Metabolic syndrome (MetS) is highly prevalent, affecting more than 47 million US residents. This condition is also multifaceted, potentially leading to significant disturbance of numerous physiologic processes. This review article evaluates the literature regarding metabolic syndrome and male reproductive health. Links between obesity, dyslipidemia, hypertension, and insulin resistance are each examined with regard to their associated detrimental effects on male fertility. At the end of this manuscript, we propose a new MetS/male infertility paradigm. Additional studies specifically addressing the components of MetS and their impact on male reproduction will enhance our understanding of the underlying pathophysiology. These studies may also help clarify the role for therapeutic intervention.

Amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) is a progressive neurodegenerative disorder of Chamorro residents of Guam and the Mariana Islands, characterized by abundant neuron loss and tau neurofibrillary pathology similar to that observed in Alzheimer's disease (AD). A variety of neurodegenerative diseases with tau pathology including ALS/PDC also have alpha-synuclein positive pathology, primarily in the amygdala. We further characterized the tau and alpha-synuclein pathology in the amygdala of a large series of 30 Chamorros using immunohistochemical and biochemical techniques. Tau pathology was readily detected in both affected and unaffected Chamorros. In contrast, alpha-synuclein pathology was detected in 37% of patients with PDC but not detected in Chamorros without PDC or AD. The alpha-synuclein aggregates often co-localized within neurons harboring neurofibrillary tangles suggesting a possible interaction between the two proteins. Tau and alpha-synuclein pathology within the amygdala is biochemically similar to that observed in AD and synucleinopathies, respectively. Thus, the amygdala may be selectively vulnerable to developing both tau and alpha-synuclein pathology or tau pathology may predispose it to synuclein aggregation. Furthermore, in PDC, tau and alpha-synuclein pathology occurs independent of beta-amyloid deposition in amygdala thereby implicating the aggregation of these molecules in the severe neurodegeneration frequently observed in this location.

Increasing evidence recently has pointed toward a relationship between lower urinary tract symptoms (LUTS) and the presence of metabolic syndrome. This relationship has been supported by recent epidemiologic findings. Possible pathophysiologic links also have been proposed to explain the relationship between these two syndromes. The increasing prevalence of obesity in the United States makes this an increasingly relevant problem. Animal studies support a link between autonomic nervous system (ANS) overactivity and the development of urinary symptoms, low bladder compliance, compensatory prostatic hyperplasia, and blockage of the same using α-blockade. There appears to be a significant link between ANS overactivity as part of the metabolic syndrome and LUTS secondary to benign prostatic hyperplasia (BPH). However, it is unlikely that ANS overactivity could be responsible for the development of LUTS. Rather, ANS overactivity plays a key role in increasing the severity of LUTS above an intrinsic basal intensity that is determined by the genitourinary anatomic/pathophysiologic characteristics of each BPH patient. This paper defines metabolic syndrome as a collection of abnormalities, including being overweight (visceral abdominal fat distribution), dyslipidemia, hypertension, impaired glucose metabolism, elevated C-reactive protein (chronic inflammation), and autonomic-sympathetic overactivity, with insulin resistance as the hypothesized underlying pathogenic mechanisms.

Increasing evidence recently has pointed toward a relationship between lower urinary tract symptoms (LUTS) and the presence of metabolic syndrome. This relationship has been supported by recent epidemiologic findings. Possible pathophysiologic links also have been proposed to explain the relationship between these two syndromes. The increasing prevalence of obesity in the United States makes this an increasingly relevant problem. Animal studies support a link between autonomic nervous system (ANS) overactivity and the development of urinary symptoms, low bladder compliance, compensatory prostatic hyperplasia, and blockage of the same using alpha-blockade. There appears to be a significant link between ANS overactivity as part of the metabolic syndrome and LUTS secondary to benign prostatic hyperplasia (BPH). However, it is unlikely that ANS overactivity could be responsible for the development of LUTS. Rather, ANS overactivity plays a key role in increasing the severity of LUTS above an intrinsic basal intensity that is determined by the genitourinary anatomic/pathophysiologic characteristics of each BPH patient. This paper defines metabolic syndrome as a collection of abnormalities, including being overweight (visceral abdominal fat distribution), dyslipidemia, hypertension, impaired glucose metabolism, elevated C-reactive protein (chronic inflammation), and autonomic-sympathetic overactivity, with insulin resistance as the hypothesized underlying pathogenic mechanisms.

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