The osteoprotegerin/RANK/RANKL system: a bone key to vascular disease

Owing to the common coincidence of osteoporosis and vascular disease, pathophysiological links between both disorders have long been sought. The osteoprotegerin (OPG)/receptor activator of NF-kappaB (RANK)/receptor activator of NF-kappaB ligand (RANKL) cytokine network, a key regulatory system in bone homeostasis, has been implicated recently in vascular calcification, changes in matrix composition and diabetic macroangiopathy, aortic aneurysm development, heart failure and, most importantly, advanced atherosclerosis, plaque destabilization and manifestation of cardiovascular diseases. The concept of an active role of RANKL and OPG in vascular pathophysiology is intriguing and is gaining increasing support from both epidemiological and basic research. OPG serum level is considered to be a stable and reliable indicator of the overall activity of the OPG/RANK/RANKL axis and may find application as a biomarker of vascular risk and prognosis. RANKL in turn may be a suitable target for novel therapies. Pharmacological strategies for specific interference with the OPG/RANK/RANKL axis are currently being developed and evaluated in osteoporosis therapy.     

Moderate to vigorous physical activity and sedentary behavior changes in self-isolating adults during the COVID-19 pandemic in Brazil: a cross-sectional survey exploring correlates

Sport Sciences for Health - The COVID-19 pandemic imposed major changes on daily-life routine worldwide. To the best of our knowledge, no study quantified the changes on moderate to vigorous...     

Oxidized low-density lipoprotein autoantibodies, chronic infections, and carotid atherosclerosis in a population-based study.

OBJECTIVES: We investigated whether associations exist between immune reactions to oxidized low-density lipoproteins (OxLDLs), chronic infections, and carotid atherosclerosis as quantified by ultrasound. BACKGROUND: Atherosclerosis is a chronic immuno-inflammatory disease wherein both oxidized lipids and infectious agents are incriminated as possible contributors. METHODS: We measured immunoglobulin (Ig)G and IgM autoantibody titers to copper-oxidized-LDL and malondialdehyde-LDL (OxLDL-AB), IgG and IgM apolipoprotein B-100-immune complexes (ApoB-IC), and titers of antibodies to Escherichia coli and chlamydial lipopolysaccharide (LPS), mycobacterial heat shock protein 65 (mHSP65), Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus and evaluated their relationship to cardiovascular risk factors, chronic infections, and incident/progressive carotid atherosclerosis in the Bruneck study. RESULTS: The OxLDL-AB and ApoB-IC levels remained stable over time as indicated by strong correlations between 1995 and 2000 measurements (p < 0.001 each). Significant associations existed between all OxLDL markers and antibody titers to pathogens, especially to E. coli-LPS and mHSP65. Both OxLDL-AB and ApoB-IC levels showed a rise with increasing pathogen burden. Notably, OxLDL-ABs were also elevated in subjects with chronic infection as defined by clinical criteria. Titers of IgG, but not IgM, OxLDL-AB, or ApoB-IC inversely correlated with total cholesterol, LDL cholesterol, and apoB concentrations. The IgG OxLDL markers were positively and IgM markers were inversely associated with incident and progressive carotid atherosclerosis in univariate analyses but were not independent predictors in multivariate analyses. CONCLUSIONS: Our study provides evidence for an association between human oxLDL markers and chronic infections. Moreover, in this population-based study, neither IgG nor IgM OxLDL autoantibodies were independently predictive of atherosclerosis progression in the carotid arteries.     

Oxidized phospholipids predict the presence and progression of carotid and femoral atherosclerosis and symptomatic cardiovascular disease: five-year prospective results from the Bruneck study.

OBJECTIVES: The purpose of this work was to determine the predictive value of oxidized phospholipids (OxPLs) present on apolipoprotein B-100 particles (apoB) in carotid and femoral atherosclerosis. BACKGROUND: The OxPLs are pro-inflammatory and pro-atherogenic and may be detected using the antibody E06 (OxPL/apoB). METHODS: The Bruneck study is a prospective population-based survey of 40- to 79-year-old men and women initiated in 1990. Plasma levels of OxPL/apoB and lipoprotein (a) [Lp(a)] were measured in 765 of 826 (92.6%) and 671 of 684 (98.1%) subjects alive in 1995 and 2000, respectively, and correlated with ultrasound measures of carotid and femoral atherosclerosis. RESULTS: The distribution of the OxPL/apoB levels was skewed to lower levels and nearly identical to Lp(a) levels. The OxPL/apoB and Lp(a) levels were highly correlated (r = 0.87, p < 0.001), and displayed long-term stability and lacked correlations with most cardiovascular risk factors and lifestyle variables. The number of apolipoprotein (a) kringle IV-2 repeats was inversely related to Lp(a) mass (r = -0.48, p < 0.001) and OxPL/apoB levels (r = -0.46, p < 0.001). In multivariable analysis, OxPL/apoB levels were strongly and significantly associated with the presence, extent, and development (1995 to 2000) of carotid and femoral atherosclerosis and predicted the presence of symptomatic cardiovascular disease. Both OxPL/apoB and Lp(a) levels showed similar associations with atherosclerosis severity and progression, suggesting a common biological influence on atherogenesis. CONCLUSIONS: This study suggests that pro-inflammatory oxidized phospholipids, present primarily on Lp(a), are significant predictors of the presence and extent of carotid and femoral atherosclerosis, development of new lesions, and increased risk of cardiovascular events. The OxPL biomarkers may provide valuable insights into diagnosing and monitoring cardiovascular disease.     

Urinary albumin excretion is independently associated with carotid and femoral artery atherosclerosis in the general population.

AIMS: In diabetic patients, increased urinary albumin excretion (UAE), termed microalbuminuria when in the range between 30 and 300 mg/dL per day, is associated with a higher risk of atherosclerosis and its complications. Whether or not this notion applies to the general population is a matter of ongoing controversy because none of the few previous investigations among non-diabetics strictly represent the general community. METHODS AND RESULTS: Urinary albumin-to-creatinine ratio (uACR), a measure of UAE, was assessed from overnight spot urine samples in a population-based cohort of 684 individuals. The ratio was significantly related to age, gender, blood pressure, diabetes, markers of systemic inflammation, liver enzymes, and parathyroid hormone levels (P<0.001 each). Moreover, uACR emerged as a highly significant risk predictor of carotid and femoral artery atherosclerosis in the general community and the non-diabetic subpopulation alike (age/sex-adjusted P<0.001 each). In multivariable logistic regression analyses, odds ratios (95% CI) of carotid and femoral atherosclerosis amounted to 1.28 (1.01-1.61) and 1.44 (1.15-1.81) for a one unit increase in log(e)-transformed uACR (P=0.040 and 0.002). Corresponding odds ratios in non-diabetic subjects were 1.41 (1.09-1.84) and 1.54 (1.19-1.99) (P=0.010 and 0.001). Multivariable linear regression analyses yielded significant, or near significant, relations with carotid and femoral artery intima-media thickness and atherosclerosis scores (P=0.058-0.001). CONCLUSION: The uACR is significantly and independently associated with the presence and severity of atherosclerosis in the general population. The relation obtained was of a dose-response type and extended to levels far below what is termed microalbuminuria. The novel aspects of our study are its focus on various vascular territories and representivity of the general healthy population.     

High-sensitivity C-reactive protein and risk of nontraumatic fractures in the Bruneck study

BACKGROUND: Chronic inflammatory diseases are associated with bone loss and an enhanced fracture risk. It is unknown, however, whether low-grade inflammation in healthy individuals, as estimated by the high-sensitivity C-reactive protein (hs-CRP) level, interferes with bone metabolism and affects the risk of nontraumatic fractures. METHODS: Lifetime bone fractures were carefully recorded in the cohort of the population-based Bruneck Study (n = 919) along with information on the date of occurrence and associated circumstances. The serum level of hs-CRP was measured from blood samples collected during the 1990 baseline examination and the 1995, 2000, and 2005 follow-up examinations. In addition, lifestyle and demographic characteristics, bone ultrasonographic data at the heel, and variables of bone metabolism were assessed. RESULTS: Between September 1, 1990, and August 31, 2005, 69 subjects experienced nontraumatic hip or vertebral fractures. The incidence of nontraumatic fractures was 1.3, 3.8, and 13.9 per 1000 person-years in the tertile groups for hs-CRP. In multivariate pooled logistic regression analysis, the adjusted relative risk (95% confidence interval) of nontraumatic fracture in the highest vs lowest tertile group for hs-CRP was 9.4 (3.6-24.8) (P < .001). The exclusion of subjects with cardiovascular disease, dementia, malignancies, and chronic inflammatory disease had little effect on the results obtained. The hs-CRP level was unrelated to ultrasonographic measures of bone density, but showed an inverse relation to laboratory markers of bone turnover, like beta-crosslaps and osteocalcin concentration (P < .001). CONCLUSIONS: The hs-CRP level is a significant and independent risk predictor of nontraumatic fracture. This finding is consistent with the hypothesis of a tight interplay between low-grade inflammation and bone turnover.