Interleukin-6, Diabetes, and Metabolic Syndrome in a Biracial Cohort: The Reasons for Geographic and Racial Differences in Stroke Cohort.

OBJECTIVE: Black Americans have a greater risk of type 2 diabetes than White Americans. The proinflammatory cytokine interleukin-6 (IL-6) is implicated in diabetes pathogenesis, and IL-6 levels are higher in Black individuals. This study investigated associations of IL-6 with incident diabetes and metabolic syndrome in a biracial cohort. RESEARCH DESIGN AND METHODS: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study enrolled 30,239 Black and White adults age ≥45 years in 2003-2007, with a follow-up ∼9.5 years later. Baseline plasma IL-6 was measured in 3,399 participants at risk of incident diabetes and 1,871 at risk of metabolic syndrome. Relative risk (RR) by IL-6 was estimated with modified Poisson regression for both groups. RESULTS: Incident diabetes occurred in 14% and metabolic syndrome in 20%; both rates rose across IL-6 quartiles. There was a three-way interaction of IL-6, race, and central adiposity for incident diabetes (P = 8 × 10-5). In Black participants with and without central adiposity, RRs were 2.02 (95% CI 1.00-4.07) and 1.66 (1.00-2.75) for the fourth compared with first IL-6 quartile, respectively. The corresponding RRs were 1.73 (0.92-3.26) and 2.34 (1.17-4.66) in White participants. The pattern was similar for IL-6 and metabolic syndrome. CONCLUSIONS: Although IL-6 was higher in Black than in White participants and those with central adiposity, the association of IL-6 with diabetes risk was statistically significant only among White participants without central adiposity. The association with metabolic syndrome risk was similarly stronger in low-risk groups. The results support the concept of interventions to lower inflammation in diabetes prevention, but to reduce race disparities, better biomarkers are needed.

Association of Rurality With Survival and Guidelines-Concordant Management in Early-stage Non-Small Cell Lung Cancer.

BACKGROUND: Rural populations of the United States have not experienced a similar degree of decline in lung cancer mortality recently seen nationwide. Several investigations examining survival differences in rural lung cancer patients have been incongruent. We investigated the association of rural residence with survival outcomes and receipt of guidelines-concordant treatment in early-stage non-small cell lung cancer (NSCLC). METHODS: Retrospective study of National Cancer Data Base patients with NSCLC diagnosed from 2004 to 2015. Comparisons of survival outcomes and guidelines-concordant management with lobectomy or stereotactic body radiation therapy among rural and nonrural patients, classified according to the US Department of Agriculture's Rural-Urban Continuum Codes. RESULTS: We identified 840,566 patients; 18.7% resided in rural areas. Rurality was associated with greater proportions of males, white patients, and higher comorbidities. Larger proportions of rural stage I patients (53.4%) did not undergo guidelines-concordant management with lobectomy or stereotactic body radiation therapy relative to nonrural patients (50.1%, P<0.001). Although rural patients within each stage at diagnosis have a significant disparity in overall survival (OS), stage I NSCLC had the largest absolute difference (nonrural=61.4 mo, rural=50.3 mo, difference of 11.1 mo, P<0.0001). In multivariable Cox regression, rurality was independently associated with impaired survival in both all-stages (hazard ratio=1.08, P<0.001) and stage I NSCLC (hazard ratio=1.09, P<0.001). CONCLUSIONS: Small differences exist in OS among all rural NSCLC patients, but rural patients with stage I NSCLC have a marked disadvantage in OS. Rurality is an independent risk factor for decreased survival in all-stages and stage I NSCLC.