good, well referenced discussion of how Testosterone support for those with low T can improve Diabetes, insulin function, improve energy balance, and reduce cardiovascular disease risk. The discussion discusses many of the moving parts in how testosterone improves CVD risk.
decreased bifidobacterium gut flora results in increased absorption of LPS in high fat diets resulting in endotoxemia. This plays a significant role in diabetes
The relationship of low testosterone to MetS often is considered to be bidirectional; however, the relationships probably are not direct
Many of the components of the MetS are recognized risk factors for the development of cardiovascular disease (CVD)
Multiple cross-sectional studies have found low TT and low sex hormone binding globulin (SHBG) levels in Caucasian and African-American men with the MetS, irrespective of age
Low TT and SHBG levels also are prevalent in Chinese [7],[8] and Korean [9] men with the MetS
Normally 40%-50% of TT is bound to SHBG, so reducing SHBG levels will decrease TT.
Hyperinsulinism suppresses SHBG synthesis and secretion by the liver
significant increase in SHBG levels occurred after acutely lowering insulin levels in obese men
Estradiol levels are increased in men with the MetS, and they are positively correlated with the number of abnormal components of the MetS.
Although it is known that estrogen will increase SHBG levels, apparently the hyperinsulinism associated with obesity has a greater effect on SHBG levels
Estradiol also can inhibit luteinizing hormone (LH) secretion
Inflammatory cytokines are thought to have a direct effect on the pituitary to reduce LH secretion [15] and also a direct effect on Leydig cell secretion of testosterone
Low TT Levels have been shown to predict development of the MetS in men with normal BMI
Men in the lowest quartiles of serum TT, calculated free testosterone (cFT) and SHBG at baseline had the highest odds ratios for developing the MetS or DM during the 11 years follow-up
More recently, investigators conducting population-based studies have reported that only SHBG is associated with future development of the MetS
Additional evidence that low TT increases the risk of MetS comes from androgen deprivation treatment of prostate cancer
Low TT and low bioavailable testosterone (bT) were each significantly associated with elevated 20 years risk of CVD mortality in an older population in which cause-specific mortality was age, adiposity, and lifestyle-adjusted.
combination of low bT and ATP III-defined MetS is associated with increased cardiovascular mortality in men aged 40 years and above
in elderly men, testosterone may weakly protect against CVD. Alternatively, low TT may indicate poor general health
Muraleedharan and Jones [27] concluded that there is convincing evidence that low T is a biomarker for disease severity and mortality.
The evidence that TRT improves insulin sensitivity and glucose control is conflicted
It is widely recognized that testosterone treatment can reduce fat mass and increase lean body mass; however, until recently most reports have not been associated with much weight loss
Changes in body composition and weight loss are considered potential mechanisms by which testosterone treatment improves insulin sensitivity and glucose control in patients with diabetes. Effects on inflammatory cytokines [38] and changes in oxidative metabolism [39] also have been reported to improve glucose metabolism.
Testosterone replacement therapy has been reported to improve some or all of the components of the MetS.