Risk factors of osteoporosis in healthy Moroccan men

The association of coffee consumption with the risk of osteoporosis and fractures: a systematic review and meta-analysis

To elucidate the association of coffee and bone health would help fracture risk reduction via dietary intervention. Although those who had higher coffee consumption were less likely to have osteoporosis, the associations between coffee consumption and fracture risk need further investigations with better study designs.

INTRODUCTION

The associations between coffee consumption and the risk of osteoporosis and fracture remain inconclusive. We aimed to better quantify these associations by conducting meta-analyses of observational studies.

METHODS

Relevant studies were systematically searched on PubMed, Web of Science, Cochrane library, and Embase Database up to November 25, 2021. The odds ratio (OR) or relative risk (RR) with 95% confidence intervals (CI) was pooled and a dose-response analysis was performed.

RESULTS

Four studies with 7114 participants for osteoporosis and thirteen studies with 391,956 participants for fracture incidence were included in the meta-analyses. High versus low coffee consumption was associated with a lower risk of osteoporosis [pooled OR (95% CI): 0.79 (0.65-0.92)], while it was non-significantly associated with fracture incidence [pooled OR (95% CI): 0.86 (0.67-1.05) at hip and 0.89 (0.42-1.36) at non-hip]. A non-linear association between the level of coffee consumption and hip fracture incidence was shown (P = 0.004). The pooled RR (95% CI) of hip fracture risk in those who consumed 1, 2-3, 4, and ≥ 9 cups of coffee per day was 0.92 (0.87-0.97), 0.89 (0.83-0.95), 0.91 (0.85-0.98), and 1.10 (0.76-1.59), respectively. The significance in the association between coffee consumption and the hip fracture incidence decreased in those studies that had larger sample size, higher quality, and more adjustments.

CONCLUSIONS

A dose-dependent relationship may exist between coffee consumption and hip fracture incidence. The effect of high versus low coffee consumption was influenced by study designs. Further studies with dedicated designs are needed to confirm the independent effects of coffee consumption on bone health.

Caffeine Consumption through Coffee: Content in the Beverage, Metabolism, Health Benefits and Risks

Caffeine (1,3,7-trimethylxanthine) is the most consumed psychoactive substance in the world, acting by means of antagonism to adenosine receptors, mainly A1 and A2A. Coffee is the main natural source of the alkaloid which is quite soluble and well extracted during the brew’s preparation. After consumption, caffeine is almost completely absorbed and extensively metabolized in the liver by phase I (cytochrome P450) enzymes, mainly CYP1A2, which appears to be polymorphically distributed in human populations. Paraxanthine is the major caffeine metabolite in plasma, while methylated xanthines and methyluric acids are the main metabolites excreted in urine. In addition to stimulating the central nervous system, caffeine exerts positive effects in the body, often in association with other substances, contributing to prevention of several chronic diseases. The potential adverse effects of caffeine have also been extensively studied in animal species and in humans. These aspects will be approached in the present review.

Physical inactivity, gender and culture in Arab countries: a systematic assessment of the literature

Background

Physical inactivity is associated with excess weight and adverse health outcomes. We synthesize the evidence on physical inactivity and its social determinants in Arab countries, with special attention to gender and cultural context.

Methods

We searched MEDLINE, Popline, and SSCI for articles published between 2000 and 2016, assessing the prevalence of physical inactivity and its social determinants. We also included national survey reports on physical activity, and searched for analyses of the social context of physical activity.

Results

We found 172 articles meeting inclusion criteria. Standardized data are available from surveys by the World Health Organization for almost all countries, but journal articles show great variability in definitions, measurements and methodology. Prevalence of inactivity among adults and children/adolescents is high across countries, and is higher among women. Some determinants of physical inactivity in the region (age, gender, low education) are shared with other regions, but specific aspects of the cultural context of the region seem particularly discouraging of physical activity. We draw on social science studies to gain insights into why this is so.

Conclusions

Physical inactivity among Arab adults and children/adolescents is high. Studies using harmonized approaches, rigorous analytic techniques and a deeper examination of context are needed to design appropriate interventions.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5472-z) contains supplementary material, which is available to authorized users.

Inhibition of parathyroid hormone secretion by caffeine in human parathyroid cells

CONTEXT AND OBJECTIVE

Caffeine is a highly consumed psychoactive substance present in our daily drinks. Independent studies have reported associations between caffeine consumption, low bone mineral density, and urinary calcium loss, as well as impaired bone development in vitro and in vivo. Calcium (Ca(2+)), vitamin D, and PTH are critical regulators of bone remodeling. A possible association between caffeine and parathyroid gland function has been suggested in the literature.

DESIGN, SETTING, AND PATIENTS

Effects of caffeine on PTH secretion and Ca(2+) levels were determined by batch incubation and Fura-2, respectively, in pathological parathyroid cells. Protein expressions were studied by Western blot and immunohistochemistry in normal and parathyroid adenoma tissues. Alterations in gene expressions of adenosine receptor A1 (ADORA1) and A2 (ADORA2A) and PTH were quantified by PCR; intracellular cAMP levels and protein kinase A activity were analyzed by an antibody-based assay.

RESULTS

We studied physiological concentrations of caffeine ranging from 1 to 50 μm and found that 50 μm caffeine caused a significant decrease of PTH secretion and PTH gene expression. This decrease occurred in parallel with a decrease of the intracellular cAMP level, protein kinase A activity, and ADORA1 gene expression, indicating a possible causal relationship. The intracellular level of Ca(2+) was unaffected even by high concentrations of caffeine. Protein expressions demonstrated two main targets for caffeine-ADORA1 and ADORA2A.

CONCLUSION

A physiological high dose of caffeine inhibits PTH secretion in human parathyroid cells, possibly due to a decrease of the intracellular level of cAMP. The observation demonstrates a functional link between caffeine and parathyroid cell function.

Physical activity and dark skin tone: protective factors against low bone mass in Mexican men

A cross-sectional study was conducted on 268 Mexican men between the ages of 13 and 80 yr to evaluate the association of clinical factors related with bone mass. Men from high schools, universities, and retirement homes were invited to participate. Body mass index (BMI) was measured, and bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry for L1-L4 and total hip. Factors related to bone mass were assessed by questionnaire and analyzed using a logistic regression model. Demographic factors (age, education, and occupation), clinical data (BMI, skin tone, previous fracture, history of osteoporosis [OP], and history of fractures), and lifestyle variables (diet, physical activity, sun exposure, and smoking) were evaluated. Physical activity (≥ 60 min/5 times a week) reduced the risk for low BMD for age, osteopenia, and OP at the spine and total hip (odds ratio [OR]: 0.276; 95% confidence interval [CI]: 0.099-0.769; p=0.014; and OR: 0.184; 95% CI: 0.04-0.849; p=0.03, respectively). Dark skin tone was a protective factor, decreasing the risk by up to 70%. In this population of healthy Mexican men (aged 13-80 yr), dark skin and physical activity were protective factors against low bone mass.

Prevalence of osteoporosis among cancer patients in Germany: prospective data from an oncological rehabilitation clinic

In this prospective study, we measured bone mineral density (BMD) in 1,041 cancer patients undergoing an oncological rehabilitation program in an inpatient rehabilitation clinic. There was an osteoporosis prevalence of approximately 16%, independent of sex, which is considerably higher than in the community-dwelling population.

INTRODUCTION

There is evidence that cancer patients are at risk of an increased BMD-loss following the disease and its therapy. Nevertheless, there is only little data available about the prevalence of osteoporosis in German cancer patients. Therefore, we measured BMD in 1,041 oncological inpatients undergoing rehabilitation.

METHODS

From February 2006 to September 2009, BMD was measured in oncological patients with dual-energy x-ray absorptiometry (DXA; femur and spine). Statistical analysis for prevalence of osteoporosis was done in descriptive manner calculating means, standard deviation, frequencies, and 95% confidence intervals. To compare the prevalence of osteoporosis in different subgroups, χ (2) tests were done with p < 0.05. To create a risk profile, odds ratios were calculated using uni- and multivariate logistic regression.

RESULTS

In 1,041 patients with a mean age of 57.1 years (11.0 years), DXA-measures were performed. Of them, 22% were male and 78% were female. The osteoporosis prevalence was about 16% (13.8, 18.2), independent of sex (p = 0.9722) or cancer type (p = 0.7174). As risk factors influencing the development of osteoporosis, age, weight, menopausal state, and hormone replacement therapy were identified in women and weight only in men.

CONCLUSIONS

Compared to the general population, the rate of osteoporosis is distinctly elevated in German cancer patients independent of sex or cancer type. Hence, a general recommendation for a DXA screening in these patients appears to be justified.