News | New Findings on Testicular Aging: Obesity May Accelerate Decline in Sperm Function
A study published in Developmental Cell used single-cell RNA sequencing to systematically analyze human testicular tissue for the first time. It found that obesity may worsen age-related abnormalities in sperm cells and impair male fertility.
The study was co-led by Bradley Cairns and Jingtao Guo, PhD, of the University of Utah School of Medicine and examined whether a high body mass index (BMI) accelerates the decline in testicular function.
Two Patterns of Testicular Aging, Divided by Obesity
Age-related declines in male fertility are well recognized, but the molecular and genetic mechanisms of testicular aging remain poorly understood. In particular, there has been little direct evidence on whether lifestyle factors such as obesity worsen this process.
To address this gap, the team used single-cell RNA sequencing to analyze autopsy testicular samples from 4 younger and 8 older men, comprising more than 44,000 cells. All older donors had fathered children when younger, confirming fertility earlier in life.
The results showed:
Samples from the younger group clustered closely, had intact spermatogenesis, and showed no clear signs of aging.
Samples from the older group divided clearly into two subgroups:
In the first subgroup, testicular cells retained good sperm-producing capacity and molecular characteristics similar to those of the younger group.
The second subgroup showed substantial reproductive decline and very limited spermatogenic potential.
The most prominent factor distinguishing the two subgroups was BMI.
BMI: A Numerical Divide in Testicular Outcomes
The data showed:
All older donors in the first subgroup had a BMI below 27.
All donors in the second subgroup had a BMI above 30, within the range of obesity.
This key finding suggests that a high BMI may accelerate deterioration in testicular stem-cell function. When obesity and aging occur together, impaired spermatogenesis and infertility may become more likely.
“Aging itself causes modest molecular changes that leave the testes more vulnerable to dysregulation. When aging is combined with obesity, that dysregulation may be substantially amplified.”
—Dr. Bradley Cairns
Future Research: Questions That Remain
Although the study identified a possible association between obesity and testicular aging, many questions remain:
Does obesity simply accelerate aging, or does it cause a separate pathway of testicular aging?
How do diet, exercise, diabetes, hormonal changes, and other lifestyle factors contribute?
At what age does dysfunction in testicular support cells begin, and can it be reversed?
“We have provided a detailed single-cell atlas that offers an important data foundation for further research into how human testes respond to aging.”
—Dr. Jingtao Guo
The study also noted that once molecular markers of testicular aging are identified, precise diagnostic tools and interventions may potentially be developed for subfertility in older men.
News | New Findings on Testicular Aging: Obesity May Accelerate Decline in Sperm Function
News | New Findings on Testicular Aging: Obesity May Accelerate Decline in Sperm Function
A study published in Developmental Cell used single-cell RNA sequencing to systematically analyze human testicular tissue for the first time. It found that obesity may worsen age-related abnormalities in sperm cells and impair male fertility.
The study was co-led by Bradley Cairns and Jingtao Guo, PhD, of the University of Utah School of Medicine and examined whether a high body mass index (BMI) accelerates the decline in testicular function.
Two Patterns of Testicular Aging, Divided by Obesity
Age-related declines in male fertility are well recognized, but the molecular and genetic mechanisms of testicular aging remain poorly understood. In particular, there has been little direct evidence on whether lifestyle factors such as obesity worsen this process.
To address this gap, the team used single-cell RNA sequencing to analyze autopsy testicular samples from 4 younger and 8 older men, comprising more than 44,000 cells. All older donors had fathered children when younger, confirming fertility earlier in life.
The results showed:
Samples from the younger group clustered closely, had intact spermatogenesis, and showed no clear signs of aging.
Samples from the older group divided clearly into two subgroups:
In the first subgroup, testicular cells retained good sperm-producing capacity and molecular characteristics similar to those of the younger group.
The second subgroup showed substantial reproductive decline and very limited spermatogenic potential.
The most prominent factor distinguishing the two subgroups was BMI.
BMI: A Numerical Divide in Testicular Outcomes
The data showed:
All older donors in the first subgroup had a BMI below 27.
All donors in the second subgroup had a BMI above 30, within the range of obesity.
This key finding suggests that a high BMI may accelerate deterioration in testicular stem-cell function. When obesity and aging occur together, impaired spermatogenesis and infertility may become more likely.
“Aging itself causes modest molecular changes that leave the testes more vulnerable to dysregulation. When aging is combined with obesity, that dysregulation may be substantially amplified.”
—Dr. Bradley Cairns
Future Research: Questions That Remain
Although the study identified a possible association between obesity and testicular aging, many questions remain:
Does obesity simply accelerate aging, or does it cause a separate pathway of testicular aging?
How do diet, exercise, diabetes, hormonal changes, and other lifestyle factors contribute?
At what age does dysfunction in testicular support cells begin, and can it be reversed?
“We have provided a detailed single-cell atlas that offers an important data foundation for further research into how human testes respond to aging.”
—Dr. Jingtao Guo
The study also noted that once molecular markers of testicular aging are identified, precise diagnostic tools and interventions may potentially be developed for subfertility in older men.
Story source:
Collected online