Stovitz, Steven D.

Introduction: Heart failure (HF) with preserved ejection fraction (HFpEF) is now the predominant HF subtype, largely driven by the syndemic of physical inactivity and overweight/obesity in an aging population. Deranged skeletal muscle energetics and regional ectopic adipose depots are key cardiometabolic pathways in the pathogenesis of HFpEF, both of which may be favorably modified by 1-2 hours/week of resistance exercise (RE). However, its association with HFpEF risk has not been thoroughly examined. We investigated the association between midlife RE behaviors and incident HFpEF in the Atherosclerosis Risk in Communities (ARIC) study. Hypothesis: Participation in RE at midlife is inversely associated with the risk of incident HFpEF. Methods: Our exposure (RE)—including weightlifting and bodyweight resistance exercises—was assessed using the validated Baecke questionnaire and reported weekly RE duration was averaged across Visits 1 and 3 (1987-1995). We dichotomized averaged RE as 0 hr/wk (‘No RE’, reference) and >0 hr/wk (‘Any RE’). Our outcome (incident HFpEF) was identified through committee-adjudicated HF hospitalizations (January 1, 2005 to December 31, 2023) using medical chart abstraction. Participants with prevalent HF, death, or loss to follow-up before January 1, 2005 were excluded. We constructed Cox regression models to evaluate the association between midlife RE and incident HFpEF. Model 1 adjusted for age, sex, race, field center, education, smoking status, alcohol consumption, and non-RE physical activity. Given that adiposity may lie on the causal pathway, waist-height ratio (WHtR; both measured in cm) was added in Model 2. Results: 10,751 Black and White participants (803 incident HFpEF cases) were analyzed over a median follow-up time of 14.4 years (mean±SD Visit 1 age, 53.3±5.6 years; average Visit 1 and 3 WHtR, 0.58±0.08; 24.7% Black; 57.4% female). 1,217 participants (11.3%) reported engaging in RE at Visits 1 and/or 3, with a median duration of 0.84 hr/wk (IQR, 0.50-1.61). Compared to No RE, the fully adjusted hazard ratio (HR) for Model 1 for Any RE was: 0.78 (95% CI, 0.61-1.00, P = 0.05). The association was attenuated after adjustment for WHtR: HR = 0.84 (0.65-1.07, P = 0.16). Conclusion: Participation in RE at midlife is associated with a 22% lower risk of incident HFpEF. To inform public health and clinical guidelines, further studies are needed to clarify the role of RE in HFpEF prevention.

ABSTRACT Objective This study aimed to examine the effect on continuously monitored blood glucose (BG) among participants with impaired fasting glucose (IFG) who used a height-adjustable desk while working. Methods The study was a repeated-measures pilot study in overweight or obese women who had IFG (BG >100 mg·dL −1 ) and a sedentary job. BG was monitored with continuous glucose monitoring devices during two 1-wk periods at work: 1 wk in the seated position and 1 wk using alternate bouts of sitting and standing (by adjusting their desks) throughout the workday. Results Ten women completed the study. Sedentary time significantly predicted BG independently of diet and overall physical activity ( P = 0.02). Dietary carbohydrates, protein, and fat were significant predictors of BG ( P < 0.001). Conclusions Sedentary time is a strong predictor of increased BG in women with IFG and a sedentary job.

Objective: This study was conducted to determine whether installation of sit-stand desks (SSDs) could lead to decreased sitting time during the workday among sedentary office workers. Methods: A randomized cross-over trial was conducted from January to April, 2012 at a business in Minneapolis. 28 (nine men, 26 full-time) sedentary office workers took part in a 4 week intervention period which included the use of SSDs to gradually replace 50% of sitting time with standing during the workday. Physical activity was the primary outcome. Mood, energy level, fatigue, appetite, dietary intake, and productivity were explored as secondary outcomes. Results: The intervention reduced sitting time at work by 21% (95% CI 18%–25%) and sedentary time by 4.8 min/work-hr (95% CI 4.1–5.4 min/work-hr). For a 40 h work-week, this translates into replacement of 8 h of sitting time with standing and sedentary time being reduced by 3.2 h. Activity level during non-work hours did not change. The intervention also increased overall sense of well-being, energy, decreased fatigue, had no impact on productivity, and reduced appetite and dietary intake. The workstations were popular with the participants. Conclusion: The SSD intervention was successful in increasing work-time activity level, without changing activity level during non-work hours.