Determinants Of Bone Health Research Articles

271 Effects of Bariatric Surgery on Metabolic and Hormonal Balance: A 10-Year Retrospective Study

Abstract Background The increasing demand on Gastric bypass and other weight-loss surgeries known collectively as bariatric surgery is well documented but the long-term effects on some parameters have not been satisfactorily analysed over the years. Surgeons are dealing with a level of uncertainty regarding the most likely reason behind this metabolic derangement following such procedures in the follow up clinics. Aim To study the long-term effects of bariatric surgery and weight reduction procedures on Parathyroid function, calcium levels, Vitamin D and determinants of bone health. Method 10-year retrospective study looking at patients underwent bariatric surgery between the years 2006 – 2008 within the Yorkshire area and their follow up data. Results We found that the median calcium levels have decreased significantly compared to its level prior to the operation, even though the absolute value of calcium remained within the normal reference range, it was lower than that of the baseline for each individual, resulting in an increased PTH and ALP levels to a low statistical significance and important clinical significance. Conclusions Calcium levels being lower than the baseline but still within the normal reference range is affecting both PTH and ALP leaving the patient at increased risk of bone weakness complications and other hormonal disturbances. Recommendation During the post-operative follow up plan, calcium levels should be adjusted to mimic the levels of the individuals’ pre-operative values, and the baseline should be the reference range rather than the actual lab reference assuming Calcium levels preoperatively were within the normal range.

B vitamins and homocysteine as determinants of bone health: A literature review of human studies.

Although there are several factors related to bone diseases such as physical activity, gender (oestrogen), race/ethnicity, smoking and alcohol habits, nutrition is a modifiable risk factor that could be employed to prevent or manage the onset of bone health diseases such as osteoporosis in humans. Aside from calcium and vitamin D, B vitamins are a group of water-soluble vitamins that play a vital role in cell metabolism. In this review, current evidence on B vitamins and bone health is assessed. Clinical trials (interventions) indicate that treatment with B vitamins impact the concentrations of total plasma/serum homocysteine concentrations (tHcy); however, most studies have reported the lack of an effect of low homocysteine concentrations on bone turnover markers, bone mineral density or fracture risks. Current studies have been inconsistent in their reports on the role of B vitamins and homocysteine in bone health. More data are therefore required to show the mechanism and effect of tHcy and B vitamins on bone mineral density, bone metabolism and fracture risk.

Identification of PDXDC1 as a novel pleiotropic susceptibility locus shared between lumbar spine bone mineral density and birth weight

An increasing number of epidemiological studies have suggested that birth weight (BW) may be a determinant of bone health later in life, although the underlying genetic mechanism remains unclear. Here, we applied a pleiotropic conditional false discovery rate (cFDR) approach to the genome-wide association study (GWAS) summary statistics for lumbar spine bone mineral density (LS BMD) and BW, aiming to identify novel susceptibility variants shared between these two traits. We detected 5 novel potential pleiotropic loci which are located at or near 7 different genes (NTAN1, PDXDC1, CACNA1G, JAG1, FAT1P1, CCDC170, ESR1), among which PDXDC1 and FAT1P1 have not previously been linked to these phenotypes. To partially validate the findings, we demonstrated that the expression of PDXDC1 was dramatically reduced in ovariectomized (OVX) mice in comparison with sham-operated (SHAM) mice in both the growth plate and trabecula bone. Furthermore, immunohistochemistry assay with serial sections showed that both osteoclasts and osteoblasts express PDXDC1, supporting its potential role in bone metabolism. In conclusion, our study provides insights into some shared genetic mechanisms for BMD and BW as well as a novel potential therapeutic target for the prevention of OP in the early stages of the disease development.Key messagesWe investigated pleiotropy-informed enrichment between LS BMD and BW.We identified genetic variants related to both LS BMD and BW by utilizing a cFDR approach.PDXDC1 is a novel pleiotropic gene which may be related to both LS BMD and BW.Elevated expression of PDXDC1 is related to higher BMD and lower ratio n-6/n-3 PUFA indicating a bone protective effect of PDXDC1.

Factors associated with bone health status of Malaysian pre-adolescent children in the PREBONE-Kids Study

BackgroundModifiable lifestyle factors and body composition can affect the attainment of peak bone mass during childhood. This study performed a cross-sectional analysis of the determinants of bone health among pre-adolescent (N = 243) Malaysian children with habitually low calcium intakes and vitamin D status in Kuala Lumpur (PREBONE-Kids Study).MethodsBody composition, bone mineral density (BMD), and bone mineral content (BMC) at the lumbar spine (LS) and total body (TB) were assessed using dual-energy X-ray absorptiometry (DXA). Calcium intake was assessed using 1-week diet history, MET (metabolic equivalent of task) score using cPAQ physical activity questionnaire, and serum 25(OH) vitamin D using LC-MS/MS.ResultsThe mean calcium intake was 349 ± 180 mg/day and mean serum 25(OH)D level was 43.9 ± 14.5 nmol/L. In boys, lean mass (LM) was a significant predictor of LSBMC (β = 0.539, p < 0.001), LSBMD (β = 0.607, p < 0.001), TBBMC (β = 0.675, p < 0.001) and TBBMD (β = 0.481, p < 0.01). Height was a significant predictor of LSBMC (β = 0.346, p < 0.001) and TBBMC (β = 0.282, p < 0.001) while fat mass (FM) (β = 0.261, p = 0.034) and physical activity measured as MET scores (β = 0.163, p = 0.026) were significant predictors of TBBMD in boys. Among girls, LM was also a significant predictor of LSBMC (β = 0.620, p < 0.001), LSBMD (β = 0.700, p < 0.001), TBBMC (β = 0.542, p < 0.001) and TBBMD (β = 0.747, p < 0.001). Calcium intake was a significant predictor of LSBMC (β = 0.102, p = 0.034), TBBMC (β = 0.122, p < 0.001) and TBBMD (β = 0.196, p = 0.002) in girls.ConclusionsLM was the major determinant of BMC and BMD among pre-adolescent Malaysian children alongside other modifiable lifestyle factors such as physical activity and calcium intake.

Determinants of bone health in elderly Japanese men: study design and key findings of the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) cohort study

BackgroundThe Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study was launched to investigate risk factors for osteoporotic fractures, interactions of osteoporosis with other non-communicable chronic diseases, and effects of fracture on QOL and mortality.MethodsFORMEN baseline study participants (in 2007 and 2008) included 2012 community-dwelling men (aged 65–93 years) in Nara prefecture, Japan. Clinical follow-up surveys were conducted 5 and 10 years after the baseline survey, and 1539 and 906 men completed them, respectively. Supplemental mail, telephone, and visit surveys were conducted with non-participants to obtain outcome information. Survival and fracture outcomes were determined for 2006 men, with 566 deaths identified and 1233 men remaining in the cohort at 10-year follow-up.CommentsThe baseline survey covered a wide range of bone health-related indices including bone mineral density, trabecular microarchitecture assessment, vertebral imaging for detecting vertebral fractures, and biochemical markers of bone turnover, as well as comprehensive geriatric assessment items. Follow-up surveys were conducted to obtain outcomes including osteoporotic fracture, cardiovascular diseases, initiation of long-term care, and mortality. A complete list of publications relating to the FORMEN study can be found at https://www.med.kindai.ac.jp/pubheal/FORMEN/Publications.html.

A Health Production Approach to Bone Health in Kenya

Reduced density and quality in bones increase fracture risk, which becomes evident later in life through recognition of osteoporosis which is a skeletal disorder characterized by compromised bone strength, pre-disposing to an increased risk of fracture and is a global health problem that affects men as well as women. Shocks are inevitable to everyone everywhere and in the wake of shock of chronic/severe illness like Corona virus (Covid-19) which is infecting and affecting individuals worldwide and countrywide; the response may be negative or positive. The negative responses acts like additional shocks, hence focus will be on the positive responses (good reports) which are meant to counter the shocks and improve individuals and consequently household’s welfare. In some cases covid-19 results to death of a household member, this calls for immediate response to the shock. During the outbreak of corona virus, many individuals have lost their employment and at such a time when loss of salaried employment or non-payment of salary results, individuals may need to respond to the shock positively. A time like this the health care facilities are overstrained with many hospitalizations as a result of day to day increase in the shocks (corona virus) and its associated shocks like loss of employment and death. Likewise, the governments’ curfews have made individuals to experience business failure, limit their movements, reduce physical activity, and change their food and nutrition and as a result may affect their health outcomes. This study sought to establish the determinants of bone health, based on the health production approach by isolating the effects of response to shocks, and food and nutrition on bone health. The current study found that good report (positive response to shocks), exercising (through use of non-motorized transport), completing secondary education, taking wine, consuming fruits like apples, pineapples and melons and vegetables such as lettuce, cucumber and courgette, and increased consumption of peanut butter, tinned fish, and minced meat, chocolate and cheese significantly helps in improvement of bone health as they reduce bone fracture. However, bad reports deteriorate bone health, increased consumption of bread and corned beef significantly depletes bone health as they increase the occurrence of fracture. This study recommends that in order to improve individuals’ bone health there is need to convey good reports especially during shocks like Covid-19. Individuals who have experienced non-agricultural household business failure due to the outbreak of corona virus, they need not to give up but ought to respond by starting a new business. For improved bone health, individuals also need to continually exercise by using non-motorized means of travel like walking or cycling; they may need to take a little wine especially as their age increases; and strengthening their bones through increased consumption of apples, pineapples and melons, lettuce, cucumber and courgette, peanut butter, tinned fish, and minced meat, chocolate and cheese. Keywords: Bone Health, Health Production, Corona Virus, Covid-19, Response to Shocks, Food and Nutrition DOI: 10.7176/JHMN/85-15 Publication date: January 31 st 2021

Lower Trabecular Bone Score and Spine Bone Mineral Density Are Associated With Bone Stress Injuries and Triad Risk Factors in Collegiate Athletes.

Determinants of bone health and injury are important to identify in athletes. Bone mineral density (BMD) is commonly measured in athletes with Female Athlete Triad (Triad) risk factors; the trabecular bone score (TBS) has been proposed to predict fracture risk independent of BMD. Evaluation of TBS and spine BMD in relation bone stress injury (BSI) risk has not been studied in female collegiate athletes. We hypothesized that spine BMD and TBS would each independently predict BSI and that the combined measures would improve injury prediction in female collegiate athletes. We also hypothesized that each measure would be correlated with Triad risk factors. Retrospective cohort. Academic Institution. Dual energy x-ray absorptiometry (DXA) of the lumbar spine was used to calculate BMD and TBS values. Chart review was used to identify BSI that occurred after the DXA measurement and to obtain Triad risk factors. We used logistic regression to examine the ability of TBS and BMD alone or in combination to predict prospective BSI. Within 321 athletes, 29 (9.0%) sustained a BSI after DXA. BMD and TBS were highly correlated (Pearson correlation r = 0.62, P < .0001). Spine BMD and TBS had similar ability to predict BSI; the C-statistic and 95% confidence intervals were 0.69 (0.58 to 0.81) for spine BMD versus 0.68 (0.57 to 0.79) for TBS. No improvement in discrimination was observed with combined BMD + TBS (C-statistic 0.70, 0.59 to 0.81). Both TBS and BMD predicted trabecular-rich BSI (defined as pelvis, femoral neck, and calcaneus) better than cortical-rich BSI. Both measures had similar correlations with Triad risk factors. Lower BMD and TBS values are associated with elevated risk for BSI and similar correlation to Triad risk factors. TBS does not improve prediction of BSI. Collectively, our findings suggest that BMD may be a sufficient measure of skeletal integrity from DXA in female collegiate athletes.

Are Probiotics the New Calcium and Vitamin D for Bone Health?

Calcium and vitamin D supplementation is recommended for patients at high risk of fracture and/or for those receiving pharmacological osteoporosis treatments. Probiotics are micro-organisms conferring a health benefit on the host when administered in adequate amounts, likely by influencing gut microbiota (GM) composition and/or function. GM has been shown to influence various determinants of bone health. In animal models, probiotics prevent bone loss associated with estrogen deficiency, diabetes, or glucocorticoid treatments, by modulating both bone resorption by osteoclasts and bone formation by osteoblast. In humans, they interfere with 25-hydroxyvitamin D levels, and calcium intake and absorption, and slightly decrease bone loss in elderly postmenopausal women, in a quite similar magnitude as observed with calcium ± vitamin D supplements. A dietary source of probiotics is fermented dairy products which can improve calcium balance, prevent secondary hyperparathyroidism, and attenuate age-related increase of bone resorption and bone loss. Additional studies are required to determine whether probiotics or any other interventions targeting GM and its metabolites may be adjuvant treatment to calcium and vitamin D or anti-osteoporotic drugs in the general management of patients with bone fragility.

Physical activity: the earlier the better. Bones awareness

IntroductionThere is scarce research on bone health in early stages due to the difficulties in accessing to bone health assessment methods in absence of pathology conditions. Consequently, there is no much information on the determinants of bone health. The aim of this study is to elucidate the association of moderate-vigorous physical activity (MVPA) and bone mineral density of children from Aragon accounting for socioeconomic, role parental modelling, dietary and sedentary behavior effects.Material &amp; MethodsThe longitudinal cohort ‘Growth and Feeding during Lactation and Early Childhood in Children of Aragon (CALINA in Spanish)’ included 1,629 born children from Aragon (Spain) in 2009. From those, after 7 years, 339 children (176 boys and 163 girls) were assessed. Bone mineral density (BMD) using Dual X-ray absorciometry (–DXA-), diet quality index (DQI) using a food frequency questionnaire(-FFQ-), sedentary behaviors by questionnaire, and physical activity (using accelerometry-actigraph 3GTX-) were evaluated, as well as if they were or not rapid weight gainers during the first year of life.ResultsFrom the 339 children, 116 boys (66.5%) and 63 girls (38.7%) met the current MVPA recommendations of at least? 1 hour/day. Boys meeting MVPA recommendations did a mean of 84.02 minutes of MVPA per day and had a BMD of 0.60 g/cm2, while those not meeting the recommendations, did a mean of 43.91 minutes of MVPA and had a BMD of 0.59 g/cm2. Girls meeting MVPA recommendation did 75.52 minutes and had a BMD of 0.59 g/cm2, and those not meeting, did 42.81 minutes of MVPA and had a BMD of 0.58. Models, include BMI z-score (age/sex adjusted based in Anthro standards from WHO), weekly sedentary time, DQI, BMI of the mother and whether or not they had been rapid weight gainers from 0–12months as confounders and were performed for BMD having MVPA as a predictor. A significant association was found only for boys between MVPA and BMD (β = 0.145, p-value = 0.02) while no association was found for girls (β = 0.06, p-value = 0.40).DiscussionThere is still an important physical activity gap between boys and girls. In boys, physical activity is positively associated with BMD, whereas in girls, no significant associations seem to exist. More research is required to elucidated the effects of lifestyle behaviors on bone health in children.

Determinants of Bone Health in Older Adults.

Objective:The objective of this study was to determine the predictors of bone health in older adults.Methods:A total of 313 subjects older than 65 years (mean age 74.2±6.4 years, 70.6% female) were included in the study. Demographic characteristics of participants such as gait speed, handgrip strength, level of physical activity (using Rapid Assessment of Physical Activity-RAPA scale), vitamin D levels, T scores of femur neck (FN) and lumbar spine (LS) were recorded.Results:Based on FN, 40.7% of participants had normal T scores whereas 46.2% and 13.1% of them were osteopenic and osteoporotic, respectively. FN was correlated with age (r:-0.184, p<0.001), BMI (r:0.269, p<0.001), and handgrip strength (r:0.149, p:0.009) in addition to the aerobic subscale of RAPA (RAPA-aerobic) (r:-0.133, p:0.02). Similarly, the LS was correlated with female gender (r:-0.207, p<0.001), age (r:0.136, p:0.016), body mass index (BMI) (r:0.246, p<0.001) and handgrip strength (r:0.217, p<0.001). The predictors of bone health were decided upon using multiple logistic regression analysis. The deterministic model consisted of age, gender, BMI, height, weight, handgrip strength, gait speed, RAPA-aerobic and vitamin D. For LS dependent variable, the overall model was significant (F:10.149, p<0.001). However, only two variables were significant predictors in the model ie. weight (β:0.389, p<0.001) and handgrip strength (β=0.186, p<0.001). Similarly for independent variable of FN, the overall model was significant (F:6.525, p<0.001) and only two variables were significant predictors: weight (β:0.371, p<0.001) and RAPA-Aerobic (β:0.148, p:0.009).Conclusion:Lower levels of body weight, participation in aerobic activity and handgrip strength might be risk factors for deterioration of bone health in older adults.

Knowledge about Osteoporosis Risk Prevention in Young and Post-Menopausal Women in Palmerston North, New Zealand

Background: Critical determinants of bone health are genetics, diet and physical activity.Women face challenges to the modifiable risk factors [...]

Effect of diabetes on BMD and TBS values as determinants of bone health in the elderly: Bushehr Elderly Health program

Considering the aging population associated with higher osteoporotic fracture risk, high prevalence of diabetes and its effect on bone health along with lack of information on bone quality using common methods (BMD) the aim of present study was to determine the association between trabecular bone score (TBS) and diabetes in an elderly population participating in Bushehr Elderly Health (BEH) program. This cross-sectional study was performed on data collected during the BEH Program, stage II. Anthropometric indices were measured based on NHANES III protocol. Diabetes and pre-diabetes were defined according to ADA Guideline 2018. Bone density was measured using DXA method (DXA, Discovery WI, Hologic Inc., USA). A software installed on the same device (TBS iNsight® software) was applied to assess TBS values. Variables related to bone health were compared based on their glycemic status (participants with diabetes, participants with prediabetes, and normoglycemic) using analysis of variance. Univariate and multivariate linear and logistic regression models were used to determine the association between TBS values and bone density in different glycemic states. The data of 2263 participant aged 60years and over were analyzed. Mean TBS values were significantly different between participants with diabetes, participants with prediabetes, and normoglycemic groups (P = 0.004;, however, P trend was not significant (0.400)). Mean BMD values at femoral neck and lumbar spine were significantly higher in diabetics compared with those diagnosed with pre-diabetes; the latter also had higher bone density compared with normoglycemic individuals (both P ANOVA test and P trends for means were < 0.01]. In univariate linear regression model, TBS values were negatively associated with pre-diabetes (β = -0.070; P < 0.001) but not with diabetes (β = -0.002, P = 0.915). This significant relationship disappeared when the results were adjusted for BMI. In fully adjusted multivariate logistic regression models, odds ratio linking pre-diabetes and diabetes with spinal osteoporosis was 0.861 (CI 95% 0.670-1.105) and 0.525 (CI 95% 0.392-0.701), respectively. As for femoral osteoporosis, odds ratio was 0.615 (CI 95% 0.407-0.928) and 0.968 (CI 95% 0.629-1.489), correspondingly. Moreover, for cumulative osteoporosis, the odds were 0.843 (CI 95% 0.676-1.106) and 0.551 (CI 95% 0.415-0.732), respectively. Our findings suggest that subjects with pre-diabetes and diabetes have higher bone mineral density than normoglycemic subjects; the quality of bone, however, was not different between them. The discordance between BMD and TBS values in participants with diabetes suggest that although these patients have higher BMD values, their quality of bone microarchitecture may not be better than normoglycemic subjects.

Nutritional influence on bone: role of gut microbiota.

Gut microbiota (GM) located within the intestinal tract lumen comprises the largest number of cells (10E14) in the human body. The gut microbiome refers to the collection of genomes and genes present in gut microbiota. GM can vary according to age, sex, genetic background, immune status, geography, diet, prebiotics, which are non-digestible fibers metabolized in the distal part of the gastrointestinal tract, probiotics, which are micro-organisms conferring a health benefit on the host when administered in adequate amounts, living conditions, diseases and drugs. A source of probiotics is fortified fermented dairy products, which in addition provide calcium, protein, phosphorus and various micronutrients. Bone homeostasis is influenced by GM composition and/or products. GM appears to be a major player in the various determinants of bone health. However, it remains to be demonstrated in well conducted long-term randomized controlled trials, whether interventions changing GM composition and/or function are capable of reducing fracture risk.

Bone health in facioscapulohumeral muscular dystrophy: A cross-sectional study.

Herein we provide a comprehensive overview of bone health in facioscapulohumeral muscular dystrophy (FSHD). Ninety-four adult individuals with FSHD type 1 from 2 sites were included in this cross-sectional study. Clinical characteristics and determinants of bone health were examined. Relationships between bone mineral density (BMD), strength, and function were explored. Nearly a third of subjects were deficient in vitamin D3 . Mean whole-body BMD z-score was -0.7; 11% of subjects had greater than age-related reductions in whole-body BMD (z-score < -2.0). Whole-body and regional BMDs were associated with strength and function. Thirty-six percent had a history of fractures. Likelihood of fractures was reduced for those with normal whole-body BMD (odds ratio = 0.25, 95% confidence interval 0.04-0.78). A diagnosis of FSHD is not necessarily predictive of reduced BMD or increased fracture rate. Given the considerable variability of bone health in the FSHD population, strength and function can serve as predictors of BMD. Muscle Nerve 56: 1108-1113, 2017.

Bone Quality in Female Ballet Dancers: A Possible Determinant of Bone Health

Hypotheses:Values of serum markers related to bone quality are abnormal in young female ballet dancers. Methods: In 13 elite Japanese female ballet dancers (average age, 22 years), markers related to bone quality were investigated. These included: serum homocystein (HC), a marker of increased oxidative stress; pentosidine (Pent), a marker of glycation- or oxidation-induced non-enzymatic cross-links; markers of bone metabolism (bone alkaline phosphatase, BAP; tartrate-resistant acid phosphatase 5b, TRAP5b) and bone mineral density (BMD). It was determined whether there is a relationship between bone quality markers’ levels are related to amenorrhea and/or fatigue fractures. Results: Two dancers had fatigue fractures and 3 had a history of secondary amenorrhea. The average BMD was 1.305 ± 0.12 (g/cm2), in all these cases the Z-score was higher than -1.0. Although the serum levels of BAP, TRAP5b, and HC were normal in all examined dancers, in 2 out of 3 dancers with a history of secondary amenorrhea, pentosidine serum levels were increased. No relationship between bone quality markers’ levels and fatigue fractures was found. Conclusion: Latent deterioration of bone quality may occur in female athletes with secondary amenorrhea and otherwise normal BMD and calcium metabolism markers.

Maternal vitamin D beneficially programs metabolic, gut and bone health of mouse male offspring in an obesogenic environment.

Vitamin D is an anti-inflammatory nutrient and a determinant of bone health. Some prospective studies suggest that maternal vitamin D status is positively associated with offspring bone mass. We found that serum concentrations of lipopolysaccharide (LPS), an inflammatory molecule related to adiposity, insulin resistance and bone resorption, is lower in healthy mouse offspring exposed to high dietary vitamin D during pregnancy and lactation. LPS reaches the circulation via the gut. This study investigated whether maternal vitamin D programs metabolic, gut and bone health of male offspring in an obesogenic environment. C57BL/6J dams received an AIN-93G diet with high (H) or low (L) vitamin D during pregnancy and lactation. At weaning, offspring remained on their dam's vitamin D level (LL or HH) or were switched (LH or HL) and fed a high fat (44.2%) and sucrose (19.8%) diet. Glucose response, adiposity, systemic inflammation (LPS, cytokines), intestinal permeability and mass, strength and microarchitecture of trabecular and cortical bone were assessed in 7-month-old male offsprings. Higher maternal dietary vitamin D resulted in lower intestinal permeability (fecal albumin, P=0.010) and benefited trabecular but not cortical bone structure at the distal femur (higher trabecular number, P=0.022; less trabecular separation, P=0.015) and lumbar vertebra 2 (bone volume/total volume%, P=0.049). Higher maternal and offspring vitamin D resulted in lower fasting glucose (HH versus LL, P=0.039) and serum LPS concentrations (dam diet, P=0.011; pup diet, P=0.002). Higher offspring vitamin D resulted in lower epididymal fat pad relative weight (P=0.006). The serum concentrations of IL-6 and TNF-α did not differ among groups. Maternal dietary vitamin D beneficially programs intestinal permeability and systemic LPS concentration, which is accompanied by stronger trabecular bone in an obesogenic environment. Thus, the gut may mediate vitamin D effects. Moreover, optimizing vitamin D in early life may be critical for later health.

B-vitamins and their interaction with the MTHFR C677 T genotype as determinants of bone health in older adults from the TUDA Ageing cohort study

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The effect of supplementation with alkaline potassium salts on bone metabolism: a meta-analysis

The role of acid-base metabolism in bone health is controversial. In this meta-analysis, potassium bicarbonate and potassium citrate lowered urinary calcium and acid excretion and reduced the excretion of the bone resorption marker NTX. These salts may thus be beneficial to bone health by conserving bone mineral. The role of acid-base homeostasis as a determinant of bone health and the contribution of supplemental alkali in promoting skeletal integrity remain a subject of debate. The objective of this study was, therefore, to conduct a meta-analysis to assess the effects of supplemental potassium bicarbonate (KHCO3) and potassium citrate (KCitr) on urinary calcium and acid excretion, markers of bone turnover and bone mineral density (BMD) and to compare their effects with that of potassium chloride (KCl). A total of 14 studies of the effect of alkaline potassium salts on calcium metabolism and bone health, identified by a systematic literature search, were analysed with Review Manager (Version 5; The Cochrane Collaboration) using a random-effects model. Authors were contacted to provide missing data as required. Results are presented as the standardised (SMD) or unstandardized mean difference (MD) (95 % confidence intervals). Urinary calcium excretion was lowered by intervention with both KHCO3 (P = 0.04) and KCitr (P = 0.01), as was net acid excretion (NAE) (P = 0.002 for KHCO3 and P = 0.0008 for KCitr). Both salts significantly lowered the bone resorption marker NTX (P < 0.00001). There was no effect on bone formation markers or BMD. KHCO3 and KCitr lowered calcium excretion to a greater extent than did KCl. This meta-analysis confirms that supplementation with alkaline potassium salts leads to significant reduction in renal calcium excretion and acid excretion, compatible with the concept of increased buffering of hydrogen ions by raised circulating bicarbonate. The observed reduction in bone resorption indicates a potential benefit to bone health.

Osteoporose na artrite reumatoide: papel do sistema vitamina D/hormônio paratireóideo

Osteoporosis is a well‐established extra‐articular feature of Rheumatoid Arthritis (RA). Systemic inflammation seems to play a crucial role in causing an alteration of multiple homeostatic systems implied in bone health, such as the RANK/RANKL/Osteoprotegerin and Wnt/β catenin pathways; several other causal factors have been called into question, including the chronic use of corticosteroids. Since vitamin D exerts important immune‐regulatory roles, it has been claimed that derangement of the vitamin D/parathyroid hormone (PTH) system, a well‐known determinant of bone health, may play a pathogenic role in autoimmunity; animal models and clinical data support this hypothesis. Furthermore, RA patients seem to be relatively refractory to vitamin D‐induced PTH suppression. Therefore, the link between RA and osteoporosis might in part be due to alterations in the vitamin D/PTH system. A better understanding of the pathophysiology of this system may be crucial to prevent and cure osteoporosis in patients with inflammatory/autoimmune diseases. A major clinical correlate of the strict cooperation and interdependence between vitamin D and PTH is that correction of the vitamin D deficiency, at least in autoimmune diseases, should be targeted to PTH suppression.

B-vitamin status and the MTHFR 677C→T polymorphism as determinants of bone health in older Irish women from the TUDA ageing cohort study

B-vitamin status and the <i>MTHFR</i> 677C→T polymorphism as determinants of bone health in older Irish women from the TUDA ageing cohort study