The Emerging Role of Complement C3 as A Biomarker of Insulin Resistance and Cardiometabolic Diseases: Preclinical and Clinical Evidence

BACKGROUND

An intricate network of reciprocal interactions between adipose tissue and immune system have been largely demonstrated, leading to the well-accepted concept of insulin resistance as a low grade inflammatory state and, conversely, chronic high-grade inflammation as a dysmetabolic condition. Immune homeostasis is regulated by several players including the complement system, a complex protein network at the crossroad between the innate and adaptive arms of the human defences against pathogens.

OBJECTIVE

Complement C3 represents the nodal point of the complement cascade independently of the pathway recruited. Aim of this review is to collect the evidence supporting the role of complement C3 as a candidate biomarker of insulin resistance and other metabolic disorders.

METHODS

We reviewed the available evidence pointing to a role of complement system, and in particular complement C3, in insulin resistance and other cardiometabolic diseases including diabetes (T2D), hypertension, non-alcoholic fatty liver disease (NAFLD) and atherosclerosis.

RESULTS

Compelling preclinical evidence demonstrated a role of adipose-tissue C3 and its cleavage products C3a and acylation stimulating protein (ASP) in adipose tissue inflammation and insulin resistance. To further support this hypothesis, several clinical studies, both cross-sectional and longitudinal, confirmed this association in independent cohorts. Moreover, preliminary evidence support a role of complement C3 in other cardiometabolic diseases such as hypertension, NAFLD and atherosclerosis.

CONCLUSION

Future studies are needed to fully confirm the usefulness of C3 as a clinical biomarker and to establish accurate cut-off values. Moreover, the therapeutic potential of C3 modulation in either cardiometabolic and inflammatory diseases need to be investigated.

Prevalence of celiac disease serological markers in a cohort of Italian rheumatological patients

AIM

To assess the prevalence of celiac disease (CD) serological markers in a cohort of patients referred to an Italian rheumatological outpatient clinic.

BACKGROUND

Current guidelines do not suggest CD screening in patients with rheumatological diseases and these subjects are not considered to be at high risk for CD.

METHODS

A total of 230 sera of rheumatological patients referred to the Division of Internal Medicine at the Department of Medical and Surgical Sciences between January 2005 and December 2013 were screened for CD by testing IgA antitransglutaminase (TTG IgA), IgG deamidated gliadin peptides (DGP IgG) and IgA antiendomysium (EMA) antibodies. Of the 230 patients tested, 67 had a diagnosis of rheumatoid arthritis (RA), 52 Sjögren's syndrome (SjS), 42 systemic sclerosis (SCL), 35 systemic lupus erythematosus (SLE), 15 mixed connective tissue disease, 11 polymyositis and 10 dermatomyositis.

RESULTS

TTG IgA antibodies were identified in 7/230 cases (3%), 3 in SjS (3/42 - 5.8%), 2 in SCL (2/42 - 4.8%), 1 in RA (1/67 - 1.5%) and 1 in SLE sera (1/35 - 2.8%). All the seven sera were also positive for DGP IgG and EMA IgA. DGP IgG were the most frequent antibody detected, being found in 16 (7%) sera.

CONCLUSION

This study identified a high prevalence of CD antibodies in adult patients referred to a rheumatology outpatient clinic. These results highlight the importance of CD screening in subjects presenting with rheumatological features.

Complement C3 and fatty liver disease in Rheumatoid arthritis patients: a cross-sectional study

BACKGROUND

Recent evidence suggested a potential role of complement fraction C3 as a biomarker of nonalcoholic fatty liver disease (NAFLD) in the general population. Aim of this study was to evaluate the performance of C3 for prediction of NAFLD in RA patients.

MATERIALS AND METHODS

For the present study, consecutive RA patients were recruited. NAFLD was diagnosed according to predefined ultrasonographic (US) criteria. For comparison, the hepatic steatosis index (HSI) was calculated.

RESULTS

Of 164 consecutive RA patients, 41 (25%) were diagnosed with NAFLD. The NAFLD group had a significant lower proportion of females (P = 0·04), higher BMI (P < 0·0001), C-reactive protein (P = 0·04), complement C3 (P = 0·001) and HSI (P = 0·003). In a logistic regression model, only male sex (OR 2·65, 95% CI: 1·08-6·50, P = 0·03), increasing BMI (OR 1·22, 95% CI: 1·02-1·46, P = 0·03) and complement C3 (OR 5·05, 95% CI: 1·06-23·93, P = 0·04) were associated with higher likelihood of being diagnosed with NAFLD. Finally, we built ROC curves for BMI, complement C3 and their combination for prediction of having NAFLD. The best cut-off for BMI was 28·5 kg/m² and yielded a sensitivity of 66% and a specificity of 71%; the best cut-off for complement C3 was 1·23 g/L and yielded a sensitivity of 76% and a specificity of 64% for classification of NAFLD cases.

CONCLUSIONS

Our results provide preliminary evidence for a potential role of complement C3 as a surrogate biomarker of NAFLD in RA patients.

Biologic drugs in adult onset Still's disease: a systematic review and meta-analysis of observational studies

BACKGROUND

Biological drugs, mainly interleukin (IL)-1 and IL-6 antagonists, but also tumor necrosis factor (TNF) inhibitors, have been used in the treatment of adult onset Still's disease patients (AOSD).

METHODS

We summarised the available evidence for the effectiveness of biologic drugs in AOSD. A systematic review of the literature was performed in order to identify all the available data concerning the effectiveness of biologic drugs in AOSD. The proportion of patients achieving complete remission or any clinical response was calculated. The meta-analysis was thus performed using a random-effects model accounting for the expected high level of heterogeneity.

RESULTS

Nineteen observational published studies were included in the meta-analysis. The pooled analysis under a random-effects model showed an overall rate of clinical response of 0.85 (95% CI: 0.77-0.91, p < 0.0001) and an overall rate of complete remission of 0.66 (95% CI: 0.54-0.77, p = 0.01). The heterogeneity across studies was high (Q = 59.82 with df = 19.0, p < 0.0001, I² = 68.23%).

CONCLUSIONS

Our meta-analysis suggests that AOSD patients may experience a clinical response and/or a complete remission when treated with biologic drugs. Specifically designed and powered studies are needed to fully investigate the role of such medications in the management of AOSD patients.

Prevalence of type 2 diabetes and impaired fasting glucose in patients affected by rheumatoid arthritis: Results from a cross-sectional study

Although the better management of rheumatoid arthritis (RA) has significantly improved the long-term outcome of affected patients, a significant proportion of these may develop associated comorbidities including cardiometabolic complications. However, it must be pointed out that a comprehensive cardiometabolic evaluation is still poorly integrated into the management of RA patients, due to a limited awareness of the problem, a lack of appropriate clinical studies, and optimal strategies for cardiovascular (CV) risk reduction in RA. In addition, although several studies investigated the possible association between traditional CV risk factors and RA, conflicting results are still available.On this basis, we planned this cross-sectional study, aimed at investigating the prevalence of type 2 diabetes (T2D) and impaired fasting glucose (IFG) in RA patients compared with age- and gender- matched control individuals. Furthermore, we analyzed the role of both traditional and RA-related CV risk factors in predicting T2D and IFG.We observed an increased prevalence of T2D in RA patients when compared with age- and gender-matched controls. Regression analyses demonstrated that the presence of high blood pressure (HBP), a longer disease duration, and exposure to corticosteroids (CCS) were significantly associated with an increased likelihood of being classified as T2D. In addition, we observed an increased prevalence of IFG in RA patients when compared with age- and gender-matched controls. Regression analyses demonstrated that a higher body mass index (BMI), the presence of metabolic syndrome (MetS), higher levels of total cholesterol, the presence of radiographic damage, and higher serum levels of C-reactive protein (CRP) were significantly associated with an increased likelihood of presenting IFG.In this cross-sectional study, we observed an increased prevalence of T2D and IFG in an Italian cohort of RA patients when compared with age- and gender-matched control individuals. Interestingly, both RA-specific features, such as disease duration, CCS exposure, and radiographic damage, and traditional CV risk factors, such as HBP and MetS, were significantly associated with glucose metabolism abnormalities.

Functional correlates of TSH, fT3 and fT4 in Alzheimer disease: a F-18 FDG PET/CT study

The present study was aimed to investigate the relationships between thyroid stimulating hormone (TSH), freeT3 (fT3) and freeT4 (fT4) and brain glucose consumption as detectable by means of 2-deoxy-2-(F-18) fluoro-D-glucose (F-18 FDG) Positron Emission Tomography/Computed Tomography (PET/CT) in a selected population with Alzheimer disease (AD). We evaluated 87 subjects (37 males and 50 females, mean age 70 (±6) years old) with AD. All of them were subjected to TSH, fT3 and fT4 assay and to cerebrospinal fluid amyloid (Aβ1-42) and tau [phosphorylated-tau (p-tau) and total-tau (t-tau)] assay prior PET/CT examination. Values for TSH, fT3 and fT4 were in the normal range. The relationships were evaluated by means of statistical parametric mapping (SPM8) using age, sex, MMSE, scholarship and CSF values of amyloid and tau as covariates. We found a significant positive correlation between TSH values and cortical glucose consumption in a wide portion of the anterior cingulate cortex bilaterally (BA32) and left frontal lobe (BA25) (p FWE-corr <0.001; p FDRcorr <0.000; cluster extent 66950). No significant relationships were found between cortical F-18 FDG uptake and T3 and T4 serum levels. The results of our study suggest that a cortical dysfunction in anterior cingulate and frontal lobes may affect serum values of TSH in AD patients.

Poor clinical response in rheumatoid arthritis is the main risk factor for diabetes development in the short-term: A 1-year, single-centre, longitudinal study

OBJECTIVES

Despite of the European League Against Rheumatism (EULAR) provided different sets of recommendations for the management of cardiovascular risk in inflammatory arthritis patients, it must be pointed out that cardiometabolic comorbidity, such as type 2 diabetes (T2D), remains still underdiagnosed and undertreated in patients affected by rheumatoid arthritis (RA).

METHODS

In this work, we designed a single centre, prospective study in order to better investigate the occurrence of T2D during the course of 1 year of follow-up. Furthermore, we evaluated the role of both traditional cardiovascular and RA-specific related risk factors to predict the occurrence of new T2D.

RESULTS

In this study, we evaluated 439 consecutive RA patients and we observed that 7.1% of our patients (31/439) developed T2D, after 12 month of prospective follow-up. The regression analysis showed that the presence of high blood pressure, the impaired fasting glucose (IFG) at the first observation and the poor EULAR-DAS28 response, after 12 months of follow-up, were significantly associated with an increased likelihood of being classified as T2D. Similarly, we observed that 7.7% of our patients (34/439) showed IFG after 12 months of prospective follow-up. The regression analysis showed that the presence of high blood pressure and the poor EULAR-DAS28 response after 12 months of follow-up, were significantly associated with an increased likelihood of showing IFG.

CONCLUSIONS

Our study supports the hypothesis of a significant short-term risk of T2D in RA patients and of a close associations between uncontrolled disease activity and glucose metabolism derangement. Further multicentre, randomised-controlled studies are surely needed in order to elucidate these findings and to better ascertain the possible contribution of different therapeutic regimens to reduce this risk.

Plantar fascia enthesopathy is highly prevalent in diabetic patients without peripheral neuropathy and correlates with retinopathy and impaired kidney function

BACKGROUND

Aim of this study was to evaluate the prevalence of plantar fascia (PF) enthesopathy in Type 2 diabetes mellitus (T2DM) patients without distal peripheral neuropathy (DPN).

METHODS

We recruited 50 T2DM patients without DPN and 50 healthy controls. DPN was excluded using the Michigan Neuropathy Screening Instrument (MNSI). All patients underwent a bilateral sonographicevaluation of the enthesealportion of the PF.

RESULTS

PF thickness was significantly higher in T2DM patients (p<0.0001). T2DM patients presented a higher prevalence of entheseal thickening (p = 0.002), enthesophyte (p = 0.02) and cortical irregularity (p = 0.02). The overall sum of abnormalities was higher in T2DM patients (p<0.0001), as was the percentage of bilateral involvement (p = 0.005). In a logistic regression analysis, retinopathy predicted entheseal thickening (OR 3.5, p = 0.05) and enthesophytes (OR 5.13, p = 0.001); reduced eGFR predicted enthesophytes (OR 2.93, p = 0.04); body mass index (BMI) predicted cortical irregularity (OR 0.87, p = 0.05); mean glucose predicted enthesophyte (OR 1.01, p = 0.03); LDL cholesterol predicted cortical irregularity (OR 0.98, p = 0.02).

CONCLUSIONS

Our data suggest that T2DM is associated with PF enthesopathyindependently of DPN.

Monitoring safety and use of old and new treatment options for type 2 diabetic patients: a two-year (2013-2016) analysis

OBJECTIVE

To compare patients' and physicians' perceptions regarding effectiveness and tolerability of non-insulin hypoglycemic drugs in a cohort of type 2 diabetic patients; to verify whether a possible tridimensional link between effectiveness, tolerability, and adherence affects long-term therapeutic outcomes.

METHODS

A two-year observational study was performed in 1389 Type 2 diabetic patients by involving general practitioner clinics and Diabetes Centers. A decimal scale and the Morisky questionnaire were used, respectively, to assess effectiveness and tolerability perceptions, and medication adherence.

RESULTS

Physicians perceived therapy as more efficacious compared to their patients: perceived effectiveness was steady for physicians during the study whereas patients' perception not significantly decreased (mean score from >8 to 7.84 ± 1.69). Physicians assigned higher tolerability scores compared to patients but only at the beginning of the study; interestingly, physicians' tolerability perception was poorer than patients' perception at last follow-up (mean score = 7.57 ± 1.40 vs. 7.88 ± 1.84). Favorable (score >7) patients' perceptions about treatment effectiveness and tolerability were associated with higher adherence. Patients showed medium adherence across the study.

CONCLUSIONS

A mutual relationship between clinical effectiveness, adverse drug reactions, and adherence has been established, significantly impacting the clinical management of diabetic patients. A careful monitoring of this link by clinicians appears therefore necessary.

High Prevalence of Achilles Tendon Enthesopathic Changes in Patients with Type 2 Diabetes Without Peripheral Neuropathy

BACKGROUND

Metabolic disorders are known to alter the mechanical properties of tendons. We sought to evaluate the prevalence of asymptomatic Achilles tendon enthesopathic changes in patients with type 2 diabetes mellitus (T2DM) without peripheral neuropathy.

METHODS

We recruited 43 patients with T2DM and 40 controls. Neuropathy was excluded with the Michigan Neuropathy Scoring Instrument. Bilateral ultrasonography of the Achilles tendon enthesis was performed.

RESULTS

Patients with T2DM had a higher prevalence of hypoechogenicity (26.7% versus 2.5%; P = .0001), entheseal thickening (24.4% versus 8.7%; P = .007), and enthesophytes (74.4% versus 57.5%; P = .02). No differences were found in the number of patients with erosions (1.2% versus 0%; P > .99), cortical irregularities (11.6% versus 3.7%; P = .09), bursitis (5.8% versus 3.7%; P = .72), or tears (2.3% versus 1.2%; P > .99). The mean ± SD sum of abnormalities was higher in patients with T2DM (1.5 ± 1.1 versus 0.7 ± 0.6; P < .0001), as was the percentage of bilateral involvement (72.1% versus 45.0%; P = .01). Mean ± SD thickness did not differ between patients and controls (4.4 ± 1.1 mm versus 4.2 ± 0.8 mm; P = .07).

CONCLUSIONS

According to our data, there is an elevated prevalence of asymptomatic Achilles tendon enthesopathic changes in patients with T2DM independent of peripheral neuropathy.

Old But Good: Modified-Release Prednisone in Rheumatoid Arthritis

BACKGROUND

Since more than 50 years glucocorticoids represent the milestone in the treatment of inflammatory diseases, including rheumatoid arthritis (RA). However, many patients with RA present a circadian rhythm in symptoms severity with a significant worsening in the morning, that correlates with cyclic changes in circulating hormones and cytokines. Classical steroid therapy given in the morning fails to intercept this pathophysiological phenomenon. In the last years, a novel formulation of prednisone has been developed in order to better fit these variations, improve efficacy and minimize adverse events (chronotherapy). This modified-release (MR) prednisone is administered in the evening at 10.00 p.m. and absorbed after about 4 hours.

METHODS

In this article, we reviewed the recent clinical trials evaluating the efficacy of MR prednisone in RA patients, including two randomized controlled double-blind clinical trials Circadian Administration of Prednisone in Rheumatoid Arthritis - 1 (CAPRA-1) and CAPRA-2 and other nonrandomized observational studies.

RESULTS

According to the available evidence, MR prednisone seems effective in ameliorating morning stiffness in RA patients.

CONCLUSION

In conclusion, the use of MR prednisone in the treatment regimen could be a costeffective choice in a significant proportion of RA patients, particularly in those with a clinical phenotype characterized by morning stiffness or morning recrudescence of pain. With regards to the safety, MR prednisone adverse events profile does not differ from that of IR glucocorticoids.

Serum complement C3 strongly correlates with whole-body insulin sensitivity in rheumatoid arthritis

OBJECTIVES

Rheumatoid arthritis (RA) is characterised by an excess of cardiovascular diseases (CVD) risk, attributable to a synergy between under-diagnosed traditional risk factors (i.e. insulin resistance) and inflammatory disease activity. The aim of the present study was to evaluate the correlation between inflammatory measures and insulin sensitivity in RA patients.

METHODS

Forty non-diabetic RA patients (19 males) were recruited. All patients underwent anthropometric measurements, laboratory evaluation and oral glucose tolerance test (OGTT). Insulin sensitivity index (ISI) was calculated with the equation proposed by Matsuda et al., from dynamic values of glucose and insulin obtained during OGTT.

RESULTS

In the univariate analysis, lnISI correlated inversely with age, BMI, waist circumference, sBP, ESR, lnCRP and complement C3, but not with disease duration, dBP or complement C4. In non-obese patients (BMI <30 kg/m2, n=28), only age, BMI, lnCRP and C3 maintained their correlation with lnISI. In a stepwise multiple regression using lnISI as the dependent variable and BMI, age, lnCRP and complement C3 as predictors, only BMI and C3 entered the equation and accounted for 38.2% of the variance in lnISI. In non-obese patients, only C3 entered the regression equation, accounting for 32.2% of the variance in lnISI. Using a ROC curve, we identified the best cut-off for complement C3 of 1.22 g/L that yielded a sensitivity of 67% and a specificity of 79% for classification of insulin resistant patients.

CONCLUSIONS

In RA patients, complement C3 correlates strongly with insulin sensitivity, in both obese and non-obese individuals.

Complement C3 Is the Strongest Predictor of Whole-Body Insulin Sensitivity in Psoriatic Arthritis

Objectives

To evaluate the correlation between inflammatory measures and whole-body insulin sensitivity in psoriatic arthritis (PsA) patients.

Methods

For the present study, 40 nondiabetic PsA patients were recruited. A standard oral glucose tolerance test (OGTT) was performed. The insulin sensitivity index (ISI), insulinogenic index (IGI) and oral disposition index (ODI) were calculated from dynamic values of glucose and insulin obtained during OGTT.

Results

In our study population, mean ISI was 3.5 ± 2.5, median IGI was 1.2 (0.7–1.8), mean ODI 4.5 ± 4.5. In univariate correlation analysis, ISI correlated inversely with systolic blood pressure (sBP) (R = -0.52, p = 0.001), diastolic blood pressure (dBP) (R = -0.45, p = 0.004) and complement C3 (R = -0.43, p = 0.006) and ODI correlated inversely with sBP (R = -0.38, p = 0.02), dBP (R = -0.35, p = 0.03) and complement C3 (R = -0.37, p = 0.02). No significant correlations were found between analyzed variables and IGI. In a stepwise multiple regression, only complement C3 entered in the regression equation and accounted for approximately 50% of the variance of ISI. Using a receiver operating characteristic (ROC) curve we identified the best cut-off for complement C3 of 1.32 g/L that yielded a sensitivity of 56% and a specificity of 96% for classification of insulin resistant patients.

Conclusions

In conclusion, our data suggest that serum complement C3 could represent a useful marker of whole-body insulin sensitivity in PsA patients.

Effects of moderate beer consumption on health and disease: A consensus document

A large evidence-based review on the effects of a moderate consumption of beer on human health has been conducted by an international panel of experts who reached a full consensus on the present document. Low-moderate (up to 1 drink per day in women, up to 2 in men), non-bingeing beer consumption, reduces the risk of cardiovascular disease. This effect is similar to that of wine, at comparable alcohol amounts. Epidemiological studies suggest that moderate consumption of either beer or wine may confer greater cardiovascular protection than spirits. Although specific data on beer are not conclusive, observational studies seem to indicate that low-moderate alcohol consumption is associated with a reduced risk of developing neurodegenerative disease. There is no evidence that beer drinking is different from other types of alcoholic beverages in respect to risk for some cancers. Evidence consistently suggests a J-shaped relationship between alcohol consumption (including beer) and all-cause mortality, with lower risk for moderate alcohol consumers than for abstainers or heavy drinkers. Unless they are at high risk for alcohol-related cancers or alcohol dependency, there is no reason to discourage healthy adults who are already regular light-moderate beer consumers from continuing. Consumption of beer, at any dosage, is not recommended for children, adolescents, pregnant women, individuals at risk to develop alcoholism, those with cardiomyopathy, cardiac arrhythmias, depression, liver and pancreatic diseases, or anyone engaged in actions that require concentration, skill or coordination. In conclusion, although heavy and excessive beer consumption exerts deleterious effects on the human body, with increased disease risks on many organs and is associated to significant social problems such as addiction, accidents, violence and crime, data reported in this document show evidence for no harm of moderate beer consumption for major chronic conditions and some benefit against cardiovascular disease.