AB1018 TREATMENT RESPONSE OF HYDRONEPHROSIS ASSOCIATED WITH IDIOPATHIC RETROPERITONEAL FIBROSIS, FOCUSING ON RATIO OF IgG4/IgG3 SERUM CONCENTRATION

Background:

Hydronephrosis, a common complication of idiopathic retroperitoneal fibrosis (iRPF), may lead to poor renal outcomes unless it is resolved. Pathological confirmation can help to identify the aetiology of the disease and determine the treatment strategy. But, in most cases, it is difficult to obtain sufficient tissue due to the location of fibrosis. In a recent study, parts of iRPF are correlated with IgG4-related disease characterised by elevated serum IgG4 levels (>135 mg/dL). Normal serum IgG3 level (21–176 mg/dL) has been known to be higher than normal serum IgG4 level (4–86 mg/dL). The reverse IgG4/IgG3 ratio has been suggested to be an IgG4-related disease component that distinguishes it from primary sclerosing cholangitis [1]. However, the ratio of IgG3 and IgG4 may be reversed in iRPF patients with hydronephrosis.

Objectives:

We aimed to investigate the ratio of IgG subclasses as a predictive factor associated with treatment response of hydronephrosis in patients with iRPF.

Methods:

We retrospectively recruited 19 iRPF patients with hydronephrosis who evaluated serum IgG subclasses in a tertiary hospital between 2004 and 2019. Hydronephrosis was evaluated on the basis of imaging findings. Medications and clinical and laboratory findings, including IgG subclasses, were reviewed following the diagnosis of hydronephrosis. Hydronephrosis improvement on subsequent images was evaluated to assess treatment response. Categorised data were compared using chi-square or Fisher’s exact test. Continuous variables were compared using Mann–Whitney U test.

Results:

At baseline, median serum IgG3 and IgG4 levels were 64 (IQR 37–82) mg/dL and 71 (IQR 40–171) mg/dL. Five patients had serum IgG4 levels > 135 mg/dL and 11 patients had the reverse serum level of IgG4/IgG3. On subsequent images (median follow-up at 3.2 [IQR 1.7–4.0] months), 11 patients showed hydronephrosis improvement. The proportions of positive ratio of serum IgG4/IgG3 (81.8% vs. 25%, p = 0.024), periaortic involvement (81.8% vs. 25%, p = 0.024) and high-dose glucocorticoid treatment (45.5% vs. 0%, p = 0.045) were significantly higher in patients with improvement than in those without improvement (Table 1). Interestingly, even in cases with normal serum IgG4 levels, patients with improvement showed a higher serum IgG4/IgG3 ratio than in those without improvement (median 1.5 vs. 0.7, p = 0.038).

Table 1.

Clinical characteristics and treatment according to the shortterm outcome of hydronephrosis

Improvement(n = 11)No improvement(n = 8)p-valueTime to subsequent imaging (months)a2.2 (1.3–4.2)3.2 (2.0–3.8)0.778Males (n, %)8 (72.7%)7 (87.5%)0.603Periaortic involvement (n, %)9 (81.8%)2 (25%)0.024Impaired renal function (n, %)b5 (45.5%)2 (25%)0.633Serum IgG4 (mg/dL)a114 (59–172)43 (35–109)0.152Elevated serum IgG4 (n, %)4 (36.4%)1 (12.5%)0.338Serum IgG4/IgG3 ratioa2.1 (1.2–4.9)0.8 (0.4–1.0)0.041Positive ratio of serum IgG4/IgG3 (n, %)9 (81.8%)2 (25%)0.024Medical treatment (n, %)7 (63.6%)1 (12.5%)0.059High-dose glucocorticoid treatment (n, %)5 (45.5%)0 (0%)0.045Surgical intervention (n, %)8 (72.7%)4 (50%)0.377

aValues are median and interquartile range (25th–75thpercentile)

bDefined as serum creatinine level > 1.24 mg/dL

Conclusion:

The reverse ratio of serum IgG4/IgG3 was associated with hydronephrosis treatment response, thus suggesting favourable responses to high-dose corticosteroid.

References:

[1]Boonstra K, Culver EL, de Buy Wenniger LM, et al. Serum immunoglobulin G4 and immunoglobulin G1 for distinguishing immunoglobulin G4-associated cholangitis from primary sclerosing cholangitis. Hepatology 2014;59:1954-63.

Disclosure of Interests:

None declared

FRI0088 CHANGE IN SERUM BILIRUBIN SUGGESTS TREATMENT RESPONSE IN RHEUMATOID ARTHRITIS PATIENTS TREATED WITH MOLECULAR-TARGETED AGENTS

Background:

Bilirubin is an antioxidant with anti-inflammatory properties. In previous reports, serum bilirubin levels were correlated with disease activity of autoimmune diseases including rheumatoid arthritis (RA). Various molecular-targeted agents have been developed for RA, and targets, such as IL-6 and TNFα, are associated with liver function. However, the association between serum bilirubin and treatment response in RA patients treated with molecular-targeted agents is still unknown.

Objectives:

We aimed to evaluate the role of serum bilirubin in the prediction of the early treatment response in RA patients who initiated molecular-targeted agents.

Methods:

We retrospectively recruited biologic naïve RA patients (n=292) with moderate-to-high disease activity from a tertiary hospital between Jan 2013 and Dec 2019. Patients with viral hepatitis, drug-induced hepatitis, or alcoholic liver disease were excluded. Molecular-targeted agents included tocilizumab (TCZ, n=40), adalimumab (ADA, n=59), etanercept (ETN, n=66), golimumab (GOL, n=60), abatacept (ABA, n=31), and tofacitinib (TOF, n=36). Clinical and laboratory data were collected from electronic medical records. Patients were categorised into an increased bilirubin group (higher serum bilirubin at 3 months than at baseline) and decreased bilirubin group (equal or lower serum bilirubin at 3 months than at baseline). At 6 months of treatment, good response (defined as a DAS28 score ≤3.2) was evaluated. Multivariate logistic regression analysis and multiple linear regression analysis were used to evaluate the association between serum bilirubin and treatment response. The variables included in the multiple logistic and linear regression analyses were age, female sex, rheumatoid factor, prednisolone, DMARDs, baseline liver enzymes, baseline DAS28 score, and components.

Results:

The mean serum bilirubin level at baseline was 4.7±1.8 mg/L. After 6 months of treatment, 180 (61.6%) patients achieved good responses. The mean serum bilirubin levels at 3 and 6 months were 5.3±2.3 and 5.5±2.2 mg/L, respectively. At 6 months, a good response was more frequent in the increased bilirubin group than in the decreased bilirubin group (71.2% [99/139] vs. 52.9% [81/153], p=0.001). In multivariate logistic regression analysis, the ORs among good responders at 6 months were 1.221 (95% CI 1.014–1.471, p=0.036) for baseline serum bilirubin and 1.377 (95% CI 1.146–1.654, p=0.001) for the change in serum bilirubin at 3 months. According to target agents, the mean changes in serum bilirubin from baseline to 6 months were 1.9±2.5 for TCZ, 1.0±1.5 for ADA, 0.7±1.9 for ETN, 0.6±2.2 for GOL, 0.3±1.2 for ABA, and 0.4±2.2 for TOF (Figure 1). Among the target agents, TCZ showed a significant increase in the mean serum bilirubin level at 3 and 6 months from baseline. In multiple linear regression analysis performed on TCZ, the change in bilirubin at 3 months was associated with the DAS28 score at 6 months (β=−0.349, p=0.020).

Figure 1.

Change in serum bilirubin during treatment with molecular-targeted agents in rheumatoid arthritis patients

Conclusion:

High baseline serum bilirubin and an increase in serum bilirubin during treatment are helpful to predict a good response to molecular-targeted agents, especially TCZ.

Disclosure of Interests:

None declared

FRI0248 PROGNOSTIC FACTORS FOR STEROID-FREE REMISSION IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES: IMPORTANCE OF ANTHROPOMETRIC MEASUREMENTS

Background:

Several studies have been conducted on factors associated with mortality in idiopathic inflammatory myopathies (IIM), but few studies have assessed prognostic factors for steroid-free remission in IIM.

Objectives:

We investigated the various clinical factors, including body measurements, that affect IIM treatment outcomes.

Methods:

Patients who were newly diagnosed with IIM between 2000 and 2018 were included. Steroid-free remission was defined as at least three months of normalisation of muscle enzymes and no detectable clinical disease activity. The factors associated with steroid-free remission were evaluated by a Cox regression analysis.

Results:

Of the 106 IIM patients, 35 displayed steroid-free remission during follow-up periods. In the multivariable Cox regression analyses, immunosuppressants’ early use within one month after diagnosis [hazard ratio (HR) 6.21, 95% confidence interval (CI) 2.61–14.74, p < 0.001] and sex-specific height quartiles (second and third quartiles versus first quartile, HR 3.65, 95% CI 1.40–9.51, p = 0.008 and HR 2.88, 95% CI 1.13–7.32, p = 0.027, respectively) were positively associated with steroid-free remission. Polymyositis versus dermatomyositis (HR 0.21, 95% CI 0.09–0.53, p = 0.001), presence of dysphagia (HR 0.15, CI 0.05–0.50, p = 0.002) and highest versus lowest quartile of waist circumference (WC) (HR 0.24, 95% CI 0.07–0.85, p = 0.027) were negatively associated with steroid-free remission.

Conclusion:

The early initiation of immunosuppressant therapy, type of myositis and presence of dysphagia are strong predictors of steroid-free remission in IIM; moreover, height and WC measurements at baseline may provide additional important prognostic value.

Disclosure of Interests:

None declared

0387 Effect of Air Pollution on the Quality of Sleep - Korean Nationwide Cross-Sectional Study

Introduction

Poor sleep quality is associated with adverse health outcomes, such as cardiovascular disease, diabetes and obesity. Several studies have indicated the association between exposure to air pollution and sleep quality. However, the evidence is very limited in South Korea.

Methods

We conducted a cross-sectional study using data from a nationwide sample of 165,193 individuals aged 19 years or older from the 2018 Korea Community Health Survey. Perceived air pollution was measured in the baseline survey. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Poor sleep quality was defined by the global score of PSQI &gt; 5. The associations between perceived air pollution and sleep quality were examined using the regression models. Additionally, the average concentration of PM2.5 was measured in each region using a satellite-based prediction to see the association between perceived air pollution and long term exposure of fine dust.

Results

After adjusted for age, education, and income, the adjusted odds ratios (95% confidence interval) of poor sleep quality associated with perceived air pollution was 1.45. The average of daily concentrations of PM2.5 over 3 years was highest in Incheon area, followed by Seoul and Busan city. Among Gyeonggi Province, the most populous region in South Korea, the PM2.5 concentrations was the highest in Ansan. In each region in Korea, Incheon had the highest poor sleep quality rate of 48.0%, while Ansan in Gyeonggi Province had the highest rate of 61.5%. The results are in line with the distribution of PM2.5 concentrations by region.

Conclusion

Perceived air pollution and long term exposure of fine dust were associated with poor sleep quality in South Korea. Improvement of air quality may help to improve sleep quality. More studies are in need in the future to explore the biological mechanism for the relationship, and to also examine such relationship among different populations and in difference environments.

Support

For this study, we used raw data from the 2018 Korea Community Health Survey (KCHS), conducted by the Korea Centers for Disease Control and Prevention

0935 Association Between Chronotype, Sleep Duration, Weekend Catch-Up Sleep, and Depression Among Korean High School Students

Introduction

The present study aimed to examine the association between chronotype, sleep duration, weekend catch-up sleep (CUS) duration, and depression among Korean high school students.

Methods

A total of 8,565 high school students who were analyzed from 15 nationwide districts in South Korea completed an online self-report questionnaire. Depressive mood was assessed using the Korean version of the Beck Depression Inventory. The following sleep characteristics were assessed: weekday and weekend sleep durations, weekend CUS duration, chronotype, perceived sufficiency of sleep, self-reported snoring and sleep apnea, daytime sleepiness, and sleep environment. Age, sex, body mass index, number of private classes, and proneness to internet addiction were also measured. Logistic regression analysis was conducted to compute odds ratios for the association between depression and sleep characteristics, after controlling for relevant covariates.

Results

The prevalence of depression (BDI ≥ 16) was 1,794 (20.9%). In the analyses of multivariate logistic regression, the late chronotype (odds ratio [OR], 1.71; 95% CI, 1.47-1.99), female (OR, 2.24; 95% CI, 1.99-2.53), underweight (OR, 1.27; 95% CI, 1.02-1.57) and obesity (OR, 1.41; 95% CI, 1.13-1.75), weekday sleep duration (OR, 0.86; 95% CI, 0.81-0.91), weekend CUS duration ≥ 2 hours (OR, 0.68; 95% CI, 0.55-0.85), ESS (OR, 1.08; 95% CI, 1.07-1.10), much (OR, 2.15; 95% CI, 1.63-2.84) and insufficient (OR, 1.71; 95% CI, 1.46-2.01) perceived sleep, snoring (OR, 1.27; 95% CI, 1.11-1.46) and witnessed apnea (OR, 2.10; 95% CI, 1.75-2.52), increased internet addiction (OR, 1.06; 95% CI, 1.05-1.06), high number of private education (OR, 0.76; 95% CI, 0.60-0.95), and poor sleep environment (OR, 1.86; 95% CI, 1.56-2.21) were associated with depression.

Conclusion

Eveningness preference, insufficient weekday sleep duration, short weekend CUS duration, and self-reported snoring and sleep apnea were associated with an increased risk for depression.

Support

 

Abstract ES4-2: Single cell transcriptomics reveals multi-step adaptations to endocrine therapy

Resistant tumours are thought to arise from the action of Darwinian selection on genetically heterogenous cancer cell populations. However, simple clonal selection is inadequate to describe the late relapses often characterising luminal breast cancers treated with endocrine therapy (ET), suggesting a more complex interplay between genetic and non-genetic factors. During this talk, I will briefly introduce a series of molecular tools that can be used to study transcriptional changes at the single cell level in relevant models. I will then show how used these tools to dissect the contributions of clonal genetic diversity and transcriptional plasticity during the early and late phases of ET at single-cell resolution. Using single-cell RNA-sequencing and imaging we could disentangle the transcriptional variability of plastic cells and define a rare subpopulation of pre-adapted (PA) cells which undergoes further transcriptomic reprogramming and copy number changes to acquire full resistance. We find evidence for sub-clonal expression of a PA signature in primary tumours and for dominant expression in clustered circulating tumour cells. I will then update the audience on how it is possible to integrate these technologies directly into clinical studies and what developments are happening in the field of single cell technologies. I will finally propose a multi-step model for ET resistance development and advocate the use of stage-specific biomarkers.

Citation Format: L Magnani, I Barozzi, S Hong. Single cell transcriptomics reveals multi-step adaptations to endocrine therapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr ES4-2.

Diabetes mellitus and tuberculosis in Korean adults: impact on tuberculosis incidence, recurrence and mortality

<sec id="st1"> <title>SETTING</title> The prevalence of diabetes mellitus (DM) worldwide is increasing markedly, and many countries with rising rates also have a high incidence rate of tuberculosis (TB). </sec> <sec id="st2"> <title>OBJECTIVE</title> To investigate the relationships of fasting serum glucose (FSG) and DM with TB incidence, recurrence and mortality risk in a prospective cohort study in South Korea. </sec> <sec id="st3"> <title>DESIGN</title> Our study comprised 1 267 564 Koreans who received health insurance from the National Health Insurance System, had an initial medical evaluation between 1997 and 2000 and were prospectively followed biennially. </sec> <sec id="st4"> <title>RESULTS</title> Participants with DM had a higher risk for incident TB (hazard ratio [HR] 1.81, 95%CI 1.71-1.91 in males, HR 1.33; 95%CI 1.20-1.47 in females) than those without DM. There was a strong positive trend for TB risk with rising FSG among males. The risk for recurrent TB among those with previous TB was significantly higher in males (HR 1.58, 95%CI 1.43-1.75) and in females with DM (HR 1.38, 95%CI 1.08-1.76). The increased risk of death from TB during follow-up was also significant in men (HR 1.91, 95%CI 1.87-1.95) and in women (HR 1.71, 95%CI 1.65-1.77). </sec> <sec id="st5"> <title>CONCLUSIONS</title> A diagnosis of DM is a risk factor for TB, TB recurrence and death from TB. Screening for TB should be considered among people living with DM in Korea, particularly those with severe DM. </sec>.

Recovery of renal function in patients with lupus nephritis and reduced renal function: the beneficial effect of hydroxychloroquine

Background

Reduced renal function is associated with worse renal outcome in patients with lupus nephritis (LN). However, there is insufficient knowledge regarding renal function recovery in patients with LN with reduced baseline renal function. Therefore, the present study aimed to investigate renal function recovery and related factors in patients with reduced baseline renal function.

Methods

The present retrospective longitudinal cohort study included patients with LN and reduced renal function. Reduced renal function was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2. Recovery of renal function was determined by an eGFR of >60 mL/min/1.73 m2 at six months after baseline, and factors associated with it were evaluated using logistic regression analysis.

Results

We included 90 patients with LN, with a mean eGFR value of 37.2 ± 13.9 mL/min/1.73 m2. Forty-six (51.1%) patients recovered their renal function after six months. On multivariate analysis, hydroxychloroquine use (odds ratio (OR) = 3.891, 95% confidence interval (CI) 1.196–12.653, p = 0.024), prolonged LN (OR = 0.926, 95% CI 0.874–0.981, p = 0.009) and high-grade tubular atrophy (OR = 0.451, 95% CI 0.208–0.829, p = 0.013) were associated with renal function recovery. During follow up, 25 patients were on end-stage renal disease (ESRD). Kaplan–Meier analysis revealed that renal function recovery after six months and lower probability of ESRD are associated.

Conclusions

In patients with LN and reduced renal function, renal function recovery at six months was associated with use of hydroxychloroquine and inversely related to longer duration of LN and higher grade of tubular atrophy.

Impact of stringent response in proteinuria on long-term renal outcomes in proliferative lupus nephritis

Objectives

Favourable long-term prognosis in proliferative lupus nephritis (LN) is associated with the achievement of complete renal response (CR), which is defined as a urine protein/creatinine ratio (UPCR) of < 0.5. However, it is unclear whether a more stringent cut-off for proteinuria (normal value of proteinuria; UPCR < 0.15) is better than CR. We aimed to evaluate the effect of stringent CR, defined as a UPCR of <0.15, on long-term renal outcomes in proliferative LN.

Methods

We included 87 patients with class III or IV LN who achieved CR at one year after induction therapy. Clinical and laboratory data were compared between the stringent and non-stringent CR groups. Logistic regression analysis was performed to identify factors associated with achievement of stringent CR. Cox analysis was performed to analyse the risk factors for renal flare and development of chronic kidney disease (CKD).

Results

The stringent and non-stringent CR groups included 58 and 29 patients, respectively. The two groups showed no significant baseline differences in terms of the clinical, laboratory and pathological classification. The sustained CR rates during five years were 91.3% and 50.0% ( p = 0.014) in the stringent and non-stringent CR groups, respectively. In Cox analyses, the achievement of stringent CR was associated with a lower risk of five-year renal flare rate (hazard ratio (HR) = 0.161, 95% confidence interval (CI) 0.063–0.411, p < 0.01) and development of CKD (HR = 0.189, 95% CI 0.047–0.752, p = 0.018). Mycophenolate mofetil induction therapy was associated with achievement of stringent CR at a borderline level of significance (HR = 7.268, 95% CI 0.894–59.089, p = 0.064).

Conclusion

Achievement of stringent CR predicted lower risk of renal flare and development of CKD in proliferative LN. These findings suggest that stringent CR is a valuable treatment target in proliferative LN.

A66 Tracing the evolutionary history of an emerging Salmonella 4,[5],12:i:- clone in the United States

Salmonellosis is one of the leading causes of foodborne disease worldwide, with an estimated one million cases a year in the United States. Salmonella 4,[5],12: i:-, a monophasic variant of Salmonella typhimurium, is an emerging serovar that has been associated with multiple foodborne outbreaks throughout the world, mostly attributed to pig and pig products. Recently, we have demonstrated that two distinct groups of Salmonella 4,[5],12:i:- circulate in the USA and Europe, with the majority of isolates recovered during recent years belonging to an emerging multidrug-resistant clade (Elnekave et al. 2018). We applied Bayesian phylodynamic reconstruction to uncover the evolutionary history of this clade. We used a dataset of whole-genome sequences of 1446 4,[5],12:i:- isolates from different sources (livestock, human, food products, and others) from the USA (n = 752) and Europe (n = 694), collected between 2008 and 2017 and belonging to the Multilocus Subtype 34, which was predominant in the emerging clade (Elnekave et al. 2018). A subset (n = 110) of Salmonella 4,[5],12:i: isolates was then randomly selected after stratifying by location and year of isolation in order to achieve balanced sampling. Evidence of temporal signal was confirmed by looking at root-to-tip divergences using TempEst. Evolutionary hypotheses using strict and relaxed-clock models were tested using BEAST for a variety of demographic models and assuming a general time reversible substitution model. Model selection was performed by estimating Bayes Factors using path sampling and stepping-stone sampling. The selected model was then used for applying discrete trait models comparing different scenarios of transmission between locations (i.e. bidirectional symmetric/asymmetric or unidirectional). Our preliminary phylodynamic inference results indicate that the origin of this subtype was in Europe and dates back to 1990 (HPD 95%: 1984–2001). We report an exponential growth rate of 0.362 per year, which corresponds to a doubling time of 1.43 years. Our results suggest that this subtype was introduced to the US in the year 2000 (HPD 95%: 1994–2006). Phylodynamic analysis suggests that the recent increase in isolation of Salmonella 4,[5],12:i:- from different sources in the USA may be due to the exponential expansion of an emerging clone which originated in Europe and then expanded to the USA. The emergence and expansion of this serovar is of great public health importance due to the high prevalence of multidrug resistance traits found in USA isolates from this group and especially due to the presence of plasmid-mediated resistance genes for quinolones and extended spectrum cephalosporins, key antimicrobials used for the treatment of invasive Salmonella infections.

The effects of cortisol and adrenal androgen on bone mass in Asians with and without subclinical hypercortisolism

Analyses using the largest Korean cohort of adrenal incidentaloma (AI) revealed that subtle cortisol excess in premenopausal women and reduced dehydroepiandrosterone-sulfate (DHEA-S) in postmenopausal women and men are associated with bone mineral density (BMD) reduction in Asian patients with subclinical hypercortisolism (SH).

INTRODUCTION

Few studies evaluated bone metabolism in Asians with SH. We investigated associations of cortisol and DHEA-S, an adrenal androgen, with BMD in Asians with AI, with or without SH.

METHODS

We used cross-sectional data of a prospective multicenter study from Korea. We measured BMD, bone turnover markers, cortisol levels after 1-mg dexamethasone suppression test (1-mg DST), DHEA-S, and baseline cortisol to DHEA-S ratio (cort/DHEA-S) in 109 AI patients with SH (18 premenopausal, 38 postmenopausal women, and 53 men) and 686 with non-functional AI (NFAI; 59 premenopausal, 199 postmenopausal women, and 428 men).

RESULTS

Pre- and postmenopausal women, but not men, with SH had lower BMDs at lumbar spine (LS) than those with NFAI (P = 0.008~0.016). Premenopausal women with SH also had lower BMDs at the hip than those with NFAI (P = 0.009~0.012). After adjusting for confounders, cortisol levels after 1-mg DST demonstrated inverse associations with BMDs at all skeletal sites only in premenopausal women (β = - 0.042~- 0.033, P = 0.019~0.040). DHEA-S had positive associations with LS BMD in postmenopausal women (β = 0.096, P = 0.001) and men (β = 0.029, P = 0.038). The cort/DHEA-S had inverse associations with LS BMD in postmenopausal women (β = - 0.081, P = 0.004) and men (β = - 0.029, P = 0.011). These inverse associations of cort/DHEA-S remained significant after adjusting for cortisol levels after 1-mg DST (β = - 0.079~- 0.026, P = 0.006~0.029). In postmenopausal women, the odds ratios of lower BMD by DHEA-S and cort/DHEA-S was 0.26 (95% CI, 0.08-0.82) and 3.40 (95% CI, 1.12-10.33), respectively.

CONCLUSION

Subtle cortisol excess in premenopausal women and reduced DHEA-S in postmenopausal women and men may contribute to BMD reduction in Asians with SH.

MMP-8-Responsive Polyethylene Glycol Hydrogel for Intraoral Drug Delivery

Currently available drug delivery systems for oral diseases suffer from short retention time and poor local concentrations at the target site. A biodegradable stimulus-responsive hydrogel was synthesized in the present study to evaluate its application as an environmentally sensitive carrier for on-demand intraoral drug delivery. The hydrogel was synthesized from diacrylate-containing polyethylene glycol-based scaffolds and a cysteine-terminated peptide crosslinker (CGPQG↓IWGQC) via a Michael-type addition reaction. Because CGPQG↓IWGQC can be cleaved by matrix metalloproteinase 8 (MMP-8), minocycline hydrochloride, bovine serum albumin, or an antibacterial peptide (KSL) was incorporated into the scaffolds to evaluate the MMP-8-responsive release behavior of the on-demand drug delivery system. Hydrogel characterization and gelation kinetics were examined with gel time, Fourier-transform infrared spectroscopy, scanning electron microscopy, and measurements of rheologic parameters. Degradation behavior and MMP-8-responsive drug release were performed by high-performance liquid chromatography and protein-specific assay. Biocompatibility evaluation indicated that the hydrogels were noncytotoxic. Antibacterial testing demonstrated that the released drugs were able to maintain bioactivity. Taken together, these results suggest that the MMP-8-sensitive hydrogel is a promising candidate for on-demand intraoral localized drug delivery. Because MMP-8 is one of the most important biomarkers for periodontitis, the MMP-8-responsive hydrogel has potential to be used for in situ adaptive degradation in response to chronic periodontitis and peri-implantitis. This notion has to be tested in animal models of periodontal disease.

6-year change in resting heart rate is associated with incident type 2 diabetes mellitus

BACKGROUND AND AIMS

Elevated resting heart rate (RHR) is associated with risk of type 2 diabetes mellitus (T2DM). However, the association of change in RHR (ΔRHR) and incident T2DM is not fully elucidated. We aimed to assess the dose-response association between 6-year ΔRHR and T2DM.

METHODS AND RESULTS

A total of 12155 non-T2DM participants ≥18 years old were enrolled during 2007-2008 and followed up during 2013-2014. ΔRHR was calculated by subtracting the baseline RHR from the RHR value at 6-year follow-up. Age-, sex-, and RHR-specific relative risks (RRs) and 95% confidence intervals (CIs) for the effect of ΔRHR on incident T2DM were calculated by using modified Poisson regression models. As compared with ΔRHR of 0 beats/min, the adjusted risk of T2DM was significantly increased with RHR increment and reduced with RHR reduction. ΔRHR was positively associated with future risk of T2DM [RR per unit increase: 1.03 (1.03-1.04)]. As compared with stable change in RHR group (-5<ΔRHR<5 beats/min), for ΔRHR ≤ -10 beats/min, -10<ΔRHR ≤ -5 beats/min, 5≤ΔRHR<10 beats/min, and ΔRHR ≥10 beats/min groups, the pooled adjusted RR (95% CI) of T2DM was 0.69 (0.55-0.86), 0.90 (0.73-1.11), 1.31 (1.07-1.61), and 1.90 (1.59-2.26), respectively. This significant association still existed on subgroup analyses based on age, sex, and baseline RHR and sensitivity analyses.

CONCLUSIONS

Dynamic RHR change was significantly associated with incident T2DM. Our study suggests that RHR may be a non-invasive clinical indicator for interventions aiming to reduce incident T2DM in the general population.