The role of race and ethnicity in sleep, circadian rhythms and cardiovascular health

In recent years, strong evidence has emerged suggesting that insufficient duration, quality, and/or timing of sleep are associated with cardiovascular disease (CVD), and various mechanisms for this association have been proposed. Such associations may be related to endophenotypic features of the sleep homeostat and the circadian oscillator, or may be state-like effects of the environment. Here, we review recent literature on sleep, circadian rhythms and CVD with a specific emphasis on differences between racial/ethnic groups. We discuss the reported differences, mainly between individuals of European and African descent, in parameters related to sleep (architecture, duration, quality) and circadian rhythms (period length and phase shifting). We further review racial/ethnic differences in cardiovascular disease and its risk factors, and develop the hypothesis that racial/ethnic health disparities may, to a greater or smaller degree, relate to differences in parameters related to sleep and circadian rhythms. When humans left Africa some 100,000 years ago, some genetic differences between different races/ethnicities were acquired. These genetic differences have been proposed as a possible predictor of CVD disparities, but concomitant differences in culture and lifestyle between different groups may equally explain CVD disparities. We discuss the evidence for genetic and environmental causes of these differences in sleep and circadian rhythms, and their usefulness as health intervention targets

Reduction mammaplasty in patients with history of breast cancer : The incidence of occult cancer and high-risk lesions

Introduction: Contralateral reduction mammaplasty is regularly included in the treatment of breast cancer patients. We analyzed the incidence of occult breast cancer and high-risk lesions in reduction mammaplasty specimens of women with previous breast cancer. We also analyzed if timing of reduction mammaplasty in relation to oncological treatment influenced the incidence of abnormal findings, and compared if patients with abnormal contralateral histopathology differed from the study population in terms of demographics. Materials and methods: The study consisted of 329 breast cancer patients, who underwent symmetrizing reduction mammaplasty between 1/2007 and 12/2011. The data was retrospectively analyzed for demographics, operative and histopathology reports, oncological treatment, and postoperative follow-up. Results: Reduction mammaplasty specimens revealed abnormal findings in 68 (21.5%) patients. High-risk lesions (ADH, ALH, and LCIS) were revealed in 37 (11.7%), and cancer in six (1.9%) patients. Abnormal histopathology correlated with higher age (p = 0.0053), heavier specimen (p = 0.0491), and with no previous breast surgery (p <0.001). Abnormal histopathological findings were more frequent in patients with reduction mammaplasty performed prior to oncological treatment (p <0.001), and in patients with immediate reconstruction (p = 0.0064). Conclusion: The incidences of malignant and high-risk lesions are doubled compared to patients without prior breast cancer. Patients with abnormal histopathology cannot be preoperatively identified based on demographics. If reduction mammaplasty is performed before oncological treatment, the incidence of abnormal findings is higher. In the light of our results, contralateral reduction mammaplasty with histopathological evaluation in breast cancer patients offers a sophisticated tool to catch those patients whose contralateral breast needs increased attention. (C) 2017 Elsevier Ltd. All rights reserved.Peer reviewe

Breast Cancer Detection by Preoperative Imaging in Reduction Mammaplasty Patients : A Single Center Study of 918 Patients

Background The role of preoperative imaging and the usability of different imaging modalities is highly variable and controversial in reduction mammaplasty patients. Our study describes the imaging process in a single center in regard to modality selection, age and timing, and of the association between imaging and histopathological findings in reduction mammaplasty specimens. Methods Nine hundred eighteen women, who underwent reduction mammaplasty during 1.1.2007-31.12.2011, were retrospectively reviewed for demographics, preoperative imaging, further preoperative examinations, and pathology reports. Results Preoperative imaging had been conducted for 89.2% (n = 819) of the patients. In 49 (6.0%) patients, suspicious preoperative imaging led to further examinations revealing 2 high-risk lesions (atypical ductal hyperplasia (ADH), lobular carcinoma in situ (LCIS)), and 2 cancers preoperatively. Postoperatively abnormal histopathology specimens were revealed in 88 (10.4%) patients. The incidence of high-risk lesions was 5.5% (n = 47), and the incidence of cancer was 1.2% (n = 10). Preoperative imaging was normal (BI-RADS 1 and BI-RADS 2) in 80.8% of these patients. The sensitivity of the preoperative imaging for cancer detection was 20.0%, and the specificity was 100.0%. Conclusions Preoperative imaging and further examinations do not sufficiently detect malignant or cancer risk-increasing findings. Therefore, histopathological analysis of reduction mammaplasty specimens seems mandatory.Peer reviewe

Should we routinely analyze reduction mammaplasty specimens?

Background: Reduction mammaplasty is one of the most common plastic surgery procedures. Preoperative imaging and histopathology protocols vary among countries and institutions. We aimed to analyze the incidence of occult breast cancer and high-risk lesions in reduction mammaplasty specimens. We also analyzed whether patients with abnormal histopathology differed from the study population in terms of demographics. Patients and methods: In total, 918 women who underwent reduction mammaplasty from January 2007 to December 2011 were retrospectively reviewed for demographics, preoperative imaging, further preoperative examinations, pathology reports, and postoperative follow-up. Results: Abnormal histopathological findings were revealed in 88 (10%) patients with a mean age of 49.5 +/- 10.2 years. The incidence of breast cancer was 1.2%, and the incidence of high-risk lesions (atypical ductal and lobular hyperplasia and lobular carcinoma in situ) was 5.5%. Age and specimen weights were significantly higher in patients with abnormal histopathology. Eighty-one percent of patients with abnormal histopathology had normal preoperative imaging revealing two high-risk and two cancer findings. Two patients developed breast cancer in the same breast in which the high-risk lesion was originally detected. Conclusion: Women with abnormal histopathology cannot be sufficiently detected preoperatively. Therefore, histopathological analysis of reduction mammaplasty specimens seems mandatory. Reduction mammaplasty combined with subsequent histopathological examination offers a sufficient chance of detecting cancer and risk-increasing lesions that merits the cost of histopathology. (C) 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Using the MitoB method to assess levels of reactive oxygen species in ecological studies of oxidative stress

In recent years evolutionary ecologists have become increasingly interested in the effects of reactive oxygen species (ROS) on the life-histories of animals. ROS levels have mostly been inferred indirectly due to the limitations of estimating ROS from in vitro methods. However, measuring ROS (hydrogen peroxide, H2O2) content in vivo is now possible using the MitoB probe. Here, we extend and refine the MitoB method to make it suitable for ecological studies of oxidative stress using the brown trout Salmo trutta as model. The MitoB method allows an evaluation of H2O2 levels in living organisms over a timescale from hours to days. The method is flexible with regard to the duration of exposure and initial concentration of the MitoB probe, and there is no transfer of the MitoB probe between fish. H2O2 levels were consistent across subsamples of the same liver but differed between muscle subsamples and between tissues of the same animal. The MitoB method provides a convenient method for measuring ROS levels in living animals over a significant period of time. Given its wide range of possible applications, it opens the opportunity to study the role of ROS in mediating life history trade-offs in ecological settings

Amerindian (but not African or European) ancestry is significantly associated with diurnal preference within an admixed Brazilian population

Significant questions remain unanswered regarding the genetic versus environmental contributions to racial/ethnic differences in sleep and circadian rhythms. We addressed this question by investigating the association between diurnal preference, using the morningness–eveningness questionnaire (MEQ), and genetic ancestry within the Baependi Heart Study cohort, a highly admixed Brazilian population based in a rural town. Analysis was performed using measures of ancestry, using the Admixture program, and MEQ from 1,453 individuals. We found an association between the degree of Amerindian (but not European of African) ancestry and morningness, equating to 0.16 units for each additional percent of Amerindian ancestry, after adjustment for age, sex, education, and residential zone. To our knowledge, this is the first published report identifying an association between genetic ancestry and MEQ, and above all, the first one based on ancestral contributions within individuals living in the same community. This previously unknown ancestral dimension of diurnal preference suggests a stratification between racial/ethnic groups in an as yet unknown number of genetic polymorphisms

Distribution and heritability of diurnal preference (chronotype) in a rural Brazilian family-based cohort, the Baependi study

Diurnal preference (chronotype) is a useful instrument for studying circadian biology in humans. It harbours trait-like dimensions relating to circadian period and sleep homeostasis, but also has ontogenetic components (morningness increases with age). We used the Morningness-Eveningness questionnaire (MEQ) in the Baependi study, a family-based cohort study based in a small town in Minas Gerais, Brazil. The population is highly admixed and has a cohesive and conservative lifestyle. 825 individuals (497 female) aged 18-89 years (average ± SD = 46.4 ± 16.3) and belonging to 112 different families participated in this study. The average MEQ score was 63.5 ± 11.2 with a significant (P < 0.0001) linear increase with age. Morningness was significantly (P < 0.0001) higher in the rural (70.2 ± 9.8) than in the municipal zone (62.6 ± 11.1), and was also significantly (P = 0.025) higher in male (64.6 ± 10.9) than in female (62.8 ± 11.2) participants. Thus, in spite of universal access to electricity, the Baependi population was strongly shifted towards morningness, particularly in the rural zone. Heritability of MEQ score was 0.48 when adjusted for sex and age, or 0.38 when adjusted for sex, age, and residential zone. The reported MEQ score heritability is more akin to those of previous twin studies than previous family studies

Comparison between an African town and a neighbouring village shows delayed, but not decreased, sleep during the early stages of urbanisation

The well-established negative health outcomes of sleep deprivation, and the suggestion that availability of electricity may enable later bed times without compensating sleep extension in the morning, have stimulated interest in studying communities whose sleep pattern may resemble a pre-industrial state. Here, we describe sleep and activity in two neighbouring communities, one urban (Milange) and one rural (Tengua), in a region of Mozambique where urbanisation is an ongoing process. The two communities differ in the amount and timing of daily activity and of light exposure, with later bedtimes (≈1 h) associated with more evening and less daytime light exposure seen in the town of Milange. In contrast to previous reports comparing communities with and without electricity, sleep duration did not differ between Milange (7.28 h) and Tengua (7.23 h). Notably, calculated sleep quality was significantly poorer in rural Tengua than in Milange, and poor sleep quality was associated with a number of attributes more characteristic of rural areas, including more intense physical labour and less comfortable sleeping arrangements. Thus, whilst our data support the hypothesis that access to electricity delays sleep timing, the higher sleep quality in the urban population also suggests that some aspects of industrialisation are beneficial to sleep

Environmental and Parental Influences on Offspring Health and Growth in Great Tits (Parus major)

PMCID: PMC3728352This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Compared Heritability of Chronotype Instruments in a Single Population Sample

It is well established that the oldest chronotype questionnaire, the morningness-eveningness questionnaire (MEQ), has significant heritability, and several associations have been reported between MEQ score and polymorphisms in candidate clock genes, a number of them reproducibly across populations. By contrast, there are no reports of heritability and genetic associations for the Munich chronotype questionnaire (MCTQ). Recent genome-wide association studies (GWAS) from large cohorts have reported multiple associations with chronotype as assessed by a single self-evaluation question. We have taken advantage of the availability of data from all these instruments from a single sample of 597 participants from the Brazilian Baependi Heart Study. The family-based design of the cohort allowed us to calculate the heritability (h2) for these measures. Heritability values for the best-fitted models were 0.37 for MEQ, 0.32 for MCTQ, and 0.28 for single-question chronotype (MEQ Question 19). We also calculated the heritability for the two major factors recently derived from MEQ, “Dissipation of sleep pressure” (0.32) and “Build-up of sleep pressure” (0.28). This first heritability comparison of the major chronotype instruments in current use provides the first quantification of the genetic component of MCTQ score, supporting its future use in genetic analysis. Our findings also suggest that the single chronotype question that has been used for large GWAS analyses captures a larger proportion of the dimensions of chronotype than previously thought