Search

BACKGROUND: Although 10 000 steps per day is widely promoted to have health benefits, there is little evidence to support this recommendation. We aimed to determine the association between number of steps per day and stepping rate with all-cause mortality. METHODS: In this meta-analysis, we identified studies investigating the effect of daily step count on all-cause mortality in adults (aged ≥18 years), via a previously published systematic review and expert knowledge of the field. We asked participating study investigators to process their participant-level data following a standardised protocol. The primary outcome was all-cause mortality collected from death certificates and country registries. We analysed the dose-response association of steps per day and stepping rate with all-cause mortality. We did Cox proportional hazards regression analyses using study-specific quartiles of steps per day and calculated hazard ratios (HRs) with inverse-variance weighted random effects models. FINDINGS: We identified 15 studies, of which seven were published and eight were unpublished, with study start dates between 1999 and 2018. The total sample included 47 471 adults, among whom there were 3013 deaths (10·1 per 1000 participant-years) over a median follow-up of 7·1 years ([IQR 4·3-9·9]; total sum of follow-up across studies was 297 837 person-years). Quartile median steps per day were 3553 for quartile 1, 5801 for quartile 2, 7842 for quartile 3, and 10 901 for quartile 4. Compared with the lowest quartile, the adjusted HR for all-cause mortality was 0·60 (95% CI 0·51-0·71) for quartile 2, 0·55 (0·49-0·62) for quartile 3, and 0·47 (0·39-0·57) for quartile 4. Restricted cubic splines showed progressively decreasing risk of mortality among adults aged 60 years and older with increasing number of steps per day until 6000-8000 steps per day and among adults younger than 60 years until 8000-10 000 steps per day. Adjusting for number of steps per day, comparing quartile 1 with quartile 4, the association between higher stepping rates and mortality was attenuated but remained significant for a peak of 30 min (HR 0·67 [95% CI 0·56-0·83]) and a peak of 60 min (0·67 [0·50-0·90]), but not significant for time (min per day) spent walking at 40 steps per min or faster (1·12 [0·96-1·32]) and 100 steps per min or faster (0·86 [0·58-1·28]). INTERPRETATION: Taking more steps per day was associated with a progressively lower risk of all-cause mortality, up to a level that varied by age. The findings from this meta-analysis can be used to inform step guidelines for public health promotion of physical activity. FUNDING: US Centers for Disease Control and Prevention.

Proinflammatory cytokines in the tumor microenvironment can promote tumor growth, yet their value as therapeutic targets remain underexploited. Previously, we validated the functional significance of the cardiotrophin-like cytokine factor 1 (CLCF1)-ciliary neurotrophic factor receptor (CNTFR) signaling axis in lung adenocarcinoma (LUAD) and generated a high-affinity soluble receptor (eCNTFR-Fc) that sequesters CLCF1, thereby inhibiting its oncogenic effects. eCNTFR-Fc inhibits tumor growth in multiple xenograft models and in an autochthonous, highly aggressive genetically engineered mouse model of LUAD, driven by activation of oncogenic Kras and loss of Trp53. Abrogation of CLCF1 through eCNTFR-Fc appears most effective in tumors driven by oncogenic KRAS. From our genetically engineered mouse and our syngeneic modelling of LUAD we have observed that eCNTFR seems to work via two mechanisms, firstly in a tumor intrinsic fashion where it may modulate altered guanosine triphosphate loading, as we see differential effectiveness of eCNTFR-Fc, depending on the presence of KRAS mutations that retain the intrinsic capacity to hydrolyze guanosine triphosphate. Alternatively, eCNTFR also effects the tumor microenvironment and alters the composition of the tumor immune infiltrate, where using single cell genomics we see vast changes to the myeloid compartment, and alteration of the CAF populations, which we have previously shown to be the primary location of CLCF1 expression in mouse LUAD. To further enhance the efficacy of eCNTFR-Fc we have identified potential targets for combination therapy from both the autonomous and non-cell autonomous mechanisms of eCNTFR-Fc. We conclude that eCNTFR-Fc acts through two distinct mechanisms to be a highly effective treatment for Kras mutant LUAD, and combining eCNTER with targets, identified by a rational combination approach, could further enhance its therapeutic potential. Citation Format: Kieren D. Marini, Emma C. Champion, Jennifer R. Cochrane, E. Alejandro Sweet-Cordero. Treatment with an engineered decoy receptor targeting the CLCF1-CNTFR signaling axis prevents oncogenesis in Kras mutant lung adenocarcinoma via both cell autonomous and non-cell autonomous mechanisms [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3185.