Decrements of body mass index are associated with poor outcomes of idiopathic pulmonary fibrosis patients

Abstract

BackgroundThe processes that result in progression of idiopathic pulmonary fibrosis (IPF) remain enigmatic. Moreover, the course of this disease can be highly variable and difficult to accurately predict. We hypothesized analyses of body mass index (BMI), a simple, routine clinical measure, may also have prognostic value in these patients, and might provide mechanistic insights. We investigated the associations of BMI changes with outcome, plasma adipokines, and adaptive immune activation among IPF patients.MethodsData were analyzed in an IPF discovery cohort (n = 131) from the University of Pittsburgh, and findings confirmed in patients from the University of Alabama at Birmingham (n = 148). Plasma adipokines were measured by ELISA and T-cell phenotypes determined by flow cytometry.ResultsTransplant-free one-year survivals in subjects with the greatest rates of BMI decrements, as percentages of initial BMI (>0.68%/month), were worse than among those with more stable BMI in both discovery (HR = 1.8, 95%CI = 1.1–3.2, p = 0.038) and replication cohorts (HR = 2.5, 95%CI = 1.2–5.2, p = 0.02), when adjusted for age, baseline BMI, and pulmonary function. BMI decrements >0.68%/month were also associated with greater mortality after later lung transplantations (HR = 4.6, 95%CI = 1.7–12.5, p = 0.003). Circulating leptin and adiponectin levels correlated with BMI, but neither adipokine was prognostic per se. BMI decrements were significantly associated with increased proportions of circulating end-differentiated (CD28null) CD4 T-cells (CD28%), a validated marker of repetitive T-cell activation and IPF prognoses.ConclusionsIPF patients with greatest BMI decrements had worse outcomes, and this effect persisted after lung transplantation. Weight loss in these patients is a harbinger of poor prognoses, and may reflect an underlying systemic process, such as adaptive immune activation.

A real world retrospective observational study exploring the effectiveness and safety of antifibrotics in idiopathic pulmonary fibrosis

“…This is also true for baseline BMI in both the pre-anti brotic and post-anti brotic eras [24][25]. Decline in BMI has also been shown to be a risk factor for increased mortality [26,27]. Our results are surprising as it appears patients with a normal BMI are at an increased risk of dying.…”

Pleuroparenchymal fibroelastosis in systemic sclerosis: prevalence and prognostic impact

“…Although the association was no longer significant on multivariable analysis, a low BMI may well be contributing to the poor survival in this cohort. A low or decreasing BMI is known to be an independent predictor of increased mortality in patients with IPF [17][18][19][20].…”

Analysis of body mass index, weight loss and progression of idiopathic pulmonary fibrosis

“…Some studies have suggested that lower body mass index (BMI) [5][6][7] or weight loss [8,9] may be associated with worse prognosis in patients with IPF, although this has not been observed in all studies [10][11][12]. Large weight loss in obese individuals has been associated with an improvement in FVC [13] and smaller weight reductions with an improvement in FVC in the general population [14].…”