Dr. Goodyear

low adiponectin levels associated with PCOS in women.  

High fat diet decrease hypothalamic kisspeptin levels result in decreased GNRH release.  The result is a decrease in LH/FSH and in this case decreased Testosterone.  These were animal models.

Study finds a link between Estradiol, venous insufficiency, and ED in men.  The signaling is through VEGF and NO.

This article points to the impact of T:E2 on ED in men.  A declining T:E2 increases ED in older men.  

low T strongly associated with metabolic syndrome in men.

Study found that peak serum levels of Testosterone were achieved 3-8 hours after topical scrotum application of Testosterone.

Birth control pills increase resting cortisol levels.  This study looked at salivary and urinary cortisol.

Testosterone therapy lowered HgbA1c in poorly controlled Diabetics.  These patients were followed out to 52 weeks.  Testosterone therapy, as is lifestyle change, a long term strategy of Diabetes control.  Studies in controlled Diabetics have not shown a reduction in HgbA1c consistently.  Total cholesterol and waist circumference were also reduced.

Small study of 13 men found that weight loss following bariatric surgery resulted in improved HPA function in 10/13.  Three men had resistant HPA dysfunction.  Free Testosterone was followed.

Lifestyle changes that result in weight loss can increase Total Testosterone, free Testosterone, and SHBG.

Testosterone therapy is complex in hypogonadism.  Much of the marketing-based medicine of Low T today is in fact doping.  Increasing weight is clearly associated with a declining T level in men.  Testosterone therapy should be approach individually and therapies that use the one size fits all approach never work.  This is the case whether the use of synthetics or natural hormones are employed.  Testosterone has been shown to improve dysglycemia, MetS, reduce fat and increase muscle mass.  

The prevalence of low T varies significantly between lean versus overweight men.  This suggests a significant contribution of obesity and its biologic effects as a cause of low T.  The difference is 30%.

Androgen deprivation therapy in men has been shown to worsen insulin resistance and precipitate type II Diabetes as well as stimulate weight gain.  This suggests a cause effect relationship between Testosterone and insulin sensitivity.  Other studies have pointed to a reciprocal decline in Testosterone due to hyperglycemia--both acute and chronic.   Androgen deprivation has a significant long list of cardiovascular risks and this should be discussed with the patient.

This study looked at a small number of men with low T.  Therapy was abruptly stopped and the effects were followed.  Insulin function declined.  There was a trend to increased glucose and IL-6.

Testosterone plays role in insulin resistance, metabolic syndrome, and type II diabetes in men.

SHBG associated with increased metabolic syndrome risk, not Testosterone in this study.  Total Testosterone, when low, has been suggested to be more predictive of Mets than free T.

Low Testosterone in men with Diabetes predictive of an increase in all-cause mortality.  This fits with other data.  

Testosterone was inversely associated with weight and age.  This study points to this as the primary driver of low T, even in Diabetics.  Total Testosterone was inversely associated with BMI and free (calculated) Testosterone was associated with age.

Low Total Testosterone, low SHBG, and symptoms of low T are associated with an increase risk (relative) of Mets, especially in normal weight men.