Leng, Iris

Abstract There are no circulating markers exclusive to cell senescence for clinical trials in middle-aged/older adults. In this study we evaluated T-cell expression of tumor suppressor protein p16INK4a and plasma senescence associated secretory proteins (SASP)-factors in the context of an 18-week randomized trial of caloric restriction (CR) compared to a weight stable Control. The analysis includes 55 middle-aged/older adults (75%Women; 33%African American; 57.6±5.8 years) with obesity and prediabetes. We measured mRNA expression of select senescence and apoptosis gene transcripts (p16INK4a, p21, BCL2L, BAK1) in peripheral blood CD3+ T-cells (quantitative-RT-PCR) and a panel of 27 plasma SASP proteins (Luminex/multiplex; ELISA). Weight loss in those randomized to CR was -10.8±0.9 kg compared to +0.5±0.9 kg in Control. Using mixed models, T-cell expression of senescence-biomarkers p16INK4a, p21, BCL-2L, and apoptosis-marker BAK1 were not different between CR and control at 18 weeks (time × treatment adjusted for age, race, and sex, all p>0.05). We explored associations between biomarkers with weight loss; moderate spearman correlations (rs=0.28 to 0.64) were observed between weight loss and change in plasma SASP-factors (Activin A, I-CAM, MMP1, PAI-1, TNF-RI, TNF-RII, VEGF, uPAR, p< 0.05 all), but not T-cell biomarker expression. We evaluated associations between biomarkers and found change in T-cell p16INK4a was associated with change in plasma SASP-factors, Fas (rs=0.51), osteopontin (rs=0.34), myeloperoxidase (rs=0.39), and MMP2 (rs=0.40) (CR+Control combined). Among middle-aged/older persons with obesity undergoing 18-weeks CR, changes in T cell p16INK4a expression were correlated with reductions in key SASP factors, and weight loss was associated with lower pro-inflammatory SASP profile.

Background: Heart failure (HF), a leading cause of morbidity and mortality in women, continues to disproportionately affect African-American (AA) women compared to women of other races/ethnicities. In a large cohort of post-menopausal women, we investigated if AA women progress through HF stages and coronary heart disease (CHD) death more rapidly than Caucasian (Cau) or Hispanic/Latina (HL) women. Methods: We assessed the American College of Cardiology/American Heart Association (ACC/AHA) HF stage A upon enrollment into the Women’s Health Initiative (1993-1998) and the progression from Stage A to Stage C, Stage C to CHD death, up to the last date of follow-up (2010). Cox proportional hazard regressions models were used to assess disease progression risk. We adjusted for age, baseline comorbidities, duration of comorbidities, interval development of myocardial infarction, ejection fraction at HF diagnosis, socioeconomic factors, and sex specific variables. Results: At baseline, AA women were younger and had a higher percentage of Stage A HF (76%) than Cau (54%) and HL (55%) women. Overall, AA and HL women had significantly lower risk of progressing from Stage A to Stage C compared to Cau women [AA vs. Cau adjusted Hazard Ratio (HR) 0.77 (95% Confidence Interval (CI) 0.64 -0.93) p = 0.0055; HL vs. Cau HR 0.54 (95% CI 0.40 -0.71) p < 0.0001]. After stratifying by age groups(<65, 65-69, >70 years), AA women had a similar risk of progression from stage A to C compared to Cau women. When compared to Cau women, AA had an insignificant increased risk of progressing from Stage C to CHD death [adjusted HR 1.29 (95% CI 0.72 -2.32) p = 0.3883)]. Conclusions: Cau women were at higher risk for HF progression from Stage A to Stage C compared to HL women, but at similar risk as AA women. AA women had an insignificant but increased risk of progression from Stage C to CHD death compared to Cau women.