The polymorphisms of C-reactive protein gene modify the association between central obesity and lung function in taiwan asthmatics

The Association of Prenatal C-Reactive Protein Levels With Childhood Asthma and Atopy

BACKGROUND

The pathogenesis of childhood asthma is complex, and determinants of risk may begin in utero.

OBJECTIVE

To describe the association of systemic prenatal inflammation, measured by plasma C-reactive protein (CRP), with childhood asthma, eczema, and allergic rhinitis.

METHODS

A total of 522 maternal-offspring pairs from the Vitamin D Antenatal Asthma Reduction Trial were included. Prenatal plasma CRP level was measured between 10 and 18 weeks of gestation and between 32 and 38 weeks of gestation. Offspring asthma, eczema, and allergic rhinitis were assessed quarterly between birth and age 6 years. We performed mediation analyses of prenatal CRP on the association between several maternal characteristics and offspring asthma.

RESULTS

Elevated early and late prenatal CRP and an increase in CRP from early to late pregnancy were associated with asthma by age 6 years (early: adjusted odds ratio [aOR], 1.76, 95% CI, 1.12-2.82, P = .02; late: aOR, 2.45, 95% CI, 1.47-4.18, P < .001; CRP increase: aOR, 2.06, 95% CI, 1.26-3.39, P < .004). Prenatal CRP and childhood asthma associations were strengthened among offspring with atopic asthma (early: aOR, 3.78, 95% CI, 1.49-10.64, P = .008; late: aOR, 4.84, 95% CI, 1.68-15.50, P = .005; CRP increase: aOR, 3.01, 95% CI, 1.06-9.16, P = .04). Early and late prenatal CRP mediated 96% and 86% of the association between maternal prepregnancy body mass index and offspring asthma, respectively.

CONCLUSIONS

Higher prenatal CRP and an increase in CRP from early to late pregnancy are associated with childhood asthma. Systemic inflammation during pregnancy associated with modifiable maternal characteristics may be an important determinant of childhood asthma risk.

Association between abdominal obesity and pulmonary function in apparently healthy adults: A systematic review

BACKGROUND

Obesity, especially abdominal obesity as a chronic disorder is associated with a high risk of developing non-communicable diseases such as respiratory diseases. Impaired lung function is a sign of early respiratory injury. This review summarizes the current knowledge of the effects of abdominal obesity on pulmonary function in apparently healthy adults.

METHODS

Google Scholar, PubMed, Science Direct, and Scopus databases were searched from 2014 up to August 2020 using relevant keywords. All original articles written in English evaluating the effects of abdominal obesity on pulmonary function in apparently healthy adults were eligible for this review.

RESULTS

A total of 26 studies (23 cross-sectional and three cohort) involving 68,024 participants were included in this review. More than 88% of the included studies reported that abdominal obesity significantly inversely was associated with pulmonary function.

CONCLUSION

The findings indicate that in subjects with abdominal obesity respiratory function decline possibly due to mechanical compression and obesity-induced airway inflammation. Therefore, nutrition and lifestyle interventions are required for the reduction of abdominal obesity that leads to improving pulmonary function and metabolic disease.

Quantile-dependent expressivity of serum C-reactive protein concentrations in family sets

Background

“Quantile-dependent expressivity” occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g., C-reactive protein, CRP) is high or low relative to its distribution. We have previously shown that the heritabilities (h²) of coffee and alcohol consumption, postprandial lipemia, lipoproteins, leptin, adiponectin, adiposity, and pulmonary function are quantile-specific. Whether CRP heritability is quantile-specific is currently unknown.

Methods

Serum CRP concentrations from 2,036 sibships and 6,144 offspring-parent pairs were analyzed from the Framingham Heart Study. Quantile-specific heritability from full-sib (β_FS, h² ={(1 + 8r_spouseβ_FS)^0.5 − 1}/(2r_spouse)) and offspring-parent regression slopes (β_OP, h² = 2β_OP/(1 + r_spouse)) were estimated robustly by quantile regression with nonparametric significance determined from 1,000 bootstrap samples.

Results

Quantile-specific h² (±SE) increased with increasing percentiles of the offspring’s age- and sex-adjusted CRP distribution when estimated from β_OP (P_trend = 0.0004): 0.02 ± 0.01 at the 10th, 0.04 ± 0.01 at the 25th, 0.10 ± 0.02 at the 50th, 0.20 ± 0.05 at the 75th, and 0.33 ± 0.10 at the 90th percentile, and when estimated from β_FS (P_trend = 0.0008): 0.03±0.01 at the 10th, 0.06 ± 0.02 at the 25th, 0.14 ± 0.03 at the 50th, 0.24 ± 0.05 at the 75th, and 0.53 ± 0.21 at the 90th percentile.

Conclusion

Heritability of serum CRP concentration is quantile-specific, which may explain or contribute to the inflated CRP differences between CRP (rs1130864, rs1205, rs1800947, rs2794521, rs3091244), FGB (rs1800787), IL-6 (rs1800795, rs1800796), IL6R (rs8192284), TNF-α (rs1800629) and APOE genotypes following CABG surgery, stroke, TIA, curative esophagectomy, intensive periodontal therapy, or acute exercise; during acute coronary syndrome or Staphylococcus aureus bacteremia; or in patients with chronic rheumatoid arthritis, diabetes, peripheral arterial disease, ankylosing spondylitis, obesity or inflammatory bowel disease or who smoke.

Anthropometric determinants of lung function in apparently healthy individuals

Background

Forced vital capacity (FVC) and peak expiratory flow rate (PEFR) are used to assess and monitor the management of lung pathology.

Objectives

Our study documented spirometry reference values for apparently healthy Nigerians and developed predictive equations for pulmonary function.

Method

A cross-sectional survey involving healthy adult Nigerians included anthropometric measurements of weight, height, waist, hip circumference (HC), sagittal abdominal diameter (SAD) and percentage body fat. Anthropometric indices (body mass index [BMI] and waist-to-hip ratio [WHR]) were estimated and pulmonary function tests (FVC, forced expiratory volume in 1 s [FEV1], PEFR, FEV1/FVC ratio) measured. The association amongst selected anthropometric and socio-demographic variables and pulmonary function test parameters were established using t-tests and Pearson’s product moment correlation tests. The predictors of pulmonary function were established using stepwise multiple linear regression models.

Results

Four hundred and forty-four adults (156 [35.1%] men) were included, mean age 37.3 ± 8.25 (range 22–25) years. Male participants had significantly higher lung volumes than females (p < 0.05). Age, height, weight and percentage body fat had significant low correlations with lung function test parameters (p < 0.05). Fat-free mass (FFM), fat mass (FM), SAD, height and age of participants were main predictors of FVC and FEV1 (R² = 0.43 and 0.41, respectively). Fat-free mass and SAD were main predictors of PEFR (R² = 0.53). Sagittal abdominal diameter and age were main predictors of FEV1/FVC ratio (R² = 0.34).

Conclusion

Fat-free mass, FM, height, age and SAD are important determinants of lung volumes and key variables for predictive equations of pulmonary function.

Clinical implications

An accurate documentation of pulmonary function values for apparently healthy Nigerian adults may be useful in identifying deviations from normative values thereby giving an index of suspicion for the diagnosis of pulmonary dysfunction.

Keywords

anthropometric; lung function; spirometry; fat-free mass; apparently healthy.

Obese asthmatics are characterized by altered adipose tissue macrophage activation

BACKGROUND

Adipose tissue-derived inflammation is linked to obesity-related comorbidities. This study aimed to quantify and immuno-phenotype adipose tissue macrophages (ATMs) from obese asthmatics and obese non-asthmatics and to examine associations between adipose tissue, systemic and airway inflammation.

METHODS

Visceral (VAT) adipose tissue and subcutaneous (SAT) adipose tissue were collected from obese adults undergoing bariatric surgery and processed to obtain the stromovascular fraction. Pro-inflammatory (M1) and anti-inflammatory (M2) macrophages were quantified by flow cytometry. Cytospins of induced sputum were stained for differential cell counts. Plasma C-reactive protein (CRP) and CD163 were measured by ELISA.

RESULTS

VAT contained a higher number of ATMs compared to SAT. A higher percentage of M1 ATMs was observed in VAT of obese asthmatics compared to obese non-asthmatics. The M1:M2 ratio in VAT was negatively associated with FEV₁ %. Sputum macrophage count was correlated positively with M1 ATMs and negatively with M2 ATMs in VAT. In obese asthmatics, CRP was positively associated with M1:M2 ratio in VAT. There were no associations with CD163. An elevated ratio of M1:M2 ATMs was observed in VAT of obese asthmatics with increased disease severity.

CONCLUSIONS AND CLINICAL RELEVANCE

Visceral inflammation with increased pro-inflammatory macrophages (M1) occurs in obese asthma and may be a determinant of systemic inflammation and asthma severity.

Low-grade inflammation markers in children and adolescents: Influence of anthropometric characteristics and CRP and IL6 polymorphisms

Overweight and obesity are associated with chronic and subclinical inflammation due to an imbalance of inflammatory mediators. However, the association with gene polymorphism has been rarely studied in children. The aim of this study was to determine if serum concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) are related to the IL6 rs1800795, IL6 rs2069845 and CRP rs1205 polymorphisms (SNPs) according to body mass index (BMI) in a sample of children and adolescents. A cross-sectional study in 470 students between 7 and 17yearsof age of anthropometric characteristics, high sensitivity-CRP (Hs-CRP) and IL-6 levels and three SNPs genotyped. The prevalence ratio of hs-CRP>3mg/L in obese individuals was 4.15 (CI 2.43-7.06; p=0.01), and it was 1.91 (CI 1.03-3.55; p=0.03) in overweight individuals and 1.74 (CI 1.05-2.88 p=0.03) in females. Individuals with waist circumference (WC) and body fat percentage (BF%) alterations showed elevated levels of hs-CRP (p=4.3×10^-5 and p=5.3×10^-6). The combination of any two anthropometric measurement increases CRP levels, especially combinations with obesity body mass index (BMI): BMI+WC and BMI+BF%. Among the overweight/obesity group, T allele carriers of CRP rs1205 showed lower levels of hs-CRP (0.5, IQR=0.3-1.8mg/L) than CC homozygotes (1.5, IQR=0.4-3.4mg/L, p=0.018). Additionally, considering subjects with two or three anthropometric alterations for CRP rs1205: rs1205 T allele carriers had lower levels of hs-CRP (0.7, IQR=0.3-2.7mg/L) than CC homozygotes (1.2, IQR=0.5-3.5mg/L, p=0.02). In conclusion, carriers of the rs1205/T allele with higher BMIs had lower levels of hs-CRP. Schoolchildren who were overweight/obese had higher levels of CRP and IL-6, whereas individuals with WC and BF% alterations had higher levels of CRP.

Association of CRP gene polymorphisms with serum CRP level and handgrip strength in community-dwelling elders in Taiwan: Taichung Community Health Study for Elders (TCHS-E)

Low handgrip strength is one component of frailty, characterized by loss of reserves, including energy, physical ability, cognition and health. This study rated the effect of five single-nucleotide polymorphisms (SNPs) in C-reactive protein (CRP) gene on the serum CRP level and handgrip strength in elderly Taiwanese. Five SNPs (rs2794520, rs1205, rs1130864, rs1800947, and rs3093059) of CRP gene were utilized to genotype 472 unrelated elderly subjects (mean age 73.8years). Handgrip strength was measured by handgrip dynamometer (TTM Dynamometer, Tsutsumi, Tokyo). Our study demonstrated that minor alleles of rs2794520 and rs1205 were C, whereas they were T in most ethnic groups. There exist significant associations of three CRP polymorphisms (rs2794520, rs1205 and rs3093059) with serum CRP level and handgrip strength. All three had simultaneous influence on raising CRP levels and reducing handgrip strength. Genotype and sex interactions emerged for rs2794520 and rs1205 in relation to CRP levels (p<0.05). In addition, haplotype C-C-C-C-C was associated with higher levels of CRP (exp(β)=1.45; p<0.001) and lower handgrip strength (β=-1.00kg, p<0.05). We conclude that SNPs rs2794520, rs1205, and rs3093059 of CRP gene, as well as haplotype C-C-C-C-C may be important biomarkers for susceptibility to low handgrip strength and high serum CRP level in elders; further studies are required.

Immunometabolism in obese asthmatics: are we there yet?

Obesity is now recognised as a worldwide epidemic. The recent International Association for the Study of Obesity/International Obesity Taskforce (IASO/IOTF) analysis estimates that approximately 1.0 billion adults are currently overweight and a further 475 million are obese. Obesity has huge psychosocial impact with obese children and adolescents facing discrimination and stigmatization in many areas of their lives leading to body dissatisfaction, low self-esteem and depression. Indeed, obesity is recognised as an important risk factor for the development of several chronic diseases such as hypertension, cancer, asthma and metabolic syndrome. Chronic low grade systemic inflammation is considered as a hallmark of obesity and may possibly explain the link between obesity and chronic disease, in particular the increased incidence, prevalence and severity of asthma in obese individuals. There is now strong evidence for infiltration of immune and inflammatory cells into adipose tissue that drives systemic inflammation and subsequent end organ damage. In addition to adipocytes, the key adipose tissue resident immune cells are macrophages and mast cells. Immunometabolism, as an emerging field of investigation, explores the pivotal role of these immune cells in translating immunological changes to metabolic effects in obesity. Abundance of free fatty acids, along with other inflammatory cytokines shift the balance of metabolic homeostasis to pro-inflammatory status by influencing the development of inflammatory cell lineage, which, further exhibits distinct functional phenotypes. There is emerging evidence for macrophage activation and functional polarization of an anti-inflammatory M₂ phenotype towards a pro-inflammatory M₁ phenotype of macrophages in obese adipose tissue. Similarly, studies in both obese humans and murine models reveal the pathognomic presence of an increased number of mast cells in visceral adipose tissue. These suggest a possible contribution of mast cells to the unique metabolome of obese asthma. This review examines proposed multilevel interactions between metabolic and immune systems in obese asthmatics that underlie the negative effects of obesity and may offer significant therapeutic promise.