Association of serum cholesterol and triglyceride levels with agitation and cognitive function in a geropsychiatry unit

Associations of the metabolic syndrome and its components with cognitive impairment in older adults

Background

The metabolic syndrome (MetS) is an established cardiovascular risk factor. Here, we investigated its role in cognitive impairment.

Methods

Baseline data from 202 participants (aged 65 to 87 years) of the BioCog study were used. All were free of clinical dementia (MMSE≥24/30). Cognitive impairment was defined as the lowest tertile of a cognitive summary score. Multiple logistic regression analyses examined associations of body mass index (BMI), triglycerides (TG), high-density lipoprotein (HDL-C), glucose and glycated hemoglobin A1c (HbA1c) levels with the odds of cognitive impairment. MetS was defined as ≥3 of its 5 components obesity (BMI ≥ 30 kg/m²), elevated TG (TG ≥1.7 mmol/L), reduced HDL-C (males: < 1.0 mmol/L; females: < 1.3 mmol/L), elevated glucose (glucose ≥5.5 mmol/L and/or diagnosed diabetes) and elevated blood pressure (history of hypertension). Analyses controlled for age, sex and smoking history.

Results

Lower HDL-C was significantly associated with a higher odds of cognitive impairment (OR 2.70 per 1 mmol/L reduction; 95% CI 1.25, 5.56; p = 0.011), whereas BMI, TG, glucose and HbA1c were not (all p > 0.05). Results for HDL-C were similar when HDL-C, glucose, BMI and TG were entered into a single model (OR 2.56 per 1 mmol/L reduction, 95% CI 1.09, 5.88, p = 0.031) and when cerebrovascular disease and coronary heart disease were additionally controlled for (OR 2.56 per 1 mmol/L reduction, 95% CI 1.06, 6.25, p = 0.036). Among the 5 MetS components, participants with elevated TG were at 2-fold increased odds of impairment (OR 2.09, 95% CI 1.08, 4.05, p = 0.028) including when the remaining 4 MetS components were entered (OR 2.23, 95% CI 1.07, 4.65, p = 0.033), but the finding was no longer statistically significant when cerebrovascular disease and coronary heart disease were additionally controlled for (p = 0.11). Presence of MetS and of obesity, reduced HDL-C, elevated glucose or elevated blood pressure were not significantly associated with impairment (all p > 0.05).

Conclusion

Our findings support low HDL-C as an independent risk marker of cognitive impairment in older age. The need for research into mediatory and confounding factors, and re-evaluation of traditional cut-off points is highlighted.

Trial registration

The study was registered on 15th October 2014 at clinicaltrials.gov (NCT02265263).

The Atorvastatin/Donepezil in Alzheimer's Disease Study (LEADe): design and baseline characteristics

BACKGROUND

Growing evidence suggests that elevated cholesterol levels in mid-life are associated with increased risk of developing Alzheimer's disease (AD), and that statins might have a protective effect against AD and dementia. The Lipitor's Effect in Alzheimer's Dementia (LEADe) study tests the hypothesis that a statin (atorvastatin 80 mg daily) will provide a benefit on the course of mild to moderate AD in patients receiving background therapy of a cholinesterase inhibitor (donepezil 10 mg daily).

METHODS

This is an international, multicenter, double-blind, randomized, parallel-group study with a double-blind randomized withdrawal phase of patients with mild to moderate AD (Mini-Mental State Examination [MMSE] score, 13 to 25). Inclusion criteria included age 50 to 90 years, receiving donepezil 10 mg for at least 3 months before randomization, and low-density lipoprotein cholesterol levels (LDL-C) 2.5 to 3.5 mmol/L (95 to 195 mg/dL). Co-primary end points are changes in AD Assessment Scale-cognitive subscale (ADAS-cog) and AD Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) scale scores. A confirmatory end point is rate of change in whole brain and hippocampal volumes in patients who enrolled in the magnetic resonance imaging substudy.

RESULTS

Enrollment of 641 subjects is complete. The baseline mean data are age 74 +/- 8 years, 53% women, MMSE 22 +/- 3, ADAS-cog 23 +/- 10, AD Functional Assessment and Change Scale (ADFACS) 13 +/- 9, Neuropsychiatric Inventory (NPI) 10 +/- 11, and Clinical Dementia Rating-Sum of Boxes (CDR-SB) 6 +/- 3. Mean prior donepezil treatment was 409 +/- 407 days. Mean baseline lipid levels are total cholesterol 5.8 +/- 0.8 mmol/L (224 +/- 33 mg/dL), LDL-C 3.7 +/- 0.7 mmol/L (143 +/- 26 mg/dL), triglycerides 1.5 +/- 0.7 mmol/L (132 +/- 64 mg/dL), and high-density lipoprotein cholesterol 1.6 +/- 0.5 mmol/L (64 +/- 18 mg/dL).

CONCLUSIONS

LEADe will report in 2008 and is expected to provide a more definitive evaluation of the potential for statins in the treatment of people with AD.

Impact of plasma lipids and time on memory performance in healthy elderly without dementia

OBJECTIVE

To examine the association of plasma lipid levels to changes in cognitive function in elderly subjects without dementia.

METHODS

The authors examined changes in performance in tests of memory, visuospatial/cognitive, and language abilities in 1,147 elderly individuals without dementia or cognitive impairment at baseline followed for 7 years using generalized estimating equations.

RESULTS

Performance in all cognitive domains declined significantly over time, while there was no association between levels of any plasma lipid or lipid lowering treatment and memory, cognitive/visuospatial, or language performance at any interval. Higher age at baseline was related to lower scores in all three domains at each interval, while higher education and white ethnicity were associated with higher scores in all domains. Analyses relating plasma lipids to performance in color trails tests using proportional hazards regression showed no association. In subsequent analyses excluding subjects with incident dementia, memory performance declined over time, while cognitive/visuospatial and language performance did not. Higher plasma high density lipoprotein and total cholesterol were associated with higher scores in language performance at baseline; this domain declined faster among individuals with higher total cholesterol, but this result was not significant after taking multiple comparisons into account. Plasma triglycerides, low density lipoprotein, or treatment with lipid lowering agents were not associated with changes in cognitive performance.

CONCLUSIONS

Plasma lipid levels or treatment with lipid lowering agents in the elderly were not associated with changes in cognitive function.

Minor thalassemia may be a risk factor for impulsiveness

Frequent studies have demonstrated the relationship between low cholesterol levels and increased aggression as well as suicide. In primates, cholesterol reduction has been linked to increased behavioral acts of aggression. Patients with low cholesterol show hypersensitivity in the detection of anger and sadness. It is documented that minor thalassemics have lower serum cholesterol levels than the general population. Therefore, it could be postulated that minor thalassemics may be predisposed to impulsiveness due to the decrement of serum cholesterol levels.

A unifying hypothesis of Alzheimer's disease. III. Risk factors

Normal ageing and Alzheimer's disease (AD) have many features in common and, in many respects, both conditions only differ by quantitative criteria. A variety of genetic, medical and environmental factors modulate the ageing-related processes leading the brain into the devastation of AD. In accordance with the concept that AD is a metabolic disease, these risk factors deteriorate the homeostasis of the Ca(2+)-energy-redox triangle and disrupt the cerebral reserve capacity under metabolic stress. The major genetic risk factors (APP and presenilin mutations, Down's syndrome, apolipoprotein E4) are associated with a compromise of the homeostatic triangle. The pathophysiological processes leading to this vulnerability remain elusive at present, while mitochondrial mutations can be plausibly integrated into the metabolic scenario. The metabolic leitmotif is particularly evident with medical risk factors which are associated with an impaired cerebral perfusion, such as cerebrovascular diseases including stroke, cardiovascular diseases, hypo- and hypertension. Traumatic brain injury represents another example due to the persistent metabolic stress following the acute event. Thyroid diseases have detrimental sequela for cerebral metabolism as well. Furthermore, major depression and presumably chronic stress endanger susceptible brain areas mediated by a host of hormonal imbalances, particularly the HPA-axis dysregulation. Sociocultural and lifestyle factors like education, physical activity, diet and smoking may also modulate the individual risk affecting both reserve capacity and vulnerability. The pathophysiological relevance of trace metals, including aluminum and iron, is highly controversial; at any rate, they may adversely affect cellular defences, antioxidant competence in particular. The relative contribution of these factors, however, is as individual as the pattern of the factors. In familial AD, the genetic factors clearly drive the sequence of events. A strong interaction of fat metabolism and apoE polymorphism is suggested by intercultural epidemiological findings. In cultures, less plagued by the 'blessings' of the 'cafeteria diet-sedentary' Western lifestyle, apoE4 appears to be not a risk factor for AD. This intriguing evidence suggests that, analogous to cardiovascular diseases, apoE4 requires a hyperlipidaemic lifestyle to manifest as AD risk factor. Overall, the etiology of AD is a key paradigm for a gene-environment interaction. Copyright 2000 John Wiley & Sons, Ltd.

No correlation of serum cholesterol levels with measures of violence in patients with schizophrenia and non-psychotic disorders

Epidemiological studies, animal studies, and clinical studies yielded conflicting results concerning a supposed association between increased risk for suicide and violence, and low serum cholesterol levels. Until now, no data has been available for patients with schizophrenia, a disorder with a well-known increased risk of violence. Correlations of serum cholesterol levels at admission and measures of violence were investigated in 103 consecutively admitted patients (44 males, 59 females) of a general psychiatric admission unit. Seventy subjects were diagnosed as suffering from schizophrenia or schizoaffective disorder (ICD-10 F 20, F25), and 33 were diagnosed as suffering from non-psychotic disorders (mainly personality disorders). The level of total exhibited violence during the inpatient treatment period was measured in each patient by the Modified Overt Aggression Scale (MOAS), the Social Dysfunction and Aggression Scale (SDAS), the Staff Observation Aggression Scale (SOAS), and the Violence Scale (VS). Correlations of all violence measures were high (0.75-0.90), but no correlation was found with cholesterol levels, neither for psychotic nor for non-psychotic subjects, neither for men nor for women. The hypothesis of associations of violence and cholesterol levels is not supported by the data.