Association of circulating C-reactive protein and high-sensitivity C-reactive protein with components of sarcopenia: A systematic review and meta-analysis of observational studies

BACKGROUND

Sarcopenia, a multi-faceted skeletal muscle disorder in the older population, has poor health outcomes. Some previous observational studies investigated the association between circulating inflammatory markers and sarcopenia components to evaluate chronic inflammation as a risk factor for sarcopenia in the elderly population. Nevertheless, the association between circulating C-reactive protein (CRP) and hs-CRP, as the recognized markers of systemic inflammation and components of sarcopenia, is unclear. This meta-analysis aimed to investigate the association of muscle strength, muscle mass, and muscle function with two serum inflammatory markers, circulating C-reactive protein (CRP) and high-sensitive CRP (hs-CRP).

METHODS

We assessed all observational studies across different electronic databases including PubMed, Scopus, and Google Scholar using keywords such as "muscle strength", "muscle mass", "muscle function", CRP and hs-CRP from inception until the 30th of July 2019. Only studies that investigated the association between components of sarcopenia and CRP or hs-CRP levels were included. Participants' country, age, sex, BMI, and screening tool for sarcopenia were retrieved. The correlations between muscle strength, muscle mass, and muscle function with CRP, and hs-CRP were expressed as the correlation coefficient (r) with 95% confidence intervals (CIs). Begg's test and Egger's test were conducted to evaluate risk of publication bias in this study.

RESULTS

Initially, we found fifty-nine studies for the qualitative synthesis. Ultimately, nineteen adult cross-sectional studies comprising 14,650 subjects were included in the meta-analysis. Of them, fourteen studies measured the correlation between CRP or hs-CRP and muscle strength. There were significant inverse correlation between CRP and hs-CRP concentrations with muscle strength (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), respectively. No publication bias was found between muscle strength and CRP (P = 0.53) or hs-CRP (P = 0.62) respectively.

CONCLUSION

Among diagnostic components of sarcopenia, impairment of muscle strength was independently associated with both inflammatory biomarkers. However, future cohort studies are essential to clarify the causal correlation.

Long-Term Improvement of Chronic Low-Grade Inflammation After Bariatric Surgery

PURPOSE

Bariatric surgery (BS) was shown to improve inflammatory markers in previous short-term follow-up studies. The aim of the present study was to assess the long-term effects of BS on chronic low-grade inflammation markers related to severe obesity. Moreover, the meaning of the type of BS procedure as well as the remission of type 2 diabetes (T2D) for inflammatory status up to 4 years after BS was analyzed.

MATERIALS AND METHODS

In a retrospective cohort study including 163 patients at baseline, inflammatory and metabolic parameters were assessed at 4 time points: before surgery (baseline), 6 months after surgery (visit 1), 2 years after surgery (visit 2), and 4 years after surgery (visit 3). Univariate regression analysis was used to identify variables that were thought to determine change in inflammatory parameters.

RESULTS

CRP, hs-CRP, leucocytes, and ferritin significantly declined in the mid- and long-term according to the U-shaped curve of weight loss (p<0.001). Change in body mass index (BMI) at long-time follow-up showed a significant linear effect on change in leucocytes (B=0.082; p<0.001) and change in hs-CRP (B=0.03; p<0.05). There was a strong, positive correlation between T2D and hs-CRP at visit 2 (r_s=0.195; p<0.05) and visit 3 (r_s=0.36; p=0.001). With regard to type of surgery and gender, there were no significant differences in inflammatory parameters.

CONCLUSION

BS is able to reduce obesity-related chronic low-grade inflammation up to 4 years after surgical intervention. The improvement in metaflammation is related to the change in BMI and remission of T2D in the long-term.

Inflammatory Biomarkers During Bacterial Acute Rhinosinusitis

PURPOSE OF REVIEW

Diagnosis of bacterial acute rhinosinusitis is difficult. Several attempts have been made to clarify the diagnostic criteria. Inflammatory biomarkers are easily obtainable variables that could shed light on both the pathophysiology and diagnosis of bacterial acute rhinosinusitis. The purpose of this review article is to assess literature concerning the course of inflammatory biomarkers during acute rhinosinusitis and the use of inflammatory biomarkers in diagnosing bacterial acute rhinosinusitis.

RECENT FINDINGS

We included C-reactive protein, erythrocyte sedimentation rate, white blood cell counts, procalcitonin, and nasal nitric oxide in this review and found that especially elevated C-reactive protein and erythrocyte sedimentation rate are related to a higher probability of a bacterial cause of acute rhinosinusitis. Still, normal levels of these two biomarkers are quite common as well, or the levels can be heightened even during viral respiratory infection without suspicion of bacterial involvement. Elevated levels of C-reactive protein or erythrocyte sedimentation rate support diagnosis of bacterial acute rhinosinusitis, but due to a lack of sensitivity, they should not be used to screen patients for bacterial acute rhinosinusitis.

Circulating angiopoietin-2 and its soluble receptor Tie-2 concentrations are related to inflammatory markers in the general population

BACKGROUND

The Angiopoietin/Tie (Tyrosine kinase with Ig and EGF homology domains) signaling axis has crucial influences on angiogenesis and the vasculature's reorganization. Moreover, angiopoietin-2 (Ang2) is discussed as a biomarker for diseases' severity and development. Previous studies reported increased Ang2 levels in patients with inflammatory diseases and associations of Ang2 with inflammation markers in relatively small samples. We aimed to assess the relation of Ang2 and Tie2 with inflammation markers in the general population.

METHODS AND RESULTS

Data of 6624 participants of the population-based Study of Health in Pomerania (SHIP-1) and the independent SHIP-Trend were used. Ang2, Tie2 and inflammatory biomarkers, including fibrinogen, high-sensitive C-reactive protein (hsCRP) and white blood cell count (WBC), were measured. Adjusted analysis of variance (ANOVA) and linear/logistic regression models were performed in the entire sample and in individuals free of hypertension and diabetes. ANOVA [adjusted means of the 1st vs. 4th Ang2 quartile: fibrinogen 3.0 vs. 3.2 g/l; hsCRP 1.2 vs. 1.6 mg/l; WBC 5.9 vs. 6.6 Gpt/l] and regression models adjusted for potential confounders revealed positive relations of Ang2 with all considered inflammation markers. These associations persisted after the exclusion of individuals with hypertension and diabetes. In contrast, Tie2 showed no clear association pattern with the investigated inflammatory markers even if a trend toward a positive relation with fibrinogen became apparent.

CONCLUSION

Ang2 was positively associated with fibrinogen, hsCRP and WBC in a large population-based setting. These findings partly agree with previous results, largely obtained in clinical samples. Ang2 has diverse postulated effects on inflammation processes, like increase of vascular leakage or influences on the adhesion of leukocytes to the vessel wall. The proinflammatory character of these effects is similar to these of fibrinogen which conforms to our findings of relations between the markers. However, further research is needed to elucidate possible functional mechanisms.

Biomarkers of airway and systemic inflammation in obese asthmatic paediatric patients

BACKGROUND

It is thought that airway inflammation is more common in obese asthmatic patients because inflammation is harder to control and does not respond well to glucocorticoid treatment.

OBJECTIVE

This study's aim was to investigate the effect of obesity on airway and systemic inflammation in children with asthma and to identify the biomarkers that play a role in this inflammation.

METHODS

The study included patients aged 6-16 years who were diagnosed with asthma in the paediatric allergy outpatient clinic of Bagcilar Training and Research Hospital in Turkey. Complete blood count parameters were compared between three groups: obese asthmatic (n=43), obese non-asthmatic (n=45), and non-obese non-asthmatic (control group, n=30). Levels of high-sensitive CRP (hs-CRP), neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN), and matrix metalloproteinase-9 (MMP-9), and 25(OH)-vitamin D were compared between the groups.

RESULTS

No statistically significant differences were observed in 25(OH)-vitamin D, NGAL, OPN, hs-CRP, and MMP-9 levels between groups. There was a statistically significant negative correlation between FEV1/FVC and NGAL and MMP-9.

CONCLUSION

This is the first study to investigate levels of hs-CRP, NGAL, OPN, MMP-9, and 25(OH)-vitamin D in obese asthmatic children. Larger studies with sputum and BAL examinations are required to determine the potential of biomarkers for identifying inflammation in obese asthmatic children.

Visceral adiposity index levels in overweight and/or obese, and non-obese patients with polycystic ovary syndrome and its relationship with metabolic and inflammatory parameters

BACKGROUND

Visceral adiposity index (VAI) is a proposed parameter to evaluate visceral obesity instead of waist circumference (WC) in patients with polycystic ovary syndrome (PCOS). We aimed to evaluate VAI levels in overweight and/or obese, and non-obese PCOS patients and investigate the association between metabolic and inflammatory parameters.

METHODS

Seventy-six PCOS patients between 18 and 40, and 38 age- and BMI-matched controls were enrolled into the study. Both PCOS groups and controls were classified into two subgroups according to body mass index (BMI) <25 and ≥25 kg/m².

RESULTS

In PCOS patients, waist/hip ratio (WHR) (p = 0.023), diastolic blood pressure (DBP) (p = 0.001), insulin (p = 0.011), homeostasis of model assessment (HOMA-IR) (p = 0.006) and uric acid (UA) (p = 0.002) were higher than controls. In overweight and/or obese PCOS group, DBP (p < 0.001), insulin (p = 0.002), HOMA-IR (p = 0.001), triglyceride (p = 0.015) and VAI (p = 0.031) were higher than overweight and/or obese controls. In non-obese PCOS group, WHR (p = 0.016), WC (p = 0.030), DBP (p = 0.010) and UA (p < 0.001) were higher than non-obese controls. Similar VAI levels were found in all PCOS and non-obese PCOS subgroups than peer controls. Overweight and/or obese PCOS group had higher VAI levels than non-obese PCOS group (p < 0.001). VAI levels were positively correlated with WHR, glucose, HOMA-IR, high-sensitive CRP and UA in PCOS group. In controls, VAI levels were positively correlated with WHR, insulin and HOMA-IR.

CONCLUSION

We found that VAI levels were higher in overweight and/or obese PCOS patients compared to peer controls and non-obese PCOS patients, and associated with some metabolic and inflammatory parameters.

High-sensitive CRP as a predictive marker of long-term outcome in juvenile idiopathic arthritis

To evaluate whether C-reactive protein (CRP), including variation within the normal range, is predictive of long-term disease outcome in Juvenile Idiopathic Arthritis (JIA). Consecutive patients with newly diagnosed JIA were included prospectively from defined geographic areas of the Nordic countries from 1997 to 2000. Inclusion criteria were availability of a baseline serum sample within 12 months after disease onset and 8-year clinical assessment data. Systemic onset JIA was not included. CRP was measured by high-sensitive ELISA (detection limit of 0.2 mg/l). One hundred and thirty participants with a median follow-up time of 97 months (range 95-100) were included. At follow-up, 38% of the patients were in remission off medication. Absence of remission was associated with elevated level of CRP at baseline (odds ratio (OR) 1.33, confidence interval (CI) 1.08-1.63, p = 0.007). By applying a cutoff at the normal upper limit (>10 mg/l), the risk of not achieving remission was increased to an OR of 8.60 (CI 2.98-24.81, p < 0.001). Variations of CRP within the normal range had no predictive impact on disease activity at follow-up. Baseline levels of ESR were available in 80 patients (61%) and elevated ESR was associated with absence of remission in a multivariable logistic regression analysis (OR 2.32, CI 1.35-4.00, p = 0.002). This results of this study indicate that baseline CRP concentrations above 10 mg/l are predictive of a poor outcome at 8-year follow-up. We could not demonstrate any predictive value of CRP variations within the normal range.

The mean platelet volume and neutrophil to lymphocyte ratio in obese and lean patients with polycystic ovary syndrome

PURPOSE

Mean platelet volume (MPV) and neutrophil to lymphocyte ratio (NLR) are the new markers of the detection of inflammation. Our aim is to investigate MPV and NLR in lean and obese patients with polycystic ovary syndrome (PCOS).

METHODS

This study was designed to investigate MPV, NLR, and high-sensitive C-reactive protein (hsCRP) levels in 25 obese patients with PCOS and 16 lean patients with PCOS, and our study group was matched with 16 obese and 14 non-obese controls, respectively.

RESULTS

PCOS group had higher MPV, NLR, neutrophil count, neutrophil to total leucocyte ratio, basophil count, waist circumference (WC), insulin, glucose, and HOMA-IR rates than those of controls. hsCRP levels were similar in both groups. Subgroup analyses revealed that obese PCOS group had higher insulin and HOMA-IR levels, compared to those of controls. In this subgroup, total leucocyte counts, MPV, and hsCRP levels were similar. On the other hand, lean PCOS group had higher WC, NLR, MPV, and basophil count than controls. In correlation analysis, hsCRP was positively correlated with body mass index (BMI), WC, total leucocyte count, neutrophil count, while negatively correlated with lymphocyte ratio. Although leucocyte count was positively correlated with BMI, MPV was negatively correlated with BMI, total leucocyte, platelet, and neutrophil counts. NLR was positively correlated with HOMA-IR, hsCRP, BMI, WC, and insulin.

CONCLUSION

Our study demonstrated that MPV and NLR levels are increased despite similar hsCRP levels in patients with PCOS. However, we failed to demonstrate these differences in obese PCOS patients. Further studies with larger sample size are required to determine the significance of BMI in the inflammation of PCOS patients.