Skeletal Effects of Smoking

Approximation of bone mineral density and subcutaneous adiposity using T1-weighted images of the human head

Bones and brain are intricately connected and scientific interest in their interaction is growing. This has become particularly evident in the framework of clinical applications for various medical conditions, such as obesity and osteoporosis. The adverse effects of obesity on brain health have long been recognised, but few brain imaging studies provide sophisticated body composition measures. Here we propose to extract the following bone- and adiposity-related measures from T1-weighted MR images of the head: an approximation of skull bone mineral density (BMD), skull bone thickness, and two approximations of subcutaneous fat (i.e., the intensity and thickness of soft non-brain head tissue). The measures pertaining to skull BMD, skull bone thickness, and intensi-ty-based adiposity proxy proved to be reliable ( r =.93/.83/.74, p <.001) and valid, with high correlations to DXA-de-rived head BMD values (rho=.70, p <.001) and MRI-derived abdominal subcutaneous adipose volume (rho=.62, p <.001). Thickness-based adiposity proxy had only a low retest reliability ( r =.58, p <.001).The outcomes of this study constitute an important step towards extracting relevant non-brain features from available brain scans.

Musculoskeletal crosstalk in chronic obstructive pulmonary disease and comorbidities: Emerging roles and therapeutic potentials

Chronic Obstructive Pulmonary Disease (COPD) is a multifaceted respiratory disorder characterized by progressive airflow limitation and systemic implications. It has become increasingly apparent that COPD exerts its influence far beyond the respiratory system, extending its impact to various organ systems. Among these, the musculoskeletal system emerges as a central player in both the pathogenesis and management of COPD and its associated comorbidities. Muscle dysfunction and osteoporosis are prevalent musculoskeletal disorders in COPD patients, leading to a substantial decline in exercise capacity and overall health. These manifestations are influenced by systemic inflammation, oxidative stress, and hormonal imbalances, all hallmarks of COPD. Recent research has uncovered an intricate interplay between COPD and musculoskeletal comorbidities, suggesting that muscle and bone tissues may cross-communicate through the release of signalling molecules, known as "myokines" and "osteokines". We explored this dynamic relationship, with a particular focus on the role of the immune system in mediating the cross-communication between muscle and bone in COPD. Moreover, we delved into existing and emerging therapeutic strategies for managing musculoskeletal disorders in COPD. It underscores the development of personalized treatment approaches that target both the respiratory and musculoskeletal aspects of COPD, offering the promise of improved well-being and quality of life for individuals grappling with this complex condition. This comprehensive review underscores the significance of recognizing the profound impact of COPD on the musculoskeletal system and its comorbidities. By unravelling the intricate connections between these systems and exploring innovative treatment avenues, we can aspire to enhance the overall care and outcomes for COPD patients, ultimately offering hope for improved health and well-being.

Nutrition-Based Support for Osteoporosis in Postmenopausal Women: A Review of Recent Evidence

Postmenopausal osteoporosis stands as the predominant bone disorder in the developed world, posing a significant public health challenge. Nutritional factors play a crucial role in bone health and may contribute to its prevention or treatment. Calcium and vitamin D, extensively studied with robust scientific evidence, are integral components of the non-pharmacological treatment for this disorder. Nevertheless, other less-explored nutritional elements appear to influence bone metabolism. This review provides a comprehensive summary of the latest evidence concerning the relationship between various nutrients, such as phosphorus, magnesium, vitamins, phytate, and phytoestrogens; specific foods like dairy or soy, and dietary patterns such as the Mediterranean diet with bone health and osteoporosis.

Association of secondhand smoke with fracture risk in community-dwelling nonsmoking adults in Korea

Although the detrimental effects of active smoking on bone health have been widely recognized, the impact of secondhand smoke exposure on fracture risk in non-smokers remains less understood. A total of 4843 nonsmokers aged 40-69 yr, who participated in the Korean Genome and Epidemiology Study from 2001 to 2018, were analyzed. The participants were categorized into two groups based on their exposure status to secondhand smoke: currently exposed and unexposed. The exposure group was subsequently divided into two subgroups based on the median weekly exposure time (high vs low). The incidence of new fractures was determined using self-reported questionnaires. The identified fractures were categorized according to the fracture site: overall, vertebral, hip, non-vertebral, and non-vertebral non-hip fractures. The mean age of the participants was 52.4 yr (84.1% women). Exposure to secondhand smoke was associated with an increased risk of fracture (adjusted hazard ratio [aHR]: 1.27, P = 0.028) after adjusting for multiple covariates including age, sex, BMI, household income, bone density of mid-shaft tibia, C-reactive protein, alcohol consumption, and fracture history. Secondhand smoke remained as a significant risk factor for fracture, independent of the major osteoporotic fracture probabilities estimated using a fracture risk assessment tool (aHR: 1.24, P = 0.038). The high exposure group had higher risk of fracture than that of the unexposed group (aHR: 1.33, P = 0.025), whereas the fracture risk did not differ significantly between low exposure and unexposed groups (aHR: 1.18, P = 0.253), suggesting a potential dose-response relationship. Secondhand smoke showed robust association with increased risk of non-vertebral (aHR: 1.37, P = 0.008) or non-vertebral non-hip fractures (aHR: 1.36, P = 0.013), while its association with vertebral fracture was attenuated (aHR: 1.03, P = 0.908). Secondhand smoke was associated with an elevated risk of fracture in nonsmokers, independent of clinical risk factors.

Association between smoking and incident back pain: A prospective cohort study with 438 510 participants

Background

Although smoking is a known potential contributor to back pain, there is still a lack of quantitative studies on the effects of different doses on back pain (BP) occurrence, including a lack of a longitudinal cohorts. To address this gap, we aimed to investigate the association between various smoking-related exposures and back pain incidence to advance global efforts toward smoking cessation and guide primary prevention of BP.

Methods

In this prospective cohort study, we retrieved data on 438 510 patients from the UK Biobank who were free of back pain and who were recruited in 2006-2010, and followed them up from baseline through 1 April 2022. We extracted data on smoking-related exposures, including smoking status (SS), number of cigarettes smoked daily (CPD), and pack-years of own smoking (PY) and examined back pain incidence as an outcome. We used a Cox proportional hazard model adjusted for several covariates, multiple imputation methods, and population attribution fraction.

Results

During the median follow-up of 12.98 years, 31 467 participants developed BP, with incidence rates in former and current smokers of 1.13 (95% confidence interval (CI) = 1.10-1.16, P < 0.000) and 1.50 (95% CI = 1.45-1.56, P < 0.000), respectively. The hazard ratios (HRs) of participants who smoked more than 30 CPD and those with more than 30 PY were 1.45 (95% CI = 1.36-1.55, P < 0.000) and 1.45 (95% CI = 1.40-1.50, P < 0.000), respectively. Relative to male, female smokers were at more risk of developing BP. Not smoking, quitting smoking, and reducing CPD and PY could lower the BP risk by 7.8%, 5.4%, 9.8%, and 18.0%, respectively.

Conclusions

Ever smoking, higher cigarette consumption daily, and increased smoking intensity were associated with an increased BP risk. This association was stronger in female smokers. Not smoking, smoking cessation, and reducing smoking volume and intensity were effective measures to prevent BP occurrence.

Health-Related Behavior and Psychosocial Characteristics of Adolescent Female Smokers in Korea, Compared with Adolescent Male Smokers

This study aimed to investigate the relationship between health-related behavior and psychosocial characteristics among adolescent female smokers in South Korea using data from the 17th Korea Youth Risk Behavior Web-based Survey (KYRBWS) conducted in 2021. The analysis participants comprised 2407 adolescent smokers who were currently smoking, out of a sample of 54,835 participants. The characteristics of adolescent female smokers were examined by comparing them with those of adolescent male smokers. The results showed that male and female adolescent smokers accounted for 69.2% and 30.8% of the sample, respectively. Multiple logistic regression analysis identified school type, subjective socioeconomic status, physical activity, breakfast consumption, alcohol consumption, sexual experience, stress, generalized anxiety, and suicidal ideation as significant factors associated with adolescent female smokers. These findings provide important foundational data for the development of smoking-cessation programs and policies tailored specifically to adolescent female smokers.

Transgenerational effects of maternal exposure to nicotine on structures of pituitary-gonadal axis of rats

Smoking can lead to several diseases and cause a reduction in fertility in men and women. Among the various components of cigarettes harmful during pregnancy, nicotine stands out. It can cause a reduction in placental blood flow, compromising the development of the baby with neurological, reproductive and endocrine consequences. Thus, we aimed to evaluate the effects of nicotine on the pituitary-gonadal axis of rats exposed during pregnancy and breastfeeding (1st generation - F1), and whether the possible damage observed would reach the 2nd generation (F2). Pregnant Wistar rats received 2 mg/kg/day of nicotine throughout the entire gestation and lactation. Part of the offspring was evaluated on the first neonatal day (F1) for macroscopic, histopathological and immunohistochemical analyses of brain and gonads. Another part of the offspring was kept until 90 days-old for mating and obtainment of progenies that had the same parameters evaluated at the end of pregnancy (F2). The occurrence of malformations was more frequent and diversified in nicotine-exposed F2. Brain alterations, including reduced size and changes in cell proliferation and death, were seen in both generations of nicotine-exposed rats. Male and female gonads of F1 exposed rats were also affected. The F2 rats showed reduced cellular proliferation and increased cell death on the pituitary and ovaries, besides increased anogenital distance in females. The number of mast cells was not enough altered to indicate an inflammatory process in brain and gonads. We conclude that prenatal exposure to nicotine causes transgenerational alterations in the structures of pituitary-gonadal axis in rats.

Associations between smoke exposure and osteoporosis or osteopenia in a US NHANES population of elderly individuals

BACKGROUND

Tobacco exposure is considered to be a risk factor for reduced bone mineral density (BMD), which may result in osteopenia. Cotinine, a metabolite of nicotine, is commonly utilized as a marker of tobacco exposure. Nevertheless, there are limited clinical data on the associations between osteoporosis (OP) or osteopenia and smoking status or serum cotinine level.

METHODS

We thoroughly examined the NHANES cross-sectional data from 2005 to 2010, 2013 to 2014, and 2017 to 2018. Multivariate logistic regression models were applied to assess the associations among smoking status and serum cotinine levels as well as OP and osteopenia. The relationships between serum cotinine level and OP and osteopenia were also assessed using the restricted cubic spline (RCS) method.

RESULTS

A total of 10,564 participants were included in this cross-sectional study. The mean age of the study population was 64.85 ± 9.54 years, and the patients were predominantly male (51.9%). We found that the relationships between higher serum cotinine levels (≥3 ng/ml) and the prevalence of osteoporosis (Model 1: OR=2.27 [1.91-2.69]; Model 2: OR=2.03 [1.70-2.43]; Model 3: OR=2.04 [1.70-2.45]; all p for trend <0.001) remained significant after adjustment for covariates by applying the lowest serum cotinine levels (<0.05 ng/ml) as the reference. Similar results were observed for current smokers, who were more likely to develop OP compared with nonsmokers (Model 1: OR=2.30 [1.90-2.79]; Model 2: OR=2.16 [1.77-2.64]; Model 3: OR=2.16 [1.77-2.65]). Moreover, higher serum cotinine levels were found to be strongly and positively correlated with the prevalence of osteopenia (OR=1.60 [1.42-1.80]). A similar relationship was observed between current smokers and the prevalence of osteopenia compared with nonsmokers (OR=1.70 [1.49-1.94]). RCS regression also showed that serum cotinine levels were nonlinearly and positively correlated with OP and osteopenia, with inflection points of 5.82 ng/ml and 3.26 ng/ml, respectively.

CONCLUSION

This study showed that being a smoker was associated with the prevalence of OP or osteopenia compared with being a nonsmoker and that there was a strong nonlinear positive dose-response relationship between serum cotinine levels and OP and osteopenia.

Osteoporosis and Alveolar Bone Health in Periodontitis Niche: A Predisposing Factors-Centered Review

Periodontitis is a periodontal inflammatory condition that results from disrupted periodontal host-microbe homeostasis, manifested by the destruction of tooth-supporting structures, especially inflammatory alveolar bone loss. Osteoporosis is characterized by systemic deterioration of bone mass and microarchitecture. The roles of many systemic factors have been identified in the pathogenesis of osteoporosis, including endocrine change, metabolic disorders, health-impaired behaviors and mental stress. The prevalence rate of osteoporotic fracture is in sustained elevation in the past decades. Recent studies suggest that individuals with concomitant osteoporosis are more vulnerable to periodontal impairment. Current reviews of worse periodontal status in the context of osteoporosis are limited, mainly centering on the impacts of menopausal and diabetic osteoporosis on periodontitis. Herein, this review article makes an effort to provide a comprehensive view of the relationship between osteoporosis and periodontitis, with a focus on clarifying how those risk factors in osteoporotic populations modify the alveolar bone homeostasis in the periodontitis niche.

Genetic Risk for Osteoporosis and the Benefit of Adherence to Healthy Lifestyles

Objectives: We aimed to explore how healthy lifestyles and genetic factors influence the risk of Osteoporosis (OP). Methods: In this prospective cohort study, we first performed a genome-wide association study (GWAS) of estimated bone mineral density (eBMD) and constructed the genetic risk score (GRS) based on the effect of single nucleotide polymorphism (SNP) on eBMD. We then assessed the effect of three-level GRS and adherence to healthy lifestyles on the risk of OP and fracture, respectively. Finally, we assessed the joint effects of GRS and lifestyle on the OP and fracture risk. Results: People with higher GRS have a lower risk of OP and fracture. Negative associations were detected between healthy lifestyle factors and the risk of OP and fracture. Compare with the group with high GRS and favorable lifestyles, the group with low GRS and unfavorable lifestyles had a high Hazard Ratio (HR). Conclusion: The findings suggest that adherence to healthy lifestyles can reduce the risk of OP and fracture in people with different genetic risks.

Modifiable risk factors for bone health & fragility fractures

Osteoporosis is an ageing disorder characterised by poor microstructural architecture of the bone and an increase in the risk of fragility fractures, which often leads to hospitalisation and eventually a loss of mobility and independence. By 2050, it is estimated that more than 30 million people in Europe will be affected by bone diseases, and European hospitalisation alone can approximately cost up to 3.5 billion euros each year [1]. Although inherited variation in bone mineral density (BMD) is pre-determined by up to 85% [2], there is a window of opportunity to optimise BMD and reduce fracture risk through key modifiable lifestyle factors during the life course. An optimal diet rich in micronutrients, such as calcium, vitamin D, and potassium, has long been considered an important modifiable component of bone health, which is attributed to their direct roles within bone metabolism. Recently, there has been emerging evidence to suggest that protein and even an adequate intake of fruit and vegetables may also play an important role in improving BMD [3,4]. Maintaining a physically active lifestyle is not only protective from non-communicable diseases such as cardiovascular disease but it also has been shown to lessen the risk of fractures later in life, thereby making it an imperative modifiable factor for bone health, particularly as it also supports peak bone mass attainment during childhood/adolescence and can facilitate the maintenance of bone mass throughout adulthood [5]. Other key lifestyle factors that could be potentially modified to reduce the risk of osteoporosis or osteoporotic fractures later in life include smoking status, alcohol intake, and body composition [6]. Therefore, the principle aim of this review is to highlight the recent evidence pertaining to modifiable lifestyle factors that contribute to optimal bone health and the prevention of fragility fractures in later life.

Functional capacity, sarcopenia, and bone health

Bone and muscle are recognised as interacting tissues, the so-called 'muscle-bone unit', in which these two tissues communicate to coordinate their development (chemically and metabolically), as well as their response to loading or injury. Musculoskeletal disorders of ageing, specifically osteoporosis and sarcopenia, are highly prevalent in older individuals. They signify a significant burden for older people affecting their mobility, confidence, and quality of life, as well as being a major cost to healthcare systems worldwide. This review considers the coexistence of osteoporosis and sarcopenia in individuals and describes risk factors, clinical consequences, approaches to management, and the link with functional capacity.

Smoking and fracture risk in men: a meta-analysis of cohort studies, using both frequentist and Bayesian approaches

Past studies indicate that men are more likely to smoke and be at higher risk of smoking-related conditions than women. Our research aimed, through meta-analysis, to assess the association between smoking and fracture risk in men. The following databases were searched, including MEDLINE, EMBASE, Scopus, PsycINFO, ISI Web of Science, Google Scholar, WorldCat, and Open Grey, for identifying related studies. A random-effects model was used to pool the confounder-adjusted relative risk (R.R.). Frequentist and Bayesian hierarchical random-effects models were used for the analysis. The heterogeneity and publication bias were evaluated in this study. Twenty-seven studies met the inclusion criteria. Overall, smoking is associated with a significantly increased risk of fracture in both the frequentist approach (R.R., 1.37; 95% confidence interval: 1.22, 1.53) and the Bayesian approach (R.R., 1.36; 95% credible interval: 1.22, 1.54). Significant heterogeneity was observed in the meta-analysis (Higgin's I² = 83%) and Cochran's Q statistic (p < 0.01). A significant association was also observed in multiple pre-specified sensitivity and subgroup analyses. Similar results were observed in the group containing a large sample size (≥ 10,000 participants), and the group has a small sample size (< 10,000 participants); the pooled R.R was 1.23 (95% confidence interval, 1.07–1.41) and 1.56 (95% confidence interval, 1.37–1.78), respectively. With the Bayesian method, the effect size was 1.23 (95% credible interval, 1.05, 1.45) for the large sample size group and 1.57 (95% credible interval, 1.35, 1.82) for the small sample size group. Smoking is associated with a significant increase in fracture risk for men. Thus, smoking cessation would also greatly reduce fracture risk in all smokers, particularly in men.

Patient preferences for lifestyle behaviours in osteoporotic fracture prevention: a cross-European discrete choice experiment

Using a discrete choice experiment, we aimed to assess patients' preferences with regard to adopting lifestyle behaviours to prevent osteoporotic fractures. Overall, the 1042 patients recruited from seven European countries were favourable to some lifestyle behaviours (i.e., engaging in moderate physical activity, taking calcium and vitamin D supplements, reducing their alcohol consumption and ensuring a normal body weight).

INTRODUCTION

Alongside medical therapy, healthy lifestyle habits are recommended for preventing osteoporotic fractures. In this study, we aimed to assess patients' preferences with regard to adopting lifestyle changes to prevent osteoporotic fractures.

METHODS

A discrete choice experiment was conducted in seven European countries. Patients with or at risk of osteoporosis were asked to indicate to what extent they would be motivated to adhere to 16 lifestyle packages that differed in various levels of 6 attributes. The attributes and levels proposed were physical activity (levels: not included, moderate or high), calcium and vitamin D status (levels: not included, taking supplements, improving nutrition and assuring a minimal exposure to sunlight daily), smoking (levels: not included, quit smoking), alcohol (levels: not included, moderate consumption), weight reduction (levels: not included, ensure a healthy body weight) and fall prevention (levels: not included, receiving general advice or following a 1-day fall prevention program). A conditional logit model was used to estimate a patient's relative preferences for the various attributes across all participants and per country.

RESULTS

In total, 1042 patients completed the questionnaire. Overall, patients were favourable to lifestyle behaviours for preventing osteoporotic fractures. However, among the lifestyle behaviours proposed, patients were consensually not prone to engage in a high level of physical activity. In addition, in Ireland, Belgium, the Netherlands and Switzerland, patients were also not inclined to participate in a 1-day fall prevention program and Belgian, Swiss and Dutch patients were not prone to adhere to a well-balanced nutritional program. Nevertheless, we observed globally that patients felt positively about reducing their alcohol consumption, engaging in moderate physical activity, taking calcium and vitamin D supplements and ensuring a normal body weight, all measures aimed at preventing fractures.

CONCLUSIONS

In a patient-centred approach, fracture prevention should take these considerations and preferences into account.

An Overlooked Bone Metabolic Disorder: Cigarette Smoking-Induced Osteoporosis

Cigarette smoking (CS) leads to significant bone loss, which is recognized as an independent risk factor for osteoporosis. The number of smokers is continuously increasing due to the addictive nature of smoking. Therefore it is of great value to effectively prevent CS-induced osteoporosis. However, there are currently no effective interventions to specifically counteract CS-induced osteoporosis, owing to the fact that the specific mechanisms by which CS affects bone metabolism are still elusive. This review summarizes the latest research findings of important pathways between CS exposure and bone metabolism, with the aim of providing new targets and ideas for the prevention of CS-induced osteoporosis, as well as providing theoretical directions for further research in the future.

Management of osteoporosis in postmenopausal women: the 2021 position statement of The North American Menopause Society

OBJECTIVE

To review evidence regarding osteoporosis screening, prevention, diagnosis, and management in the past decade and update the position statement published by The North American Menopause Society (NAMS) in 2010 regarding the management of osteoporosis in postmenopausal women as new therapies and paradigms have become available.

DESIGN

NAMS enlisted a panel of clinician experts in the field of metabolic bone diseases and/or women's health to review and update the 2010 NAMS position statement and recommendations on the basis of new evidence and clinical judgement. The panel's recommendations were reviewed and approved by the NAMS Board of Trustees.

RESULTS

Osteoporosis, especially prevalent in older postmenopausal women, increases the risk of fractures that can be associated with significant morbidity and mortality. Postmenopausal bone loss, related to estrogen deficiency, is the primary contributor to osteoporosis. Other important risk factors for postmenopausal osteoporosis include advanced age, genetics, smoking, thinness, and many diseases and drugs that impair bone health. An evaluation of these risk factors to identify candidates for osteoporosis screening and recommending nonpharmacologic measures such as good nutrition (especially adequate intake of protein, calcium, and vitamin D), regular physical activity, and avoiding smoking and excessive alcohol consumption are appropriate for all postmenopausal women. For women at high risk for osteoporosis, especially perimenopausal women with low bone density and other risk factors, estrogen or other therapies are available to prevent bone loss. For women with osteoporosis and/or other risk factors for fracture, including advanced age and previous fractures, the primary goal of therapy is to prevent new fractures. This is accomplished by combining nonpharmacologic measures, drugs to increase bone density and to improve bone strength, and strategies to reduce fall risk. If pharmacologic therapy is indicated, government-approved options include estrogen agonists/antagonists, bisphosphonates, RANK ligand inhibitors, parathyroid hormone-receptor agonists, and inhibitors of sclerostin.

CONCLUSIONS

Osteoporosis is a common disorder in postmenopausal women. Management of skeletal health in postmenopausal women involves assessing risk factors for fracture, reducing modifiable risk factors through dietary and lifestyle changes, and the use of pharmacologic therapy for patients at significant risk of osteoporosis or fracture. For women with osteoporosis, lifelong management is necessary. Treatment decisions occur continuously over the lifespan of a postmenopausal woman. Decisions must be individualized and should include the patient in the process of shared decision-making.

Modifiable lifestyle factors associated with fragility hip fracture: a systematic review and meta-analysis

INTRODUCTION

Among the various hip fracture predictors explored to date, modifiable risk factors warrant special consideration, since they present promising targets for preventative measures. This systematic review and meta-analysis aims to assess various modifiable risk factors.

MATERIAL AND METHODS

We searched four online databases in September 2017. We included studies that reported on modifiable lifestyle risk factors for sustaining fragility hip fractures. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS). The inclusion criteria consisted of (1) adult patients with osteoporotic hip fracture, (2) original study, (3) availability of full text articles in English, and (4) report of a modifiable lifestyle risk factor.

RESULTS

Thirty-five studies, containing 1,508,366 subjects in total, were included in this study. The modifiable risk factors that were significantly associated with an increased risk of hip fracture were the following: weight < 58 kg (128 lbs) (pooled OR 4.01, 95% CI 1.62-9.90), underweight body mass index (BMI) (< 18.5) (pooled OR 2.83, 95% CI 1.82-4.39), consumption of ≥ 3 cups of coffee daily (pooled OR 2.27, 95% CI 1.04-4.97), inactivity (pooled OR 2.14, 95% CI 1.21-3.77), weight loss (pooled OR 1.88, 95% CI 1.32-2.68), consumption of ≥ 27 g (approx. > 2 standard drinks) alcohol per day (pooled OR 1.54, 95% CI 1.12-2.13), and being a current smoker (pooled OR 1.50, 95% CI 1.22-1.85). Conversely, two factors were significantly associated with a decreased risk of hip fracture: obese BMI (> 30) (pooled OR 0.58, 95% CI 0.34-0.99) and habitual tea drinking (pooled OR 0.72, 95% CI 0.66-0.80).

CONCLUSION

Modifiable factors may be utilized clinically to provide more effective lifestyle interventions for at risk populations. We found that low weight and underweight BMI carried the highest risk, followed by high coffee consumption, inactivity, weight loss, and high daily alcohol consumption.

Smoking Is Associated with Sex-Specific Effects on Bone Microstructure in Older Men and Women

BACKGROUND

Smoking is a risk factor for fracture, but the mechanism by which smoking increases fracture risk is unclear.

METHODS

Musculoskeletal health was compared with dual energy X-ray absorptiometry (DXA), high resolution peripheral quantitative computed tomography (HR-pQCT), trabecular bone score, and vertebral fracture assessment in current and past smokers and nonsmokers from a multiethnic study of adults ≥ age 65. Skeletal indices were adjusted for age and weight.

RESULTS

Participants (n = 311) were mean age (±SD) 76.1 ± 6.5 years, mostly female (66.0%) and non-white (32.7% black/39.4% mixed race/26.3% white). Mean pack-years was 34.6 ± 20.4. In men (n = 106), weight and BMI were lower (both p < 0.05) in current vs past smokers. Male smokers consumed half the calcium of never and past smokers. BMD by DXA did not differ by smoking status at any skeletal site in either sex. Current male smokers had 13.5%-15.3% lower trabecular bone score vs never and past smokers (both p < 0.05). By HR-pQCT, trabecular volumetric BMD was 26.6%-30.3% lower and trabeculae were fewer, thinner and more widely spaced in male current vs past and never smokers at the radius (all p < 0.05). Cortical indices did not differ. Tibial results were similar, but stiffness was also 17.5%-22.2% lower in male current vs past and never smokers (both p< 0.05). In women, HR-pQCT trabecular indices did not differ, but cortical porosity was almost twice as high in current vs never smokers at the radius and 50% higher at the tibia (both p < 0.05).

CONCLUSIONS

In summary, current smoking is associated with trabecular deterioration at the spine and peripheral skeleton in men, while women have cortical deficits. Smoking may have sex-specific skeletal effects. The consistent association with current, but not past smoking, suggests the effects of tobacco use may be reversible with smoking cessation.

Skeletal System Biology and Smoke Damage: From Basic Science to Medical Clinic

Cigarette smoking has a negative impact on the skeletal system, as it reduces bone mass and increases fracture risk through its direct or indirect effects on bone remodeling. Recent evidence demonstrates that smoking causes an imbalance in bone turnover, making bone vulnerable to osteoporosis and fragility fractures. Moreover, cigarette smoking is known to have deleterious effects on fracture healing, as a positive correlation between the daily number of cigarettes smoked and years of exposure has been shown, even though the underlying mechanisms are not fully understood. It is also well known that smoking causes several medical/surgical complications responsible for longer hospital stays and a consequent increase in the consumption of resources. Smoking cessation is, therefore, highly advisable to prevent the onset of bone metabolic disease. However, even with cessation, some of the consequences appear to continue for decades afterwards. Based on this evidence, the aim of our review was to evaluate the impact of smoking on the skeletal system, especially on bone fractures, and to identify the pathophysiological mechanisms responsible for the impairment of fracture healing. Since smoking is a major public health concern, understanding the association between cigarette smoking and the occurrence of bone disease is necessary in order to identify potential new targets for intervention.

Effects of sex, tobacco smoking, and alcohol consumption osteoporosis development: Evidence from Taiwan biobank participants

INTRODUCTION

Osteoporosis is major public health concern, but the long-term impacts of tobacco and alcohol consumption on its development are unclear. This study analyzed the relationship between tobacco and alcohol use and osteoporosis by using data from the Taiwan Biobank (TWB), established in 2012.

METHODS

Participants in TWB were included in our study, with a total of 18394 respondents included for analysis. To investigate the relationship between tobacco and alcohol use and osteoporosis, we surveyed their bone mineral density (BMD), consumption of tobacco and alcohol and other covariate data.

RESULTS

We found that participants in the tobacco smoking only group (OR=1.24; 95% CI: 1.08–1.42, p=0.003) and the group that both smoked and consumed alcohol (OR=1.39; 95% CI: 1.09–1.77, p=0.008) were more likely to develop osteoporosis than were participants who neither drank alcohol nor smoked. Menopause is strongly associated with osteoporosis in women, and we found that women who used alcohol or tobacco were not at a significantly higher risk than those in the reference group (tobacco only, OR=1.15; 95% CI: 0.86–1.53, p=0.345; both tobacco and alcohol, OR=0.61; 95% CI: 0.14–2.60, p=0.5040). However, men in these groups were at a significantly higher risk than the reference group (tobacco only, OR=1.26; 95% CI: 1.07–1.48, p=0.006; both tobacco and alcohol, OR=1.32; 95% CI: 1.03–1.70, p=0.030). Menopause was a significant risk factor for osteoporosis (OR=2.46; 95% CI: 1.77–3.41, p<0.001).

CONCLUSIONS

The influence of tobacco use on osteoporosis was significant, particularly in men, but the effects of alcohol consumption were equivocal in our study. The interactions between tobacco use, alcohol use, and menopausal status on osteoporosis should be considered in future studies.

Advances in the occurrence and biotherapy of osteoporosis

Osteoporosis (OP) is a bone metabolic disease, is characterized by degeneration of bone structure and decreased bone mass. It happens in more than 1/3 women and 1/5 men of over than 50 years old, which affects the health and lives of people. The main mechanism of OP is mainly that the dynamic balance between the bone formation and resorption is broken, so that bone resorption is more than bone formation. It is prone to result in bone metabolism disorder. There are many precipitating factor such as elder age, low hormone level, genetic factors and bad hobbies. At the same time, the occurrence of the OP and its complications has different degrees of impact on people's quality of life. Based on the current understanding of the OP, we summarized the etiology, current clinical drugs and potential targeting therapy for OP. Although the research have made many progress in explore what is the novel mechanism and how to improve the effect, there are still many problems in the treatment method that limit its application prospects and need to be solved. In this review, we mainly focus on the mechanism of OP and related research on the targeted treatment of OP. Hopefully, our summary will provide a reference to develop some novel strategies for the target therapy of OP.

Chronic Nicotine Exposure Minimally Affects Rat Supraspinatus Tendon Properties and Bone Microstructure

Cigarette smoking is the largest cause of preventable deaths, and a known risk factor for musculoskeletal issues including rotator cuff tendon tears. Tendon degeneration is believed to be due in part to changes in tendon cell health and collagen structure. Several studies have demonstrated that exposure to nicotine negatively impacts tendon healing, but surprisingly, nicotine exposure was shown to increase rat supraspinatus tendon stiffness. In order to address this seeming contradiction, the objective of this study was to comprehensively investigate the effects of long-term (18 weeks) exposure of nicotine on tendon-to-bone microstructural properties in a rat model. We hypothesized that long term subcutaneous nicotine delivery would lead to diminished tendon mechanical properties, decreased bone microstructure in the humeral head, and altered tendon cell morphology compared to age-matched control rats receiving saline. Results demonstrated a small decrease in tendon size and stiffness, with decreased cell density in the tendon midsubstance. However, no differences were found in the enthesis fibrocartilage or in the underlying subchondral or trabecular bone. In conclusion, our study revealed limited effects of nicotine on the homeostatic condition of the supraspinatus tendon, enthesis, and underlying bone. Future studies are needed to ascertain effects of other components of tobacco products.

Impact of Cigarette Smoking on the Risk of Osteoporosis in Inflammatory Bowel Diseases

Cigarette smoking constitutes one of the most important modifiable factors of osteoporosis, as well as contributes to an early death, tumors, and numerous chronic diseases. The group with an increased risk of a lower bone mineral density are patients suffering from inflammatory bowel diseases. In fact, tobacco smoke, which contains more than 7000 chemical compounds, affects bone mineral density (BMD) both directly and indirectly, as it has an impact on the RANK-RANKL-OPG pathway, intestinal microbiota composition, and calcium-phosphate balance. Constant cigarette use interferes with the production of protective mucus and inhibits the repair processes in the intestinal mucus. Nicotine as well as the other compounds of the cigarette smoke are important risk factors of the inflammatory bowel disease and osteoporosis. Additionally, cigarette smoking may decrease BMD in the IBD patients. Interestingly, it affects patients with Crohn's disease and ulcerative colitis in different ways-on the one hand it protects against ulcerative colitis, whereas on the other it increases the risk of Crohn's disease development. Nevertheless, all patients should be encouraged to cease smoking in order to decrease the risk of developing other disorders.

Antidiabetic Treatment, Level of Glycemic Control, and Risk of Fracture in Type 2 Diabetes: a Nested, Case-Control Study

CONTEXT

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of low-trauma fractures. However, the effect of antidiabetic medication in relation to glycemic control on the risk of fracture is poorly understood.

OBJECTIVE

This work aimed to evaluate the association between the level of glycemic control, use of antidiabetic medication, and risk of low-trauma fractures in patients with newly diagnosed T2DM.

METHODS

We conducted a nested case-control analysis among individuals registered in the Clinical Practice Research Datalink. The base population consisted of patients with newly diagnosed T2DM from 1995 to 2017. Cases were patients with a low-trauma fracture after T2DM diagnosis. We matched 4 controls to each case. Exposures of interest were glycemic control (last glycated hemoglobin [HbA1c] level before fracture) and type of diabetes treatment. We conducted conditional logistic regression analyses adjusted for several confounders.

RESULTS

We identified 8809 cases and 35 219 controls. Patients with current metformin use and HbA1c levels of less than 7.0% and between 7.0-8.0% had a reduced risk of fractures (adjusted odds ratio 0.89; 95% CI, 0.83-0.96 and 0.81; 95% CI, 0.73-0.90, respectively) compared with untreated patients. However, in patients receiving metformin plus 1 or 2 other antidiabetic drugs, or insulin (alone or in addition to other antidiabetic medication), the level of glycemic control was not associated with the risk of fracture compared with untreated patients.

CONCLUSIONS

While patients with good or medium glycemic control receiving current metformin monotherapy had a lower risk of fracture compared with untreated patients, glycemic control in patients receiving treatment other than metformin was not associated with risk of fracture.

Idiopathic Osteoporosis and Nephrolithiasis: Two Sides of the Same Coin?

Idiopathic osteoporosis and nephrolithiasis are formidable health problems showing a progressive increase in their incidence and prevalence in the last decades. These temporal trends were observed in both pediatric and adult populations worldwide. Epidemiological and experimental studies indicate that both disorders show several common pathogenic environmental and genetic factors. In this review, we analyzed the clinical characteristics common to the two disorders and the state-of-the-art knowledge regarding the genetic predisposition and the environmental factors recognized as triggers in adult and pediatric ages. As a result of this work, we propose to consider idiopathic nephrolithiasis and osteoporosis as two possible expressions of a unique clinical syndrome. Accordingly, the clinical approach to both disorders should be modified in order to program an efficient primary and secondary prevention strategy.

History of tobacco, vitamin D and women

Tobacco usage kills more than 8 million people a year. Approximately 7 million of those deaths are the result of direct tobacco use, while approximately 1.2 million are the result of non-smokers being exposed to second-hand smoke. About 200 million of the world's one billion smokers are women and usage among women is increasing in some countries. Nicotine from smoking tobacco, specifically its metabolite cotinine, has negative effects on human health causing lung cancer, COPD and non-respiratory problems. Over a billion people worldwide are Vitamin D deficient or insufficient, which is prevalent across all age-groups, geographic regions, and sunlight. With the discovery of Vitamin D in 1919, a new chapter in the prevention of rickets was introduced opening the door to its therapeutic properties for other diseases. Since 1919, there have been many clinical and epidemiolocal studies performed globally on the effect of the vitamin on prevention of other diseases, including but not limited to, cancer, autoimmune disorders, cardiovascular diseases, and osteoporosis. Exposure to environmental tobacco smoke has been associated with reduced levels of Vitamin D in the blood stream and sinus tissues. Manavi et al. (2015) demonstrated that among three smoking categories (heavy, light, non-smokers), black female heavy smokers have lower vitamin D (13.374 ng/ml), than Hispanic (19.213 ng/ml) or white (24.929 ng/ml) females correlating to higher levels of cotinine. Therefore, blood serum concentrations of cotinine contribute to decreased Vitamin D concentrations in addition to other factors such as gender and ethnicity. Further information is provided in the text.

Smoking Increases Postoperative Complications After Distal Radius Fracture Fixation: A Review of 417 Patients From a Level 1 Trauma Center

Background: Unstable distal radius fractures that undergo surgical stabilization have varying complication rates in the literature. Smoking is known to affect bone healing and implant fixation rates but has never been definitively shown to affect postoperative outcomes of surgically managed distal radius fractures. Methods: A retrospective review was performed of patients with surgically treated distal radius fractures at a Level 1 Trauma Center who had at least 6 weeks of follow-up over a 5-year period. Charts were reviewed for basic demographic information, comorbidities, details about the operative procedure, and early complications. Notable physical examination findings were noted, such as wrist stiffness and distal radius tenderness to palpation. Statistical analysis was performed to compare the smoking and nonsmoking groups. To control for confounding differences, a hierarchical multivariable regression analysis was performed. Results: Four hundred seventeen patients were included in the study, and 24.6% were current smokers at the time of surgery. The overall complication rate for smokers was 9.8% compared with 5.6% in nonsmokers. The smoking cohort showed significantly higher rates of hardware removal, nonunion, revision procedures, wrist stiffness, and distal radius tenderness. When controlling for the confounding variables of diabetes and obesity, smokers still had significantly higher rates of the same complications. Conclusion: Patients who smoke have a statistically significant higher rate of postoperative distal radius tenderness, wrist stiffness, nonunion, hardware removal, and revision procedures compared with those who do not smoke in a review of 417 total patients undergoing surgical fixation for distal radius fractures.

Assessment of tobacco heating system 2.4 on osteogenic differentiation of mesenchymal stem cells and primary human osteoblasts compared to conventional cigarettes

BACKGROUND

Cigarette smoking (CS) is the most common method of consuming tobacco. Deleterious effects on bone integrity, increased incidence of fractures, and delayed fracture healing are all associated with CS. Over 150 of the 6500 molecular species contained in cigarette smoke and identified as toxic compounds are inhaled by CS and, via the bloodstream, reach the skeletal system. New technologies designed to develop a reduced-risk alternative for smokers are based on electronic nicotine delivery systems, such as e-cigarettes and tobacco heating systems (THS). THS are designed to heat tobacco instead of burning it, thereby reducing the levels of harmful toxic compounds released.

AIM

To examine the effects of THS on osteoprogenitor cell viability and function compared to conventional CS.

METHODS

Human immortalized mesenchymal stem cells (n = 3) and primary human pre-osteoblasts isolated from cancellous bone samples from BG Unfall Klinik Tübingen (n = 5) were osteogenically differentiated in vitro with aqueous extracts generated from either the THS 2.4 “IQOS” or conventional “Marlboro” cigarettes for up to 21 d. Cell viability was analyzed using resazurin conversion assay (mitochondrial activity) and calcein-AM staining (esterase activity). Osteogenic differentiation and bone cell function were evaluated using alkaline phosphatase (AP) activity, while matrix formation was analyzed through alizarin red staining. Primary cilia structure was examined by acetylated α-tubulin immunofluorescent staining. Free radical production was evaluated with 2’,7’-dichlorofluorescein-diacetate assay.

RESULTS

Our data clearly show that THS is significantly less toxic to bone cells than CS when analyzed by mitochondrial and esterase activity (P < 0.001). No significant differences in cytotoxicity between the diverse flavors of THS were observed. Harmful effects from THS on bone cell function were observed only at very high, non-physiological concentrations. In contrast, extracts from conventional cigarettes significantly reduced the AP activity (by two-fold) and matrix mineralization (four-fold) at low concentrations. Additionally, morphologic analysis of primary cilia revealed no significant changes in the length of the organelle involved in osteogenesis of osteoprogenitor cells, nor in the number of ciliated cells following THS treatment. Assessment of free radical production demonstrated that THS induced significantly less oxidative stress than conventional CS in osteoprogenitor cells.

CONCLUSION

THS was significantly less harmful to osteoprogenitor cells during osteogenesis than conventional CS. Additional studies are required to confirm whether THS is a better alternative for smokers to improve delays in bone healing following fracture.

Effects of smoking habit change on hospitalized fractures: a retrospective cohort study in a male population

We examined effects of smoking habit change on fracture risk in men. Long-term quitters and never smokers showed decreased risk for overall fractures, lumbar fractures, and other site fractures. Short-term quitters did not show decreased risk. Longer time since smoking cessation may lead to decreased fracture risk in men.

PURPOSE

Cigarette smoking is a well-known modifiable risk factor of osteoporosis and fractures. This study investigated the effects of change in smoking habits on risks of all types of fractures in men using a nationwide health claims database.

METHODS

Retrospective study was performed using the Korean National Health Insurance Service-National Sample Cohort Data. Cox proportional hazards regression analyses were performed to estimate risks of all types of hospitalized fractures, hip fractures, lumbar fractures, and other site fractures (all other fractures excluding the lumbar and hip areas).

RESULTS

Compared to continued smokers, long-term quitters and never smokers showed decreased risk for all types of fractures (adjusted hazard ratio (aHR) 0.83, 95% confidence interval (CI) 0.78-0.88 and aHR 0.84, 95% CI 0.80-0.89, respectively). According to skeletal site, long-term quitters and never smokers showed decreased risk for lumbar fractures (aHR 0.82, 95% CI 0.68-0.98 and aHR 0.85, 95% CI 0.73-0.99, respectively) and other site fractures (aHR 0.83, 95% CI 0.78-0.89 and aHR 0.85, 95% CI 0.81-0.90, respectively). Hip fractures were decreased in never smokers (aHR 0.77, 95% CI 0.62-0.94). Short-term quitters did not show decreased risk for fractures.

CONCLUSIONS

Longer time since smoking cessation in men may lead to decreased risk for fractures, especially lumbar and other site fractures. Physicians should counsel patients at risk for fractures both to quit smoking and to maintain abstinence from smoking. Further studies may be required to help comprehend how smoking cessation can affect fracture risk.

Comparison of Bone Turnover Markers between Young Adult Male Smokers and Nonsmokers

Background

This study aims to compare the differences in the means of bone formation and resorption markers between young adult male smokers and nonsmokers.

Methods

This study employed a cross-sectional, descriptive design. Thirty-five smokers and 38 nonsmokers were recruited. All participants completed self-reported questionnaires about demographics, physical activity, and smoking status. In addition, blood specimens were collected to determine serum levels of bone turnover markers.

Results

Regarding bone formation markers, the least square means (LSM) for osteoprotegerin (OPG) and procollagen type I N-terminal propeptide (PINP) were similar for smoking and nonsmoking groups. Regarding bone resorption markers, the LSM serum carboxyl-terminal telopeptide of collagen type I (CTXI) level was found to be significantly lower in smokers than nonsmokers [0.82 ± 0.83 vs. 1.30 ± 0.82 ng/mL, F (1, 66) = 5.73, p = 0.020]. The LSM for soluble-receptor activator of nuclear factor-kappa B ligand (sRANKL) [1.64 ± 0.60 vs. 1.69 ± 0.62 ng/mL, F (1,64) = 10.74, p = 0.002] and RANKL/OPG [2.62 ± 1.09 vs. 2.81 ± 1.10 ng/mL, F (1,65) = 5.88, p = 0.018] were different for smoking and nonsmoking groups. Exploration of the moderating influence of physical activity on smoking effects revealed significant effect for the interaction between smoking status and physical activity on sRANKL [F (2, 64) = 8.63, p = 0.001] and RANKL/OPG ratio [F (2, 65) = 5.49, p = 0.006].

Conclusion

Our study provides evidence for the effect of smoking on bone resorption markers in young adult males. Such effects should be carefully considered side by side with other lifestyles that may lead to poor bone health and increased risk for osteoporosis.

Prevention and management of osteoporosis and osteoporotic fractures in persons with a spinal cord injury or disorder: A systematic scoping review

Objectives: The primary objective was to review the literature regarding methodologies to assess fracture risk, to prevent and treat osteoporosis and to manage osteoporotic fractures in SCI/D.Study Design: Scoping review.Settings/Participants: Human adult subjects with a SCI/D.Outcome measures: Strategies to identify persons with SCI/D at risk for osteoporotic fractures, nonpharmacological and pharmacological therapies for osteoporosis and management of appendicular fractures.Results: 226 articles were included in the scoping review. Risk of osteoporotic fractures in SCI is predicted by a combination of DXA-defined low BMD plus clinical and demographic characteristics. Screening for secondary causes of osteoporosis, in particular hyperparathyroidism, hyperthyroidism, vitamin D insufficiency and hypogonadism, should be considered. Current antiresorptive therapies for treatment of osteoporosis have limited efficacy. Use of surgery to treat fractures has increased and outcomes are good and comparable to conservative treatment in most cases. A common adverse event following fracture was delayed healing.Conclusions: Most of the research in this area is limited by small sample sizes, weak study designs, and significant variation in populations studied. Future research needs to address cohort definition and study design issues.

Multiple vertebral compression fractures after sleeve gastrectomy and a subsequent pregnancy: a case report

We report that a 33-year-old woman developed multiple compression fractures several years after a sleeve gastrectomy followed by pregnancy. Despite normal areal BMD values assessed by dual-energy X-ray absorptiometry and no family history of osteoporosis, the patient demonstrated low lumbar spine trabecular bone score, as well as low peripheral trabecular volumetric BMD and deterioration of trabecular microarchitecture assessed by high-resolution peripheral quantitative computed tomography. Women of reproductive age should be provided with lifestyle management targeting bone health following bariatric surgery.

The Effect of Tobacco Smoking on Bone Mass: An Overview of Pathophysiologic Mechanisms

Recent evidence demonstrates that tobacco smoking causes an imbalance in bone turnover, leading to lower bone mass and making bone vulnerable to osteoporosis and fracture. Tobacco smoke influences bone mass indirectly through alteration of body weight, parathyroid hormone-vitamin D axis, adrenal hormones, sex hormones, and increased oxidative stress on bony tissues. Also, tobacco smoke influences bone mass through a direct effect on osteogenesis and angiogenesis of bone. A RANKL-RANK-OPG pathway is an essential regulatory pathway for bone metabolism and its importance lies in its interaction with most of the pathophysiologic mechanisms by which smoking influences bone mass. Both first- and secondhand smoke adversely affect bone mass; smoking cessation seems to reverse the effect of smoking and improve bone health. Recent advances in research on bone turnover markers could advance scientific knowledge regarding the mechanisms by which smoking may influence bone mass.

Smoking Increases Postoperative Complications After Distal Radius Fracture Fixation: A Review of 417 Patients From a Level 1 Trauma Center

Background: Unstable distal radius fractures that undergo surgical stabilization have varying complication rates in the literature. Smoking is known to affect bone healing and implant fixation rates but has never been definitively shown to affect postoperative outcomes of surgically managed distal radius fractures. Methods: A retrospective review was performed of patients with surgically treated distal radius fractures at a Level 1 Trauma Center who had at least 6 weeks of follow-up over a 5-year period. Charts were reviewed for basic demographic information, comorbidities, details about the operative procedure, and early complications. Notable physical examination findings were noted, such as wrist stiffness and distal radius tenderness to palpation. Statistical analysis was performed to compare the smoking and nonsmoking groups. To control for confounding differences, a hierarchical multivariable regression analysis was performed. Results: Four hundred seventeen patients were included in the study, and 24.6% were current smokers at the time of surgery. The overall complication rate for smokers was 9.8% compared with 5.6% in nonsmokers. The smoking cohort showed significantly higher rates of hardware removal, nonunion, revision procedures, wrist stiffness, and distal radius tenderness. When controlling for the confounding variables of diabetes and obesity, smokers still had significantly higher rates of the same complications. Conclusion: Patients who smoke have a statistically significant higher rate of postoperative distal radius tenderness, wrist stiffness, nonunion, hardware removal, and revision procedures compared with those who do not smoke in a review of 417 total patients undergoing surgical fixation for distal radius fractures.

Cigarette smoke increases pro-inflammatory markers and inhibits osteogenic differentiation in experimental exposure model

Tobacco smokers have slowed bone growth and regeneration and more frequent implant failures than non-smokers, but the effect of cigarette smoking on the host response to bone-dwelling biomaterials is poorly understood. Macrophages and mesenchymal stem cells (MSCs) are essential in the healing response after implant placement. This study examined the effects of an experimental model of cigarette smoke exposure using cigarette smoke extract (CSE) on bone architecture in vivo and differentiation and inflammatory cytokine production on clinically relevant microstructured surfaces in vitro. CSE was prepared by bubbling mainstream smoke from one research cigarette (3R4F) in 1 mL phosphate-buffered saline. For in vivo studies, bone morphometry was examined in femurs isolated from mice injected with diluted CSE for 25 days. For in vitro studies, osteogenic markers and interleukins were measured in human MSCs and murine macrophages cultured on rough or rough-hydrophilic titanium (Ti) surfaces in culture media ± CSE for seven days. In vivo, CSE exposure decreased in bone area, volume, and interconnectivity in a dose-dependent manner. In vitro, macrophages exposed to CSE increased production of pro-inflammatory cytokines, abolishing the increase in anti-inflammatory cytokines typically seen on rough-hydrophilic surfaces. MSCs exposed to CSE had lower mRNA expression of osteoblast differentiation markers, increased levels of pro-inflammatory mRNA, and reduced production of osteogenic proteins. Our results demonstrate that CSE decreases osteogenic differentiation and anti-inflammatory interleukin production while increasing pro-inflammatory interleukin production in macrophages and MSCs, suggesting that compounds in CSE strongly affect stem cell differentiation and may compromise bone formation following biomaterial placement.

STATEMENT OF SIGNIFICANCE

The study of implantable materials' interaction with biological systems occurs nearly exclusively in healthy cell and animal models. However, 15% of the US population smokes cigarettes, which is known to modulate immune response and tissue regeneration. To explore this interaction, we created a method of capturing smoke compounds as CSE for in vivo and in vitro use. We found chronic injection into mice produced an osteoporotic, pro-inflammatory phenotype similar to direct smoke models. Furthermore, CSE attenuated osteogenic differentiation and promoted a pro-inflammatory profile in MSCs and macrophages, respectively, when cultured on titanium surfaces. These results demonstrate that this CSE model may be useful for predicting how chronic tobacco exposure may adversely affect the outcome of biomedical implants in pre-clinical models.

Nicotine induces apoptosis in human osteoblasts via a novel mechanism driven by H2O2 and entailing Glyoxalase 1-dependent MG-H1 accumulation leading to TG2-mediated NF-kB desensitization: Implication for smokers-related osteoporosis

Nicotine contained in cigarette smoke contributes to the onset of several diseases, including osteoporosis, whose emerging pathogenic mechanism is associated with osteoblasts apoptosis. Scanty information is available on the molecular mechanisms of nicotine on osteoblasts apoptosis and, consequently, on an important aspect of the pathogenesis of smokers-related osteoporosis. Glyoxalase 1 (Glo1) is the detoxification enzyme of methylglyoxal (MG), a major precursor of advanced glycation end products (AGEs), potent pro-apoptotic agents. Hydroimidazolone (MG-H1) is the major AGE derived from the spontaneous MG adduction of arginine residues. The aim of this study was to investigate whether, and by means of which mechanism, the antiglycation defence Glo1 was involved in the apoptosis induced by 0.1 and 1µM nicotine in human primary osteoblasts chronically exposed for 11 and 21 days. By using gene overexpression/silencing and scavenging/inhibitory agents, we demonstrated that nicotine induces a significant intracellular accumulation of hydrogen peroxide (H₂O₂) that, by inhibiting Glo1, drives MG-H1 accumulation/release. MG-H1, in turn, triggers H₂O₂ overproduction via receptor for AGEs (RAGE) and, in parallel, an apoptotic mitochondrial pathway by inducing Transglutaminase 2 (TG2) downregulation-dependent NF-kB desensitization. Measurements of H₂O₂, Glo1 and MG-H1 circulating levels in smokers compared with non-smokers or in smokers with osteoporosis compared with those without this bone-related disease supported the results obtained in vitro. Our findings newly pose the antiglycation enzymatic defense Glo1 and MG-H1 among the molecular events involved in nicotine-induced reactive oxygen species-mediated osteoblasts apoptosis, a crucial event in smoker-related osteoporosis, and suggest novel exposure markers in health surveillance programmes related to smokers-associated osteoporosis.

Second hand tobacco smoke adversely affects the bone of immature rats

OBJECTIVES

To evaluate the influence of secondhand cigarette smoke exposure on longitudinal growth of the tibia of growing rats and some parameters of bone quality.

METHODS

Forty female rats were randomly divided into four groups: control: rats were sham exposed; 30 days: rats were exposed to tobacco smoke for 30 days; 45 days: rats were exposed to tobacco smoke for 45 days; and 60 days: rats were exposed to tobacco smoke for 60 days. Blood samples were collected to evaluate the levels of cotinine and alkaline phosphatase. Both tibias were dissected and weighed; the lengths were measured, and the bones were then stored in a freezer for analysis of bone mineral content and mechanical resistance (maximal load and stiffness).

RESULTS

Exposure of rats to tobacco smoke significantly compromised bone health, suggesting that the harmful effects may be time dependent. Harmful effects on bone growth were detected and were more pronounced at 60-day follow-ups with a 41.8% reduction in alkaline phosphatase levels (p<0.01) and a decrease of 11.25% in tibia length (p<0.001). Furthermore, a 41.5% decrease in bone mineral density was observed (p<0.001), leading to a 42.8% reduction in maximum strength (p<0.001) and a 56.7% reduction in stiffness (p<0.001).

CONCLUSION

Second hand cigarette smoke exposure in rats affected bones that were weaker, deforming them and making them osteopenic. Additionally, the long bone was shorter, suggesting interference with growth. Such events seem to be related to time of exposure.

The Effect of Smoking on Spinal Fusion

BACKGROUND

Spinal fusion surgery is performed about half a million times per year in the United States and millions more worldwide. It is an effective method for reducing pain, increasing stability, and correcting deformity in patients with various spinal conditions. In addition to being a well-established risk factor for a variety of medical conditions, smoking has deleterious effects on the bone healing of spinal fusions. This review aims to specifically analyze the ways in which smoking affects the outcomes of spinal fusion and to explore ways in which these negative consequences can be avoided.

PURPOSE

This article provides a complete understanding of the ways smoking affects spinal fusion from a biochemical and clinical perspective. Recommendations are also provided for ways in which surgeons can limit patient exposure to the most serious negative outcomes associated with cigarette smoking.

STUDY DESIGN/SETTING

This study was a retrospective literature review done using the NCBI database. The research was compiled at NYU Hospital for Joint Diseases and the NYU Center for Musculoskeletal Care.

METHODS

A comprehensive literature review was done spanning research on a variety of subjects related to smoking and spinal fusion surgery. The biochemistry of smoking and fusion healing were examined in great detail. In addition, both in vivo animal studies and human clinical studies were evaluated to explore fusion success related to the effects of smoking and its biochemical factors on spinal fusion surgery.

RESULTS

Smoking significantly increases the risk of pseudoarthrosis for patients undergoing both lumbar and cervical fusions. In addition to nonunion, smoking also increases the risk of other perioperative complications such as infection, adjacent-segment pathology, and dysphagia. Treatment options are available that can be explored to reduce the risk of smoking-related morbidity, such as nicotine replacement therapy and use of bone morphogenetic proteins (BMPs).

CONCLUSIONS

It has been clearly demonstrated from both a biochemical and clinical perspective that smoking increases the rate of perioperative complications for patients undergoing spinal fusion surgery, particularly pseudoarthosis. It has also been shown that there are certain approaches that can reduce the risk of morbidity. The most important recommendation is smoking cessation for four weeks after surgery. In addition, patients may be treated with certain surgical techniques, including the use of BMPs, to reduce the risk of pseudoarthrosis. Lastly, nicotine replacement therapy is an area of continued interest in relation to spinal fusion outcomes and more research needs to be done to determine its efficacy moving forward.

Electronic Cigarette Smoke Impairs Normal Mesenchymal Stem Cell Differentiation

Electronic cigarettes (e-cigarettes) are promoted as low-risk alternatives to combustible cigarettes. However, the effects of chronic inhalation of potential toxicants emitted by ecigarettes remain largely unexamined. It is conceivable that smoking-induced chronic diseases result in cellular injury, in the absence of effective repair by stem cells. This study evaluates the effect of cigarette and e-cigarette aerosol extracts on the survival and differentiation of bone marrow-derived mesenchymal stem cells (MSCs). MSC growth and osteogenic differentiation were examined after exposure to smoke extracts. Data revealed detrimental effects of both cigarette and e-cigarette extracts on MSC morphology and growth. Levels and activity of alkaline phosphatase, an osteogenic marker, decreased and induction of osteoblastic differentiation was impaired. Both smoke extracts prevented osteogenic differentiation from progressing, evident by decreased expression of terminal osteogenic markers and mineralization. Elevated levels of reactive oxygen species (ROS) were detected in cells exposed to smoke extracts. Moreover, decreased differentiation potential was concomitant with severe down-regulation of Connexin 43 expression, leading to the loss of gap junction-mediated communication, which together with elevated ROS levels, could explain decreased proliferation and loss of differentiation potential. Hence, e-cigarettes present similar risk as combustible cigarettes with respect to tissue repair impairment.

The Role of Body Weight on Bone in Anorexia Nervosa: A HR-pQCT Study

Anorexia nervosa (AN) is associated with decreased bone mineral density and increased risk of fracture. The aim of this study was to assess bone geometry, volumetric bone mineral density (vBMD), trabecular microarchitecture and estimated failure load in weight-bearing vs. non-weight-bearing bones in AN. We included twenty-five females with AN, and twenty-five female controls matched on age and height. Bone geometry, vBMD and trabecular microarchitecture were assessed using high-resolution peripheral quantitative computed tomography of the distal radius and tibia. At both sites, cortical perimeter and total bone area were similar in patients and controls. Total vBMD was lower in the AN group in the tibia (p < 0.0005) but not in the radius. In the tibia, cortical thickness was approximately 25% lower (p < 0.0005) in the AN group, whereas there was no significant difference in the radius. In terms of trabecular microarchitecture, all indices [bone volume/tissue volume (BV/TV); trabecular thickness (Tb.Th.), trabecular number (Tb.N) and trabecular spacing (Tb.Sp.)] were impaired in AN in the tibia (p values range < 0.01-0.0001). In the radius, BV/TV and Tb.N were lower (p < 0.05 and p < 0.001, respectively); Tb.Sp. was higher (p < 0.001), whereas Tb.Th. did not differ, compared to controls. Estimated failure load was lower in patients in both the radius and the tibia (p < 0.0005 and p < 0.0001, respectively), most pronounced in the tibia. In conclusion, the impairment of cortical thickness and estimated failure load were significantly more pronounced in the weight-bearing tibia, compared to the non-weight-bearing radius, implying a direct effect of low body weight on bone loss in AN.

Cardiovascular calcification and subcortical bone demineralization in hypertension

The present study investigated cardiovascular calcification, peripheral bone mineral density (BMD), and lab indices in hypertensive patients aged 55-74 years without severe kidney dysfunction. Cardiovascular calcification was investigated by ultrasound examinations at eight sites: aortic valve, left and right common carotid artery, left and right carotid artery bifurcation, left and right internal carotid artery, and abdominal aorta. The presence/absence of calcification at each site was coded as 1/0, respectively, for the calculation of a cumulative score. Peripheral bone mineral density was assessed by forearm quantitative computed tomography (pQCT) and was defined as low if the T-score was <-1. Lab work-up included plasma creatinine, calcium, phosphorus, parathyroid hormone and 25-(OH) vitamin D measurements. Ninety-one patients were studied. The range was 2-8 for the calcification score and 229-492 mg cm^-3 for bone mineral density. The prevalence of low bone densitometry was 83.5%. The calcification score and bone densitometry were inversely correlated in a non-adjusted analysis (R=-0.297, P=0.004) and in multivariable regression (beta=-0.335, P=0.003). The association was significant for subcortical bone (beta=-0.302, P=0.007) but not for cortical bone or trabecular bone (P⩾0.194 in both cases). The calcification score was associated with a low prevalence of bone densitometry in the non-adjusted analysis (odds ratio=2.53, 95% CI=1.41/4.54, P=0.002) and in the multivariable logistic regression (odds ratio=2.46, 95% CI=1.25/4.81, P=0.009). Cardiovascular calcification was independently associated with peripheral bone densitometry in hypertensive patients. The data support the hypothesis that vascular calcification and low bone densitometry share some determinants in hypertensive patients.

Pelvic insufficiency fracture (PIF) incidence in patients treated with intensity-modulated radiation therapy (IMRT) for gynaecological or anal cancer: single-institution experience and review of the literature

OBJECTIVE

To summarize the results of pelvic insufficiency fracture (PIF) incidence in patients with anal or gynaecological cancer treated by pelvic intensity-modulated radiation therapy (IMRT).

METHODS

The clinical and morphological (CT and/or pelvic MRI) characteristics of patients treated by IMRT at our institution between 2007 and 2014 were analyzed. The global incidence of PIF after external beam radiotherapy and the impact of tumour site (gynaecological or anal cancer) were determined. A dosimetric study was then performed to compare patients with and without pelvic fracture.

RESULTS

341 patients were treated by IMRT for gynaecological or anal cancer between 2007 and 2014. 15 patients experienced at least 1 pelvic fracture after external beam radiotherapy, corresponding to an overall incidence of 4.4%. Age and menopausal status were correlated with an increased fracture risk (p = 0.0274 and p < 0.0001, respectively). The site of the primary tumour (gynaecological or anal canal) was not associated with an excess fracture risk. The median maximum dose received at the fracture site was 50.3 Gy (range: 40.8-68.4 Gy).

CONCLUSION

The incidence of pelvic fracture after IMRT is low, but is higher after the age of 50 and in patients who are postmenopausal. Pre-treatment evaluation of bone density by bone densitometry and phosphorus-calcium assessment could be useful prior to the management of these patients. Advances in knowledge: Pelvic fractures are a frequent complication after radiotherapy. The influence of IMRT and clinical characteristics were evaluated in this study.

Exposure to Secondhand Smoke Impairs Fracture Healing in Rats

BACKGROUND

Nonsmokers may be affected by environmental tobacco smoke (secondhand smoke), but the effects of such exposure on fracture healing have not been well studied.

QUESTIONS/PURPOSES

To explore the possible effects of passive inhalation of tobacco smoke on the healing of a diaphyseal fracture in femurs of rats. We hypothesized that secondhand exposure to tobacco smoke adversely affects fracture healing.

METHODS

A mid-diaphyseal fracture was created in the femur of 41 female Wistar rats and fixed with an intramedullary metallic pin; 14 rats were excluded (nine for inadequate fractures and five for K wire extrusion). Tobacco exposure was provided by a smoking machine on a daily basis of four cigarettes a day. Each cigarette yielded 10 mg tar and 0.8 mg nicotine, and was puffed by alternating injections of fresh air for 30 seconds and smoke air for 15 seconds. The smoke exposure was previously adjusted to provide serum levels of cotinine similar to human secondhand tobacco exposure. Cotinine is a predominant catabolite of nicotine that is used as a biological biomarker for exposure to tobacco smoke. In one group (n = 11), the animals were intermittently exposed to tobacco smoke before sustaining the fracture but not afterward. In another group (n = 7), the exposure occurred before and after the fracture. The control group (n = 9) was sham-exposed before and after the fracture. We evaluated the specimens 28 days after bone fracture. The callus quality was measured by dual-energy x-ray absorptiometry (bone mineral density [BMD], bone mineral content [BMC], and callus area), μCT (callus volume and woven bone fraction), and mechanical bending (maximum force and stiffness).

RESULTS

Tobacco exposure resulted in delayed bone callus formation, which is represented by decreased BMD (Control: 0.302 ± 0.008 g/cm² vs Preexposed: 0.199 ± 0.008 g/cm² and Pre- and Postexposed: 0.146 ± 0.009 g/cm²; mean difference = 0.103 g/cm², 95% CI, 0.094-0.112 g/cm²and mean difference = 0.156 g/cm², 95% CI, 0.147-0.167 g/cm²; p < 0.01), BMC (Control: 0.133 ± 0.005 g vs Preexposed: 0.085 ± 0.0034 g and Pre- and Postexposed: 0.048 ± 0.003 g; mean difference = 0.048 g, 95% CI, 0.045-0.052 g and mean difference = 0.085 g, 95% CI, 0.088-0.090 g; p < 0.01), callus volume (Control: 7.656 ± 1.963 mm³ vs Preexposed: 17.952 ± 1.600 mm³ and Pre- and Postexposed: 40.410 ± 3.340 mm³; mean difference = -10.30 mm³, 95% CI, -14.12 to 6.471 mm³ and mean difference, -32.75 mm³, 95% CI, -36.58 to 28.93 mm³; p < 0.01), woven bone fraction (Control: 42.076 ± 3.877% vs Preexposed: 16.655 ± 3.021% and Pre- and Postexposed: 8.015 ± 1.565%, mean difference = 0.103%, 95% CI, 0.094-0.112% and mean difference = 0.156%, 95% CI, 0.147-0.166%; p < 0.01), maximum force (Control: 427.122 ± 63.952 N.mm vs Preexposed: 149.230 ± 67.189 N.mm and Pre- and Postexposed: 123.130 ± 38.206 N.mm, mean difference = 277.9 N.mm, 95% CI, 201.1-354.7 N.mm and mean difference = 304 N.mm, 95% CI, 213.2-394.8 N.mm; p < 0.01) and stiffness (Control: 491.397 ± 96.444 N.mm/mm vs Preexposed: 73.157 ± 36.511 N.mm/mm and Pre- and Postexposed: 154.049 ± 134.939 N.mm/mm, mean difference = 418.2 N.mm/mm, 95% CI, 306.3-530.1 N.mm/mm and mean difference = 337.3 N.mm/mm, 95% CI, 188.8-485.9 N.mm/mm; p < 0. 01).

CONCLUSIONS

Rats exposed to tobacco smoke showed delayed fracture healing and callus that was characterized by decreased maturity, density, and mechanical resistance, which was confirmed by all assessment methods of this study. Such effects were more evident when animals were exposed to tobacco smoke before and after the fracture. Future studies should be done in human passive smokers to confirm or refute our findings on fracture callus formation.

CLINICAL RELEVANCE

The potential hazardous effects of secondhand smoke on fracture healing in rodents should stimulate future clinical studies in human passive smokers.

Bone density loss on computed tomography at 3-year follow-up in current compared to former male smokers

OBJECTIVES

Cigarette smoking negatively affects bone quality and increases fracture risk. Little is known on the effect of smoking cessation and computed tomography (CT)-derived bone mineral density (BMD) decline in the spine. We evaluated the association of current and former smoking with BMD decline after 3-year follow-up.

METHODS

Male current and former smokers participating in a lung cancer screening trial who underwent baseline and 3-year follow-up CT were included. BMD was measured by manual placement of a region of interest in the first lumbar vertebra and expressed in Hounsfield Unit (HU). Multiple linear regression analysis was used to evaluate the association between pack years smoked and smoking status with BMD decline.

RESULTS

408 participants were included with median (25th-75th percentile) age of 59.4 (55.9-63.5) years. At the start of the study, 197 (48.3%) participants were current smokers and 211 (51.7%) were former smokers and had a similar amount of pack years. Current smokers had quit smoking for 6 (4-8) years prior to inclusion. There was no difference in BMD between current and former smokers at baseline (109±34 HU vs. 108±32 HU, p=0.96). At 3-year follow-up, current smokers had a mean BMD decline of -3±13 HU (p=0.001), while BMD in former smokers did not change as compared to baseline (1±13 HU, p=0.34). After adjustment for BMD at baseline and body mass index, current smoking was independently associated with BMD decline (-3.8 HU, p=0.003). Age, pack years, and the presence of a fracture at baseline did not associate with BMD decline.

CONCLUSIONS

Current smokers showed a more rapid BMD decline over a 3-year period compared to former smokers. This information might be important to identify subjects at risk for osteoporosis and emphasizes the importance of smoking cessation in light of BMD decline.

Femoral Neck Bone Mineral Density in Persons Over 50 Years Performing Shiftwork: An Epidemiological Study

OBJECTIVE

Shiftwork has been associated with bone loss due to hormonal fluctuations. Our aim was to assess the femoral neck bone mineral density and content in persons over 50 years performing shiftwork.

METHODS

We performed analysis on the femoral neck bone mineral parameters in persons over age 50 years from the National Health and Nutrition Examination Survey cross-sectional data for 2010 to 2011 in regular and shiftworkers. We also assessed the degree of moderate physical activity and smoking in both groups.

RESULTS

Middle-aged men performing shiftwork had significantly higher total femur bone mineral content (37.33 ± 11.00 vs 34.09 ± 10.45, P = 0.01) and femoral neck bone mineral content (4.57 ± 1.07 vs 4.29 ± 1.0, P = 0.03). This difference was not seen in middle aged women.

CONCLUSIONS

Shiftwork does not seem to affect bone mineral density in those performing moderate physical activity.