Dr. Ron’s Research Review – July 8, 2020

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This week’s research review focuses on the post-prandial decline in testosterone.
A study published in Andrologia investigated the post-prandial decline in testosterone in reproductive-aged men. The Department of Obstetrics Gynaecology and Reproductive Medicine, Flinders University, Adelaide, South Australia conducted the study. (Tremellen et al., 2019)
The study included overweight or obese men. 18 participants were enrolled in the study. Ten participated in both the high saturated fat “fast food” mixed meal and fasting control; and eight in the intravenous Intralipid arm and five in the oral Intralipid arm.
After an overnight fast, they consumed a high‐fat mixed meal and the Intralipid fat liquid meal. A second study involved intravenous Intralipid following an overnight fast, identical to the conditions outlined in the meal study arms.
The high‐fat mixed meal consisted of an English muffin containing sausage, egg and cheese plus two potato hash browns (McDonald's Australia). The polyunsaturated vegetable fat liquid meal consisted of a 125 ml oral dose of Intralipid 20% (Fresenius Kabi).
Ingestion of a high-fat "fast food" mixed meal, a common practice for obese men, produced a 25% fall in serum testosterone within an hour of eating, with levels remaining suppressed below fasting baseline for up to 4 hr. These changes in serum testosterone were not associated with any significant changes in serum gonadotrophins. The nadir in serum testosterone preceded the post-prandial increase in serum IL-6/IL-17 by several hours, suggesting that inflammation was unlikely the cause. Furthermore, intravenous administration of fat (Intralipid) had no impact on testosterone levels, while an identical oral dose of fat did suppress testosterone.
These results suggest that fat does not directly impair Leydig cell function, but rather the passage of fat through the intestinal tract elicits a response that indirectly elicits a post-prandial fall in testosterone. (Tremellen et al., 2019)

 

Dr. Ron

 


Articles

 

Mechanistic insights into the aetiology of post-prandial decline in testosterone in reproductive-aged men.
            (Tremellen et al., 2019)  Download
Obesity is known to be associated with impaired testicular function potentially resulting in androgen deficiency and subfertility. While the underlying cause of obesity-related male hypogonadism is multi-factorial, here, we investigated the impact of dietary fat on testicular endocrine function. Ingestion of a high-fat "fast food" mixed meal, a common practice for obese men, produced a 25% fall in serum testosterone within an hour of eating, with levels remaining suppressed below fasting baseline for up to 4 hr. These changes in serum testosterone were not associated with any significant changes in serum gonadotrophins. The nadir in serum testosterone preceded the post-prandial increase in serum IL-6/IL-17 by several hours, suggesting that inflammation was unlikely the cause. Furthermore, intravenous administration of fat (Intralipid) had no impact on testosterone levels, while an identical oral dose of fat did suppress testosterone. These results suggest that fat does not directly impair Leydig cell function, but rather the passage of fat through the intestinal tract elicits a response that indirectly elicits a post-prandial fall in testosterone.

 

References

Tremellen, K, A Hill, and K Pearce (2019), ‘Mechanistic insights into the aetiology of post-prandial decline in testosterone in reproductive-aged men.’, Andrologia, 51 (10), e13418. PubMed: 31475727