Objective Little is known about factors influencing the rate of progression of Alzheimer’s dementia. Using data from the Cache County Dementia Progression Study, we examined the link between clinically significant neuropsychiatric symptoms in mild Alzheimer’s dementia and progression to severe dementia or death. Method The Cache County Dementia Progression Study is a longitudinal study of dementia progression in incident cases of the condition. Survival analyses included unadjusted Kaplan-Meier plots and multivariate Cox proportional hazard models. Hazard ratio estimates controlled for age of dementia onset, dementia duration at baseline, gender, education level, General Medical Health Rating, and apolipoprotein E epsilon 4 (APOE-ε4) genotype. Results Three hundred thirty-five patients with incident Alzheimer’s dementia were studied. Sixty-eight (20%) developed severe dementia over the follow-up. Psychosis (hazard ratio=2.007, p=0.028), agitation/aggression (hazard ratio=2.946, p=0.004), and any one clinically significant neuropsychiatric symptom (domain score of ≥4, hazard ratio=2.682, p=0.001) were associated with more rapid progression to severe dementia. Psychosis (hazard ratio=1.537, p=0.011), affective symptoms (hazard ratio=1.510, p=0.003), agitation/aggression (hazard ratio=1.942, p=0.004), mildly symptomatic neuropsychiatric symptoms (domain score of 1–3, hazard ratio=1.448, p=0.024), and clinically significant neuropsychiatric symptoms (hazard ratio=1.951, p=<0.001) were associated with earlier death. Conclusions Specific neuropsychiatric symptoms are associated with shorter survival time from mild Alzheimer’s dementia to severe dementia and/or death. The treatment of specific neuropsychiatric symptoms in mild Alzheimer’s dementia should be examined for its potential to delay time to severe dementia or death.

Objective Insomnia is prevalent in knee osteoarthritis (KOA). Research indicates that sleep disruption may amplify clinical pain by altering central pain modulation, suggesting that treating insomnia may improve pain. We sought to: 1) evaluate the efficacy of Cognitive-Behavioral Therapy for Insomnia (CBT-I) in KOA, 2) determine whether improvements in sleep predict reduced pain, and 3) determine whether alterations in pain modulation mediate improvements in clinical pain. Methods We conducted a double-blinded, randomized, active placebo-controlled clinical trial of CBT-I in 100 KOA patients with insomnia [Mean Age = 59.5(9.5)]. Patients were randomized to 8-sessions of CBT-I or Behavioral Desensitization-Placebo. We conducted in-home polysomnograms, diary assessment, and sensory tests of pain modulation at baseline, posttreatment, 3-and 6-months. Results Intent-to-treat analyses demonstrated that both groups yielded substantial improvements in sleep. CBT-I demonstrated significantly greater reductions in wake after sleep onset time (WASO), measured via diary and actigraphy [PSG trended, (p=.075)]. Both groups reported significant and comparable reductions in pain over 6 months with a third demonstrating ≥ 30% reduction in pain severity. Baseline-to-posttreatment reductions in Diary and PSG WASO predicted subsequent decreases in clinical pain. This effect was significantly greater for CBT-I compared to BD. We found no significant changes in laboratory measures of pain modulation. Conclusion Compared to active placebo, CBT-I was efficacious in reducing sleep maintenance insomnia. Treatment decreased clinical pain, but not pain modulation, suggesting that CBT-I has potential to augment pain management in KOA. Future work is needed to identify the mechanisms by which improved sleep reduces clinical pain.

SummaryIt has been increasingly recognized at the basic science level that perturbations in ceramide metabolism are associated with the development and progression of many age‐related diseases. However, the translation of this work to the clinic has lagged behind. Understanding the factors longitudinally associated with plasma ceramides and dihydroceramides (DHCer) at the population level and how these lipid levels change with age, and by sex, is important for the clinical development of future therapeutics and biomarkers focused on ceramide metabolism. We, therefore, examined factors cross‐sectionally and longitudinally associated with plasma concentrations of ceramides and DHCer among Baltimore Longitudinal Study of Aging participants (n = 992; 3960 total samples), aged 55 years and older, with plasma at a mean of 4.1 visits (range 2–6). Quantitative analyses were performed on a high‐performance liquid chromatography‐coupled electrospray ionization tandem mass spectrometer. Linear mixed models were used to assess the relationships between plasma ceramide and DHCer species and demographics, diseases, medications, and lifestyle factors. Women had higher plasma concentrations of most ceramide and DHCer species and showed steeper trajectories of age‐related increases compared to men. Ceramides and DHCer were more associated with waist–hip ratio than body mass index. Plasma cholesterol and triglycerides, prediabetes, and diabetes were associated with ceramides and DHCer, but the relationship showed specificity to the acyl chain length and saturation. These results demonstrate the importance of examining the individual species of ceramides and DHCer, and of establishing whether intra‐individual age‐ and sex‐specific changes occur in synchrony to disease onset and progression.

Objective The use of psychotropic medications in Alzheimer’s disease (AD) has been associated with both deleterious and potentially beneficial outcomes. We examined the longitudinal association of psychotropic medication use with cognitive, functional, and neuropsychiatric symptom (NPS) trajectories among community-ascertained incident AD cases from the Cache County Dementia Progression Study. Methods A total of 230 participants were followed for a mean of 3.7 years. Persistency index (PI) was calculated for all antidepressants, selective serotonin reuptake inhibitors (SSRIs), antipsychotics (atypical and typical), and benzodiazepines as the proportion of observed time of medication exposure. Mixed-effects models were used to examine the association between PI for each medication class and Mini-Mental State Exam (MMSE), Clinical Dementia Rating Sum of Boxes (CDR-Sum), and Neuropsychiatric Inventory – Total (NPI-Total) trajectories, controlling for appropriate demographic and clinical covariates. Results At baseline, psychotropic medication use was associated with greater severity of dementia and poorer medical status. Higher PI for all medication classes was associated with a more rapid decline in MMSE. For antidepressant, SSRI, benzodiazepine, and typical antipsychotic use, a higher PI was associated with a more rapid increase in CDR-Sum. For SSRIs, antipsychotics, and typical antipsychotics, a higher PI was associated with more rapid increase in NPI-Total. Conclusions Psychotropic medication use was associated with more rapid cognitive and functional decline in AD, and not with improved NPS. Clinicians may tend to prescribe psychotropic medications to AD patients at risk of poorer outcomes, but one cannot rule out the possibility of poorer outcomes being caused by psychotropic medications.

Sphingomyelin metabolism has been linked to several diseases and to longevity. However, few epidemiological studies have quantified individual plasma sphingomyelin species (identified by acyl-chain length and saturation) or their relationship between demographic factors and disease processes. In this study, we determined plasma concentrations of distinct sphingomyelin species in 992 individuals, aged 55 and older, enrolled in the Baltimore Longitudinal Study of Aging. Participants were followed, with serial measures, up to 6 visits and 38 years (3972 total samples). Quantitative analyses were performed on a high-performance liquid chromatography-coupled electrospray ionization tandem mass spectrometer. Linear mixed models were used to assess variation in specific sphingomyelin species and associations with demographics, diseases, medications or lifestyle factors, and plasma cholesterol and triglyceride levels. We found that most sphingomyelin species increased with age. Women had higher plasma levels of all sphingomyelin species and showed steeper trajectories of age-related increases compared to men. African Americans also showed higher circulating sphingomyelin concentrations compared to Caucasians. Diabetes, smoking, and plasma triglycerides were associated with lower levels of many sphingomyelins and dihydrosphingomyelins. Notably, these associations showed specificity to sphingomyelin acyl-chain length and saturation. These results demonstrate that longitudinal changes in circulating sphingomyelin levels are influenced by age, sex, race, lifestyle factors, and diseases. It will be important to further establish the intra-individual age- and sex-specific changes in each sphingomyelin species in relation to disease onset and progression.

Background Cellular and animal studies demonstrated relationships between sphingolipid metabolism and Alzheimer's disease (AD) pathology. High blood ceramide levels have been shown to predict cognitive impairment and AD, but these studies had small sample sizes and did not assess differences in risk by sex or APOE genotype. Objective To determine whether plasma ceramides and sphingomyelins were associated with risk of AD, and whether the association varied by sex and APOE genotype. Methods Participants included 626 men and 366 women, aged 55 years and older, enrolled in the Baltimore Longitudinal Study of Aging. Plasma ceramides and sphingomyelins were determined using quantitative analyses performed on a high-performance liquid chromatography coupled electrospray ionization tandem mass spectrometer. Cox proportional hazards models, stratified by sex, were used to examine the relationship of plasma ceramides and sphingomyelins with risk of AD over a mean (SD) follow-up of 15.0 (7.0) years for men and 13.1 (5.9) years for women. Results Among men, the highest tertile of most ceramides and sphingomyelins were associated with an increased risk of AD. Among women, there were no associations between any of the ceramides and risk of AD. In contrast, women in the highest tertile of most sphingomyelins had a reduced risk of AD, which was most pronounced among APOE ε4 carriers. Conclusion These results provide further evidence for the role of sphingolipid metabolism in AD and highlight the importance of considering sex and APOE genotype in assessing this relationship.

DNA alterations in mitochondria are believed to play a role in carcinogenesis and are found in smoking-related cancers. We sought to replicate earlier findings for the association of smoking with increased mitochondrial DNA (mtDNA) content in buccal cells and further hypothesized that there would be an increased number of somatic mtDNA mutations in smokers. Buccal cells and blood lymphocytes were studied from 42 healthy smokers and 30 non-smokers. Temporal temperature gradient electrophoresis screening and sequencing was used to identify mtDNA mutations. The relative mtDNA content was determined by real-time polymerase chain reaction. Assuming that mtDNA in lymphocytes represents the inherited sequence, it was found that 31% of smokers harbored at least one somatic mtDNA mutation in buccal cells with a total of 39 point mutations and 8 short deletions/insertions. In contrast, only 23% of non-smokers possessed mutations with a total of 10 point mutations and no insertions/deletions detected. mtDNA somatic mutation density was higher in smokers (0.68/10 000 bp per person) than in non-smokers (0.2/10 000 bp per person). There was a statistically significant difference in the pattern of homoplasmy and heteroplasmy mutation changes between smokers and non-smokers. Whereas non-smokers had the most mutations in D-loop region (70%), smokers had mutations in both messenger RNA encoding gene (36%) and D-loop region (49%). The mean ratio of buccal cells to lymphocytes of mtDNA content in smokers was increased (2.81) when compared with non-smokers (0.46). These results indicate that cigarette smoke exposure affects mtDNA in buccal cells of smokers. Additional studies are needed to determine if mitochondrial mutation assays provide new or complementary information for estimating cigarette smoke exposure at the cellular level or as a cancer risk biomarker.

Background Several observational studies suggested a link between health status and rate of decline among individuals with Alzheimer’s disease (AD). We sought to quantify the relationship in a population-based study of incident AD, and to compare global comorbidity ratings to counts of comorbid conditions and medications as predictors of AD progression. Methods Design Case-only cohort study arising from population-based longitudinal study of memory and aging. Setting Cache County, Utah Participants 335 individuals with incident AD followed for up to 11 years. Measurements Patient descriptors included sex, age, education, dementia duration at baseline, and APOE genotype. Measures of health status made at each visit included the GMHR (General Medical Health Rating), number of comorbid medical conditions, and number of non-psychiatric medications. Dementia outcomes included the Mini-Mental State Exam (MMSE), Clinical Dementia Rating – sum of boxes (CDR-sb), and the Neuropsychiatric Inventory (NPI). Results Health Status tended to fluctuate over time within individuals. None of the baseline medical variables (GMHR, comorbidities, non-psychiatric medications) were associated with differences in rates of decline in longitudinal linear mixed effects models. Over time, low GMHR ratings, but not comorbidities or medications, were associated with poorer outcomes (MMSE: β=−1.07 p=0.01; CDR-sb: β=1.79 p<0.001; NPI: β=4.57 p=0.01) Conclusions Given that time-varying GMHR, but not baseline GMHR, was associated with the outcomes, there is likely a dynamic relationship between medical and cognitive health. GMHR is a more sensitive measure of health than simple counts of comorbidities or medications. Since health status is a potentially modifiable risk factor, further study is warranted.