitecture and a decrease in biomechanical properties. Both doses of PTH (1-84) partially (low dose) or totally (high dose) restored the ORX-induced changes. Serum C-telopeptide of type I collagen/5b isoenzyme of tartrate-resistant acid phosphatase (CTX/TRAP) resorption index increased after orchidectomy. Osteocalcin (bone Gla protein; BGP) levels were not affected by orchidectomy. PTH (1-84) treatment did not produce any changes in the levels of CTX/TRAP with respect to the ORX group. BGP levels increased with PTH treatment. CONCLUSION: PTH (1-84) is able to restore the adverse effects of orchidectomy on bone as measured by BMD, microstructural and biomechanical properties and bone remodeling markers.

Effects of kalsis, a dietary supplement, on bone metabolism in the ovariectomized rats.

We studied the ability of Kalsis, a food supplement that contains selenium, citric acid, and vitamin E, to prevent the effects of ovariectomy on bone loss. Six-month-old, Wistar female rats were studied. Groups (n = 12): SHAM: sham-operated rats; OVX: ovariectomized rats, treated with vehicle; OVX + Kalsis: ovariectomized rats treated with Kalsis (25 mg/kg/day) for 3 months. Bone mineral density (BMD) was determined by DXA in lumbar spine and femur. Computerized microtomography (µCT) in femur and serum osteocalcin (BGP), aminoterminal propeptide of procollagen I (PINP), ß-isomer of carboxyterminal telopeptide of collagen I (CTX), and 5b isoenzyme of tartrate-resistant acid phosphatase (TRAP) were performed. Treatment with Kalsis prevented BMD loss in OVX group. µCT showed a decrease in BV/TV, and trabecular number, and an increase in trabecular separation in OVX rats. Kalsis administration attenuated partially bone loss observed by µCT due to ovariectomy. BGP, PINP, and the resorption index (CTX/TRAP) were increased in OVX group. Treatment with Kalsis maintained this increase. The mechanism of action of this supplement is not through a decrease in bone remodelling rate. The antioxidant action of this food supplement, due to the synergism of all its components, as a cause of its beneficial effect is suggested.

Risk factors for prediction of inadequate response to antiresorptives.

Some patients sustain fractures while on antiresorptives. Whether this represents an inadequate response (IR) to treatment or a chance event has not been elucidated. We performed a study to identify which patients are more likely to fracture while on treatment. This is a multicentric, cross-sectional study of postmenopausal women on antiresorptives for osteoporosis in 12 Spanish hospitals, classified as adequate responders (ARs) if on treatment with antiresorptives for 5 years with no incident fractures or inadequate responders (IRs) if an incident fracture occurred between 1 and 5 years on treatment. Poor compliance, secondary osteoporosis, and previous anti-osteoporosis treatment other than the assessed were exclusion criteria. Clinical, demographic, analytical, dual-energy X-ray absorptiometry (DXA) variables, and proximal femur structure analysis (ImaTx™) and structural/fractal analyses of distal radius were performed. A total of 179 women (76 IRs; mean (SD): age 68.2 (9.0) years; 103 ARs, age 68.5 (7.9) years) were included. History of prior fracture (p = 0.005), two or more falls in the previous year (p = 0.032), low lumbar spine bone mineral density (BMD) (p = 0.02), 25 hydroxyvitamin D (p = 0.017), and hip ImaTx fracture load index (p = 0.004) were associated with IR. In the logistic regression models a fracture before treatment (odds ratio [OR], 3.60; 95% confidence interval [CI], 1.47-8.82; p = 0.005) and levels of 25 hydroxyvitamin D below 20 ng/mL (OR, 3.89; 95% CI, 1.55-9.77; p = 0.004) significantly increased risk for IR, while increased ImaTx fracture load (OR, 0.96; 95% CI, 0.93-0.99; p = 0.006; per every 100 units) was protective, although the latter became not significant when all three variables were fitted into the model. Therefore, we can infer that severity of the disease, with microarchitectural and structure deterioration, as shown by previous fracture and hip analysis, and low levels of 25 hydroxy vitamin D carry higher risk of inadequate response to antiresorptives. More potent regimes should be developed and adequate supplementation implemented to solve this problem.

Calcium citrate and vitamin D in the treatment of osteoporosis.

The combination of calcium with vitamin D (vitamin D(3) [colecalciferol]) forms the basis of preventive and therapeutic regimens for osteoporosis. A number of studies have suggested that the combination of calcium and vitamin D is effective when administered at respective dosages of at least 1200 mg and 800 IU per day, although efficacy is, as expected, affected by patient compliance. Overall, treatment with this combination appears to be effective in reducing the incidence of non-vertebral and hip fractures. Also, in all drug studies (of antiresorptive and anabolic agents and strontium ranelate) that demonstrated a reduction in risk of osteoporotic fractures, patients also took calcium and vitamin D supplements. An important finding in this regard is that vitamin D levels have been demonstrated to be inadequate in more than half of women treated for osteoporosis in the US and Europe. The capacity of the small intestine to absorb calcium salts depends on the solubility and ionization of the salts. These properties vary for different salts, with fasting calcium citrate absorption being greater than that of calcium lactogluconate and calcium carbonate. Calcium citrate formulations taken between meals may help to prevent abdominal distension and flatulence, as well as minimize the risk of renal calculus formation, thus helping to optimize patient compliance. Therefore, calcium citrate combined with vitamin D is the combination of choice for the prevention or treatment of osteoporosis.

Prevalence of vertebral fracture in postmenopausal women with lumbar osteopenia using MorphoXpress® (OSTEOXPRESS Study).

BACKGROUND AND AIMS: Vertebral fracture (VF) is the most common complication of osteoporosis. However, more than half of all VF are asymptomatic and may go unnoticed, even in patients with osteoporosis. Our aim was to assess the prevalence of VF in postmenopausal women with osteopenic lumbar densitometry by means of vertebral morphometry, using the MorphoXpress® software. PATIENTS AND METHODS: This was an epidemiological, cross-sectional, multicenter study conducted among 289 postmenopausal women (>1 year of amenorrhoea), diagnosed with lumbar osteopenia (not due to chronic treatment with corticosteroids or immobilization). Vertebral deformities ≥20% were considered as VF. RESULTS: Demographic and clinical characteristics showed mean age (±SD) 64±9 years, body mass index 27±5 kg/m2, and time from diagnosis of 2±3 years. A total of 25% of subjects had a family history of osteoporotic fracture in first-degree relatives, and 23% had previous fragility fracture. The prevalence of VF was 50% (CI 95% 44-56), the most frequent being the dorsal wedge (34%). Previous fragility fracture was a risk factor for VF (OR 3.13, p=0.0004). A total of 76.5% of patients were receiving treatment, mainly calcium and vitamin D supplements (70%) and bisphosphonates (27%). CONCLUSIONS: MorphoXpress® revealed that 50% of postmenopausal women with osteopenic lumbar densitometry showed VF. This result is important since only 7% of all evaluated subjects had previously been diagnosed with VF.

Characterization of a new experimental model of osteoporosis in rabbits.

To characterize an experimental model of osteoporosis in rabbits induced either by ovariectomy (OVX), glucocorticoids, or by a combination of both. Thirty-five rabbits were randomly allocated into five groups: bilateral OVX, daily methylprednisolone hemisuccinate (MPH) injections at a 1.5 mg/kg/day dose for 4 consecutive weeks (MPH group), or variable dose of MPH between 0.5 and 2 mg/kg/day in combination with OVX (OVX + MPH at low, medium, and high dose). Twenty-two animals were killed 6 weeks after OVX, and 13 were killed 16 weeks later. Dual-energy X-ray absorptiometry was obtained at baseline and 6 and 16 weeks after OVX. High-resolution magnetic resonance imaging (MRI) was carried out at 0 and 6 weeks after OVX. Glucose, total cholesterol, triglyceride, and oestradiol blood levels before and 16 weeks after OVX were determined. Bone mineral density (BMD) decreased significantly at lumbar spine in MPH and OVX + MPH medium-dose groups, and at global knee and subchondral bone of the knee in MPH, OVX + MPH low- and medium-dosage groups (P < 0.05). BMD variations in OVX rabbits were not significant in any of the three anatomical locations analyzed. BMD variation 16 weeks after OVX was significant at lumbar spine and global knee in the OVX + MPH medium-dose group and only at global knee in the OVX + MPH low-dose group (P < 0.05). MRI did not show bone or cartilage changes. Osteoporosis can be induced experimentally in rabbits through isolated MPH or by a combination of OVX and medium dose corticosteroid for 4 weeks. OVX alone was not sufficient to induce osteoporosis.

Occurrence of hypercalciuria in patients with osteoporosis treated with teriparatide.

CONTEXT: Teriparatide (TPTD) [recombinant human PTH(1-34)] given sc once daily transiently increases serum calcium concentrations at 4-6 h after dosing, but its effects on urinary calcium excretion are less well studied. OBJECTIVE: Our objective was to evaluate urinary calcium excretion, a prespecified safety endpoint, for up to 12 months of TPTD treatment. DESIGN: This study included two prospective, randomized, double-blind placebo-controlled clinical trials. PARTICIPANTS: A total of 2074 participants with osteoporosis or low bone mass (study 1, 1637 postmenopausal women; study 2, 437 men) were included. INTERVENTIONS: Participants were given calcium (1000 mg/d) and vitamin D (400-1200 IU/d) supplements, and were randomized to placebo, TPTD 20 mug/d, or TPTD 40 mug/d. MAIN OUTCOME MEASURES: Urinary calcium excretion was measured in 24-h collections at baseline, 1, 6, and 12 months. RESULTS: In each study, baseline urinary calcium excretion was similar among groups. All groups had significantly increased urinary calcium excretion, compared with baseline, at most post-baseline time points. Post-baseline urinary calcium excretion was increased in the TPTD 20 microg/d group by up to 32 mg/d compared with placebo at the same time point (P < 0.05) in study 1. A total of seven participants (0.3%), of which three and four were in the placebo and TPTD groups, respectively, discontinued study drug due to repeated hypercalciuria (>300 mg/d). CONCLUSION: Urinary calcium excretion was increased with TPTD treatment for up to 12 months, compared with placebo and baseline values, but the magnitude of these changes is unlikely to be clinically relevant or warrant urinary calcium monitoring for most patients.