Something to think about... Seasonal T levels

[HRTstudent]

Just saw this abstract, but I don't have access to the full text. It certainly seems like good food for thought.



http://www.ncbi.nlm.nih.gov/pubmed/23294933

The evidence for seasonal variations of testosterone in men.

Smith RP, Coward RM, Kovac JR, Lipshultz LI.

Scott Department of Urology, Baylor College of Medicine, Houston, TX, United States. Electronic address: [email protected].
Abstract

Ample evidence exists to support the concept of diurnal variations in testosterone levels ; however, substantiation for seasonal fluctuations is sparse and inconsistent. Since circadian disparities exist, laboratory screening for hypogonadism has traditionally been conducted using serum testosterone levels obtained in the early morning. Should circannual variability of testosterone be confirmed, it would make the monitoring of testosterone levels more difficult while forcing the development of seasonal reference standards to allow for comparison. Moreover, decisions to begin treatment and adjustment of practice patterns would likely follow. This review thoroughly explores all of the available evidence concerning seasonal variations in testosterone levels. The impacts of melatonin, vitamin D, sleep-wake cycles, light exposure, physical activity, BMI, and waist circumference are also discussed. Current research suggests that while some evidence exists to support the notion of seasonal testosterone variations, the discussed inconsistencies preclude the incorporation of this concept into current clinical standards.

[M302_Imola]

good post! I've been reading some stuff on another forum about how circadian rhythm has a big impact on test levels. This sounds like an interesting study!