^ Mehta PH, Jones AC, Josephs RA (Jun 2008). "The social endocrinology of dominance: basal testosterone predicts cortisol changes and behavior following victory and defeat" (PDF). Journal of Personality and Social Psychology. 94 (6): 1078–93. CiteSeerX 10.1.1.336.2502. doi:10.1037/0022-3518.104.22.1688. PMID 18505319. Archived from the original (PDF) on April 19, 2009.
Type 2 diabetes is an important condition in terms of morbidity and mortality, and the prevalence is increasing in the developed and developing world. The prevalence also increases with age. Insulin resistance is a primary pathological feature of type 2 diabetes and predates the onset of diabetes by many years, during which time raised serum insulin levels compensate and maintain normoglycemia. Insulin resistance and/or impaired glucose tolerance are also part of the metabolic syndrome which also comprises an abnormal serum lipid profile, central obesity and hypertension. The metabolic syndrome can be considered to be a pre-diabetic condition and is itself linked to cardiovascular mortality. Table 1 shows the three commonly used definitions of the metabolic syndrome as per WHO, NCEPIII and IDF respectively (WHO 1999; NCEPIII 2001; Zimmet et al 2005).
Next, while testosterone levels do decline with age, this may simply be because the older that men get, the less they take care of themselves – they stop exercising, start putting on weight, and don’t pay as much attention to their diet. A recent study suggests that age-related T decline is not inevitable, and that if you keep living a healthy lifestyle, you can maintain healthy testosterone levels. So if you’re an older guy, try to do all you can as far as lifestyle changes before you get on the prescription T. I don’t mean doing a little cardio a few times a week, using the machines at the gym, and eating “pretty” healthy. Follow the guidelines above, and see what happens first.
Testosterone has two major effects on bones: (a) through conversion to estradiol by way of the enzyme, aromatase, testosterone inhibits osteoclastic activity and hence bone resorption; and (b) through conversion to DHT via 5-α-reductase, it stimulates osteoblastic activity and so enhances the laying down of bone (Tivesten et al 2004; Davey and Morris 2005). Hypogonadal men are at risk for the development of osteopenia or osteoporosis and hence for subsequent fracture (Fink et al 2006). About one-third of all osteoporotic hip fractures occur in men and the risk of any osteoporotic fracture in men over 50 is as high as 25 percent (Seeman 1997; Adler 2006). Although treatment with testosterone in hypogonadal men increases bone mineral density (Katznelson et al 1996), it has not yet been established that this results in a reduction in fracture rate.
Prostate hyperplasia (BPH), or simply an enlarged prostate, is a serious problem among men, especially those over age 60. As I’ve pointed out, high testosterone levels are not a precursor to an enlarged prostate or cancer; rather, excessive DHT and estrogen levels formed as metabolites of testosterone are. Conventional medicine uses two classes of drugs to treat BPH, each having a number of serious side effects. These are:
^ Southren AL, Gordon GG, Tochimoto S, Pinzon G, Lane DR, Stypulkowski W (May 1967). "Mean plasma concentration, metabolic clearance and basal plasma production rates of testosterone in normal young men and women using a constant infusion procedure: effect of time of day and plasma concentration on the metabolic clearance rate of testosterone". The Journal of Clinical Endocrinology and Metabolism. 27 (5): 686–94. doi:10.1210/jcem-27-5-686. PMID 6025472.
Overall, it seems that both estrogen and testosterone are important for normal bone growth and maintenance. Deficiency or failure of action of the sex hormones is associated with osteoporosis and minimal trauma fractures. Estrogen in males is produced via metabolism of testosterone by aromatase and it is therefore important that androgens used for the treatment of hypogonadism be amenable to the action of aromatase to yield maximal positive effects on bone. There is data showing that testosterone treatment increases bone mineral density in aging males but that these benefits are confined to hypogonadal men. The magnitude of this improvement is greater in the spine than in the hip and further studies are warranted to confirm or refute any differential effects of testosterone at these important sites. Improvements seen in randomized controlled trials to date may underestimate true positive effects due to relatively short duration and/or baseline characteristics of the patients involved. There is no data as yet to confirm that the improvement in bone density with testosterone treatment reduces fractures in men and this is an important area for future study.
Testosterone levels generally peak during adolescence and early adulthood. As you get older, your testosterone level gradually declines — typically about 1 percent a year after age 30 or 40. It is important to determine in older men if a low testosterone level is simply due to the decline of normal aging or if it is due to a disease (hypogonadism).