Dominique Lorrain

Sleep quality and 1-year incident cognitive impairment in community-dwelling older adults.

STUDY OBJECTIVES To examine in cognitively intact older men and women the associations between subjective sleep quality and 1-yr incident cognitive impairment. DESIGN Prospective cohort study. SETTING General community. PARTICIPANTS 1,664 cognitively intact individuals age 65 to 96 years. MEASUREMENTS AND RESULTS Sleep quality at baseline was measured using the Pittsburgh Sleep Quality Index (PSQI). Cognitive functioning was assessed at baseline and 12 months later using the Mini-Mental State Examination (MMSE). Incident general cognitive impairment was defined according to a follow-up MMSE score below the 15(th) percentile according to normative data and of at least 2 points below baseline. General cognitive impairments were also separated into amnestic and nonamnestic subtypes according to MMSE delayed recall performance. Associations between sleep quality indicators at baseline and incident cognitive impairment were assessed by odds ratio (OR) adjusted for age, education, baseline MMSE score, psychotropic drug use, anxiety, depressive episodes, cardiovascular conditions, and chronic diseases. Results revealed that global PSQI score was significantly linked with incident cognitive impairment (OR 1.17, 95% confidence interval (CI) 1.05-1.30) in men, but not in women. In women, sleep disturbance score (OR 2.62, 95% CI 1.41-4.86) and long sleep duration (≥ 9 hr; OR 3.70, 95% CI 1.49-9.17) were associated with nonamnestic and amnestic incident cognitive impairment, respectively. In men, short sleep duration (≤ 5 hr; OR 4.95, 95% CI 1.72-14.27) and habitual sleep efficiency score (OR 1.94, 95% CI 1.42-2.66) were associated with amnestic and general incident cognitive impairment, respectively. CONCLUSIONS Sleep quality in older adults should receive particular attention by clinicians because poor sleep quality can be an early sign of cognitive decline.

Emotional Recognition from Face, Voice, and Music in Dementia of the Alzheimer Type

Persons with dementia of the Alzheimer type (DAT) are impaired in recognizing emotions from face and voice. Yet clinical practitioners use these mediums to communicate with DAT patients. Music is also used in clinical practice, but little is known about emotional processing from music in DAT. This study aims to assess emotional recognition in mild DAT. Seven patients with DAT and 16 healthy elderly adults were given three tasks of emotional recognition for face, prosody, and music. DAT participants were only impaired in the emotional recognition from the face. These preliminary results suggest that dynamic auditory emotions are preserved in DAT.

Thyroid Function and Cognition during Aging.

We summarize here the studies examining the association between thyroid function and cognitive performance from an aging perspective. The available data suggest that there may be a continuum in which cognitive dysfunction can result from increased or decreased concentrations of thyroid hormones. Clinical and subclinical hypothyroidism as well as hyperthyroidism in middle-aged and elderly adults are both associated with decreased cognitive functioning, especially memory, visuospatial organization, attention, and reaction time. Mild variations of thyroid function, even within normal limits, can have significant consequences for cognitive function in the elderly. Different cognitive deficits possibly related to thyroid failure do not necessarily follow a consistent pattern, and L-thyroxine treatment may not always completely restore normal functioning in patients with hypothyroidism. There is little or no consensus in the literature regarding how thyroid function is associated with cognitive performance in the elderly.

Daily hassles, physical illness, and sleep problems in older adults with wishes to die.

BACKGROUND Factors associated with the wish to die should be investigated in order to gain more opportunities for preventive interventions targeting older adults at risk for suicide. The goal of the research was to study the prevalence and associated factors of wishes to die in older adults living in the community using the data from a survey on the prevalence of mental disorders in this population. METHODS With a representative sample of community living older adults aged 65 years and over (N = 2777), we compared individuals with the wish to die (n = 163) to those without the wish to die on the basis of the presence and severity of daily hassles, physical illness, and sleep quality. RESULTS Logistic regression revealed that when depression and sociodemographic variables were held constant, self-rated physical health, number of chronic illnesses, number and intensity of daily hassles, as well as sleep problems were significantly associated with the wish to die in older adults. Painful illnesses and daytime dysfunction due to sleep problems were also associated factors with the wish to die. CONCLUSION Since desire for death is the first step into the suicidal process, health professionals should seriously consider the important and unique contribution of these variables in order to have more opportunities for detection and intervention.

Subjective sleep characteristics associated with anxiety and depression in older adults: a population-based study

Sleep complaints are often associated with anxiety and depression, but the specific complaints related to each syndrome are poorly characterized, especially in older adults. The objective was to identify subjective sleep characteristics specific to anxiety and depression in this population.

Benzodiazepine use and quality of sleep in the community-dwelling elderly population.

Background: About 50% of the elderly population report being dissatisfied with their sleep. Although benzodiazepines are the most prescribed drugs to treat sleep complaints, the effectiveness of their use on the quality of sleep is not well documented. Objectives: This study aimed to assess the association between benzodiazepine use and global sleep quality, as well as six components of sleep quality. Methods: Data from the cross-sectional Quebec Survey on Seniors’ Health (n = 2798) conducted in 2005–2006 were used. Quality of sleep was self-reported and use of benzodiazepines was assessed during the previous year. Results: Benzodiazepine users reported poorer quality of sleep than non-users. The association between benzodiazepine use and each of the six quality of sleep components studied were similar except for the daytime dysfunction component. Conclusion: The results suggest that there is no evidence that using benzodiazepines is associated with better quality of sleep than non-users in the elderly population. Future longitudinal population-based studies are needed to assess improvements in quality of sleep in the elderly associated with the use of benzodiazepines.

Kinetics of 13C-DHA before and during fish-oil supplementation in healthy older individuals

BACKGROUND Docosahexaenoic acid (DHA) kinetics appear to change with intake, which is an effect that we studied in an older population by using uniformly carbon-13-labeled DHA ((13)C-DHA). OBJECTIVE We evaluated the influence of a fish-oil supplement over 5 mo on the kinetics of (13)C-DHA in older persons. DESIGN Thirty-four healthy, cognitively normal participants (12 men, 22 women) aged between 52 and 90 y were recruited. Two identical kinetic studies were performed, each with the use of a single oral dose of 40 mg (13)C-DHA. The first kinetic study was performed before participants started taking a 5-mo supplementation that provided 1.4 g DHA/d plus 1.8 g eicosapentaenoic acid (EPA)/d (baseline); the second study was performed during the final month of supplementation (supplement). In both kinetic studies, blood and breath samples were collected ≤8 h and weekly over 4 wk to analyze (13)C enrichment. RESULTS The time × supplement interaction for (13)C-DHA in the plasma was not significant, but there were separate time and supplement effects (P < 0.0001). The area under the curve for plasma (13)C-DHA was 60% lower while subjects were taking the supplement than at baseline (P < 0.0001). The uniformly carbon-13-labeled EPA concentration was 2.6 times as high 1 d posttracer while patients were taking the supplement as it was at baseline. The mean (±SEM) plasma (13)C-DHA half-life was 4.5 ± 0.4 d at baseline compared with 3.0 ± 0.2 d while taking the supplement (P < 0.0001). Compared with baseline, the mean whole-body half-life was 61% lower while subjects were taking the supplement. The loss of (13)C-DHA through β-oxidation to carbon dioxide labeled with carbon-13 increased from 0.085% of dose/h at baseline to 0.208% of dose/h while subjects were taking the supplement. CONCLUSIONS In older persons, a supplement of 3.2 g EPA + DHA/d increased β-oxidation of (13)C-DHA and shortened the plasma (13)C-DHA half-life. Therefore, when circulating concentrations of EPA and DHA are increased, more DHA is available for β-oxidation. This trial was registered at clinicaltrials.gov as NCT01577004.

Exercise increases tryptophan availability to the brain in older men age 57-70 years.

PURPOSE Many aspects of serotonergic activity, both central and peripheral in origin, undergo significant changes with human aging. These alterations might predispose elderly people to develop mood disorders. Because previous work showed that increasing the peripheral availability of tryptophan (TRP) to the brain holds antidepressant properties, this study evaluated whether TRP availability to the brain is increased during prolonged exercise in older men. METHODS Nineteen males age 64 ± 3 yr completed a treadmill exercise bout at an HR eliciting ∼68% V˙O(2peak) for 60 min. Fasting blood was collected at rest, after 30 and 60 min of exercise, and at 90 min (after exercise). Branched-chain amino acids (BCAA), total and free TRP, prolactin, ammonia, nonesterified fatty acids, glucose, and lactate were measured. RESULTS Changes in free TRP/BCAA ratio and prolactin were used as peripheral proxies of central serotonin synthesis rate and activity. The free TRP/BCAA ratio observed at baseline was increased by 102% after 1 h of exercise (P < 0.0001) and remained elevated after exercise (78% above baseline, P < 0.001). The free TRP portion in serum increased from 2.8 ± 0.7 to 5.7 ± 1.8 μmol·L⁻¹ after 1 h of exercise (P < 0.001) and was strongly correlated with plasma nonesterified fatty acid contents (r₁₇ = 0.887, P < 0.0001, all time points). Serum prolactin was significantly elevated after 1 h of exercise (8.6 ± 2.4 μg·L⁻¹, P < 0.001) and was positively correlated with free TRP/BCAA ratio (r₁₆ = 0.48, P < 0.05, all time points). CONCLUSIONS These results concur with previous observations in younger men and unveil that significant elevations in TRP availability to the brain are encountered during sustained exercise in older men. These results provide support to the hypothesis that increases in serotonin synthesis and activity might be involved in the antidepressant effect of exercise in the elderly.

Bezafibrate Mildly Stimulates Ketogenesis and Fatty Acid Metabolism in Hypertriglyceridemic Subjects

Our objective was to determine whether bezafibrate, a hypotriglyceridemic drug and peroxisome proliferator-activated receptor (PPAR)-α agonist, is ketogenic and increases fatty acid oxidation in humans. We measured fatty acid metabolism and ketone levels in 13 mildly hypertriglycemic adults (67 ± 11 years old) during 2 metabolic study days lasting 6 h, 1 day before and 1 day after bezafibrate (400 mg of bezafibrate per day for 12 weeks). β-Hydroxybutyrate, triglycerides, free fatty acids, fatty acid profiles, insulin, and glucose were measured in plasma, and fatty acid β-oxidation was measured in breath after an oral 50-mg dose of the fatty acid tracer [U-13C]linoleic acid. As expected, 12 weeks on bezafibrate decreased plasma triglycerides by 35%. Bezafibrate tended to raise postprandial β-hydroxybutyrate, an effect that was significant after normalization to the fasting baseline values (p = 0.03). β-Oxidation of [U-13C]linoleic acid increased by 30% (p = 0.03) after treatment. On the metabolic study day after bezafibrate treatment, postprandial insulin decreased by 26% (p = 0.01), and glucose concentrations were lower 2 to 5 h postprandially. Thus, in hypertriglyceridemic individuals, bezafibrate is mildly ketogenic and significantly changes fatty acid metabolism, effects that may be linked to PPARα stimulation and to moderately improved glucose metabolism.

Changes in markers of brain serotonin activity in response to chronic exercise in senior men

Aging is associated with noticeable impairments in brain serotonin transmission, which might contribute to increased vulnerability to developing depression in later life. Animal and human studies have shown that aerobic exercise can stimulate brain serotonin activity and trigger parallel elevations in tryptophan (TRP, the serotonin precursor) availability in blood plasma. However, the influence of chronic exercise on serotonergic activity in older adults is not yet known. Sixteen men aged 64 ± 3 years exercised for 1 h (67%-70% peak oxygen consumption) at baseline and following 16 weeks of aerobic training. The main outcome measures were cardiorespiratory fitness, body composition, branched-chain amino acids (BCAA), TRP, prolactin, lactate, and free fatty acids (FFA). Changes in plasma free-TRP/BCAA and prolactin served as surrogates for TRP availability and serotonin activity, respectively. Chronic exercise decreased body mass (P < 0.05) whilst it increased ventilatory threshold 2 (P < 0.01). Although training did not affect plasma TRP availability to the brain at rest, both pre- and post-training exercise challenges markedly increased TRP availability (P < 0.001). The free-TRP/BCAA values reached a ceiling during exercise that was lower following training (P < 0.05), whereas similar patterns were found for prolactin, lactate, and FFA. These data show that aerobic exercise elicits consistent transient elevations in plasma TRP availability to the brain in older men; the elevations were independent from physical training, although less pronounced following training. The data support the contention that repeated elevations in brain serotonin activity might be involved in the antidepressant effect of exercise training in older adults.