Effects of 96 Weeks of Rosuvastatin on Bone, Muscle, and Fat in HIV-Infected Adults on Effective Antiretroviral Therapy

The Effect of Statin Therapy on Bone Metabolism Markers and Mineral Density: Aa GRADE-Assessed Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Purpose

Statin therapy is widely used for the management of dyslipidemia and the prevention of cardiovascular diseases (CVDs). However, there is a growing concern about its potential effects on bone metabolism markers and mineral density. The aim of this systematic review and meta-analysis was to investigate the effect of statin therapy on these parameters.

Methods

PubMed/MEDLINE, Scopus, and Clarivate Analytics Web of Science databases were searched from inception to August 2023, using MESH terms and keywords.

Results

After screening 2450 articles, 16 studies that met the inclusion criteria were included, of which 12 randomized controlled trials (RCTs) were used for meta-analysis. The findings showed that statin therapy significantly reduced bone-specific alkaline phosphatase (B-ALP) levels (WMD=-1.1 U/L; 95% CI -2.2 to -0.07; P=0.03; I2=0%,), and bone mineral density (BMD) at different sites (WMD=-0.06 g/cm2; 95% CI -0.08 to -0.04; P<0.001; I2=97.7%, P<0.001). However, this treatment did not have a significant effect on osteocalcin, serum C-terminal peptide of type I collagen (S-CTx), serum N-telopeptides of type I collagen (NTx) concentration, or overall fracture risk.

Conclusion

This systematic review and meta-analysis provide evidence that statin therapy is associated with a significant reduction in B-ALP levels and BMD at different sites of the skeleton. Further studies are needed to investigate the long-term effects of statin therapy on bone health and to identify the potential underlying mechanisms.

Pharmacological and Behavioral Interventions to Mitigate Premature Aging in Patients with HIV

PURPOSE OF REVIEW

We sought to review pharmacological and behavioral interventions that have been publicly presented, published, or are currently ongoing to prevent or mitigate the effect of premature HIV-associated comorbidities.

RECENT FINDINGS

Multiple studies have been conducted in hopes of finding an effective intervention. While the choice of antiretroviral regimen influences recovery of immune function, several drugs used as adjunct treatments have proven effective to mitigate premature aging. Additionally, few behavioral interventions have exhibited some efficacy. Statins, angiotensin-receptor blockers, and anti-hyperglycemic agents as well as optimal adherence, exercise, and intermittent fasting among others have had beneficial impact on markers of immune activation and levels of inflammatory biomarkers. However, several investigations had inconclusive outcomes so further studies with larger sample sizes are warranted.

A Systematic Review and Meta-Analysis on the Impact of Statin Treatment in HIV Patients on Antiretroviral Therapy

The rate of new human immunodeficiency virus (HIV) infections globally is alarming. Although antiretroviral therapy (ART) improves the quality of life among this group of patients, ARTs are associated with risk of cardiovascular diseases (CVD). Moreover, virally suppressed patients still experience immune activation associated with HIV migration from reservoir sites. Statins are widely recommended as therapeutic agents to control ART-related CVD; however, their impacts on the cluster of differentiation (CD)4 count and viral load are inconsistent. To assess the effect of statins on markers of HIV infections, immune activation and cholesterol, we thoroughly reviewed evidence from randomised controlled trials. We found 20 relevant trials from three databases with 1802 people living with HIV (PLHIV) on statin-placebo treatment. Our evidence showed no significant effect on CD4 T-cell count standardised mean difference (SMD): (-0.59, 95% confidence intervals (CI): (-1.38, 0.19), p = 0.14) following statin intervention in PLHIV on ART. We also found no significant difference in baseline CD4 T-cell count (SD: (-0.01, 95%CI: (-0.25, 0.23), p = 0.95). Our findings revealed no significant association between statins and risk of viral rebound in PLHIV with undetectable viral load risk ratio (RR): (1.01, 95% CI: (0.98, 1.04), p = 0.65). Additionally, we found a significant increase in CD8⁺CD38⁺HLA-DR⁺ T-cells (SMD (1.10, 95% CI: (0.93, 1.28), p < 0.00001) and CD4⁺CD38⁺HLA-DR⁺ T-cells (SMD (0.92, 95% CI: (0.32, 1.52), p = 0.003). Finally, compared to placebo, statins significantly reduced total cholesterol (SMD: (-2.87, 95% CI: (-4.08, -1.65), p < 0.0001)). Our results suggest that the statin lipid-lowering effect in PLHIV on ART may elevate immune activation without influencing the viral load and CD4 count. However, due to the limited evidence synthesised in this meta-analysis, we recommend that future powered trials with sufficient sample sizes evaluate statins' effect on CD4 count and viral load, especially in virally suppressed patients.

Effect of different antiretroviral therapy on muscle mass, bone mineral density, and trabecular bone score in Chinese HIV-infected males

This is the first study to report both greater BMD loss and muscle loss in Chinese HIV-infected males with lamivudine (3TC)-tenofovir disoproxil fumarate (TDF)-efavirenz (EFV) regimen, which highlights the importance of closely monitoring muscle mass and bone mineral density in patients treated with 3TC-TDF-EFV regimen and provides a foundation for the clinical intervention of sarcopenia and osteoporosis.

PURPOSE

To compare the effect initiating different antiretroviral therapy (ART) regimens have on muscle mass, bone mineral density (BMD), and trabecular bone score (TBS).

METHODS

We designed a retrospective study of ART-naive Chinese males with HIV (MWH) undergoing two different regimens at 1-year follow-up. All subjects underwent dual-energy absorptiometry (DXA) for BMD and muscle mass prior to ART initiation, and again 1 year later. TBS iNsight software was used for TBS. We analyzed differences in muscle mass, BMD, and TBS after different treatment arms and associations between ART regimens and changes in them.

RESULTS

A total of 76 men were included (mean age 31.83 ± 8.75 years). Mean absolute muscle mass decreased significantly from baseline to follow-up after initiation of lamivudine (3TC)-tenofovir disoproxil fumarate (TDF)-efavirenz (EFV), whereas increased significantly after initiation of 3TC-zidovudine(AZT)/Stavudine(d4T)-Nevirapine(NVP). Assignment to 3TC-TDF-EFV resulted in greater percentage loss in BMD at lumbar spine (LS) and total hip (TH) compared to 3TC-AZT/d4T-NVP, but this difference was not statistically significant at the femoral neck BMD and TBS. In the multivariable logistic regression model adjusted for covariates, the 3TC-TDF-EFV regimen was associated with higher odds of decreased appendicular and total muscle mass, LS and TH BMD.

CONCLUSIONS

This is the first study to report not only greater BMD loss but also muscle loss in Chinese MWH with 3TC-TDF-EFV regimen. Our work highlights the importance of closely monitoring muscle mass and BMD in patients treated with 3TC-TDF-EFV regimen and provides a foundation for the clinical intervention of sarcopenia and osteoporosis in them.

Statin protects men but not women with HIV against loss of muscle mass, strength, and physical function: a pilot study

Statins are cholesterol-lowering drugs commonly used among people with HIV, associated with an increased risk of myopathies. Considering that cardiovascular disease, statin therapy, and sarcopenia are independently prevalent in people with HIV, clarity on the potential benefits or harms of statin therapy on muscle health is useful to provide insight into ways to maximize skeletal muscle health and minimize CVD risk in this population. We aimed to study the effects of statin therapy on strength, muscle mass, and physical function parameters in people with HIV. This was a pilot cross-sectional study. People with HIV on continuous statin therapy (n = 52) were paired 1:1 according to age (people with HIV 53.9 ± 8.2 and people with HIV on statins 53.9 ± 8.4 years), sex, body mass index (Body mass index, people with HIV 28.6 ± 5.3 and people with HIV on statins 28.8 ± 6.3 kg/m²), and race with people with HIV not using statin (n = 52). Participants were evaluated for muscle strength (i.e. handgrip strength), lean and fat body mass (using bioelectric impedance analysis), and physical function (i.e. Short Physical Performance Battery-SPPB). Isokinetic strength and appendicular lean mass (using dual-energy X-ray absorptiometry), more accurate strength and body composition measures, were determined in 38% of the participants. Overall, statin usage does not exacerbated loss of muscle strength (32.2 ± 11.5 vs. 30.3 ± 9.6 kg, p > 0.05) muscle mass (7.6 ± 1.8 vs. 7.7 ± 1.1 kg/m², p > 0.05), and impaired physical performance (10.1 ± 1.8 vs. 9.7 ± 2.1 points, p > 0.05) of PLWH. When analyzed by sex, men living with HIV on statins usage presented higher appendicular muscle mass (28.4 ± 3.1 vs. 26.2 ± 4.9 kg, p < 0.05) handgrip strength (42.1 ± 8.8 vs. 37.1 ± 8.3 kg, p < 0.05) and physical function through SPPB score (10.9 ± 1.3 vs. 9.5 ± 2.1, p < 0.05) than men living with HIV not on statins treatment. The same protection was not observed in women. This data was demonstrated when muscle mass and strength were determined clinically (i.e. handgrip strength and electrical impedance) and when more precise laboratory measurements of muscle mass and strength were conducted (i.e. isokinetic strength and DXA scans). Statin does not exacerbate muscle wasting, strength loss, or muscle dysfunction among people with HIV. Indeed, statins may protect men, but not woman with HIV against HIV and antiretroviral therapy-induced loss of muscle mass and strength.

Statins in High Cardiovascular Risk Patients: Do Comorbidities and Characteristics Matter?

Atherosclerotic cardiovascular disease (ASCVD) morbidity and mortality are decreasing in high-income countries, but ASCVD remains the leading cause of morbidity and mortality in high-income countries. Over the past few decades, major risk factors for ASCVD, including LDL cholesterol (LDL-C), have been identified. Statins are the drug of choice for patients at increased risk of ASCVD and remain one of the most commonly used and effective drugs for reducing LDL cholesterol and the risk of mortality and coronary artery disease in high-risk groups. Unfortunately, doctors tend to under-prescribe or under-dose these drugs, mostly out of fear of side effects. The latest guidelines emphasize that treatment intensity should increase with increasing cardiovascular risk and that the decision to initiate intervention remains a matter of individual consideration and shared decision-making. The purpose of this review was to analyze the indications for initiation or continuation of statin therapy in different categories of patient with high cardiovascular risk, considering their complexity and comorbidities in order to personalize treatment.

Effect of Statin Therapy on Age-Associated Changes in Physical Function Among Men With and Without HIV in the Multicenter AIDS Cohort Study

BACKGROUND

The longer-term risks of statins on physical function among people with HIV are unclear.

METHODS

Longitudinal analysis of Multicenter AIDS Cohort Study men between 40 and 75 years of age with ≥2 measures of gait speed or grip strength. Generalized estimating equations with interaction terms between (1) statin use and age and (2) HIV serostatus, age, and statin use were considered to evaluate associations between statin use and physical function. Models were adjusted for demographics and cardiovascular risk factors.

RESULTS

Among 2021 men (1048 with HIV), baseline median age was 52 (interquartile range 46-58) years; 636 were consistent, 398 intermittent, and 987 never statin users. There was a significant interaction between age, statin, and HIV serostatus for gait speed. Among people with HIV, for every 5-year age increase, gait speed (m/s) decline was marginally greater among consistent versus never statin users {-0.008 [95% confidence interval (CI) -0.017 to -0.00007]; P = 0.048}, with more notable differences between intermittent and never users [-0.017 (95% CI -0.027 to -0.008); P < 0.001]. Similar results were observed among men without HIV. Significant differences in grip strength (kg) decline were seen between intermittent and never users [-0.53 (95% CI -0.98 to -0.07); P = 0.024] and differences between consistent and never users [-0.28 (95% CI -0.63 to 0.06); P = 0.11] were not statistically significant.

CONCLUSIONS

Among men with and without HIV, intermittent statin users had more pronounced declines in physical function compared with consistent and never users. Consistent statin use does not seem to have a major impact on physical function in men with or without HIV.

Physical Function Impairment and Frailty in Middle-Aged People Living With Human Immunodeficiency Virus in the REPRIEVE Trial Ancillary Study PREPARE

BACKGROUND

People with human immunodeficiency virus (PWH) are at risk for accelerated development of physical function impairment and frailty; both associated with increased risk of falls, hospitalizations, and death. Identifying factors associated with physical function impairment and frailty can help target interventions.

METHODS

The REPRIEVE trial enrolled participants 40-75 years of age, receiving stable antiretroviral therapy with CD4+ T-cell count >100 cells/mm3, and with low to moderate cardiovascular disease risk. We conducted a cross-sectional analysis of those concurrently enrolled in the ancillary study PREPARE at enrollment.

RESULTS

Among the 266 participants, the median age was 51 years; 81% were male, and 45% were black, and 28% had hypertension. Body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was 25 to <30 in 38% and ≥30 in 30%, 33% had a high waist circumference, 89% were physically inactive, 37% (95% confidence interval, 31%, 43%) had physical function impairment (Short Physical Performance Battery score ≤10), and 6% (4%, 9%) were frail and 42% prefrail. In the adjusted analyses, older age, black race, greater BMI, and physical inactivity were associated with physical function impairment; depression and hypertension were associated with frailty or prefrailty.

CONCLUSIONS

Physical function impairment was common among middle-aged PWH; greater BMI and physical inactivity are important modifiable factors that may prevent further decline in physical function with aging.

CLINICAL TRIALS REGISTRATION

NCT02344290.

Brief Report: Aging Attenuates the Association Between Coronary Artery Calcification and Bone Loss Among HIV-Infected Persons

INTRODUCTION

Studies among HIV-uninfected persons (mostly in their sixth decade of life) show that detectable coronary artery calcium (CAC) is independently associated with low bone mineral density (BMD), suggesting a possible common pathogenic mechanism.

AIM

We assessed the relationship between CAC and BMD, which has not been well described among younger to middle-aged HIV-infected persons.

METHODS

We studied participants with baseline CAC and BMD measures from a prospective cohort of HIV-infected persons enrolled in the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN) during 2004-2006. We used logistic regression to assess the association between detectable CAC (>0 Agatston score) and BMD (g/cm, T-score), and adjusted for known traditional and HIV-related risk factors.

RESULTS

Among 472 participants (76% male, 30% non-Hispanic black, median age 41 years, and 71% with HIV RNA < 400 copies/mL), the majority had no detectable CAC (82%), but had baseline osteopenia (53%) or osteoporosis (10%). In univariate analysis, participants with detectable CAC had lower femoral neck/total hip T-scores, lower femoral neck/total hip/lumbar spine BMD, and higher rates of osteopenia/osteoporosis. After adjustment for age, all associations were no longer significant; adjustment for traditional risk factors excluding age and HIV-related variables failed to attenuate these associations.

CONCLUSIONS

We found aging attenuates the association between detectable CAC and BMD in this cohort. Aging remains an important contributor to non-AIDS-defining illnesses. These data reinforce the importance of developing screening and prevention strategies for aging HIV-infected persons given their excess risk across a wide spectrum of end-organ complications.

Inflammation Strikes Again: Frailty and HIV

PURPOSE OF REVIEW

As a consequence of antiretroviral therapy, the proportion of older HIV-infected adults is increasing, with a concomitant shift in burden of illness to age-related syndromes and disease. Frailty is an age-related syndrome of increased vulnerability to stress, predictive of major adverse clinical outcomes among HIV-infected and uninfected persons alike. Understanding frailty pathogenesis is critical to developing interventions to improve health outcomes in HIV. Here, we review the current evidence for the relationship between inflammation and frailty in HIV, and the potential for novel, inflammation-targeted interventions.

RECENT FINDINGS

Dysregulated inflammation has been consistently associated with frailty in elderly HIV-uninfected persons. Dysregulated inflammation is also central to HIV pathophysiology and several recent studies have demonstrated the important association of inflammation with frailty in HIV. Some evidence suggests that anti-inflammatory therapies may be effective in ameliorating the adverse impact of frailty among aging HIV-infected adults, though further investigation is necessary. Inflammation has been implicated in frailty in HIV infection, and improved understanding of the role that inflammation plays in frailty pathogenesis is key to the development of effective therapies to slow or prevent frailty in the vulnerable HIV-infected population.

Fractures and the gut microbiome

PURPOSE OF REVIEW

The role of the gut microbiome in the pathogenesis of several inflammatory, non-AIDS comorbidities, such as cardiovascular disease, cognitive impairment and liver disease has become a focus of recent research. Low bone mineral density (BMD) and increased fracture incidence in people living with HIV (PLWH) is also widely reported, however, the relationship between alterations in the gut microbiome and bone disease in PLWH has not been previously reviewed.

RECENT FINDINGS

Murine models that manipulate the gut microbiome, either through breeding of 'germ-free' mice or antibiotic-depleted gut microbiome, show differences in bone mineral density and bone mass in those with altered gut microbiome. This effect is reported to be driven via changes in the gut-immune-skeletal axis, with changes favouring bone resorption. Several inflammatory conditions wherever bone loss is a prominent feature, such as rheumatoid arthritis and inflammatory bowel disease, have also reported alterations in the gut microbiome, which are associated with bone loss, again through changes in the gut-immune-skeletal axis.

SUMMARY

The interplay between the gut microbiome and the immune-skeletal axis in HIV represents a complex relationship. Alterations in the gut microbiome, which induce an activated immune phenotype and inflammatory milieu are associated with non-AIDS comorbidities in PLWH and bone loss in several other conditions characterized by chronic immune activation and inflammation. It is, therefore, likely that there are comparable effects between altered gut microbiome and bone loss in HIV, however, further research is required to better define this relationship in populations of PLWH.

Benefits and Risks of Statin Therapy in the HIV-Infected Population

PURPOSE OF REVIEW

HIV-infected patients face an increased risk for cardiovascular disease (CVD), estimated at 1.5- to 2-fold as compared to HIV-uninfected persons. This review provides a recent (within preceding 5 years) summary of the role of statin therapy and associated role in CVD risk reduction among HIV-infected patients on anti-retroviral therapy.

RECENT FINDINGS

Statins remain the preferred agents for reducing risk for CVD among HIV-infected populations based on guidance extrapolated from general population (HIV-uninfected) cholesterol treatment guidelines across different settings globally. However, HIV-infected patients are consistently under prescribed statin therapy when compared to their HIV-uninfected counterparts. The most commonly studied statins in clinical care and small randomized and cohort studies have been rosuvastatin and atorvastatin. Both agents are preferred for their potent lipid-lowering effects and their favorable or neutral pleotropic effects on chronic inflammation, renal function, and hepatic steatosis among others. However, growing experience with the newer glucuronidated pitavastatin suggests that this agent has virtually no adverse drug interactions with ART or effects on glucose metabolism-all marked additional benefits when compared with rosuvastatin and atorvastatin while maintaining comparable anti-lipid effects. Pitavastatin is therefore the statin of choice for the ongoing largest trial (6500 participants) to test the benefits of statin therapy among HIV-infected adults. Statins are underutilized in the prevention of CVD in HIV-infected populations based on criteria in established cholesterol guidelines. There is a potential role for statin therapy for HIV-infected patients who do not meet guideline criteria which will be further delineated through ongoing clinical trials.

Understanding mechanisms to promote successful aging in persons living with HIV

The mortality rate associated with HIV infection plummeted after the introduction of effective antiretroviral therapy pioneered two decades ago. As a result, HIV-infected people now have life expectancies comparable to that of HIV-uninfected individuals. Despite this, increased rates of osteoporosis, chronic liver disease, and in particular cardiovascular disease have been reported among people living with HIV infection. With the aging HIV-infected population, the burden of these comorbid illnesses may continue to accrue over time. In this paper, we present an overview of the aging HIV-infected population, its epidemiology and the many challenges faced. How to define and measure successful aging will also be reviewed. Finally, opportunities that may help mitigate the challenges identified and ensure successful aging among people living with HIV infection will be examined.

Bone Loss in HIV Infection

Human immunodeficiency virus (HIV) infection is an established risk factor for low bone mineral density (BMD) and subsequent fracture, and treatment with combination antiretroviral therapy (cART) leads to additional BMD loss, particularly in the first 1-2 years of therapy. The prevalence of low BMD and fragility fracture is expected to increase as the HIV-infected population ages with successful treatment with cART. Mechanisms of bone loss in the setting of HIV infection are likely multifactorial, and include viral, host, and immune effects, as well as direct and indirect effects of cART, particularly tenofovir disoproxil fumarate (TDF) and the protease inhibitors (PIs). Emerging data indicate that BMD loss following cART initiation can be mitigated by prophylaxis with either long-acting bisphosphonates or vitamin D and calcium supplementation. In addition, newer antiretrovirals, particularly the integrase strand transfer inhibitors and tenofovir alafenamide (TAF), are associated with less intense bone loss than PIs and TDF. However, further studies are needed to establish optimal bone sparing cART regimens, appropriate screening intervals, and preventive measures to address the rising prevalence of fragility bone disease in the HIV population.

Does systemic inflammation and immune activation contribute to fracture risk in HIV?

PURPOSE OF REVIEW

There is increasing evidence pointing toward an important role of heightened immune activation and inflammation in people living with HIV contributing to the development of non-AIDS comorbidities. This review aims to explore low bone mineral density (BMD) in HIV with a focus on the underlying mechanisms and relationships between the immune and skeletal systems.

RECENT FINDINGS

Baseline immune activation and inflammation negatively impact BMD at antiretroviral therapy (ART) initiation. B- and T-cell alterations in HIV lead to an imbalance in the osteoblastic osteoprotegerin (OPG) and osteoclastic receptor activator of NF-κB ligand (RANKL) cytokines which favours osteoclastogenesis and bone resorption. These findings suggest an important role for immune-mediated mechanisms in the pathogenesis of low BMD in HIV.

SUMMARY

Bone homeostasis is in part regulated by cells of the immune system through complex interactions with the RANK/RANKL/OPG axis. Disturbances in the normal functioning of T, B cells, and monocytes in HIV and the resulting proinflammatory state may contribute to dysregulation of this finely controlled balance leading to increased bone loss. Pre-ART levels of immune activation and inflammation have a consistently negative effect on BMD and further suggest the immunocentric basis of bone loss in HIV alongside supporting the benefits of earlier ART initiation. Further longitudinal studies will help determine the effect this will have on fracture risk in people living with HIV.

Incidental findings on chest computed tomography are common and linked to inflammation in HIV-infected adults

BACKGROUND

Chest imaging is performed for a variety of reasons in HIV-infected adults. There are limited data on the prevalence of incidental findings, progression of these findings over time and the relationship with inflammation in antiretroviral therapy (ART)-treated HIV-infected adults.

METHODS

This study utilized data from a randomized clinical trial of rosuvastatin in HIV-infected adults on ART. Incidental findings were reported from chest computed tomography (CT) scans obtained for coronary artery calcium score at entry, week 48 and 96. Markers of immune activation and inflammation were measured concurrently. Poisson regression and generalized estimating equations were used.

RESULTS

A total of 147 participants were enrolled. Median age was 46 years, 78% were male, 68% African American and 63% current smokers. At baseline, 57% of participants had at least one incidental lung finding (ILF) and four additional participants had at least one ILF by week 96. At baseline, older age, current smoking, lower nadir CD4⁺ T-cell count and low-density lipoprotein and higher lipoprotein-associated phospholipase A2 (Lp-PLA2) were independently associated with having a greater number of ILFs. In the longitudinal analyses, older age, lower nadir CD4⁺ T-cell count and higher baseline soluble tumour necrosis factor α-receptor I (sTNF-RI) were independently associated with having a greater number of ILFs over 96 weeks.

CONCLUSIONS

Over half of participants had at least one incidental finding on chest CT. Beyond traditional factors of older age and smoking, lower nadir CD4⁺ T-cell count and higher markers of inflammation were associated with having a greater number of ILFs in HIV-infected adults on ART.

The influence of oral administration of rosuvastatin on calvarial bone healing in rats

The purpose of this study is to investigate the potential of the systemic administration of different doses of rosuvastatin (RSV) on autogenous grafted critical-sized cortical bone defects. Twenty-four rats were divided into three groups: Group C (control), Group RSV-2 and Group RSV-5. A 5-mm diameter critical-size defect was created in the calvarium of each animal. In Group C, the defect was filled by autogenous graft only and rats were given saline solution with oral gavage for 28 days. In Group RSV-2 defects were filled with autogenous graft and rats were given 2 mg/kg rosuvastatin with oral gavage for 28 days. In Group RSV-5 defects were filled with autogenous graft and rats were given 5 mg/kg rosuvastatin with oral gavage for 28 days. All animals were euthanized at 28 days postoperative. Stereologic and micro-CT analyses were performed. New bone area (NBA) and connective tissue volumes were measured. Stereologic analysis showed that Group RSV-5 and RSV-2 had significantly more new bone at 4 weeks compared with group C. Connective tissue volumes were also significantly higher in RSV applicated groups. New bone and connective tissue volumes' difference were not statistically significant between RSV groups. Micro-CT results were similar with stereologic analyses. Orally administered RSV enhances bone regeneration in critical size calvarial rat defects filled with autogenous graft furthermore possible inflammatory effect should be investigated.