Individualized Relative-Intensity Physical Activity Accelerometer Cut Points.

PURPOSE: Physical activity (PA) intensity is expressed as either absolute or relative intensity. Absolute intensity refers to the energy required to perform an activity. Relative intensity refers to a level of effort that takes into account how hard an individual is working relative to their maximum capacity. We sought to develop methods for obtaining individualized relative-intensity accelerometer cut points using data from a maximal graded exercise treadmill test (GXT) so that each individual has their own cut point. METHODS: A total of 2363 men and women 38 to 50 yr old from the CARDIA fitness study wore ActiGraph 7164 accelerometers during a maximal GXT and for seven consecutive days in 2005-2006. Using mixed-effects regression models, we regressed accelerometer counts on heart rate as a percentage of maximum (%HRmax) and on RPE. Based on these two models, we obtained a moderate-intensity (%HRmax = 64% or RPE = 12) count cut point that is specific to each participant. We applied these subject-specific cut points to the available CARDIA accelerometer data. RESULTS: Using RPE, the mean moderate-intensity accelerometer cut point was 4004 (SD = 1120) counts per minute. On average, cut points were higher for men (4189 counts per minute) versus women (3865 counts per minute) and were higher for Whites (4088 counts per minute) versus African Americans (3896 counts per minute). Cut points were correlated with body mass index (rho = -0.11) and GXT duration (rho = 0.33). Mean daily minutes of absolute- and relative-intensity moderate to vigorous PA were 34.1 (SD = 31.1) min·d and 9.1 (SD = 18.2) min·d, respectively. RPE cut points were higher than those based on %HRmax. This is likely due to some participants ending the GXT before achieving their HRmax. CONCLUSIONS: Accelerometer-based relative-intensity PA may be a useful measure of intensity relative to maximal capacity.

Real-World Study of Once-Daily, Extended-Release Tacrolimus Versus Twice-Daily, Immediate-Release Tacrolimus in Kidney Transplantation: Clinical Outcomes and Healthcare Resource Utilization.

INTRODUCTION: Real-world data with extended-release tacrolimus (ER-T) are lacking in the USA. This study examined clinical outcomes and healthcare resource utilization in kidney transplant patients receiving ER-T in clinical practice. METHODS: This was a retrospective, single-center analysis (February-June 2016) using data from Northwestern University's Enterprise Data Warehouse. Adult patients receiving a kidney transplant in the preceding 4 years, treated de novo or converted to ER-T from immediate-release tacrolimus (IR-T) within 10 days post-transplantation, and maintained on ER-T (at least 3 months) were included. Patients were matched for demographic and clinical characteristics with IR-T-treated control patients. Endpoints included clinical outcomes and healthcare resource utilization up to 1 year post-transplantation. RESULTS: A total of 19 ER-T-treated patients were matched with 55 IR-T-treated patients. No ER-T-treated patients experienced biopsy-confirmed acute rejection (BCAR) or graft failure versus 3 (5.5%) and 3 (5.5%) IR-T-treated patients, respectively. Mean estimated glomerular filtration rate (eGFR), the number of all-cause outpatient visits, readmissions, and all-cause hospitalization days were comparable between groups. Tacrolimus trough levels, days to target level (6-10 ng/mL), and number of required dose adjustments were also similar. CONCLUSION: Real-world clinical outcomes and healthcare resource utilization were similar with ER-T and IR-T. Larger studies will need to investigate the trend toward fewer BCAR events, and increased graft survival with ER-T. FUNDING: Astellas Pharma Global Development, Inc. Plain language summary available for this article.

Pre-pregnancy blood pressure and body mass index trajectories and incident hypertensive disorders of pregnancy.

There are few studies examining patterns in body mass index (BMI) and blood pressure (BP) and subsequent hypertensive disorders of pregnancy (HDPs). We examined the association of BMI (n = 1342) or BP (n = 2266) trajectories in the 5 years preceding birth with HDPs using adjusted logistic regression. Compared to normal-weight BMI and low-normal BP groups, membership to the overweight BMI group (OR: 2.95, 95%CI: 1.57-5.53, p = 0.001) and higher-normal (OR: 2.74, 95%CI:1.49-5.04, p = 0.001) and prehypertensive (OR:7.27, 95%CI: 3.29-16.06, p < 0.001) BP groups were associated with higher odds of HDPs. Our data suggest maintaining normal-weight and low-normal BP in the years preceding pregnancy may help avoid HDPs.

Association of sleep characteristics with cardiovascular and metabolic risk factors in a population sample: the Chicago Area Sleep Study.

OBJECTIVES: To investigate the association of sleep characteristics with prevalent hypertension, diabetes, and obesity in a multiethnic cohort. DESIGN: This study used a population-based cross-sectional study design. SETTING: Participants were recruited between 2009 and 2011 from Chicago, Illinois, and the surrounding suburbs. PARTICIPANTS: Participants were 492 adults aged 35 to 64years who self-reported as white, black, Hispanic, or Asian and who had a low likelihood of sleep apnea based on the apnea screening questionnaires and 1 night of apnea screening using an in-home device (apnea hypopnea index <15 or oxygen desaturation index <10). MEASUREMENTS: Participants wore a wrist actigraphy monitor (Actiwatch™) for 7days. During a clinical examination, participants completed questionnaires about sleep, other health behaviors, and medical history and had their blood pressure, anthropometric measures, and fasting blood glucose measured; metabolic risk factors were determined based on standard clinical guidelines. RESULTS: The prevalence of hypertension, obesity, and diabetes was 17.1%, 5.5%, and 35.4%, respectively. Sleep duration was not associated with any cardiovascular risk factor. There was a significantly increased odds for hypertension (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.08) and obesity (OR, 1.03; 95% CI, 1.00-1.05) associated with higher sleep fragmentation (per 1%). There was also a significantly increased odds for hypertension associated with poorer self-reported sleep quality (OR, 1.14 [95% CI, 1.05-1.24] per 1-unit higher Pittsburgh Sleep Quality Index global score). CONCLUSION: Objective and self-reported sleep quality may be more important than duration in relation to prevalent hypertension.

The Mediation of Racial Differences in Hypertension by Sleep Characteristics: Chicago Area Sleep Study.

BACKGROUND: Racial disparities in hypertension prevalence in the United States are established. Given our understanding of racial and ethnic disparities in sleep characteristics and demonstrated associations between sleep characteristics and hypertension, we tested whether sleep characteristics mediated racial disparities in hypertension. METHODS: Analyses were performed in the Chicago Area Sleep Study, a population-based cohort study of 154 Blacks, 128 Whites, 103 Hispanics, and 109 Asians without obstructive sleep apnea. Participants underwent 7 days of wrist actigraphy monitoring. Algorithms were used to determine sleep duration and sleep maintenance (the percent of sleep in the sleep period). Hypertension was determined as systolic blood pressure >140mm Hg or diastolic blood pressure >90mm Hg or the use of antihypertensive medications. We estimated sample prevalence ratios for hypertension before and after adjustment for sleep characteristics and also conducted mediation analysis. RESULTS: The sample prevalence of hypertension was highest in Blacks (36%), followed by Hispanics (14%), Asians (8%), and Whites (5%). The sample prevalence ratio for hypertension for Blacks vs. Whites was 5.52 (95% confidence interval (CI): 2.36, 13.23) after adjusting for age, sex, and education. Adjustment for sleep duration had no influence on the effect estimate, but adjustment for sleep maintenance attenuated the sample prevalence ratio to 4.55 (95% CI: 1.91, 11.14). Sleep maintenance mediated 11.4% of the difference in hypertension prevalence between Blacks and Whites in this sample. CONCLUSIONS: Sleep maintenance mediated a small but significant portion of the disparity in hypertension between Blacks and Whites. Future research should investigate the mechanisms underlying these findings.