Relationship between osteoporosis and adipose tissue leptin and osteoprotegerin in patients with chronic obstructive pulmonary disease

The impact of osteoporosis and vertebral compression fractures on mortality and association with pulmonary function in COPD: A meta-analysis

OBJECTIVE

Osteoporosis is highly prevalent among patients with chronic obstructive pulmonary disease (COPD) and most commonly presents as a vertebral compression fracture (VCF). Our objective was to quantify the effect of osteoporosis and VCFs on the mortality and pulmonary function tests (PFTs), such as forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC), of patients with COPD.

METHODS

A PubMed/Medline search was conducted using the search terms "chronic obstructive pulmonary disease", "osteoporosis" and "vertebral compression fracture". Meta-analyses were conducted to evaluate the differences in mortality and PFTs between patients with COPD with and without osteoporosis or VCFs, according to PRISMA guidelines. PROSPERO registration: CRD42019120335.

RESULTS

Of the 896 abstracts identified, 27 studies describing 7662 patients with COPD of which 1883 (24.6%) had osteoporosis or VCFs, were included. Random effects model analysis demonstrated that patients with COPD and osteoporosis or VCFs had an increased OR for mortality of 2.40 (95% CI: 1.24; 4.64, I²=89%, P<0.01), decreased FEV₁/FVC with a mean difference of -4.80% (95% CI: -6.69; -2.90, I²=83%, P<0.01) and decreased FEV₁, with a mean difference of -4.91% (95% CI: -6.51; -3.31, I²=95%, P<0.01) and -0.41 L (95% CI: -0.59; -0.24, I²=97%, P<0.01), compared to control subjects. Apart from FEV₁ (liters) in subgroup 1 (P=0.06), all subgroup analyses found significant differences between groups, as did sensitivity analysis of low risk of bias studies.

CONCLUSION

Osteoporosis and VCFs are associated with a significant reduction in survival and pulmonary function among patients with COPD.

Prevalence and Risk Factors for Osteoporosis in Individuals With COPD: A Systematic Review and Meta-analysis

BACKGROUND

Osteoporosis is prevalent in individuals with COPD. Updated evidence is required to complement the previous systematic review on this topic to provide best practice. The aim of this systematic review and meta-analysis was to quantitatively synthesize data from studies with respect to the prevalence and risk factors for osteoporosis among individuals with COPD.

METHODS

EMBASE, CINAHL, MEDLINE, and PubMed databases were searched for articles containing the key words "COPD," "osteoporosis," "prevalence," and "risk factor." Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Meta-analyses were performed to determine osteoporosis prevalence and risk factors in individuals with COPD. Meta-regression analyses were conducted to explore the sources of heterogeneity.

RESULTS

The pooled global prevalence from 58 studies was 38% (95% CI, 34-43). The presence of COPD increased the likelihood of having osteoporosis (OR, 2.83). Other significant risk factors for osteoporosis in COPD patients were BMI < 18.5 kg/m² (OR, 4.26) and the presence of sarcopenia (OR, 3.65).

CONCLUSIONS

Osteoporosis is prevalent in individuals with COPD, and the prevalence seems to be high and similar in many countries. Patients with COPD should be screened for osteoporosis and contributing risk factors.

Adipokines may mediate the relationship between resting metabolic rates and bone mineral densities in obese women

The researchers sought to test the possible link between resting metabolic rate and bone mineral density through four adipokines. Participants with lower resting metabolic rate (RMR) per kilogram demonstrated higher total bone mineral density (BMD), total T-score, and total Z-score. Omentin-1 had a mediatory effect on the relationship between RMR/kg of body weight and bone parameters.

INTRODUCTION

The previous results of studies regarding the links between obesity and bone health are controversial. For this reason, the researchers sought to test the possible link between RMR and BMD through the following four adipokines: vaspin, retinol binding protein 4, angiopoietin-like 6 (ANGPL6), and omentin-1.

METHODS

We enrolled 312 obese Iranian women (30 ≤ body mass index <40) in this cross-sectional study. In order to examine the association of serum adipokine levels with RMR and BMD, the participants were grouped based on RMR per body weight. Body composition, dietary intake, bone mineral density, and resting metabolic rate were assessed in all participants. Serum adipokine levels were quantified by the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

Low levels of RMR/kg were strongly associated with higher weight, body mass index, fat mass, and visceral fat levels. In fact, participants with an RMR/kg of body weight <20 kcal/24 h/kg were more obese (p < 0.05). Another noteworthy finding was that participants with lower RMR/kg demonstrated higher total BMD, total T-score, and total Z-score. Our results showed that omentin-1 had a mediatory effect on the relationship between RMR per kilogram of body weight and bone parameters (p < 0.05). Nevertheless, other adipokines such as vaspin, retinol-binding protein 4 (RBP4), and ANGPL6 did not affect the relationship between RMR and BMD (p > 0.05).

CONCLUSIONS

The inhibitory effect of omentin-1 on TNF-alpha seems to be able to reduce the amount of circulating leptin as adipokine, affecting energy expenditure and improving bone loss induced by estrogen deficiency and controlled effect of RMR on BMD.

Relationship between A163G osteoprotegerin gene polymorphism and other osteoporosis parameters in Roma and non-Roma postmenopausal women in eastern Slovakia

BACKGROUND

The study was focused on evaluating the possible correlation between biochemical, anthropometric, and genetic indicators of osteoporosis in postmenopausal women. The frequency of genotypes and differences in measured parameters were evaluated within two ethnically different groups of women in Slovakia.

METHODS

The study included 310 postmenopausal women divided into non-Roma and Roma groups. Based on results of densitometry, they were divided into control groups and women with osteoporosis and osteopenia. In all women, a genetic analysis of polymorphism of osteoprotegerin gene promotor region (A163G) was provided along with measurement of indicators of bone tissue metabolism.

RESULTS

There is a particularly low incidence of osteoporosis in Roma women. We found a correlation between bone mineral density (BMD), body mass index, and waist and hip circumference in women with osteoporosis and in Roma women with osteopenia. The frequency of the AG genotype was higher in non-Roma women with osteoporosis, but reached only 10.7% in Roma women with osteopenia. While the presence of the G allele in the non-Roma population was accompanied by higher BMD and markers of osteoformation, it was accompanied by significantly higher concentrations of parathyroid hormone in the Roma population.

CONCLUSION

The presence of the AG genotype has a different effect on bone metabolism in two ethnically diverse populations of women in Slovakia. In the general population, the presence of the G allele exhibited protective effects consistent with other studies, but in Roma population this appears to be the allele A. However, this requires a further study for confirmation and more detailed characterization of the differences between populations that have this work indicated.

The effects of neuromuscular facilitation techniques on osteoporosis of hemiplegia limbs and serum leptin level in patients or rats with cerebral infarction

PRIMARY OBJECTIVE

This study was to investigate the effect of proprioceptive neuromuscular facilitation techniques (NFT) on osteoporosis and serum leptin level in cerebral infarction patients or rats.

RESEARCH DESIGN

Forty cerebral infarction rats were randomly grouped into control, sham operation, conventional treatment (CT) group and CT+NFT group. Fifty-two stroke patients with hemiplegia were included in this study.

METHODS AND PROCEDURES

The bone mineral densities (BMD) of proximal hemiplegia limbs and serum ALP, BALP, BGP, IL-6 and leptin levels were detected using commercial kits.

MAIN OUTCOMES AND RESULTS

In cerebral infarction rats, the BMD, BGP, BALP, ALP and leptin concentrations in the CT+NFT group was higher compared with the control and CT group, while serum IL-6 level was more reduced by CT+NFT than control and CT. In cerebral infarction patients, both CT and CT+NFT increased the BMD, ALP, BGP and leptin levels. In addition, compared with CT, the BMD, ALP, BGP and leptin levels were markedly increased by CT+NFT. C Conclusion: NFC elevated the BMD of hemiplegia limbs, serum ALP, BGP, IL-6 and leptin levels and, thus, alleviated osteoporosis in rats and patients with cerebral infarction.

Roles of leptin in bone metabolism and bone diseases

Adipose tissue has been more accepted as an active contributor to whole body homeostasis, rather than just a fat depot, since leptin, a 16 kDa protein, was discovered as the product of the obese gene in 1994. With more and more studies conducted on this hormone, it has been shown that there is a close relationship between adipose tissue and bone, which have important effects on each other. Bone is the source of many hormones, such as osteocalcin, that can affect energy metabolism and then the anabolism or catabolism of fat tissue. In contrast, the adipose tissue synthesizes and releases a series of adipokines, which are involved in bone metabolism through direct or indirect effects on bone formation and resorption. Interestingly, leptin, one of the most important cytokines derived from fat tissue, seems to account for the largest part of effects on bone, through direct or indirect involvement in bone remodeling and by playing a significant role in many bone diseases, such as osteoporosis, osteoarthritis, rheumatic arthritis, bone tumors and even fractures. In this review, we will discuss the progress in leptin research, particularly focusing on the roles of leptin in bone diseases.

Effects of therapies for regulating and reinforcing lung and kidney on osteoporosis in rats with chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the efficacy and long-term effects of the three therapies for regulating and reinforcing lung and kidney (reinforcing lung and invigorating spleen, reinforcing lung and replenishing kidney, and supplementing Qi and nourishing kidney) in Traditional Chinese Medicine (TCM) on osteoporosis in rats with chronic obstructive pulmonary disease.

METHODS

Totally 120 rats were randomly divided into control, model, Bufeijianpi, Bufeiyishen, Yiqizishen, aminophyline groups. Repeated smoke inhalations and bacterial infections were used to duplicate the stable Chronic obstructive pulmonary disease rat model. Normal saline was given to the air control and model groups, while Bufeijianpi granule, Bufeiyishen granule, and Yiqizishen granule, and aminophylline were administrated to rats in the Bufeijianpi, Bufeiyishen, Yiqizishen, and aminophylline groups respectively from weeks 9 through 20. Another 12 weeks without medicines to observe the long-term effect. Rats were sacrificed at week 20 and week 32. Bone mass density (BMD), bone mineral content (BMC), morphology of the femoral head, lung function, and levels of serum interleukin (IL)-1β, IL-6, and tumor necrosis factor-α were detected.

RESULTS

At weeks 20 and 32, tidal volume, peak expiratory flow and expiratory flow at 50% tidal volume in the three TCM-treated groups were higher than those in the model group (P < 0.05). Femur weight, BMD, and BMC were significantly higher in the three TCM-treated groups and the aminophylline-treated group compared with the model group (P < 0.01), except for BMC in the Yiqizishen-treated group at week 20.

CONCLUSION

Bufeijianpi, Bufeiyishen, and Yiqizishen granules show good effects in the prevention and treatment of osteoporosis, which can alleviate airflow limitations and inflammation, improve BMD and BMC of the femur, and have favorable long-term effects.

Correlations between osteoprotegerin serum levels and body composition parameters in patients with sleep apnea syndrome and the possible influence on cardiovascular risk

INTRODUCTION

Osteoprotegerin (OPG) is a member of the tumor necrosis factor family and a key regulator in bone turnover; it plays a role in the development of many cardiovascular diseases and may be treated as a marker of vascular damage. Bioelectrical impedance analysis (BIA) is a reliable, non-invasive and effective technique for measuring body composition. The aim of the study was to evaluate correlations between osteoprotegerin serum levels and body composition parameters in sleep apnea patients and their influence on cardiovascular risk.

MATERIAL AND METHODS

A total of 125 patients with newly diagnosed OSA were enrolled in the study (including 34 females). The mean age was 54.48±8.81 years, mean AHI 33.16±20.44/h and mean BMI 33.76±7.18. A control group comprised 59 healthy subjects with mean age of 51.27±12.97 years and mean BMI 29.47±5.42. All subjects underwent a nocturnal respiratory polygraphy and body composition measurements were taken with bioelectrical impedance analysis. OPG serum levels were measured using the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

In OSA patients OPG correlated negatively with muscle mass percentage (MM%), phase angle, fat free mass percentage (FFM%) and body cell mass percentage (BCM%), while there was a positive correlation between osteoprotegerin and fat mass percentage (FM%). We demonstrated higher OPG serum levels in OSA patients with cardiovascular diseases than in those without comorbidities (4.01 vs 3.46pmol/l, p<0.05).

CONCLUSION

Our findings, combined with previous observations in other diseases, suggest that elevated OPG serum levels together with selected body composition parameters may be helpful in identifying OSA patients with increased cardiovascular risk.

Osteoporosis in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a lifestyle-related chronic inflammatory pulmonary disease associated with significant morbidity and mortality worldwide. COPD is associated with various comorbidities found in all stages of COPD. The comorbidities have significant impact in terms of morbidity, mortality, and economic burden in COPD. Management of comorbidities should be incorporated into the comprehensive management of COPD as this will also have an effect on the outcome in COPD patients. Various comorbidities reported in COPD include cardiovascular disease, skeletal muscle dysfunction, anemia, metabolic syndrome, and osteoporosis. Osteoporosis is a significant comorbidity in COPD patients. Various risk factors, such as tobacco smoking, systemic inflammation, vitamin D deficiency, and the use of oral or inhaled corticosteroids (ICSs) are responsible for its occurrence in patients with COPD. This review will focus on the prevalence, pathogenesis, risk factors, diagnosis, and treatment of osteoporosis in COPD patients.

Prevalence of metabolic syndrome in COPD patients and its consequences

Background

The prevalence of metabolic syndrome in COPD patients and its impact on patient related outcomes has been little studied. We evaluated the prevalence of metabolic syndrome and clinical and functional characteristics in patients with COPD and healthy subjects.

Methods

228 COPD patients and 156 healthy subjects were included. Metabolic syndrome was defined using criteria of the IDF. In all patients spirometry, body composition, functional exercise performance, and mood and health status were assessed. Groups were stratified for BMI and gender.

Results

Metabolic syndrome was present in 57% of the COPD patients and 40% of the healthy subjects. After stratification for BMI, presence of metabolic syndrome in patients with a BMI ≥25 kg/m² was higher than in healthy peers. Patients with metabolic syndrome and a BMI <25 kg/m² had higher BMI, fat free mass index and bone mineral density, and a lower 6MWD than the BMI matched patients without metabolic syndrome. Spirometry, maximal ergometry, mood and health status, and blood gases were not different between those groups. In COPD patients with metabolic syndrome self-reported co-morbidities and medication use were higher than in those without.

Conclusion

Metabolic syndrome is more prevalent in overweight or obese COPD patients than in BMI matched healthy subjects. Metabolic syndrome did not additionally impact patients' functional outcomes, but did impact the prevalence of co-morbidities.

Circulatory osteoprotegerin is related to osteoporosis of the hip in patients with COPD

BACKGROUND

Osteoprotegerin (OPG), a potent inhibitor of osteoclastogenesis, decreases bone resorption and has protective effects on bone mineral density (BMD). Recently we have shown that the adipose-tissue derived OPG relates to BMD in patients with chronic obstructive pulmonary disease (COPD), a condition associated with increased risk of osteoporosis.

OBJECTIVE

Here we aimed to investigate the potential of circulatory OPG to reflect hip BMD in patients with COPD.

PATIENTS AND METHODS

In 56 subjects with COPD [age, 61.7 ± 6.7 years; forced expiratory volume in 1 s (FEV1), 53.6 ± 19.2% predicted], total femur BMD was assessed by dual energy X-ray absorptiometry, serum OPG and β-crosslaps, a marker of increased bone resorption, by commercially available assays.

RESULTS

From patients with normal hip BMD (n = 32, T-score 0.1 ± 0.8) to those with osteopenia (n = 14, T-score -1.6 ± 0.4) and osteoporosis (n = 10, T-score -3.4 ± 0.7) serum OPG levels significantly increased (6.6 ± 1.8 versus 7.2 ± 2.9 and versus 8.6 ± 1.5 pmol/l, p = 0.036). In addition, hip T-scores were directly related to FEV1, and inversely to β-crosslaps (R = 0.40, p = 0.002; R = 0.38, p = 0.01, respectively). In multivariate analysis, OPG independently predicted hip T-scores after adjustments for age, gender, FEV1, and β-crosslaps (p = 0.011, adjusted R(2) = 0.354). Area under receiver operator curve for OPG as a discriminator of osteoporosis was 0.787 (95% CI, 0.653-0.921) (p = 0.005).

CONCLUSIONS

Present results suggest that osteoporosis of the hip is associated with increased circulatory levels of OPG in patients with COPD. OPG might serve as a biomarker of this COPD-related comorbidity.

Relationship between bone mineral density and serum osteoprotegerin in patients with chronic heart failure

Purpose

Heart failure (HF) had been reported with increased risk of hip fractures. However, the relationship between circulating biomarkers and bone mineral density (BMD) in chronic HF remained unclear.

Methods

This is a cross-sectional study which recruited stable chronic HF from registry of the Heart Failure Center of National Taiwan University Hospital. Patients underwent dual-energy x-ray absorptiometry (DEXA) measurements at hip and lumbar spines and biochemical assessments including B-type natriuretic peptide (BNP-32), myostatin, follistatin and osteoprotegerin (OPG).

Results

A total of 115 stable chronic HF individuals with left ventricular ejection fraction (EF) <45% (74% of male, mean age at 59) were recruited with 24 patients in NYHA class I, 73 patients in NYHA class II and 18 patients in NYHA class III. Results of BMD showed that Z scores of hip in NYHA III group (−0.12±1.15) was significantly lower than who were NYHA II (0.58±1.04). Serum OPG was significantly higher in subjects of NYHA III (9.3±4.6 pmol/l) than NYHA II (7.4±2.8 pmol/l) or NYHA I (6.8±3.6 pmol/l) groups. There’s a significant negative association between log transformed serum OPG and trochanteric BMD (R = −0.299, P = 0.001), which remained significant after multivariate analysis.

Conclusions

Our study demonstrated an inverse association between serum OPG and trochanteric BMD in patients with HF. OPG may be a predictor of BMD and an alternative to DEXA for identifying at risk HF patients for osteoporosis.

Association of bone mineral density, parameters of bone turnover, and body composition in patients with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) often develop osteoporosis. Many hormones regulate bone metabolism and body composition, and some of them are affected in COPD patients vs controls. In 46 COPD patients, we measured hip neck, total hip, lumbar spine, and whole-body T-score with dual-energy X-ray absorptiometry, parameters of body composition (body mass index [BMI], fat mass index [FMI], and fat-free mass index [FFMI]), and adiponectin, leptin, parathormone, osteocalcin, calcitonin, and insulin-like growth factor I (IGF-I) serum levels and correlated them with COPD stage. Our results suggest that total hip bone mineral density (BMD) is affected by FFMI and COPD stage; lumbar spine BMD is affected by FMI and COPD stage; and whole-body BMD is affected by BMI, COPD stage, and leptin. Adiponectin, parathormone, osteocalcin, calcitonin, and IGF-I levels were not significantly correlated to BMD at any of the measured sites. Our findings are in agreement with the current literature in that a decline in lung function is correlated to a decline in BMD.

Vitamin D and Chronic Obstructive Pulmonary Disease

Vitamin D is an important regulator of calcium and bone homeostasis. It is also involved in the regulation of different genes and cellular functions, particularly in the context of inflammation, regeneration and immune control. Conversely, vitamin D deficiency which is often found in chronic, infectious and inflammatory diseases is thought to drive or enhance uncontrolled inflammation. Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the airways most often because of cigarette smoking. It has been recognized that repetitive airway infections and systemic consequences or co-morbidities also contribute to the progressive nature of COPD. Vitamin D deficiency is known to sneak in from the early stages of COPD, to become highly prevalent at the more severe stages, and may thereby catalyse airway infection, inflammation and systemic consequences. Undoubtedly, vitamin D deficiency enhances bone resorption and osteoporosis in COPD for which appropriate vitamin D supplementation is recommended. However, conflicting evidence has emerged on the extra-calcemic effects of vitamin D in COPD. A recent intervention trial with high-dose supplementation in COPD was only able to reduce exacerbation frequency in the subgroup of patients with lowest baseline vitamin D levels. It confirms that severe vitamin D deficiency is a health hazard but that more clinical and experimental studies are needed to explore how vitamin D deficiency may affect airway biology and systemic effects in the context of smoke-induced lung diseases.