A global study reveals that even small rises in blood sugar, not just diabetes, can affect men’s sexual function as they age. The findings shift how researchers understand male reproduction and highlight metabolic health as a key driver. Results were presented at the Endocrine Society’s ENDO 2025 annual meeting.
Traditionally, aging and lower testosterone were seen as the main causes of reduced male sexual health. The new study, conducted at a leading German university hospital, challenges this view. While age and testosterone matter, the strongest link appears to be modest blood sugar increases and related metabolic changes. This suggests lifestyle changes and medical care can help men maintain sexual health longer.
The FAME 2.0 study followed healthy men aged 18 to 85 from 2014 to 2020. Of 200 participants, 117 completed the study, which tracked sperm quality, hormone levels, erectile function, and metabolic health, including HbA1c. None had diabetes, heart disease, or cancer, ensuring a focus on healthy individuals.
Researchers found that testosterone and overall semen quality stayed within normal ranges, but subtle elevations in blood sugar predicted declines in sperm motility and erectile performance. These sugar increases were below the diabetes threshold of HbA1c 6.5%, indicating risks that can be missed in routine screening. The study also found that testosterone’s role in libido did not independently predict erectile decline. Instead, the link between blood sugar, metabolic shifts (such as BMI changes), and sexual performance stood out. The lead researcher noted that this knowledge can help doctors and patients craft effective male sexual health maintenance plans.
For Thai and wider Asian audiences, these findings carry important implications. Rising rates of diabetes and pre-diabetes in Thailand heighten concern that moderately elevated blood sugar could quietly undermine sexual health and broader well-being. Thailand’s public health data show growing diabetes prevalence among adults, with many people unaware of the impact of early, moderate sugar elevations. This underscores the need for proactive metabolic screening, including HbA1c, across age groups.
Thai health professionals have long emphasized age, stress, and relationship factors in male sexual health. The new evidence adds metabolic health to the conversation, supporting a holistic approach that includes routine health screenings and lifestyle changes. Endocrinologists and urologists in major Thai hospitals advocate broader public education and primary care screening for metabolic indicators from early adulthood.
Culturally, Thai beliefs about vitality have often centered on hormones, aging, and traditional remedies. While massage, herbs, and talismans are common in popular lore, this study highlights the role of metabolic health. The message is clear: diet, exercise, and regular screenings can help sustain sexual vitality and overall health, aligning with Thai dietary wisdom that emphasizes balance and moderation.
Addressing sexual health openly remains a challenge in Thailand, especially among older men. Mildly elevated blood sugar can go untreated for years, risking cardiovascular and cognitive health in addition to sexual function. Culturally sensitive education and destigmatization of sexual and metabolic health discussions are essential to translate research into real-world benefits.
Looking ahead, Thailand’s rising burden of lifestyle-related diseases may lead to more integrated men’s health services. Clinics and wellness centers could incorporate systematic metabolic screening into routine checkups, while insurers may expand coverage for such testing. Local researchers may pursue longitudinal studies tailored to Thai diets and lifestyles.
Practical steps for Thai men today include:
- Request HbA1c and glucose checks as part of annual health screenings starting in early adulthood.
- Report any changes in sexual function to a healthcare professional, recognizing the link to metabolic health.
- Embrace a balanced lifestyle: maintain a healthy weight, limit refined sugars and refined carbohydrates, and engage in regular physical activity.
- Involve partners and families in creating a supportive environment that reduces stigma around sexual and metabolic health.
This research empowers men with actionable insights: by managing even small blood sugar increases and maintaining metabolic health, men can protect sexual health and quality of life as they age. As science advances, these findings may influence Thailand’s healthcare policy, preventive medicine, and public health messaging.
For further context, findings are discussed in coverage by research outlets and Endocrine Society materials, emphasizing broader implications for preventive health and patient education.