Relationships Between Testosterone Levels and Cognition in Patients With Alzheimer Disease and Nondemented Elderly Men

Seidl, Jennifer N. Travis; Massman, Paul J.

doi:10.1177/0891988714541872

Cited by 11 publications

(4 citation statements)

References 53 publications

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“…However, studies suggest that the contribution of changes in androgen levels to Alzheimer’s disease may be relatively modest—particularly in women (Hogervorst and others 2005). With respect to cognitive deficits associated with Alzheimer’s disease, circulating testosterone levels do not appear to be predictive of neuropsychological outcome (Seidl and Massman 2014). Testosterone replacement therapy has also been reported to have no significant effect on motor and nonmotor symptoms of Parkinson’s disease (Okun and others 2006) although, as is the case for many clinical studies, interpretation of the results is limited by sample size.…”

Section: Evidence For Androgen Effects On Hippocampal Functionmentioning

confidence: 99%

Androgen Modulation of Hippocampal Structure and Function

et al. 2014

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Androgens have profound effects on hippocampal structure and function, including induction of spines and spine synapses on the dendrites of CA1 pyramidal neurons, as well as alterations in long-term synaptic plasticity (LTP) and hippocampally dependent cognitive behaviors. How these effects occur remains largely unknown. Emerging evidence, however, suggests that one of the key elements in the response mechanism may be modulation of brain-derived neurotrophic factor (BDNF) in the mossy fiber (MF) system. In male rats, orchidectomy increases synaptic transmission and excitability in the MF pathway. Testosterone reverses these effects, suggesting that testosterone exerts tonic suppression on MF BDNF levels. These findings suggest that changes in hippocampal function resulting from declining androgen levels may reflect the outcome of responses mediated through normally balanced, but opposing, mechanisms: loss of androgen effects on the hippocampal circuitry may be compensated, at least in part, by an increase in BDNF-dependent MF plasticity.

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Section: Evidence For Androgen Effects On Hippocampal Functionmentioning

confidence: 99%

Androgen Modulation of Hippocampal Structure and Function

et al. 2014

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“…there have been relatively few studies that have trialed testosterone supplementation in men with AD or mild cognitive impairments (MCI) and none have evaluated testosterone treatment in individuals that are pre-symptomatic but at a greater risk of cognitive decline. These studies have shown mixed outcomes with improvements in certain cognitive domains [6], to no improvement [7, 8]. A number of factors may account for the discrepancies in the outcomes of these trials, including differences in type, mode and dosage of treatment.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Testosterone Supplementation on Cognitive Functioning in Older Men.

Wahjoepramono¹,

Asih²,

Aniwiyanti³

et al. 2016

CNSNDDT

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Reduction in testosterone levels in men during aging is associated with cognitive decline and risk of dementia. Animal studies have shown benefits for testosterone supplementation in improving cognition and reducing Alzheimer’s disease pathology. In a randomized, placebo-controlled, crossover study of men with subjective memory complaint and low testosterone levels, we investigated whether testosterone treatment significantly improved performance on various measures of cognitive functioning. Forty-four men were administered a battery of neuropsychological tests to establish the baseline prior to being randomly divided into two groups. The first group (Group A) received 24 weeks of testosterone treatment (T treatment) followed by 4 weeks washout, and then 24 weeks of placebo (P); the second group (Group B) received the same treatments, in reverse order (Placebo, washout, and then T treatment). In group A (TèP), compared to baseline, there was a modest (1 point) but significant improvement in general cognitive functioning as measured by the Mini Mental State Examination (MMSE) following testosterone treatment. This improvement from baseline was sustained following the washout period and crossover to placebo treatment. Similar Mini Mental State Examination (MMSE) scores were observed when comparing testosterone treatment with placebo. In group B (PèT) a significant increase was observed from baseline following testosterone treatment and a trend towards an increase when compared to placebo treatment. Improvements in baseline depression scores (assessed by Geriatric Depression Scale) were observed following testosterone/placebo treatment in both groups, and no difference was observed when comparing testosterone with placebo treatment. Our findings indicate a modest improvement on global cognition with testosterone treatment. Larger clinical trials with a longer follow- up and with the inclusion of blood and brain imaging markers are now needed to conclusively determine the significance of testosterone treatment.

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“…Any change or deficiency within the neural tissue is readily compensated by circulating levels in the bloodstream. Deficiency in levels of these neurosteroids has been clinically validated in AD [ 271 , 272 , 273 , 274 , 275 ], PD [ 276 , 277 ], HD [ 278 ], and MS [ 279 , 280 , 281 ]; hormonal replacement therapy depicts beneficial effects in AD [ 276 , 282 , 283 , 284 , 285 , 286 ], PD [ 276 , 277 , 287 , 288 , 289 ], HD, and MS [ 256 , 290 , 291 , 292 , 293 ].…”

Section: Future Strategiesmentioning

confidence: 99%

Neurodegenerative Diseases: Regenerative Mechanisms and Novel Therapeutic Approaches

et al. 2018

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Regeneration refers to regrowth of tissue in the central nervous system. It includes generation of new neurons, glia, myelin, and synapses, as well as the regaining of essential functions: sensory, motor, emotional and cognitive abilities. Unfortunately, regeneration within the nervous system is very slow compared to other body systems. This relative slowness is attributed to increased vulnerability to irreversible cellular insults and the loss of function due to the very long lifespan of neurons, the stretch of cells and cytoplasm over several dozens of inches throughout the body, insufficiency of the tissue-level waste removal system, and minimal neural cell proliferation/self-renewal capacity. In this context, the current review summarized the most common features of major neurodegenerative disorders; their causes and consequences and proposed novel therapeutic approaches.

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Relationships Between Testosterone Levels and Cognition in Patients With Alzheimer Disease and Nondemented Elderly Men

Abstract: Findings suggest that testosterone is not associated with most neuropsychological test performances in patients with AD.

Cited by 11 publications

References 53 publications

Androgen Modulation of Hippocampal Structure and Function

Androgen Modulation of Hippocampal Structure and Function

The Effects of Testosterone Supplementation on Cognitive Functioning in Older Men.

Neurodegenerative Diseases: Regenerative Mechanisms and Novel Therapeutic Approaches

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