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Barbara Waag Carlson

Publications and source records attributed to Barbara Waag Carlson.

4 recordsLinked to original sources
PubMed2002

Evaluation of variables to characterize respiratory periodicity during sleep in older adults.

Reliable markers of early neurological decline might guide interventions to prevent or reverse cognitive decline in older adults. Because cognitive decline is associated with hypoxemia during sleep, the authors examined 3 respiratory periodicity variables in 5 older adults. Subjects were monitored overnight using standard polysomnography. From the inductance band signal, the authors calculated the variability in duration of breathing cycles measured by standard deviation of interbreath intervals (sdIBI), frequency of breathing cycles measured by standard deviation of interbreath frequencies (sdIBF), and amplitude of breathing cycles measured by standard deviation of breathing cycle amplitudes (sdAMP). Logistic regression analysis and kappa coefficients identified variables that reliably detected 5-minute segments having central or obstructive apneas or body movements. An sdIBF > or = 4.5 cpm identified body movements (sensitivity = 0.96, specificity = 0.96, kappa = 0.90). An sdIBI > 1.2 seconds identified central apneas (sensitivity = 0.86, specificity = 0.99, kappa = 0.86), and an sdIBI > or = 1.68 seconds identified segments with 3 central apneas (sensitivity = 0.90, specificity = 0.89, kappa = 0.89). An sdAMP > or = 0.1 V and an sdIBF > or = 1.5 cpm identified obstructive apneas (kappa = 0.91). Data support the potential of these variables to identify central and obstructive apneas and to classify individuals according to different patterns of respiratory periodicity.

Aged↗
PubMedDate not supplied

Salivary cortisol values in HIV-positive people.

Fatigue is one of the most prevalent and troubling symptoms suffered by people with HIV infection. As part of a pilot study to examine physiological and psychosocial correlates of fatigue, the authors report results from a sample of 40 HIV-positive men and women who collected three saliva samples each over the course of a day. Few in the sample exhibited the normal salivary cortisol slope (a peak in the morning and falling throughout the day). There were four groups (N = 36) based on salivary cortisol plots: a normal downward trend (n = 7), an afternoon peak (n = 15), an afternoon drop (n = 9), and an upward trend (n = 5). The data in each of these groups were then analyzed on the key variables of sex, age, depression, state/trait anxiety, fatigue severity, CD4 count, and HIV viral load; the group that had an upward trend in cortisol values had a tendency toward more depression, more state and trait anxiety, higher fatigue severity, and higher HIV viral load. However, they also trended toward higher CD4 counts than the other three groups. The need to compare additional variables over a period of time is discussed.

Adult↗