Prevalence of idiopathically elevated ESR and CRP in patients undergoing primary total knee arthroplasty as a function of body mass index

BACKGROUND

Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are commonly used inflammatory markers utilized to aid in the diagnosis of periprosthetic infection (PJI). Patients with obesity, however, are known to have elevated baseline levels of these inflammatory markers. Therefore, this retrospective study aimed to determine the relationship between elevated ESR and CRP and body mass index (BMI) in patients undergoing total knee arthroplasty (TKA). In doing so, physicians can better determine whether BMI should be taken into account when evaluating the prognostic value of elevated preoperative ESR and CRP levels for risk of PJI in primary TKA patients.

METHODS

This is a retrospective case series of 181 patients who had undergone primary TKA at a single institution. Patients undergoing primary unilateral TKA were eligible unless they had undergone previous TKA, contralateral knee symptoms, or elevated white blood cell (WBC) count. A linear regression model was utilized to demonstrate the relationship between proportions of patients with elevated biomarker values and categories of BMI. Analysis of variance and independent two-sample t-tests were utilized to assess differences in mean ESR, CRP, and WBC levels between the "healthy patients" and "patients with comorbidities" subgroups within each BMI category.

RESULTS

Eligible patients (n = 181) were stratified by BMI category. Elevated ESR was associated significantly with BMI (ESR: r2 = 0.89, P < 0.001) unlike elevated CRP (r2 = 0.82, P = 0.133) and WBC count (r2 = .01; P = .626). No statistically significant differences in ESR values and WBC count between the "healthy patients" versus "patients with comorbidities" were demonstrated within any BMI category. In patients of normal weight (BMI 20-25 kg/m2), "healthy patients" had a statistically significantly higher mean CRP level than "patients with comorbidities" (1.73 mg/L vs. 0.70 mg/L, P < 0.001). There were no other statistically significant differences in mean CRP levels by health status.

CONCLUSION

Caution is advised when utilizing ESR and CRP to diagnose periprosthetic joint infection without considering BMI given that increasing preoperative levels of ESR and CRP are correlated with higher BMI.

Risk Factors for Postoperative Urinary Tract Infections Following Anterior Lumbar Interbody Fusion

BACKGROUND

Although risk factors contributing to UTI have been studied in posterior approaches to lumbar fusion, there is a lack of literature on factors contributing to UTI in anterior lumbar interbody fusion (ALIF). Our purpose was to identify preoperative independent risk factors for postoperative urinary tract infection (UTI) following anterior lumbar interbody fusion (ALIF) so that surgeons may be able to initiate preventative measures and minimize the risk of UTI-related morbidity following ALIF.

METHODS

The American College of Surgeons-National Surgical Quality Improvement Program database was queried to identify 10 232 patients who had undergone ALIF from 2005 to 2016; 144 patients (1.41%) developed a postoperative UTI while 10 088 patients (98.59%) did not. Univariate analyses were conducted to compare the 2 cohorts' demographics and preoperative comorbidities. Multivariate logistic regression models were then utilized to identify significant predictors of postoperative UTI following ALIF while controlling for differences seen in univariate analyses.

RESULTS

Age ≥ 60 years (P = .022), female sex (P < .001), alcohol use (P = .014), open wound or wound infections (P = .019), and steroid use (P = .046) were independent risk factors for postoperative UTI. Longer operative times were also independent predictors for developing UTI: 120 minutes ≤ x < 180 minutes (P = .050), 180 minutes ≤ x < 240 minutes (P = .025), and ≥ 240 minutes (P = .001). Postoperative UTI independently increased the risk for pneumonia, blood transfusions, sepsis, thromboembolic events, and extended length of stay as well.

CONCLUSIONS

Age ≥ 60 years, female sex, alcohol use, steroid use, and open wound or wound infections independently increased the risk for UTI following ALIF. Future work analyzing the efficacy of tapering alcohol and steroid use preoperatively and reducing procedural time with the aim of lowering UTI risk is warranted. Preoperative wound care is strongly encouraged to decrease UTI risk.

LEVEL OF EVIDENCE

III.

Outcomes following outpatient anterior cervical discectomy and fusion for the treatment of myelopathy

INTRODUCTION

Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for the treatment of degenerative cervical disease. With continued increase in U.S. healthcare expenditure, surgeons have begun to more closely examine the benefits of performing ACDF in an outpatient setting to increase efficiency, reduce the overall financial burden on patients/providers, and provide streamlined care for these patients. The purpose of this study was to analyze outcomes following outpatient ACDF for the treatment of myelopathy.

METHODS

14,490 patients who had undergone ACDF for myelopathy from 2010 to 2018 were included in this retrospective study, of which 2956 (20.40%) patients were considered to have undergone outpatient surgery. Pearson chi-squared tests and Fischer's Exact Tests were used to analyze differences in categorical variables of demographics, preoperative comorbidities, and postoperative complications, while Mann-Whitney-U-Tests were used to compare mean values of continuous variables. Coarsened-exact-matching (CEM) was implemented to control for baseline differences in demographics and comorbidities, and post-matching diagnostics included multivariate and univariate imbalance measure assessment. Outcomes were compared between the CEM-matched inpatient and outpatients ACDF cohorts.

RESULTS

Upon CEM-matching (L1-statistic <0.001), the outpatient cohort (n = 2610, 25.13%) demonstrated significantly lower rates of any complication (p < 0.001), minor complications (p = 0.001), urinary tract infections (p = 0.029), blood transfusions (p < 0.001), major complications (p < 0.001), deep incisional surgical site infections (p = 0.017), ventilator dependence (p = 0.027), cardiac arrest (p = 0.028), unplanned reoperations (p = 0.001), and mortality (p = 0.006) in the 30-day postoperative period when compared to inpatient controls (n = 7774, 74.87%).

CONCLUSION

ACDF has been a target amongst spinal procedures as a prime candidate for outpatient surgery. However, no previous reports have described complication rates and perioperative parameters in the sub-population of outpatient ACDF patients with myelopathy. In addition to shorter times from admission to operating room, operative time, and LOS, our study also demonstrated lower rates of major and overall complications in outpatient ACDF's for myelopathy in comparison to their inpatient counterparts. Performing ACDF's for myelopathy in an outpatient setting may help to curb costs, improve outcomes, and serve as a valuable learning resource for graduate medical education with rapid turnovers and shorter operative times.

TEK is a novel prognostic marker for clear cell renal cell carcinoma

OBJECTIVE

Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer. However, effective therapeutics for ccRCC are lacking. Novel biomarkers could provide critical information when determining prognoses for patients with ccRCC. In this study, we sought to determine if the expression of receptor tyrosine kinase (TEK) could be a potential novel prognostic biomarker for ccRCC. TEK, originally identified as an endothelial cell-specific receptor, plays an important role in the modulation of vasculogenesis and remodeling. Altered TEK expression has been observed in tumor tissues (e.g., oral squamous cell carcinomas, leukemia) and breast, gastric and thyroid cancers. However, the role of TEK in ccRCC remains unknown.

PATIENTS AND METHODS

Differential TEK expression between non-metastatic (stage M0) and metastatic (stage M1) ccRCC patient cohorts was determined from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC). Furthermore, TEK expression was assessed as a prognostic factor using the time-dependent area under the curve (AUC) of Uno's C-index, the AUC value of the receiver operating characteristics (ROC) at 5 years, Kaplan-Meier survival curves and multivariate analyses.

RESULTS

A Kaplan-Meier curve analysis revealed that the downregulation of TEK expression was associated with a poor prognosis for patients with ccRCC with good discrimination (p<0.0001 and p=0.0044 for the TGCA and ICGC cohorts, respectively). Analyses of C-indices and receiver operating characteristic AUC values further support this discriminative ability. Moreover, multivariate analyses showed the prognostic significance of TEK expression levels (p<0.001).

CONCLUSIONS

Although additional clinical investigations will be needed, our results suggest that TEK is a potential biomarker for ccRCC.

Total Hip Arthroplasty for the Sequelae of Femoral Neck Fractures in the Pediatric Patient

Although rare, total hip arthroplasty (THA) may be indicated in pediatric patients with degenerative changes of the hip joint after previous trauma. To illustrate management principles in this patient population, this study describes the case of a 15-year-old female who sustained bilateral femoral neck fractures after a generalized tonic-clonic seizure, an atypical, low-energy mechanism for this injury. These fractures were not diagnosed until 14 weeks after the seizure episode, at which point they had progressed to nonunion on the left side, malunion on the right side, and degenerative hip joint changes were developing bilaterally. Bilateral THA was ultimately performed, and the patient had favorable outcomes at 1 year postoperatively. In determining the optimal management strategy for such patients, a multidisciplinary approach should be used, with input from the patient’s family, pediatrician, pediatric endocrinologist, pediatric orthopaedic surgeon, and adult reconstruction surgeon. From a surgical standpoint, this report highlights the importance of selecting the appropriate bearing surfaces, broaching technique, mode of implant fixation, and implant features when performing THA in the active pediatric patient.

0321 Increased Slow-Wave Activity Predicts Slower Processing Speed in Toddlers

Introduction

Slow-wave activity (SWA) shows an inverted U-shaped time course during development. Specifically, maximal SWA undergoes a posteroanterior shift from 2 to 20 years of age, which may reflect cortical maturation. Previously, we showed that greater slow sigma power during sleep predicted faster reaction time in preschool-aged children. To date, little is known about the relationship between SWA and processing speed (PS), a basic fundament underlying complex cognitive skills in early development.

Methods

This project examined the relationship between SWA and PS in 2.5-3.0-year-old children (n=26, 50% males) via home-based assessments. After a 5-day stabilization sleep schedule, a baseline sleep EEG recording was performed on participants at 4 electrode placements: Fz, Oz, C3, and C4. SWA EEG spectral power was quantified in the 0.75-4.5 Hz rangeduring the first 60 minutes of NREM sleep. PS was obtained as part of a standard cognitive assessment via a computer-based task one hour after waking from a midday nap.

Results

On average, reaction time (PS) was 2111 ± 08 ms and SWA was 856.4 ± 300.7 µV2/Hz. Increased SWA in the occipital region was predictive of a longer reaction time and therefore slower PS (r = 0.44, p = 0.03). This relationship showed differences between sexes, suggesting that females (r = 0.26, p = 0.07) may show a stronger association between SWA in the occipital brain region and PS than males (r = 0.09, p = 0.33).

Conclusion

Interestingly, these findings contradict our hypothesis based on previous data with older children indicating that greater SWA was associated with more advanced behavioral and cognitive skills. This discrepancy may reflect the stark individual differences present within this rapidly maturing age group.

Support

Research support from NIH R01-MH086566 to MKL.

Comparative Analysis of Gait Speed Estimation Using Wideband and Narrowband Radars, Thermal Camera, and Motion Tracking Suit Technologies

Research has shown that cognitive and physical functioning of older adults can be reflected in indicators such as walking speed. While changes in cognition, mobility, or health cause changes in gait speed, often gradual variations in walking speed go undetected until severe problems arise. Discrete clinical assessments during clinical consultations often fail to detect changes in day-to-day walking speeds and do not reflect walking speeds in everyday environments, where most of the mobility issues happen. In this paper, we compare four walking speed measurement technologies to a GAITRite mat (gold standard): (1) an ultra wideband radar (covering the band from 3.3 GHz to 10 GHz), (2) a narrow band 24-GHz radar (with a bandwidth of 250 MHz), (3) a perception Neuron Motion Tracking suit, and (4) a thermal camera. Data were collected in parallel using all sensors at the same time for 10 healthy adults for normal and slow walking paces. A comparison of the sensors indicates better performance at lower gait speeds, with offsets (when compared to GAITRite) between 0.1 and 20% for the ultra wideband radar, 1.9 and 17% for the narrowband radar, 0.1 and 38% for the thermal camera, and 1.7 and 38% for the suit. This paper supports the potential of unobtrusive radar-based sensors and thermal camera technologies for ambient autonomous gait speed monitoring for contextual, privacy-preserving monitoring of participants in the community.

Repeat irrigation & debridement for patients with acute septic knee arthritis: Incidence and risk factors

BACKGROUND

Septic knee arthritis is considered an orthopedic emergency due to its significant morbidity and potential to be life-threatening. One important outcome in treatment of septic knee arthritis is whether return to the operating room for repeat irrigation and debridement is required. This complication presents extra burden to the patient, as well as to the health care system. This study aims to first isolate the incidence of repeat irrigation and debridement at the authors' home institution and then define risk factors for repeat washout for septic arthritis of the knee.

METHODS

Records from all patients at a single academic institution with acute septic knee arthritis who had arthroscopic or open I&D of the knee joint from January 2005-December 2015 were collected retrospectively. Patients were initially identified on the basis of diagnosis coding in the institution's medical information system. Following collection/screening based on strict inclusion/exclusion criteria, a cohort of 63 patients was ultimately included. 18 patients were assigned to a "repeat washout" (RW) cohort and 45 patients were assigned to a "no repeat washout" (NRW) cohort. Univariate analyses and multivariable regression models were performed between the two washout cohorts to identify variables associated with repeat washout.

RESULTS

Patients requiring a repeat washout (RW) had a statistically significant association with African American/Hispanic race, higher BUN levels, higher serum white blood cell (WBC) count on admission, concurrent infection, and isolated bacteremia when compared to those patients who did not require a repeat washout (NRW) (all respective P < 0.05). Multivariable regression analysis demonstrated concurrent infection and higher synovium WBC count to increase the risk for another repeat washout. Patients who had a concurrent infection were shown to have nearly 12-fold higher odds of needing a repeat washout than those without a concurrent infection (95% CI:2.40-56.88; P = 0.0023). For every 1000 unit increase in synovium WBC count, the odds of needing a repeat washout increased by 1% in patients with concurrent infection (95% CI:1-2%; P = 0.0168).

CONCLUSION

This study retrospectively isolated risk factors associated with repeat surgical lavage. In the multivariable regression analysis, both concurrent infection and increased synovial WBC count were significantly associated with the need for repeat knee I&D. This finding is significant, as it may signify a potential for increased infectious resilience for acute septic arthritis of the knee secondary to seeding from systemic infection, thus requiring multiple I&Ds to meet resolution. This finding may carry clinical significance in the early stages of patient counseling regarding hospital course and prognosis.

LEVEL OF EVIDENCE

IV.

The impact of chronic kidney disease on postoperative complications in patients undergoing revision total knee arthroplasty: A propensity matched analysis

OBJECTIVES

Though the role of chronic kidney disease (CKD) has been studied previously in primary arthroplasty procedures of the hips and knees, there is a paucity of literature analyzing CKD's impact on surgical outcomes in revision total knee arthroplasty (rTKA) patients. As the number of patients with CKD requiring revision surgery increases, more vigilant pre-operative and post-operative measures can be taken to ensure successful outcomes. This retrospective study sought to 1) determine differences in demographics and preoperative comorbidities of patients with normal or mild CKD and those with moderate/severe CKD and 2) establish moderate/severe CKD as an independent risk factor for complications in the 30-day postoperative period in patients undergoing rTKA.

METHODS

The ACS-NSQIP database was queried for patients who had undergone rTKA from 2005 to 2016. Patient were assigned to one of five CKD severity classes after eGFR calculation and were further stratified into two cohorts: stages 1/2 vs. stages 3/4/5. After propensity matching to generate a matched normal/mild CKD cohort of rTKA patients, univariate and multivariate analyses were used to assess differences and the impact of severe CKD on the risk for complications.

RESULTS

There were significant differences in several demographic features, comorbidities, and complications between the two cohorts upon univariate analyses. Upon multivariate analyses, CKD of moderate/severe/failure status was found to be a significant independent risk factor for acute renal failure (OR 18.097, 95% CI 4.970-65.902, p < 0.001), blood transfusions (OR 1.697, 95% CI 1.500-1.919, p < 0.001), return to the operating room (OR 1.257, 95% CI 1.009-1.566, p = 0.041), extended length of stay (OR 1.707, 95% CI 1.292-2.255, p < 0.001), and mortality (OR 2.165, 95% CI 1.116-4.200, p = 0.022) in the 30-day postoperative period.

CONCLUSION

This current study found moderate/severe CKD to be an independent risk factor for several complications and should guide healthcare professionals for better patient-optimization. Orthopaedic surgeons should factor in CKD severity in the management of patients undergoing rTKA to effectively mitigate the effects of adverse events.

82 Stage-specific expression of lineage marker genes and pluripotency marker distribution in porcine pre-implantation embryos

Lineage specification in pre-implantation embryos has been revealed, and it was expedited recently by single cell studies. However, data on expression marker genes and proteins in porcine embryos were still missing. We aimed to investigate the expression and distribution of marker genes and proteins, respectively, in IVF and parthenogenetically activated (PA) embryos. For this, cumulus-free oocytes were co-incubated with sperm in modified Tris-buffered medium (mTBM) for 5h and PA was performed using an electric pulse in activation medium. Following this, the embryos were incubated in porcine zygote medium 3 (PZM3). We first tested gene expression level of lineage candidates (internal control; β-actin). In IVF embryos (30, 25, 20, 15, 10, and 5 embryos pooled on Day 2, 3, 4, 5, 6, and 7; replicated 3 times), trophectoderm (TE)-specific genes (Dab2, Gata3) showed peaks on Day 4-5. Within the 2 genes, Dab2 had an earlier peak than Gata3. Inner cell mass (ICM) marker candidates (Nanog, Sox2, and Hnf4a) had diverse patterns. The Nanog and Sox2 genes had peak expression on Day 3. The Nanog expression dropped gradually, but Sox2 dropped suddenly on Day 4. Otherwise, Hnf4a expressed little in Day 3 and expression was sustained from Day 4 to 7. Primitive endoderm markers showed the highest expression on Day 4. We also checked expression level of ICM markers (Sox2, Oct4, and Nanog) in PA embryos (20, 20, 20, 10, and 5 embryos were pooled in 2, 4, 6-8 cells, morula, early, and late blastocyst stages; replicated 3 times). Expression of markers was similar (the highest in the 6-8-cell stage; at least 7.3-, 4.5-, and 3.7-fold compared with the other stages in Sox2, Oct4, and Nanog). We used analysis of variance and Tukey's test for statistical analysis. Following this, we conducted immunocytochemistry with both IVF and PA embryos (20 in each condition). Primary antibodies were treated overnight at 4°C and appropriate secondary antibodies were treated 1h at room temperature. In the case of IVF, well-known ICM markers (SOX2, OCT4, NANOG, and SOX17) showed restricted distribution in nuclei of ICM cells. However, DAB2 was distributed in the cytoplasm of TE cells. In PA embryos, SOX2 and NANOG distributions were similar to IVF. The OCT4 in ICM cells from morula to early blastocyst was restricted, but not in Day 7 embryos. In conclusion, marker genes showed diverse expression pattern in IVF, but all ICM-specific genes had a similar pattern in PA. Also, ICM marker proteins were restricted in nuclei of ICM cells only except Day 7 PA. Our results provide eye-opening information on marker contribution to lineage specification of porcine embryos. This work was supported by the National Research Foundation in Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03032256, NRF-2019R1C1C1004514).

Impact of diabetes mellitus on surgical complications in patients undergoing revision total knee arthroplasty: Insulin dependence makes a difference

OBJECTIVES

Assessing the effects of diabetes mellitus (DM), non-insulin-dependent diabetes mellitus (NIDDM), and insulin-dependent diabetes mellitus (IDDM) on revision TKA (rTKA) has become increasingly imperative due to the increased rates of revisions associated with DM. This study sought to identify complications in rTKA that were independently associated with NIDDM/IDDM compared to non-diabetic (Non-DM) patients and whether IDDM was associated with specific postoperative complications compared to NIDDM.

METHODS AND MATERIALS

16,428 rTKA patients were identified from the ACS-NSQIP database from 2005 to 2016 and stratified into three separate cohorts. 12,922 (78.66%) were Non-DM, 2335 (14.21%) had NIDDM, and 1171 (7.13%) had IDDM. Univariate analyses were utilized to assess for differences in demographics, preoperative comorbidities, and postoperative complication rates. Multivariate logistic regression analyses were then employed to control for significant differences in patients characteristics to assess NIDDM and IDDM as independent risk factors for complications in comparison to Non-DM. IDDM was further analyzed as a risk factor in comparison to NIDDM for the purpose of elucidating the impact of insulin dependence on risk for postoperative complications.

RESULTS

NIDDM was an independent risk factor for deep incisional surgical site infections (Odds Ratio (OR): 2.477) and urinary tract infections (UTI) (OR 1.862) (p < 0.05). Compared to NIDDM, IDDM was independently associated with greater risk for pneumonia (OR 2.603), septic shock (OR 6.597), blood transfusions (OR 1.326), and an extended length of stay (OR: 1.331) (p < 0.05). IDDM additionally increased the risk for acute renal failure (OR 3.269) and cardiac arrest (OR 3.268) (p < 0.05) when compared to Non-DM. DM patients overall had increased rates of worse outcomes and infectious complications.

CONCLUSION

Although differences between diabetes and non-diabetes rTKA patients were seen, differences in complication rates between diabetes patients further divided based on insulin dependence status were also noted. Future work examining whether targeting perioperative glucose levels <200 mg/dL in DM rTKA patients decreases infectious complications is warranted. Future work analyzing the role of tranexamic acid administration and 24-h postoperative antibiotics in rTKA IDDM patients may be warranted given the elevated risk of pneumonia, septic shock, and blood transfusions.

81 Linoleic acid required for reduction of apoptosis through nuclear transcription factor-kappa B during pig embryo development

Recent studies suggest that endogenous and exogenous free fatty acids play various important roles in mammalian oocyte and pre-implantation embryo development. Among fatty acids, linoleic acid (LA) has been reported to affect the apoptosis pathway via nuclear transcription factor-kappa B (NF-κB). The transcription factor NF-κB is a key modulator of apoptosis in a variety of cell types, but to date, this specific function of NF-κB has not been demonstrated in porcine pre-implantation embryos. To examine the effect of linoleic acid on invitro-produced parthenogenetic pig embryos, we treated LA by concentration (0, 10, 25, 50, and 100 µM) to identify developmental rate, NF-κB expression, and mRNA level of apoptotic-related genes. In addition, the mechanism was confirmed by examining the protein and mRNA expression of NF-kb and c-jun by immunostaining and quantitative PCR at the blastocyst stage. Linoleic acid had a positive effect on embryo development without toxicity at a certain concentration (25 µM), but toxicity was confirmed at higher (50-100μM) concentrations. Furthermore, it was confirmed that the concentration of NF-κB increased as the treatment concentration of LA increased, which was found to increase even at the concentration at which embryo development decreased. Previous studies have shown that the NF-κB pathway is involved in regulating anti- and pro-apoptotic gene expression. We also investigated the effects of LA on anti- (Bcl-xL, Mcl-1) and pro- (BAX1, TP53, Caspase3) apoptotic genes and NF-κB activation-related genes (RelA, JNK1, JNK2, IL-6) in porcine embryos. We have found that down-regulation of pro-apoptotic gene expression occurs in the LA-treated group. It was also found that Bcl-xL, one of the anti-apoptotic genes, was not affected by LA, which appears to be an effect of IL-6. In contrast, Mcl-1, an anti-apoptotic gene known not to be affected by IL-6, was found to have increased expression mRNA level in LA-treated pig embryos. Furthermore, through double-staining of apoptosis and immunocytochemistry, as the concentration of NF-kB level increases, the nuclear translocation of c-jun, the protein of which was also related with apoptosis, increased gradually depending on the LA concentration. These data could support that porcine embryo can use exogenous LA as a metabolic energy source. The data also demonstrate the important role of NF-kB in porcine early embryo development. Support was provided by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries (IPET) through the Development of High Value-Added Food Technology program funded by the Ministry of Agriculture, Food and Rural Affairs (MAFRA, 118042-03-1-HD020).

Peanut butter-based formulations of amoxicillin for pediatric applications

BACKGROUND

Child mortality is a major global health challenge, especially in regions of limited resources. Accessibility to lifesaving medicine and adequate nutrition is essential to reduce child mortality and improve the health and well-being of the world's most vulnerable children.

METHODS

We have developed NutMox, a novel pediatric formulation of the β-lactam antibiotic amoxicillin in a matrix of peanut-based ready-to-use therapeutic food (RUTF) consisting of peanut butter, sugar, vegetable oil, dry milk and vitamins. NutMox is ready to use and thermostable, requires no chewing or pill swallowing and provides both an antibiotic and nutrition.

RESULTS

Amoxicillin in NutMox formulations was stable for at least 12 months at storage temperatures of 4°C, 25°C and 37°C. Amoxicillin formulated in NutMox displayed similar pharmacokinetics in mice to that in suspension.

CONCLUSIONS

Our results demonstrated the feasibility of a peanut butter-based matrix for pediatric formulations of amoxicillin, suggesting that such a matrix can serve as a base for delivering medications in addition to its current use as an RUTF.

Combined effects of HIV and obesity on the gastrointestinal microbiome of young men who have sex with men

OBJECTIVES

The prevalence of obesity is rising among people living with HIV, which may synergistically increase inflammation and the risk of associated diseases. Disruption of gut bacterial communities may be one of the key drivers of this inflammation; however, the combined effects of HIV and obesity on the microbiome have not been explored.

METHODS

This study included 381 men who have sex with men. Thirty-nine were HIV-positive and obese (H+O+), 143 were HIV-positive and nonobese, 64 were HIV-negative and obese, and 135 were HIV-negative and nonobese. Microbiome composition was assessed by targeted sequencing of the V4 region of the 16S ribosomal RNA (rRNA) gene using rectal swab samples. Inverse probability of treatment-weighted marginal structural models were used to investigate differences in microbial composition between groups while controlling for numerous clinical and behavioural confounders.

RESULTS

Significant variability in microbial composition was explained by the combination of HIV and obesity, over and above each condition alone (R² for the marginal contribution of the H+/O+ group = 0.008; P = 0.001). H+O+ participants had the highest ratios of Prevotella to Bacteroides, a pro-inflammatory enterotype that has been described in HIV infection and obesity independently. H+O+ participants had lower levels of Bacteroides and Veillonella than all other groups, suggesting a synergistic effect of HIV and obesity on these genera.

CONCLUSIONS

Our findings support the hypothesis that HIV and obesity act together to disrupt gut microbial communities, which may help explain higher levels of generalized inflammation among people living with both HIV and obesity.