Mid-pregnancy sleep disturbances are not associated with mid-pregnancy maternal glycemia.

Background: In pregnancy, epidemiological data have consistently shown strong associations between sleep quality and duration and maternal glycemia. However, other sleep disturbances such as difficulty falling asleep and staying asleep are common in pregnancy. They may contribute to impaired maternal glycemia through sympathetic nervous system activity, systemic inflammation, and hormonal pathways. However, there is little research examining associations between these specific sleep disturbances and maternal glycemia. Objective: This study aimed to investigate the associations of sleep disturbances during mid-pregnancy and mid-pregnancy maternal glycemia and gestational diabetes subtypes. Study Design: This is a secondary data analysis of the Comparison of Two Screening Strategies for Gestational Diabetes trial. Participants (n = 828) self-reported the frequency of sleep disturbances (i.e., trouble falling asleep, trouble staying asleep, waking several times per night, and waking feeling tired or worn out) in mid-pregnancy. Gestational diabetes was diagnosed using either the International Associations of Diabetes and Pregnancy Study Groups or Carpenter-Coustan approach. We defined gestational diabetes subtypes based on the degree of insulin resistance and beta-cell dysfunction. We used multinomial logistic regression to examine associations of sleep disturbances with gestational diabetes status (i.e., normal, mild glycemic dysfunction, and gestational diabetes) and gestational diabetes subtypes (i.e., neither insulin resistance or beta-cell dysfunction, insulin resistance only, beta-cell dysfunction only, and insulin resistance and beta-cell dysfunction). Results: A total of 665 participants (80%) had normal glycemia, 81 (10%) mild hyperglycemia, and 80 (10%) had gestational diabetes. Among participants with gestational diabetes, 62 (78%) had both insulin resistance and beta-cell dysfunction, 15 (19 %) had insulin resistance only, and 3 had beta-cell dysfunction only or neither insulin resistance nor beta-cell dysfunction. Sleep disturbance frequency was not associated with maternal glycemia or gestational diabetes subtypes. Conclusions: Sleep disturbances in mid-pregnancy were not associated with maternal glycemia during mid-pregnancy. Future research should collect data on sleep disturbances at multiple time points in pregnancy and in combination with other sleep disturbances to determine whether sleep plays any role in maternal glycemic control.

Development of a Novel Accelerometry-Based Performance Fatigability Measure for Older Adults.

INTRODUCTION: Efforts to study performance fatigability have been limited because of measurement constrains. Accelerometry and advanced statistical methods may enable us to quantify performance fatigability more granularly via objective detection of performance decline. Thus, we developed the Pittsburgh Performance Fatigability Index (PPFI) using triaxial raw accelerations from wrist-worn accelerometer from two in-laboratory 400-m walks. METHODS: Sixty-three older adults from our cross-sectional study (mean age, 78 yr; 56% women; 88% White) completed fast-paced ( n = 59) and/or usual-paced 400-m walks ( n = 56) with valid accelerometer data. Participants wore ActiGraph GT3X+ accelerometers (The ActiGraph LLC, Pensacola, FL) on nondominant wrist during the walking task. Triaxial raw accelerations from accelerometers were used to compute PPFI, which quantifies percentage of area under the observed gait cadence-versus-time trajectory during a 400-m walk to a hypothetical area that would be produced if the participant sustained maximal cadence throughout the entire walk. RESULTS: Higher PPFI scores (higher score = greater fatigability) correlated with worse physical function, slower chair stands speed and gait speed, worse cardiorespiratory fitness and mobility, and lower leg peak power (| ρ | = 0.36-0.61 from fast-paced and | ρ | = 0.28-0.67 from usual-paced walks, all P < 0.05). PPFI scores from both walks remained associated with chair stands speed, gait speed, fitness, and mobility, after adjustment for sex, age, race, weight, height, and smoking status; PPFI scores from the fast-paced walk were associated with leg peak power. CONCLUSIONS: Our findings revealed that the objective PPFI is a sensitive measure of performance fatigability for older adults and can serve as a risk assessment tool or outcome measure in future studies and clinical practice.

Association of arterial rigidity with incident kidney disease and kidney function decline: the Health ABC study.

BACKGROUND AND OBJECTIVE: The association of large arterial rigidity and kidney function decline in longitudinal analyses is not well established. This study evaluated the association of aortic pulse wave velocity (aPWV) and pulse pressure (PP) with rapid kidney function decline and incident CKD in the Health, Aging and Body Composition study. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Participants were 2129 older adults with a baseline measurement of aPWV, PP, and cystatin C and at least one additional measurement of cystatin C, either at year 3 or year 10. Outcomes were rapid kidney function decline (estimated GFRcysC loss of >3 ml/min per 1.73 m(2) per year) and incident CKD (eGFRcysC < 60 ml/min per 1.73 m(2) in participants with baseline estimated GFR > 60 ml/min per 1.73 m(2)). Multivariate regression models were used to evaluate association of aPWV and PP with each outcome. RESULTS: Mean (SD) baseline estimated GFRcysC was 79±29 ml/min per 1.73 m(2). Median follow-up duration was 8.9 years. In multivariable analyses, aPWV was not associated with rapid decline (odds ratio [OR], 95% confidence interval [CI] 1.16, 0.89-1.52) but was associated with incident CKD (incident rate ratio [IRR], 95% CI, 1.39, 1.09-1.77) and PP was associated with both rapid decline (OR, 95% CI 1.10, 1.04-1.16) and incident CKD (IRR, 95% CI, 1.06, 1.01-1.11). CONCLUSIONS: Large arterial stiffness assessed by aPWV and pulsatility assessed by PP were associated with incident CKD among older adults. Pulsatility assessed by PP was associated with rapid kidney function decline and incident CKD. Future research should determine whether interventions targeting arterial rigidity will prevent CKD development and progression.