Association of systemic inflammation, adiposity, and metabolic dysregulation with asthma burden among Hispanic adults

Abstract

Rationale Obesity-related asthma is associated with higher disease burden than normal-weight asthma among Hispanics. Adiposity, metabolic dysregulation, and inflammation are all implicated in pathogenesis of obesity-related asthma, but their independent contributions are poorly understood. Objective To examine the independent contributions of body fat distribution, metabolic abnormalities and inflammation on asthma symptoms and pulmonary function among Hispanics. Methods Participants of the Hispanic Community Health Study/Study of Latinos with doctor-diagnosed asthma who completed an asthma symptom questionnaire and performed a valid spirometry were included in the analysis (n=1,126). Multivariate analysis was used to examine the independent association of general adiposity (assessed using body mass index), truncal adiposity (assessed by waist circumference), metabolic dysregulation (presence of insulin resistance and low HDL) and inflammation (high-sensitivity C-Reactive Protein≥3mg/L) with reported asthma symptoms or pulmonary function measures (FEV1, and FVC) while adjusting for demographic and clinical covariates. Results Of the 1,126 participants, 334 (29.5%) were overweight, and 648 (57.8%) were obese. FEV1 and FVC were lower in obese compared to normal-weight asthmatics. In analyses controlling for metabolic and adiposity factors, high hs-CRP (>7 mg/L) was associated with more symptoms (prevalence-ratio 1.27 (95%CI 1.05, 1.54), and lower FVC (β −138ml (95%CI −27ml, −249ml)) and FEV1 (β −155ml (95% CI −38ml, −272ml). Low HDL was also associated with lower FVC (β −111ml (−22ml, −201ml) and FEV1 (β −100ml (−12ml, −188ml)). Results were similar in men and women. Conclusions Our findings suggest that hs-CRP and low HDL, rather than general and truncal adiposity, are associated with asthma burden among overweight and obese Hispanic adults.

Preliminary development of a questionnaire to measure the extra-pulmonary symptoms of severe asthma

“…There are bidirectional causal connections between inflammation in the lung and non-specific inflammatory markers that creates an association between asthma and obesity [ 32 ]. The mean BMI of this group of patients was at the bottom of the range normally considered obese and BMI correlated significantly GSQ-A consistent with the hypothesis that the extra-pulmonary symptoms are linked to nonspecific inflammation [ 33 , 34 ]. Nonspecific inflammation is linked to many other biological abnormalities through a network of biological causal influence [ 35 ].…”

Obesity Does Not Increase the Risk of Asthma Readmissions

“…In our population of asthmatics who required any hospital readmission, more than 71% were obese or overweight, but this is not associated with the incidence of hospital readmissions. Our results are in agreement with the other authors who did not observe a relationship between obesity and exacerbations or with the control of the asthma [8,16,21,[29][30][31], although it was different from other studies where we showed a poorer control of asthma or increase in the incidence of the exacerbations with obesity [13][14][15]19,20,[32][33][34][35][36].…”

Adiposity and Asthma in a Nationwide Study of Children and Adults in the United States

“…Excess visceral/ectopic fat has been linked to insulin resistance, dyslipidemia, upregulated proinflammatory cytokines including tumor necrosis factor-a and interleukin-6, and decreased adiponectin (55). Insulin resistance has been reported as an effect modifier of the obesity-asthma association among U.S. children (56) and adults (57), and dyslipidemia has been associated with asthma symptoms and lower lung function among overweight and obese adults with asthma, independent from general or truncal adiposity (58). In our analysis, including homeostasis model assessment-estimated insulin resistance and/or total cholesterol/high-density lipoprotein cholesterol in the regression models rendered the association between dual-energy X-ray absorptiometry trunkpredominant adiposity and asthma among women nonsignificant.…”