Relationship of menopausal status and climacteric symptoms to sleep in women undergoing chemotherapy

Goals of workThe goal of this study was to examine the relationship between menopausal symptoms, sleep quality, and mood as measured by actigraphy and self-report prior to treatment and at the end of four cycles of chemotherapy in women with breast cancer.Patients and methodsData on sleep quality (measured using actigraphy and self-report) and mood were collected prior to treatment and 12 weeks later at the end of four cycles of chemotherapy in 69 women with newly diagnosed breast cancer. In addition, each filled out the Greene Climacteric Scale. Based on reported occurrence of menses, participants were categorized post hoc into three menopausal status groups: pre-menopausal before and after chemotherapy (Pre-Pre), pre-menopausal or peri-menopausal before and peri-menopausal after chemotherapy (Pre/Peri-Peri), and post-menopausal before and after chemotherapy (Post-Post).Main resultsResults suggested that women within the Pre-Pre group evidenced more fragmented sleep with less total sleep time (TST) after chemotherapy compared to baseline. Compared to the other groups, the Pre-Pre group also experienced less TST and more awakenings before and after chemotherapy. Although the Pre/Peri-Peri group evidenced a greater increase in vasomotor symptoms after chemotherapy, there was no relationship with sleep. All groups evidenced more depressive symptoms after chemotherapy, but depression was not related to measures of sleep.ConclusionsContrary to the study hypothesis, these results suggest that women who are pre-menopausal or having regular menses before and after four cycles of chemotherapy have worse sleep following chemotherapy. Those women who maintain or become peri-menopausal (irregular menses) experience an increase in climacteric symptoms but do not experience an associated worsening of sleep. These results are preliminary and more research is necessary to further explain these findings

Growth Strategies of Tropical Tree Species: Disentangling Light and Size Effects

An understanding of the drivers of tree growth at the species level is required to predict likely changes of carbon stocks and biodiversity when environmental conditions change. Especially in species-rich tropical forests, it is largely unknown how species differ in their response of growth to resource availability and individual size. We use a hierarchical Bayesian approach to quantify the impact of light availability and tree diameter on growth of 274 woody species in a 50-ha long-term forest census plot in Barro Colorado Island, Panama. Light reaching each individual tree was estimated from yearly vertical censuses of canopy density. The hierarchical Bayesian approach allowed accounting for different sources of error, such as negative growth observations, and including rare species correctly weighted by their abundance. All species grew faster at higher light. Exponents of a power function relating growth to light were mostly between 0 and 1. This indicates that nearly all species exhibit a decelerating increase of growth with light. In contrast, estimated growth rates at standardized conditions (5 cm dbh, 5% light) varied over a 9-fold range and reflect strong growth-strategy differentiation between the species. As a consequence, growth rankings of the species at low (2%) and high light (20%) were highly correlated. Rare species tended to grow faster and showed a greater sensitivity to light than abundant species. Overall, tree size was less important for growth than light and about half the species were predicted to grow faster in diameter when bigger or smaller, respectively. Together light availability and tree diameter only explained on average 12% of the variation in growth rates. Thus, other factors such as soil characteristics, herbivory, or pathogens may contribute considerably to shaping tree growth in the tropics