Circadian alignment, cardiometabolic disease, and sex specific differences in adults with overweight/obesity.

OBJECTIVE: Circadian disruption promotes weight gain and poor health. The extent to which sex plays a role in the relationship between the circadian timing of behaviors and health outcomes in individuals with overweight/obesity is unclear. We investigated the sex-specific associations between circadian alignment and cardiometabolic health markers in females and males with overweight/obesity. METHODS: Thirty volunteers with overweight/obesity (15 female; BMI≥25.1kg/m2) underwent an evening in-laboratory assessment for dim-light melatonin onset (DLMO), body composition via dual energy x-ray absorptiometry, and a fasted blood sample. Circadian alignment was determined as the time difference between DLMO and average sleep onset over 7-days (phase angle), with participants categorized into narrow/wide phase angle groups based on median phase angle split. Due to known differences in metabolic markers between sexes, participants were subdivided based on sex into narrow and wide phase angle groups. RESULTS: Males in the narrow phase angle group had higher android/gynoid body fat distribution, triglycerides, and Metabolic Syndrome risk scores, while females had higher overall body fat percentage, glucose, and resting heart rates (all p<0.04). Furthermore, a narrower phase angle in males was negatively associated with android/gynoid body fat (r=-0.53, p=0.04) and negatively associated with body fat (r=-0.62, p=0.01) and heart rate (r=-0.73, p<0.01) in females. CONCLUSION: Circadian disruption may not only promote a trajectory of weight gain but could also contribute to negative health consequences in a sex-dependent manner in those already with overweight/obesity. These data may have implications for clinical utility in sex-specific sleep and circadian interventions for adults with overweight/obesity.

Identifying an acceptable number of ambulatory blood pressure measurements for accuracy of average blood pressure and nocturnal dipping status.

We aimed to identify the minimum number of ambulatory blood pressure (ABP) measures to accurately determine daytime and nighttime systolic blood pressure (BP) averages and nocturnal dipping status (i.e., relative daytime:nighttime change). A total of 43 midlife participants wore an ABP monitor for 24 h with measurements every 20/30 min during the daytime/nighttime, as identified by a sleep diary. We calculated daytime/nighttime systolic BP average and dipping status from all available measurements per participant (i.e., normative data). We then calculated daytime and nighttime BP per participant based on a random selection of 8-20 and 4-10 measurements and replicated random selections 1,000 times. We calculated accuracy by checking the proportion from 1,000 different randomly selected samples for a particular number of measurements that systolic BP was ±5 mmHg of normative data, and dipping status remained unchanged for each participant compared with the normative value. The best fit for the regression model estimated the minimal number of measurements for an accuracy of 95% in BP averages. For a 95% accuracy in estimating daytime and nighttime systolic BP, 11 daytime and 8 nighttime measurements were required. The highest accuracy for dipping status was 91.6 ± 13.4% using 20 daytime and 10 nighttime measures, while the lowest was (83.4 ± 15.1%) using 8 daytime and 4 nighttime measures. In midlife adults, 11 daytime and 8 nighttime measurements are likely enough to calculate average systolic BPs accurately. However, no minimum number is suggested to accurately calculate dipping status.NEW & NOTEWORTHY We found that a minimum of 11 blood pressure (BP) measures are necessary to calculate an accurate average daytime BP, and 8 nighttime measures are necessary to calculate an accurate nighttime average if 95% accuracy is acceptable. Regarding BP dipping status, the current recommendations (20 daytime/7 nighttime) inaccurately classified the dipping status 10.5% of the time, suggesting that guidelines may need to be updated to classify patients as nocturnal dippers or nondippers correctly.

Belonging, endurance, and resistance: Black placemaking theory in primary care.

Black-Americans continue to experience pervasive health disparities. Factors contributing to increased disease risk include a general mistrust of biomedical institutions among Black Americans. The purpose of this focus group study was to identify, among Black patients who regularly seek care from a primary provider, salient themes regarding barriers to 1) receiving quality primary care; and 2) adhering to medical recommendations. We examined transcripts of eight focus groups held remotely with 29 Black patients (aged 30-60 years) who had established primary care providers. Using grounded theory and an inductive thematic analysis of the transcripts, we identified three themes (belonging, endurance, and resistance) consistent with Black placemaking theory. Our findings suggest that reducing health disparities for Black Americans will require clinical initiatives that emphasize: 1) attention to social influences on health behavior and to features of medical institutions that mark them as White spaces (belonging); 2) recognition of, as well as sensitivity to, community awareness of the systemic and interpersonal barriers to health and safety that many Black adults endure; and 3) reframing avoidant (resistant) behaviors as protective strategies among Black patients. Examining primary care in this way-through the lens of Black placemaking theory-reveals how culturally meaningful approaches to harnessing the specialized knowledge and resilience that clearly exists among many Black communities can improve health care delivery.