Calcium intake and risk of cardiovascular disease: a review of prospective studies and randomized clinical trials

Dietary calcium, phosphorus, and potassium intake associated with erectile dysfunction in the National Health and Nutrition Examination Survey (NHANES) 2001 to 2004

BACKGROUND

Erectile dysfunction is now a common disorder of sexual function, and its relationship to dietary calcium, phosphorus, and potassium has not been well studied. We set out to determine if dietary intakes of calcium, phosphorus, and potassium are related to erectile dysfunction in U.S. men.

METHODS

For this cross-sectional investigation, we used data from NHANES 2001-2004. To investigate the connection of dietary calcium, phosphorus, and potassium intake with erectile dysfunction, we employed multivariate logistic regression, smoothed curve fitting, and subgroup analysis.

RESULTS

This cross-sectional study comprised 3,556 eligible male subjects in total, with a weighted mean age of 49.93±18.13 years. After controlling for race and age, the greatest tertile of calcium consumption was found to have a 34% lower risk of erectile dysfunction than the lowest tertile (OR = 0.66; 95% CI = 0.52-0.84; p = 0.0006). The risk of erectile dysfunction was found to be reduced by 33% (OR = 0.67; 95% CI = 0.52-0.87; p = 0.0024) for the highest tertile of phosphorus intake compared to the lowest tertile of phosphorus intake and by 35% (OR = 0.65; 95% CI = 0.50-0.83; p = 0.0006) for the highest tertile of potassium intake compared to the lowest tertile of potassium intake in the fully adjusted model.

CONCLUSION

Erectile dysfunction and dietary consumption of calcium, phosphorus, and potassium are inversely associated with the U.S. population. To confirm the accuracy of our findings, additional prospective studies are necessary. Furthermore, it is imperative to do further fundamental research at the molecular level to gain a deeper understanding of the underlying mechanisms.

Mineral Intake and Cardiovascular Disease, Cancer, and All-Cause Mortality: Findings from the Golestan Cohort Study

Associations between mineral intake and mortality in non-Western countries have not been studied adequately. This study evaluated these associations in the Golestan Cohort Study, featuring a Middle Eastern population. The mineral intake was estimated from the baseline food frequency questionnaire, adjusted by using the nutrient density method, and divided into quintiles. We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the mortality. We analyzed 41,863 subjects with a mean age of 51.46 ± 8.73 years at the baseline. During 578,694 person-years of follow-up (median: 14.1 Years), 7217 deaths were recorded. Dietary calcium intake was inversely associated with the all-cause mortality (HRQ5 vs. Q1 = 0.91, 95%CI = 0.85-0.99). We observed significant associations between calcium (HRQ5 vs. Q1 = 0.82, 95% CI = 0.73-0.93), copper (HRQ5 vs. Q1 = 1.11, 95% CI = 0.99-1.26), and selenium intake (HRQ5 vs. Q1 = 1.14, 95% CI = 1.01-1.29) and CVD mortality. Dietary phosphorus (HRQ5 vs. Q1 = 0.81, 95%CI = 0.69-0.96) and copper intake (HRQ5 vs. Q1 = 0.84, 95%CI = 0.71-0.99) were inversely associated with cancer mortality. In this study within a Middle Eastern population, a higher dietary intake of calcium exhibited an inverse association with all-cause mortality. Furthermore, nuanced associations were observed in the cause-specific mortality, suggesting potential avenues for dietary interventions and emphasizing the importance of considering dietary factors in public health strategies.

Appraising the Causal Role of Risk Factors in Coronary Artery Disease and Stroke: A Systematic Review of Mendelian Randomization Studies

BACKGROUND Mendelian randomization (MR) offers a powerful approach to study potential causal associations between exposures and health outcomes by using genetic variants associated with an exposure as instrumental variables. In this systematic review, we aimed to summarize previous MR studies and to evaluate the evidence for causality for a broad range of exposures in relation to coronary artery disease and stroke. METHODS AND RESULTS MR studies investigating the association of any genetically predicted exposure with coronary artery disease or stroke were identified. Studies were classified into 4 categories built on the significance of the main MR analysis results and its concordance with sensitivity analyses, namely, robust, probable, suggestive, and insufficient. Studies reporting associations that did not perform any sensitivity analysis were classified as nonevaluable. We identified 2725 associations eligible for evaluation, examining 535 distinct exposures. Of them, 141 were classified as robust, 353 as probable, 110 as suggestive, and 926 had insufficient evidence. The most robust associations were observed for anthropometric traits, lipids, and lipoproteins and type 2 diabetes with coronary artery; disease and clinical measurements with coronary artery disease and stroke; and thrombotic factors with stroke. CONCLUSIONS Despite the large number of studies that have been conducted, only a limited number of associations were supported by robust evidence. Approximately half of the studies reporting associations presented an MR sensitivity analysis along with the main analysis that further supported the causality of associations. Future research should focus on more thorough assessments of sensitivity MR analyses and further assessments of mediation effects or nonlinearity of associations.

The Relationship between Mortality from Cardiovascular Diseases and Total Drinking Water Hardness: Systematic Review with Meta-Analysis

BACKGROUND

Interest in water chemical activity, its content, and its impact on human health has greatly increased throughout the last decade. Some studies suggest that drinking water with high hardness may have preventative effects on cardiovascular diseases. This study aims to investigate the association between drinking water hardness and cardiovascular disease (CVD) mortality.

METHODS

The study selection process was designed to find the association between drinking water hardness and CVDs mortality. The search included both qualitative and quantitative research and was performed in three databases: Web of Science (Clarivate Analytics, Ann Arbor, MI, USA), PubMed (National Institute of Health, Bethesda, MA, USA), and Scopus (Elsevier, RELX Group plc, London, UK). The project was registered in the International Prospective Register of Systematic Reviews (PROSPERO), registration number: CRD42020213102.

RESULTS

Seventeen studies out of a total of twenty-five studies qualitatively analyzed indicated a significant relation between total water hardness and protection from CVD mortality. The quantitative analysis concluded that high drinking water hardness has a significantly lowering effect on mortality from CVDs, however, the heterogeneity was high.

CONCLUSIONS

This systematic literature review shows that total water hardness could affect CVD prevention and mortality. Due to the many confounding factors in the studies, more research is needed.

Exploring the Potential Benefits of Natural Calcium-Rich Mineral Waters for Health and Wellness: A Systematic Review

This systematic review investigates the potential health and wellness benefits of natural calcium-rich mineral waters. It emphasizes the importance of dietary calcium sourced from natural mineral waters in promoting bone health, maintaining cardiovascular function, aiding in weight management, and enhancing overall well-being. The review process involved the comprehensive analysis of peer-reviewed articles, clinical trials, and experimental studies published within the last decade. Findings reveal that consuming calcium-rich mineral water can contribute significantly to daily calcium intake, particularly for those with lactose intolerance or individuals adhering to plant-based diets. The unique bioavailability of calcium from such waters also appears to enhance absorption, thus potentially offering an advantage over other calcium sources. The potential benefits extend to the cardiovascular system, with some studies indicating a reduction in blood pressure and the prevalence of cardiovascular diseases. Emerging evidence suggests that calcium-rich mineral water might have a role in body weight management, though further research is needed. The review identifies several areas requiring additional research, such as the potential interaction between calcium-rich mineral water and other dietary components, the effects on populations with specific health conditions, and the long-term effects of consumption. In conclusion, natural calcium-rich mineral waters show promise as a readily accessible and bioavailable sources of dietary calcium, potentially beneficial for a broad range of individuals. However, further investigation is required to fully understand its range of health impacts and define optimal intake levels.

Association of dietary calcium with mortality from all causes, cardiovascular disease and cancer in people with hypertension

Association between calcium intake and premature mortality in the general population has been well studied, but little is known about the association among specific populations. The authors aim to evaluate the association among people with hypertension and to provide a proper reference range of dietary calcium intake. This prospective cohort study included 8534 US adults with hypertension from National Health and Nutrition Examination Survey cycles 2003-2014. Dietary calcium intakes were self-reported and mortality status was ascertained by National Death Index records. During a median follow-up of 5.9 years, 1357 death occurred. Compared with participants of dietary calcium intake in quintile 1, participants in quintiles 2 and 4 had a 27% (HR: 0.73, 95% CI: 0.60-0.89) and a 29% lower risk (HR: 0.71, 95% CI: 0.57-0.88) of all-cause mortality respectively. The authors also observed a 34% lower risk (HR: 0.66, 95% CI: 0.45-0.97) of CVD death among participants in quintile 3 and a 37% lower risk (HR: 0.63, 95% CI: 0.40-0.99) of cancer-related death in participants in quintile 4 respectively. Restricted cubic spline (RCS) regression revealed a consistent protective effect of dietary calcium in participants with a daily intake of over 1000 mg, but a daily intake over 1200 mg fails to show further protective effect. Our findings suggest that elevated dietary calcium was associated with lower mortality risk from all-causes, cardiovascular disease (CVD) and cancer, and supplying sufficient dietary calcium intake, between 1000 and 1200 mg per day, in people with hypertension may be considered cost-effective to decrease risk of premature death.

Calcium Supplements and Risk of CVD: A Meta-Analysis of Randomized Trials

Background

Vitamin D supplements may only be beneficial for the prevention of osteoporotic fractures when administered with calcium and in individuals with low blood levels of 25(OH)D, but possible hazards of calcium supplements on CVD cannot be excluded.

Objectives

We conducted a meta-analysis of all placebo-controlled randomized trials assessing the effects of calcium supplements alone or with vitamin D on CHD, stroke, and all-cause mortality.

Methods

A meta-analysis of 11 trials included 7 comparisons of calcium alone compared with control (n = 8634) and 6 comparisons of calcium plus vitamin D compared with control (n = 46,804). Aggregated study-level data were obtained from individual trials and combined using a fixed-effects meta-analysis. The main outcomes included MI, CHD death, any CHD, stroke, and all-cause mortality.

Results

Among trials of calcium alone (mean daily dose 1 g), calcium was not significantly associated with any excess risk of MI (RR, 1.15; 95% CI: 0.88, 1.51; n = 219 events), CHD death (RR, 1.24; 95% CI: 0.89, 1.73; n = 142), any CHD (RR, 1.01; 95% CI: 0.75, 1.37; n = 177), or stroke (RR, 1.15; 95% CI, 0.90, 1.46, n = 275). Among 6 trials of combined treatment, supplementation with calcium plus vitamin D was not significantly associated with any excess risk of MI (RR, 1.09; 95% CI: 0.95, 1.25; n = 854), CHD death (RR, 1.04; 95% CI: 0.85, 1.27; n = 391), any CHD (RR, 1.05; 95% CI: 0.93, 1.19; n = 1061), or stroke (RR, 1.02; 95% CI: 0.89, 1.17; n = 885). Likewise, calcium alone, or with vitamin D had no significant associations with all-cause mortality.

Conclusions

This meta-analysis demonstrated that calcium supplements were not associated with any significant hazard for CHD, stroke, or all-cause mortality and excluded excess risks above 0.3%-0.5% per year for CHD or stroke. Further trials of calcium and vitamin D are required in individuals with low blood levels of 25(OH)D for the prevention of fracture and other disease outcomes.

Arterial Stiffness in Thyroid and Parathyroid Disease: A Review of Clinical Studies

Growing evidence shows that arterial stiffness measurement provides important prognostic information and improves clinical stratification of cardiovascular risk. Thyroid and parathyroid diseases are endocrine diseases with a relevant cardiovascular burden. The objective of this review was to consider the relationship between arterial stiffness and thyroid and parathyroid diseases in human clinical studies. We performed a systematic literature review of articles published in PubMed/MEDLINE from inception to December 2021, restricted to English languages and to human adults. We selected relevant articles about the relationship between arterial stiffness and thyroid and parathyroid diseases. For each selected article, data on arterial stiffness were extracted and factors that may have an impact on arterial stiffness were identified. We considered 24 papers concerning hypothyroidism, 9 hyperthyroidism and 16 primary hyperparathyroidism and hypoparathyroidism. Most studies evidenced an increase in arterial stiffness biomarkers in hypothyroidism, hyperthyroidism and primary hyperparathyroidism, even in subclinical and mild forms, although heterogeneity of measurement methods and of study designs prevented a definitive conclusion, suggesting that the assessment of arterial stiffness may be considered in the clinical evaluation of cardiovascular risk in these diseases.

Longitudinal Effects of Serum Calcium and Phosphate Levels and Their Ratio on Incident Ischemic Heart Disease among Korean Adults

Serum calcium and phosphate levels are controlled by a regulatory system, but their individual concentration tendencies and interactions may affect long-term vascular health. This study aimed to assess the effects of serum calcium and phosphate levels on incident ischemic heart disease (IHD) in a large-scale community-dwelling Korean cohort. We evaluated 15,259 non-diabetic individuals (median age, 45 years; range, 30–85) without previous IHD or ischemic stroke using the Korean National Health Insurance data. The study population was classified based on the calcium, phosphate, and calcium/phosphate ratios. Using Cox proportional hazards regression models, we estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD over 50 months after baseline enrolment. The age- and sex-adjusted incidence of IHD gradually increased with serum calcium and phosphate quartiles and decreased with calcium/phosphate ratio quartiles, with an overall crude rate of 2.1% (315/15,259). After setting the lowest calcium, phosphate, and calcium/phosphate ratio quartiles as a reference group, the HRs (95% CIs) of the highest calcium, phosphate, and calcium/phosphate ratio quartiles for IHD were 1.77 (1.15–2.72), 1.73 (1.18–2.55), and 0.58 (0.39–0.87), respectively, after adjusting for potential confounding variables. Serum calcium and phosphate levels were positively associated with IHD incidence, while the serum calcium/phosphate ratio exhibited an inverse relationship. Serum calcium and phosphate homeostasis may merit serious consideration to understand the pathogenesis of coronary atherosclerosis as a risk modifier for IHD.

Calcium Absorption from Food Products: Food Matrix Effects

This article reviews physicochemical aspects of calcium absorption from foods. Notable differences are observed between different food products in relation to calcium absorption, which range from <10% to >50% of calcium in the foods. These differences can be related to the interactions of calcium with other food components in the food matrix, which are affected by various factors, including fermentation, and how these are affected by the conditions encountered in the gastrointestinal tract. Calcium absorption in the intestine requires calcium to be in an ionized form. The low pH in the stomach is critical for solubilization and ionization of calcium salts present in foods, although calcium oxalate complexes remain insoluble and thus poorly absorbable. In addition, the rate of gastric transit can strongly affect fractional absorption of calcium and a phased release of calcium into the intestine, resulting in higher absorption levels. Dairy products are the main natural sources of dietary calcium in many diets worldwide, which is attributable to their ability to provide high levels of absorbable calcium in a single serving. For calcium from other food products, lower levels of absorbable calcium can limit contributions to bodily calcium requirements.

Calcium Supplements and Risk of Cardiovascular Disease: A Meta-Analysis of Clinical Trials

Background: Recent systematic reviews and meta-analyses of randomized, double-blind, placebo-controlled trials (double-blind, placebo-controlled RCTs) have reported controversial findings regarding the associations between calcium supplements on the risk of cardiovascular disease (CVD). This meta-analysis aimed to investigate the association between them. Methods: We searched PubMed, EMBASE, the Cochrane Library, and the bibliographies of relevant articles for double-blind, placebo-controlled RCTs in November, 2020. Relative risks (RRs) with 95% confidence intervals (CIs) for the risk of cardiovascular disease were calculated using a random effects model. The main outcomes were CVD, coronary heart disease (CHD), and cerebrovascular disease. Results: A total of 13 double-blind, placebo-controlled RCTs (n = 28,935 participants in an intervention group and 14,243 in a control group)) were included in the final analysis. Calcium supplements significantly increased the risk of CVD (RR 1.15, 95% CI 1.06–1.25], I2 = 0.0%, n = 14) and CHD (RR 1.16, 95% CI 1.05–1.28], I2 = 0.0%, n = 9) in double-blind, placebo-controlled RCTs, specifically in healthy postmenopausal women. In the subgroup meta-analysis, dietary calcium intake of 700–1000 mg per day or supplementary calcium intake of 1000 mg per day significantly increased the risk of CVD and CHD. Conclusions: The current meta-analysis found that calcium supplements increased a risk of CVD by about 15% in healthy postmenopausal women.

Carotid-femoral pulse wave velocity is significantly increased in newly diagnosed hypertensive patients with primary hyperparathyroidism and significantly related with serum calcium level

BACKGROUND

Primary hyperparathyroidism (PHP) is a rare cause of secondary hypertension (HT), but in patients with PHP, HT is very common and 20-80% of patients have HT. The aim of this study was to evaluate the change in carotid-femoral pulse wave velocity (CF-PWV) in hypertensive patients with PHP, and was to determine the clinical, laboratory, and echocardiographic parameters associated with CF-PWV.

METHODS

The study included 83 newly diagnosed hypertensive patients with PHP and 83 patients with newly diagnosed essential HT without PHP. All patients underwent echocardiography and CF-PWV measurements.

RESULTS

In patients with PHP, blood urea nitrogen, hs-CRP, uric acid, serum and urine calcium, parathyroid hormone level, CF-PWV value, LV wall thickness, LVMI, aortic and left atrium (LA) diameter, and presence of LVH and CF-PWV > 10 m/s were higher, and serum phosphorus levels were lower. Serum calcium, LA diameter, and LVMI values were closely correlated with CF-PWV. In the ROC analysis, the AUROC was calculated as 0.825 for calcium level to determine the patients with increased CF-PWV. When the serum calcium value was taken as 10 mg/dL, it was determined with CF-PWV > 10 m/s were 79.5% sensitivity and 78.2% specificity.

CONCLUSION

CF-PWV significantly increases in newly diagnosed hypertensive patients with PHP and significantly related to serum calcium level. To protect against target organ damage, high serum calcium levels should be monitored as well as blood pressure in hypertensive patients with PHP.

Effects of a multi-modal resistance exercise program and calcium-vitamin D3 fortified milk on blood pressure and blood lipids in middle-aged and older men: secondary analysis of an 18-month factorial design randomised controlled trial

PURPOSE

Physical activity and dietary interventions are recommended as front-line therapy for prevention and management of cardiovascular disease. This study investigated the independent and combined effects of low-fat, calcium-vitamin D₃ fortified milk and multi-modal exercise training on blood pressure (BP) and blood lipids in middle-aged and older men.

METHODS

This was a pre-planned secondary analysis of an 18-month, randomised controlled trial. Community-dwelling men aged 50-79 years (n = 180) were randomised into (i) exercise + fortified milk; (ii) fortified milk; (iii) exercise; or (iv) control. The low-fat milk (400 mL/day) was fortified with 1,000 mg/day calcium and 800 IU/day of vitamin-D₃, whilst the exercise intervention consisted of three sessions/week of resistance- and weight-bearing impact exercises. Resting BP and fasting lipids were assessed at baseline, 6 (lipids only), 12 and 18 months.

RESULTS

Mean ± SD serum 25(OH)D and calcium intake for the entire cohort at baseline was 86 ± 36 nmol/L and 1002 ± 397 mg/day, respectively, with 10% classified as vitamin-D insufficient and 58% reporting a calcium intake below 1000 mg/day. There were no exercise-by-fortified milk interactions, nor any main-group effects for exercise or milk on BP or lipids at any time. However, there were significant reductions from baseline to 18 months in systolic (mean change, 5-8 mmHg) and diastolic (4-6 mmHg) BP in the exercise, fortified milk and control groups. All results remained largely unchanged after adjusting for use of anti-hypertensive or lipid lowering medication, weight or fat mass, or only including men with hypertension (n = 89) or dyslipidemia (n = 130) at baseline.

CONCLUSION

Supplementation with low-fat, calcium + vitamin D₃ fortified milk and a multi-modal exercise program, alone or in combination, was not effective for improving BP or blood lipids in community-dwelling middle-aged and older men.

Vitamin D, Marine n-3 Fatty Acids, and Primary Prevention of Cardiovascular Disease Current Evidence

Whether marine omega-3 fatty acid (n-3 FA) or vitamin D supplementation can prevent cardiovascular disease (CVD) in general populations at usual risk for this outcome is unknown. A major goal of VITAL (Vitamin D and Omega-3 Trial) was to fill this knowledge gap. In this article, we review the results of VITAL, discuss relevant mechanistic studies regarding n-3 FAs, vitamin D, and vascular disease, and summarize recent meta-analyses of the randomized trial evidence on these agents. VITAL was a nationwide, randomized, placebo-controlled, 2×2 factorial trial of marine n-3 FAs (1 g/d) and vitamin D3 (2000 IU/d) in the primary prevention of CVD and cancer among 25 871 US men aged ≥50 and women aged ≥55 years, including 5106 blacks. Median treatment duration was 5.3 years. Supplemental n-3 FAs did not significantly reduce the primary cardiovascular end point of major CVD events (composite of myocardial infarction, stroke, and CVD mortality; hazard ratio [HR], 0.92 [95% CI, 0.80-1.06]) but were associated with significant reductions in total myocardial infarction (HR, 0.72 [95% CI, 0.59-0.90]), percutaneous coronary intervention (HR, 0.78 [95% CI, 0.63-0.95]), and fatal myocardial infarction (HR, 0.50 [95% CI, 0.26-0.97]) but not stroke or other cardiovascular end points. For major CVD events, a treatment benefit was seen in those with dietary fish intake below the cohort median of 1.5 servings/wk (HR, 0.81 [95% CI, 0.67-0.98]) but not in those above (P interaction=0.045). For myocardial infarction, the greatest risk reductions were in blacks (HR, 0.23 [95% CI, 0.11-0.47]; P interaction by race, 0.001). Vitamin D supplementation did not reduce major CVD events (HR, 0.97 [95% CI, 0.85-1.12]) or other cardiovascular end points. Updated meta-analyses that include VITAL and other recent trials document coronary risk reduction from supplemental marine n-3 FAs but no clear CVD risk reduction from supplemental vitamin D. Additional research is needed to determine which individuals may be most likely to derive net benefit from supplementation. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01169259.

Calcium Intake and Serum Calcium Level in Relation to the Risk of Ischemic Stroke: Findings from the REGARDS Study

BACKGROUND AND PURPOSE

Data on the association between calcium (Ca) and ischemic stroke are sparse and inconsistent. This study aimed to examine Ca intake and serum Ca levels in relation to risk of ischemic stroke.

METHODS

The primary analysis included 19,553 participants from the Reasons for Geographic And Racial Differences in Stroke (REGARDS) study. A subcohort was randomly selected to create a case-cohort study (n=3,016), in which serum Ca levels were measured. Ischemic stroke cases were centrally adjudicated by physicians based on medical records. Cox proportional hazards regression for the cohort and weighted Cox proportional hazard regression with robust sandwich estimation method for the case-cohort analysis with adjustment for potential confounders were performed.

RESULTS

During a mean 8.3-year follow-up, 808 incident cases of ischemic stroke were documented. Comparing the highest quintile to the lowest, a statistically significant inverse association was observed between total Ca intake and risk of ischemic stroke (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.55 to 0.95; Plinear-trend=0.183); a restricted cubic spline analysis indicated a threshold effect like non-linear association of total Ca intake with ischemic stroke (Pnon-linear=0.006). In the case-cohort, serum Ca was inversely associated with the risk of ischemic stroke. Compared to the lowest, the highest quintile of serum Ca had a 27% lower risk of ischemic stroke (HR, 0.73; 95% CI, 0.53 to 0.99; Plinear-trend=0.013). Observed associations were mainly mediated by type 2 diabetes, hypertension, and cholesterol.

CONCLUSION

s These findings suggest that serum Ca has inverse and Ca intake has threshold effect like association with risk of ischemic stroke.

Dairy, soy, and calcium consumption and risk of cognitive impairment: the Singapore Chinese Health Study

PURPOSE

It is unclear if midlife consumption of dairy and soy food intake, and their components of calcium and isoflavones (in soy), is related to cognitive impairment in elderly.

METHODS

We used baseline data on lifestyle and habitual diet of 16,948 participants collected during their recruitment into the Singapore Chinese Health Study from 1993 to 1998, and data on their cognitive function, measured using a 30-item Singapore modified Mini-Mental State Examination, during follow-up interviews from 2014 to 2016. We used multivariable logistic regression models to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for developing cognitive impairment.

RESULTS

Higher dairy intake was associated with a lower risk of cognitive impairment in a dose-dependent manner (P for trend = 0.009). Compared to the lowest quartile of dairy intake, ORs (95% CIs) were 0.93 (0.81-1.07) for the second, 0.88 (0.76-1.01) for the third, and 0.82 (0.72-0.94) for the fourth quartiles of intake. Similar results were found for dairy calcium intake (P for trend = 0.008). However, there was no statistically significant association for intake of soy (OR comparing extreme quartiles 0.99, 95% CI 0.87-1.14, P for trend = 0.92), isoflavones (OR 1.01, 95% CI 0.88-1.15, P for trend = 0.90) or non-dairy calcium (OR 1.06, 95% CI 0.86-1.30, P for trend = 0.81) with risk of cognitive impairment.

CONCLUSIONS

Dairy intake at midlife could have a protective association against cognitive impairment that may not be attributed to its calcium content alone, while soy or isoflavone intake was not associated with the cognition of elderly in our study.

Borderline high serum calcium levels are associated with arterial stiffness and 10-year cardiovascular disease risk determined by Framingham risk score

Recent epidemiological data indicate that the concentration of circulating calcium is related to cardiovascular disease (CVD) mortality. We determined whether serum calcium level is related to arterial stiffness and 10-year CVD risk calculated by Framingham risk score (FRS). We examined the association of normal-range serum calcium level with arterial stiffness and FRS in 565 Korean adults participating at the Health Promotion Center of Gangnam Severance Hospital between March 2016 and May 2017. High brachial-ankle pulse wave velocity (baPWV) was defined as >1460 cm/s, and high FRS was defined as ≥10 percent for 10-year CVD risk. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for high baPWV and high FRS were calculated using multiple logistic regression analysis after adjusting for confounding variables. The OR (95% CI) for high baPWV was 3.91 (1.15-7.36) per 1 mg/dL increment of serum calcium after adjusting for age, sex, body mass index, smoking status, exercise regularity, alcohol consumption, mean blood pressure, fasting plasma glucose, triglyceride, HDL-cholesterol, C-reactive protein, γ-glutamyltransferase, uric acid level, phosphate level, potassium level, and presence of hypertension, diabetes and dyslipidemia medications (P = 0.024). A positive association between serum calcium level and high FRS was also observed after adjusting for the same covariables (OR, 3.54 [95% CI, 1.01-12.44], P = 0.048). Serum calcium level was independently and positively associated with baPWV and 10-year CVD risk estimates. Early detection of higher serum calcium level may be important for the assessment of arterial stiffness and future risk of a cardiovascular event.

Prevention of low bone mass to achieve high bone density in Mexico: position of the Mexican Association for Bone and Mineral Metabolism

In Mexico, osteoporosis is a public health problem. In this document, the Mexican Association for Bone and Mineral Metabolism defines its position on calcium, vitamin D supplement use, and physical activity as an effective, safe, and cost-effective initiatives to prevent low bone mass.

INTRODUCTION

In Mexico, osteoporosis is a public health problem that is expected to increase in the decades ahead. Generally, modifiable risk factors for bone health are related with lifestyles, especially nutrition and physical activity.

METHODS

In this position paper, the Mexican Association for Bone and Mineral Metabolism (AMMOM, by its acronym in Spanish), which is a multidisciplinary group of researchers, dietitians, epidemiologists, nurses, and physicians who study bone and related tissues and communicate the best strategies for diagnosis, treatment, and prevention of bone problems, aims to analyze the association between nutrition and bone health, risk behaviors for low bone mass, and the economic impact that prevention of low bone mass represents for the health care system.

RESULTS

Addressing therapeutic management with pharmacological and non-pharmacological approaches, we emphasize the important role the patient plays in the doctor-patient relationship, both in the consulting room and in daily life. Furthermore, the AMMOM defines its position on calcium and vitamin D supplement use as an effective, safe, and cost-effective initiative to prevent low bone mass.

CONCLUSIONS

In summary, most research and clinical practice related to osteoporosis have focused on diagnosis and treatment, but general measures for primary prevention based on addressing modifiable risk factors as a public health priority to delay the onset of loss of bone mass have not been considered by Mexican authorities. Consequently, the AMMOM task force also seeks to provide information on concrete actions to prevent low bone mass.

Peroxisome proliferator-activated receptor gamma (PPARγ) regulates lactase expression and activity in the gut

Lactase (LCT) deficiency affects approximately 75% of the world's adult population and may lead to lactose malabsorption and intolerance. Currently, the regulation of LCT gene expression remains poorly known. Peroxisome proliferator activator receptorγ (PPARγ) is a key player in carbohydrate metabolism. While the intestine is essential for carbohydrate digestion and absorption, the role of PPARγ in enterocyte metabolic functions has been poorly investigated. This study aims at characterizing PPARγ target genes involved in intestinal metabolic functions. In microarray analysis, the LCT gene was the most upregulated by PPARγ agonists in Caco-2 cells. We confirmed that PPARγ agonists were able to increase the expression and activity of LCT both in vitro and in vivo in the proximal small bowel of rodents. The functional response element activated by PPARγ was identified in the promoter of the human LCT gene. PPARγ modulation was able to improve symptoms induced by lactose-enriched diet in weaned rats. Our results demonstrate that PPARγ regulates LCT expression, and suggest that modulating intestinal PPARγ activity might constitute a new therapeutic strategy for lactose malabsorption.

Inverse association of calcium intake with abdominal adiposity and C-reactive protein in Brazilian children

OBJECTIVE

To evaluate Ca intake and its association with cardiometabolic risk factors during childhood.

DESIGN

A cross-sectional study with a representative sample. Food consumption was assessed through three 24 h dietary recalls. Anthropometry, body composition and biochemical measurements were also conducted.

SETTING

Viçosa, Minas Gerais, Brazil.

SUBJECTS

Children between 8 and 9 years old (n 350) enrolled in public and private schools in the urban area of the municipality of Viçosa.

RESULTS

Almost all children had inadequate intake of Ca (97·4 %), especially those with low income, non-white and who studied in public schools. Foods that contributed most to Ca intake were 'milk' and 'cheeses and yoghurts' (R 2=0·66 and 0·13, respectively), and intake of 'milk' was correlated with 'chocolate milk powder' intake (r=0·538, P<0·01). Children with lower Ca intake had a higher prevalence of increased C-reactive protein (prevalence ratio=2·93; 95 % CI 1·21, 7·07), increased waist circumference (prevalence ratio=2·86; 95 % CI 1·01, 8·13) and a lower prevalence of high LDL cholesterol (prevalence ratio=0·64; 95 % CI 0·41, 0·99).

CONCLUSIONS

Lower Ca intake was associated with excess abdominal adiposity and subclinical inflammation in Brazilian children. Monitoring of adequate Ca intake is important, especially in poorer communities.

Dietary calcium intake is associated with serum high-sensitivity C-reactive protein level in the general Japanese population

The beneficial effects of dietary calcium intake on high-sensitivity C-reactive protein levels, a risk factor of cardiovascular disease, have not been fully elucidated. This study investigated the associations between dietary calcium intake and serum high-sensitivity C-reactive protein levels in the general Japanese population. We analyzed the data of 2,019 subjects (1,194 men and 825 women) aged 35 to 69 years in a cross-sectional study of the Japan Multi-Institutional Collaborative Cohort Study. Nutrients intake including calcium were estimated using a validated food-frequency questionnaire. Analysis using a general linear model revealed that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels (p for trend <0.001) after adjustment for age, sex, research group, leisure-time physical activity, smoking habit, drinking habit, dietary intakes (energy, dietary fiber, saturated fatty acids and vitamin D) and menopausal status. The association was slightly attenuated after additional adjustment for body mass index; however, remained significant (p for trend = 0.008). There were no significant interactions between dietary calcium intakes and sex, body mass index, or vitamin D intake for high-sensitivity C-reactive protein levels. This study have demonstrated that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels in the general population.

Yogurt and Cardiometabolic Diseases: A Critical Review of Potential Mechanisms

Associations between yogurt intake and risk of diet-related cardiometabolic diseases (CMDs) have been the subject of recent research in epidemiologic nutrition. A healthy dietary pattern has been identified as a pillar for the prevention of weight gain and CMDs. Epidemiologic studies suggest that yogurt consumption is linked to healthy dietary patterns, lifestyles, and reduced risk of CMDs, particularly type 2 diabetes. However, to our knowledge, few to no randomized controlled trials have investigated yogurt intake in relation to cardiometabolic clinical outcomes. Furthermore, there has been little attempt to clarify the mechanisms that underlie the potential beneficial effects of yogurt consumption on CMDs. Yogurt is a nutrient-dense dairy food and has been suggested to reduce weight gain and prevent CMDs by contributing to intakes of protein, calcium, bioactive lipids, and several other micronutrients. In addition, fermentation with bacterial strains generates bioactive peptides, resulting in a potentially greater beneficial effect of yogurt on metabolic health than nonfermented dairy products such as milk. To date, there is little concrete evidence that the mechanisms proposed in observational studies to explain positive results of yogurt on CMDs or parameters are valid. Many proposed mechanisms are based on assumptions that commercial yogurts contain strain-specific probiotics, that viable yogurt cultures are present in adequate quantities, and that yogurt provides a minimum threshold dose of nutrients or bioactive components capable of exerting a physiologic effect. Therefore, the primary objective of this review is to investigate the plausibility of potential mechanisms commonly cited in the literature in order to shed light on the inverse associations reported between yogurt intake and various cardiometabolic health parameters that are related to its nutrient profile, bacterial constituents, and food matrix. This article reviews current gaps and challenges in identifying such mechanisms and provides a perspective on the research agenda to validate the proposed role of yogurt in protecting against CMDs.

Maduramicin induces apoptosis and necrosis, and blocks autophagic flux in myocardial H9c2 cells

Maduramicin, a polyether ionophore antibiotic, is widely used as an anticoccidial agent in the poultry industry. It has been reported that maduramicin may cause heart and skeletal muscle cell damage, resulting in heart failure, skeletal muscle degeneration and even death in animals and humans, if improperly used. However, the molecular mechanism behind its capability to cause death of cardiac cells is not known. Here, we show that maduramicin induced apoptosis and necrosis in rat myocardial cells (H9c2). Maduramicin did not apparently upregulate the expression of pro-apoptotic proteins (e.g., BAD, BAK and BAX) or downregulate the expression of anti-apoptotic proteins (e.g. Bcl-2, Bcl-xL, Mcl-1 and survivin). Interestingly, maduramicin increased the expression of DR4 and TRAIL, activating caspases 8/3 and triggering cleavage of poly ADP ribose polymerase (PARP). In addition, maduramicin induced nuclear translocation of apoptosis inducing factor. Furthermore, maduramicin blocked autophagic flux, as evidenced by inducing accumulation of both LC3-II and p62/SQSTM1. Taken together, the above results suggest that maduramicin executes its toxicity in the myocardial cells at least by inducing caspase-dependent cell death through TRAIL/DR4-mediated extrinsic pathway and caspase-independent cell death by inducing apoptosis inducing factor nuclear translocation and blocking autophagic flux. Our findings provide a new insight into the molecular mechanism of maduramicin's toxicity in myocardial cells.

High Calcium-Magnesium Ratio in Hair Is Associated with Coronary Artery Calcification in Middle-Aged and Elderly Individuals

The interaction between calcium and magnesium as a risk modifier for cardiovascular disease (CVD) has been largely overlooked in previous studies, for the strict regulatory system in blood has been thought to keep such homeostatic interactions under tight control. This study aimed to investigate the association between calcium-magnesium ratio in hair and subclinical coronary artery calcification. Using multiple linear regression analysis, we examined the associations between calcium-magnesium ratio in hair and the coronary calcium score (CCS) in 216 Koreans aged 40 years and above (122 men and 94 women). We found that the calcium-to-magnesium ratio in hair was independently and positively associated with CCS after adjusting for age and sex (regression coefficient 6.051 ± 2.329, P = 0.010). When we assessed the association between the calcium-magnesium ratio and CCS after adjusting for potential cardiovascular risk factors and vascular function modifying drugs, we found that the strength of association with CCS was comparable to before (regression coefficient 5.434 ± 2.523, P = 0.032). Our findings suggest that among middle-aged and elderly Koreans without clinical CVD, the association between coronary artery calcification and hair calcium-magnesium ratio is stronger in those with a higher calcium-magnesium ratio in hair than in those with a lower ratio.

Calcium and Cardiovascular Disease

Circulating calcium is a risk factor for vascular disease, a conclusion arising from prospective studies involving hundreds of thousands of participants and extending over periods of up to 30 years. These associations may be partially mediated by other cardiovascular risk factors such as circulating lipid levels, blood pressure, and body mass index, but there appears to be a residual independent effect of serum calcium. Polymorphisms of the calcium-sensing receptor associated with small elevations of serum calcium are also associated with cardiovascular disease, suggesting that calcium plays a causative role. Trials of calcium supplements in patients on dialysis and those with less severe renal failure demonstrate increased mortality and/or acceleration of vascular disease, and meta-analyses of trials in those without overt renal disease suggest a similar adverse effect. Interpretation of the latter trials is complicated by a significant interaction between baseline use of calcium supplements and the effect of randomisation to calcium in the largest trial. Restriction of analysis to those who are calcium-naive demonstrates a consistent adverse effect. Observational studies of dietary calcium do not demonstrate a consistent adverse effect on cardiovascular health, though very high or very low intakes may be deleterious. Thus, obtaining calcium from the diet rather than supplements is to be encouraged.

Vitamin D supplementation has no effect on insulin sensitivity or secretion in vitamin D-deficient, overweight or obese adults: a randomized placebo-controlled trial

Background: Vitamin D supplementation has been proposed as a potential strategy to prevent type 2 diabetes. Existing clinical trials have been limited by short duration, low doses of vitamin D, variability in participants' vitamin D-deficiency status, and the use of surrogate measures of body composition, insulin sensitivity, and insulin secretion.Objective: To address existing knowledge gaps, we conducted a double-blind, randomized, placebo-controlled trial to investigate whether vitamin D supplementation that is provided in a sufficient dose and duration to vitamin D-deficient individuals would improve insulin sensitivity or secretion as measured with the use of gold-standard methods. We hypothesized that vitamin D supplementation would improve insulin sensitivity and secretion compared with placebo.Design: Sixty-five overweight or obese, vitamin D-deficient (25-hydroxyvitamin D [25(OH)D] concentration ≤50 nmol/L) adults were randomly assigned to receive either a bolus oral dose of 100,000 IU cholecalciferol followed by 4000 IU cholecalciferol/d or a matching placebo for 16 wk. Before and after the intervention, participants received gold-standard assessments of body composition (via dual X-ray absorptiometry), insulin sensitivity (via hyperinsulinemic-euglycemic clamps), and insulin secretion [via intravenous-glucose-tolerance tests (IVGTTs)].Results: Fifty-four participants completed the study [35 men and 19 women; mean ± SD age: 31.9 ± 8.5 y; body mass index (in kg/m²): 30.9 ± 4.4]. 25(OH)D increased with vitamin D supplementation compared with placebo (57.0 ± 21.3 compared with 1.9 ± 15.1 nmol/L, respectively; P = 0.02). Vitamin D and placebo groups did not differ in change in insulin sensitivity (0.02 ± 2.0 compared with -0.03 ± 2.8 mg · kg^-1 · min^-1, respectively; P = 0.9) or first-phase insulin secretion (-21 ± 212 compared with 24 ± 184 mU/L, respectively; P = 0.9). Results remained nonsignificant after adjustment for age, sex, percentage of body fat, sun exposure, physical activity, and dietary vitamin D intake (P > 0.1).Conclusions: Vitamin D supplementation does not improve insulin sensitivity or secretion in vitamin D-deficient, overweight or obese adults, despite using high-dose vitamin D supplementation and robust endpoint measures. Therefore, it is unlikely that vitamin D supplementation would be an effective strategy for reducing diabetes risk even in vitamin D-deficient populations. This trial was registered at clinicaltrials.gov as NCT02112721.

Dairy intake and risk of type 2 diabetes

BACKGROUND & AIMS

The effect of total dairy products, milk, and calcium intake on risk of type 2 diabetes (T2D) is uncertain, particularly in the Chinese population.

METHODS

The present study was based on a prospective cohort of 63,257 Chinese men and women aged 45-74 years during enrollment (1993-1998) in Singapore. Dietary information was obtained using a validated 165-item semi-quantitative food-frequency questionnaire. Information about newly diagnosed T2D was collected by self-report during two follow-up interviews in 1999-2004 and 2006-2010. Cox proportional hazard regression method was used to estimate hazard ratios (HRs) and their 95% confidence intervals (CIs) in 45,411 eligible participants.

RESULTS

Incidence rate (95% CI) of T2D was 10.5 (10.2-10.8) per 1000 person-years. Intake of dairy food was significantly associated with reduced T2D risk; compared with the lowest quartile, HRs (95% CI) for the second, third and fourth quartiles of dairy intake were 0.98 (0.91-1.06), 0.96 (0.89-1.03) and 0.90 (0.83-0.98), respectively, after adjustment for potential confounders at baseline (P-trend = 0.01). Daily drinkers of milk had a significant 12% reduction in T2D risk compared with non-drinkers. While dairy calcium was associated with a decreased risk of T2D (HR comparing extreme quartiles 0.84; 95% CI 0.76-0.93; P-trend = 0.001), no association was found for non-dairy calcium (HR 1.02; 95% CI 0.92-1.14; P-trend = 0.61).

CONCLUSIONS

In this large cohort study of Chinese adults, dairy product intake and daily milk consumption was associated with a statistically significant, although modest, decrease in risk of developing T2D, which may be independent of its calcium content.

A Mendelian randomization study of the effect of calcium on coronary artery disease, myocardial infarction and their risk factors

Meta-analyses of randomized controlled trials (RCTs) suggest calcium could have adverse effects on cardiovascular disease, although these findings are controversial. To clarify, we assessed whether people with genetically higher calcium had a higher risk of coronary artery disease (CAD), myocardial infarction (MI) and their risk factors. We used a two-sample Mendelian randomization study. We identified genetic variants (single nucleotide polymorphisms (SNPs)) that independently contributed to serum calcium at genome-wide significance which we applied to large extensively genotyped studies of CAD, MI, diabetes, lipids, glycaemic traits and adiposity to obtain unconfounded estimates, with body mass index (BMI) as a control outcome. Based on 4 SNPs each 1 mg/dl increase in calcium was positively associated with CAD (odds ratio (OR) 1.49, 95% confidence interval (CI) 1.02–2.17), MI (OR 1.58, 95% CI 1.06–2.35), LDL-cholesterol (0.21 standard deviations, 95% CI 0.01–0.4), total cholesterol (0.21 standard deviations, 95% CI 0.03-0.38) and possibly triglycerides (0.19 standard deviations, 95% CI −0.1–0.48), but was unlikely related to BMI although the estimate lacked precision. Sensitivity analysis using 13 SNPs showed a higher risk for CAD (OR 1.87, 95% CI 1.14–3.08). Our findings, largely consistent with the experimental evidence, suggest higher serum calcium may increase the risk of CAD.

Vitamin D deficiency/insufficiency from childhood to adulthood: Insights from a sunny country

Vitamin D is known to be a key regulator of bone metabolism and is associated with muscle strength. Vitamin D deficiency is widely prevalent worldwide. In adults, vitamin D deficiency has been implicated in numerous health conditions including osteoporosis, cancer, diabetes, and autoimmune diseases. Considerable changes have occurred in lifestyles and childhood activities in the past years. Studies have shown that the children population is at high risks of vitamin D deficiency. The objective of this study was to learn about the extent of vitamin D deficiency in children worldwide and especially in sunny country like Israel. In this article we reviewed the extent and severity of vitamin D deficiency worldwide and especially in Israel, through a very comprehensive review of previous reports and research studies done during the last years. We found reports on vitamin D deficiency in children, which was associated with metabolic syndromes and obesity. It was more prevalent in children who spend less time on outdoor activities, in obese children, and in cases when there was imbalance between nutritional intakes and requirements. Vitamin D deficiency is common even in children living in sunny places like Israel. Health professionals should be aware of the fact that although vitamin D deficiency is prevalent in the elderly population, it is also common in children, and can be associated with different illnesses. We encourage supplementation of vitamin D to special populations (pregnant and lactating women, infants, and high risk groups). We also encourage implementation of international food fortification programs.

Fragility Fractures Are Associated with an Increased Risk for Cardiovascular Events in Women and Men with Rheumatoid Arthritis: A Population-based Study

OBJECTIVE

Women and men with rheumatoid arthritis (RA) have an increased risk for fragility fractures and cardiovascular disease (CVD), each of which has been reported to contribute to excess morbidity and mortality in these patients. Fragility fractures share similar risk factors for CVD but may occur at relatively younger ages in patients with RA. We aimed to determine whether a fragility fracture predicts the development of CVD in women and men with RA.

METHODS

We studied a population-based cohort with incident RA from 1955 to 2007 and compared it with age- and sex-matched non-RA subjects. We identified fragility fractures and CVD events following the RA incidence/index date, along with relevant risk factors. We used Cox models to examine the association between fractures and the development of CVD, in which fractures and CVD risk factors were modeled as time-dependent covariates.

RESULTS

There were 1171 subjects (822 women; 349 men) in each of the RA and non-RA cohorts. Over followup, there were 406 and 346 fragility fractures and 286 and 225 CVD events, respectively. The overall CVD risk was increased significantly for RA subjects following a fragility fracture (HR 1.81, 95% CI 1.38-2.37) but not for non-RA subjects (HR 1.18, 95% CI 0.85-1.63). Results were similar for women and men with RA.

CONCLUSION

Fragility fractures in both women and men with RA are associated with an increased risk for CVD events and should raise an alert to clinicians to target these individuals for further screening and preventive strategies for CVD.

Effects of Calcium, Vitamin D, and Hormone Therapy on Cardiovascular Disease Risk Factors in the Women's Health Initiative: A Randomized Controlled Trial

OBJECTIVE

To analyze the treatment effect of calcium+vitamin D supplementation, hormone therapy, both, and neither on cardiovascular disease risk factors.

METHODS

We conducted a prospective, randomized, double-blind, placebo-controlled trial among Women's Health Initiative (WHI) participants. The predefined primary outcome was low-density lipoprotein cholesterol (LDL-C).

RESULTS

Between September 1993 and October 1998, a total of 68,132 women aged 50-79 years were recruited and randomized to the WHI-Dietary Modification (n=48,835) and WHI-Hormone Therapy trials (n=27,347). Subsequently, 36,282 women from WHI-Hormone Therapy (16,089) and WHI-Dietary Modification (n=25,210) trials were randomized in the WHI-Calcium+Vitamin D trial to 1,000 mg elemental calcium carbonate plus 400 international units vitamin D3 daily or placebo. Our study group included 1,521 women who participated in both the hormone therapy and calcium+vitamin D trials and were in the 6% subsample of trial participants with blood sample collections at baseline and years 1, 3, and 6. The average treatment effect with 95% confidence interval, for LDL-C, compared with placebo, was -1.6, (95% confidence interval [CI] -5.5 to 2.2) mg/dL for calcium+vitamin D alone, -9.0 (95% CI -13.0 to -5.1) mg/dL for hormone therapy alone, and -13.8 (95% CI -17.8 to -9.8) mg/dL for the combination. There was no evidence of a synergistic effect of calcium+vitamin D+hormone therapy on LDL-C (P value for interaction=.26) except in those with low total intakes of vitamin D, for whom there was a significant synergistic effect on LDL (P value for interaction=.03).

CONCLUSION

Reductions in LDL-C were greater among women randomized to both calcium+vitamin D and hormone therapy than for those randomized to either intervention alone or to placebo. The treatment effect observed in the calcium+vitamin D+hormone therapy combination group may be additive rather than synergistic. For clinicians and patients deciding to begin calcium+vitamin D supplementation, current use of hormone therapy should not influence that decision.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT00000611.

No difference in acute effects of supplementalv.dietary calcium on blood pressure and microvascular function in obese women challenged with a high-fat meal: a cross-over randomised study

Recent studies suggest that supplemental Ca (SC) increases the risk of cardiovascular events, whereas dietary Ca (DC) decreases the risk of cardiovascular events. Although frequently consumed with meals, it remains unclear whether Ca can mitigate or aggravate the deleterious effects of a high-fat meal on cardiovascular risk factors. This study aimed to evaluate the effects of SC or DC on blood pressure (BP) and microvascular function (MVF) in the postprandial period in obese women challenged with a high-fat meal. In this cross-over controlled trial, sixteen obese women aged 20–50 years were randomly assigned to receive three test meals (2908 kJ (695 kcal); 48 % fat): high DC (HDCM; 547 mg DC), high SC (HSCM; 500 mg SC–calcium carbonate) and low Ca (LCM; 42 mg DC). BP was continuously evaluated from 15 min before to 120 min after meals by digital photoplethysmography. Before and 120 min after meals, participants underwent evaluation of serum Ca and microvascular flow after postocclusive reactive hyperaemia (PORH) by laser speckle contrast imaging. Ionised serum Ca rose significantly only after HSCM. Systolic BP increased after the three meals, whereas diastolic BP increased after LCM and HDCM. Hyperaemia peak, hyperaemia amplitude and AUC evaluated after PORH decreased with LCM. After HDCM, there was a reduction in hyperaemia peak and hyperaemia amplitude, whereas HSCM decreased only hyperaemia peak. However, comparative analyses of the effects of three test meals on serum Ca, BP and MVF revealed no significant meal×time interaction. This study suggests that in obese women SC and DC do not interfere with the effects of a high-fat meal on BP and MVF.

The association of calcium supplementation and incident cardiovascular events in the Multi-ethnic Study of Atherosclerosis (MESA)

BACKGROUND AND AIMS

Many US adults use calcium supplements to address inadequate dietary intake and improve bone health. However, recent reports have suggested that use of calcium supplements may elevate cardiovascular disease (CVD) risk. In this study, we examined associations between baseline calcium supplement use and incident myocardial infarction (MI) (n = 208 events) and CVD events (n = 641 events) over 10.3 years in men and women from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort (n = 6236), with dietary calcium intake at baseline also examined as a supplementary objective.

METHODS AND RESULTS

Using Cox proportional hazards models, no compelling associations between calcium intake from supplements or diet and incident CVD events were observed upon multivariate adjustment for potential confounders. An association with lower MI risk was observed comparing those with low levels of calcium supplement use (1-499 mg) to those using no calcium supplements (hazard ratio 0.69, 95% CI 0.48, 0.98, p = 0.039). Relationships were homogeneous by gender, race/ethnicity, or chronic kidney disease. Results were also similar when the analysis was limited to postmenopausal women only.

CONCLUSION

Analysis of incident MI and CVD events in the MESA cohort does not support a substantial association of calcium supplement use with negative cardiovascular outcomes.

IMPROVEMENT IN PANCREATIC β-CELL FUNCTION WITH VITAMIN D AND CALCIUM SUPPLEMENTATION IN VITAMIN D-DEFICIENT NONDIABETIC SUBJECTS

OBJECTIVE

There are varied reports on the effect of vitamin D supplementation on β-cell function and plasma glucose levels. The objective of this study was to examine the effect of vitamin D and calcium supplementation on β-cell function and plasma glucose levels in subjects with vitamin D deficiency.

METHODS

Nondiabetic subjects (N = 48) were screened for their serum 25-hydroxyvitamin D (25-OHD), albumin, creatinine, calcium, phosphorus, alkaline phosphatase, and intact parathyroid hormone (PTH) status. Subjects with 25-OHD deficiency underwent a 2-hour oral glucose tolerance test. Cholecalciferol (9,570 international units [IU]/day; tolerable upper intake level, 10,000 IU/day; according to the Endocrine Society guidelines for vitamin D supplementation) and calcium (1 g/day) were supplemented.

RESULTS

Thirty-seven patients with 25-OHD deficiency participated in the study. The baseline and post-vitamin D/calcium supplementation and the difference (corrected) were: serum calcium, 9 ± 0.33 and 8.33 ± 1.09 mg/dL (-0.66 ± 1.11 mg/dL); 25-OHD, 8.75 ± 4.75 and 36.83 ± 18.68 ng/mL (28.00 ± 18.33 ng/mL); PTH, 57.9 ± 29.3 and 36.33 ± 22.48 pg/mL (-20.25 ± 22.45 pg/mL); fasting plasma glucose, 78.23 ± 7.60 and 73.47 ± 9.82 mg/dL (-4.88 ± 10.65 mg/dL); and homeostasis model assessment-2-percent β-cell function C-peptide secretion (HOMA-2-%B C-PEP), 183.17 ± 88.74 and 194.67 ± 54.71 (11.38 ± 94.27). Significant differences were observed between baseline and post-vitamin D/calcium supplementation serum levels of corrected calcium (Z, -3.751; P<.0001), 25-OHD (Z, -4.9; P<.0001), intact PTH (Z, -4.04; P<.0001), fasting plasma glucose (Z, -2.7; P<.007), and HOMA-2-%B C-PEP (Z, -1.923; P<.05) as determined by Wilcoxon signed rank test. Insulin resistance as measured by HOMA was unchanged.

CONCLUSION

Optimizing serum 25-OHD concentrations and supplementation with calcium improves fasting plasma glucose levels and β-cell secretory reserve. Larger randomized control studies are needed to determine if correction of 25-OHD deficiency will improve insulin secretion and prevent abnormalities of glucose homeostasis.

Calcium intake and mortality from all causes, cancer, and cardiovascular disease: the Cancer Prevention Study II Nutrition Cohort

BACKGROUND

Calcium intake may be important for bone health, but its effects on other outcomes, including cardiovascular disease (CVD) and cancer, remain unclear. Recent reports of adverse cardiovascular effects of supplemental calcium have raised concerns.

OBJECTIVE

We investigated associations of supplemental, dietary, and total calcium intakes with all-cause, CVD-specific, and cancer-specific mortality in a large, prospective cohort.

DESIGN

A total of 132,823 participants in the Cancer Prevention Study II Nutrition Cohort, who were followed from baseline (1992 or 1993) through 2012 for mortality outcomes, were included in the analysis. Dietary and supplemental calcium information was first collected at baseline and updated in 1999 and 2003. Multivariable-adjusted Cox proportional hazards models with cumulative updating of exposures were used to calculate RRs and 95% CIs for associations between calcium intake and mortality.

RESULTS

During a mean follow-up of 17.5 y, 43,186 deaths occurred. For men, supplemental calcium intake was overall not associated with mortality outcomes (P-trend > 0.05 for all), but men who were taking ≥1000 mg supplemental calcium/d had a higher risk of all-cause mortality (RR: 1.17; 95% CI: 1.03, 1.33), which was primarily attributed to borderline statistically significant higher risk of CVD-specific mortality (RR: 1.22; 95% CI: 0.99, 1.51). For women, supplemental calcium was inversely associated with mortality from all causes [RR (95% CI): 0.90 (0.87, 0.94), 0.84 (0.80, 0.88), and 0.93 (0.87, 0.99) for intakes of 0.1 to <500, 500 to <1000, and ≥1000 mg/d, respectively; P-trend < 0.01]. Total calcium intake was inversely associated with mortality in women (P-trend < 0.01) but not in men; dietary calcium was not associated with all-cause mortality in either sex.

CONCLUSIONS

In this cohort, associations of calcium intake and mortality varied by sex. For women, total and supplemental calcium intakes are associated with lower mortality, whereas for men, supplemental calcium intake ≥1000 mg/d may be associated with higher all-cause and CVD-specific mortality.

Dairy consumption and CVD: a systematic review and meta-analysis

Inverse associations between dairy consumption and CVD have been reported in several epidemiological studies. Our objective was to conduct a meta-analysis of prospective cohort studies of dairy intake and CVD. A comprehensive literature search was conducted to identify studies that reported risk estimates for total dairy intake, individual dairy products, low/full-fat dairy intake, Ca from dairy sources and CVD, CHD and stroke. Random-effects meta-analyses were used to generate summary relative risk estimates (SRRE) for high v. low intake and stratified intake dose-response analyses. Additional dose-response analyses were performed. Heterogeneity was examined in sub-group and sensitivity analyses. In total, thirty-one unique cohort studies were identified and included in the meta-analysis. Several statistically significant SRRE below 1.0 were observed, namely for total dairy intake and stroke (SRRE=0·91; 95% CI 0·83, 0·99), cheese intake and CHD (SRRE=0·82; 95% CI 0·72, 0·93) and stroke (SRRE=0·87; 95% CI 0·77, 0·99), and Ca from dairy sources and stroke (SRRE=0·69; 95% CI 0·60, 0·81). However, there was little evidence for inverse dose-response relationships between the dairy variables and CHD and stroke after adjusting for within-study covariance. The results of this meta-analysis of prospective cohort studies have shown that dairy consumption may be associated with reduced risks of CVD, although additional data are needed to more comprehensively examine potential dose-response patterns.

The impact of preadmission oral bisphosphonate use on 30-day mortality following stroke: a population-based cohort study of 100,043 patients

Purpose

Bisphosphonate use has been associated with increased risk of fatal stroke. We examined the association between preadmission use of oral bisphosphonates and 30-day mortality following hospitalization for stroke.

Patients and methods

We conducted a nationwide population-based cohort study using medical databases and identified all patients in Denmark with a first-time hospitalization for stroke between 1 July 2004 and 31 December 2012 (N=100,043). Cox regression was used to compute adjusted hazard ratios as a measure of 30-day mortality rate ratios (MRRs) associated with bisphosphonate current use (prescription filled within 90 days prior to the stroke) or recent use (prescription filled in the 90–180 days prior to the stroke). Current use was further classified as new or long-term use.

Results

We found 51,982 patients with acute ischemic stroke (AIS), 11,779 with intracerebral hemorrhage (ICH), 4,528 with subarachnoid hemorrhage (SAH), and 31,754 with unspecified stroke. Absolute 30-day mortality risks were increased among current vs nonusers of bisphosphonates for AIS (11.9% vs 8.5%), ICH (43.2% vs 34.5%), SAH (40.3% vs 23.2%), and unspecified strokes (18.8% vs 14.0%). However, in adjusted analyses, current bisphosphonate use did not increase 30-day mortality from AIS (MRR, 0.87; 95% confidence interval [CI]: 0.75, 1.01); ICH (MRR, 1.05; 95% CI: 0.90, 1.23); SAH (MRR, 1.15; 95% CI: 0.83, 1.61); or unspecified stroke (MRR, 0.94; 95% CI: 0.81, 1.09). Likewise, no association with mortality was found for recent use. Adjusted analyses by type of bisphosphonate showed increased mortality following stroke among new users of etidronate (MRR, 1.40; 95% CI: 1.01, 1.93) and reduced mortality after AIS among current users of alendronate (MRR, 0.87; 95% CI: 0.74, 1.02).

Conclusion

We found no overall evidence that preadmission bisphosphonate use increases 30-day mortality following stroke.

Self-reported calcium use in a cohort of postmenopausal women receiving osteoporosis therapy: results from POSSIBLE US™

Calcium use was common and remained high among women on osteoporosis therapy. Use of calcium-supplemented pharmacologic therapy increased from 65.1 to 76.0% in these women (mean follow-up, 27.5 months). Over 12 months, calcium discontinuation was fairly similar among women using calcium only (23.7%) and women supplementing pharmacologic therapy with calcium (22.5%).

INTRODUCTION

Calcium has an important role in bone health. This study describes calcium use and persistence in a postmenopausal osteoporosis treatment cohort.

METHODS

Subject-reported calcium use was analyzed for 3,722 participants of the Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBLE US(TM)) who used calcium either as their sole osteoporosis treatment (calcium only) or to supplement pharmacologic osteoporosis therapy (supplementers). Descriptive analyses were conducted. Kaplan-Meier methods were used to estimate the probability of discontinuing calcium therapy, and logistic regression was used to assess associations (age-adjusted odds ratios) between healthy behaviors and calcium use.

RESULTS

At entry, there were 711 calcium-only subjects and 1,960 of 3,011 subjects on pharmacologic osteoporosis therapy also supplementing with calcium (supplementers). The percentage of supplementers increased from 65.1 to 76.0% during follow-up (mean, 27.5 months). During the first 12 months on study, the probability of calcium discontinuation was 23.7% (95 % confidence interval [CI], 20.7 - 27.0) among calcium-only subjects and 22.5% (95% CI, 20.7-24.5) among supplementers. Supplementers who discontinued pharmacologic therapy were more likely to discontinue calcium than supplementers who continued pharmacologic therapy (34.9 versus 14.8%). Overall 54.2% of calcium-only subjects who discontinued calcium and 42.3% of supplementers who discontinued calcium resumed calcium use during follow-up. Regular exercise was positively correlated with calcium use at study entry.

CONCLUSIONS

Calcium supplementation in pharmacologically treated subjects increased over time. Persistence with calcium was high. Discontinuation of pharmacologic osteoporosis therapy was associated with an increased likelihood of discontinuing calcium use.

Total, dietary, and supplemental calcium intake and mortality from all-causes, cardiovascular disease, and cancer: A meta-analysis of observational studies

AIMS

This systematic review and meta-analysis of observational studies was conducted to summarize the evidence on the association between calcium intake and mortality.

METHODS AND RESULTS

PubMed, Institute for Scientific Information (ISI) (Web of Science), SCOPUS, SciRUS, Google Scholar, and Excerpta Medica dataBASE (EMBASE) were searched to identify related articles published through May 2014. We found 22 articles that assessed the association between total, dietary, and supplementary intake with mortality from all-causes, cardiovascular disease (CVD), and cancer. Findings from this meta-analysis revealed no significant association between total and dietary calcium intake and mortality from all-causes, CVD, and cancer. Subgroup analysis by the duration of follow-up revealed a significant positive association between total calcium intake and CVD mortality for cohort studies with a mean follow-up duration of >10 years (relative risk (RR): 1.35; 95% confidence interval (CI): 1.09-1.68). A significant inverse association was seen between dietary calcium intake and all-cause (RR: 0.84; 95% CI: 0.70-1.00) and CVD mortality (RR: 0.88; 95% CI: 0.78-0.99) for studies with a mean follow-up duration of ≤10 years. Although supplemental calcium intake was not associated with CVD (RR: 0.95; 95% CI: 0.82-1.10) and cancer mortality (RR: 1.22; 95% CI: 0.81-1.84), it was inversely associated with the risk of all-cause mortality (RR: 0.91; 95% CI: 0.88-0.94).

CONCLUSIONS

We found a significant relationship between the total calcium intake and an increased risk of CVD mortality for studies with a long follow-up time and a significant protective association between dietary calcium intake and all-cause and CVD mortality for studies with a mean follow-up of ≤10 years. Supplemental calcium intake was associated with a decreased risk of all-cause mortality.

Calcium Supplements and Cardiovascular Disease: A Review

Dietary or supplemental calcium intake has long been encouraged for optimal bone health. However, more recently, the safety of calcium supplementation has been questioned because of a possible association between supplemental calcium and cardiovascular risk. Whereas calcium may have a beneficial or neutral effect on cardiovascular risk factors such as blood pressure, cholesterol, weight, and diabetes, available evidence does not provide a definitive answer for an association with cardiovascular disease (CVD). To date, no calcium trials have studied cardiovascular disease as a primary end point, and larger trials with longer follow-up are needed. In this review, we present results from observational studies and randomized controlled trials (RCTs) that have evaluated calcium intake (dietary or supplemental) in relation to cardiovascular risk factors and cardiovascular disease as a secondary outcome. Results from RCTs are mixed regarding CVD risk in those using supplemental calcium with or without vitamin D, and more large-scale randomized trials designed specifically with CVD as the primary end point are needed. Evidence suggests that it is reasonable to encourage adequate dietary calcium intake, especially for postmenopausal women who are at greatest risk for osteoporotic fracture.

An overview on the treatment of postmenopausal osteoporosis

Osteoporosis is a worldwide health problem related to the aging of the population, and it is often underdiagnosed and undertreated. It is related to substantial morbidity, mortality and impairment of the quality of life. Estrogen deficiency is the major contributing factor to bone loss after menopause. The lifetime fracture risk at 50 years of age is about 50% in women. The aim of the treatment of osteoporosis is to prevent fractures. Non-pharmacological treatment involves a healthy diet, prevention of falls, and physical exercise programs. Pharmacological treatment includes calcium, vitamin D, and active medication for bone tissue such, as anti-resorptives (i.e., SERMs, hormonal replacement therapy, bisphosphonates, denosumab), bone formers (teriparatide), and mixed agents (strontium ranelate). Bisphosphonates (alendronate, risedronate, ibandronate, and zoledronate) are the most used anti-resorptive agents for the treatment of osteoporosis. Poor compliance, drug intolerance, and adverse effects can limit the benefits of the treatment. Based on the knowledge on bone cells signaling, novel drugs were developed and are being assessed in clinical trials.