Two studies here.
[Size=4]Dihydrotestosterone is a determinant of calcaneal bone mineral density in men.[/size]
Ilangovan R, Sittadjody S, Balaganesh M, Sivakumar R, Ravi Sankar B, Balasubramanian K, Srinivasan S, Subramanian C, Thompson DM, Queimado L, Srinivasan N.
SourceDepartment of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Tamil Nadu, India.
Abstract
Male osteoporosis is an increasingly important health problem worldwide. Though androgen deficiency leads to bone loss in men, information on the relative contribution of aromatizable and non-aromatizable androgens in maintaining bone mineral density (BMD) and the mechanisms involved are unclear. This cross-sectional study was designed to explore the same. Hundred osteoporotic men with age matched normal were studied for serum levels of sex steroids, PTH, IGF system components, cytokines and bone turnover markers. Our findings show that serum DHT, IGF-I, IGF-II and IGFBP-3 levels were significantly decreased while IL-1beta and bone turnover markers were significantly increased in osteoporotic men compared to normal. Pearson correlation analysis revealed that serum DHT, IGF-I, IGF-II and IGFBP-3 levels were positively and strongly correlated with BMD, while serum IL-1beta levels were negatively correlated with BMD. Serum PTH, testosterone, estradiol, IGFBP-4, TNF-alpha, IL-4 and IFN-gamma levels were similar between the two groups. We observed that DHT levels significantly declined with age. However, the significant difference in DHT between the osteoporotic and normal groups is the same regardless of age. A multiple regression model adjusted for age demonstrated that DHT/BMD association is fairly stronger among those with osteoporosis than the normal. Our findings for the first time point out that DHT is an important determinant of BMD in men. Most importantly, the strong positive correlation of serum DHT with BMD offers new perspectives in understanding the role of non-aromatizable androgen in regulating bone metabolism in men, and might serve as a potential clinical marker in the diagnosis of male osteoporosis.
ncbi.nlm.nih.gov/pubmed/19732831
This is in females but …
[Size=4]Effects of dihydrotestosterone alone and combined with estrogen on bone mineral density, bone growth, and formation rates in ovariectomized rats.[/size]
Coxam V, Bowman BM, Mecham M, Roth CM, Miller MA, Miller SC.
SourceDivision of Radiobiology, School of Medicine, University of Utah, Salt Lake City, USA.
Abstract
Androgens are associated with the greater skeletal mass and size in men compared with women and have been used as anabolic agents promoting skeletal growth and mineral accretion in both sexes, but specific effects on growth and bone formation in the female skeleton are not well understood. The effects of 5 alpha-dihydrotestosterone (DHT) alone, and in combination with 17 beta-estradiol on bone and bone growth were studied in female ovariectomized (OVX) rats with established osteopenia. Eight weeks after OVX, rats were given 0.1 mg 17 beta-estradiol and/or 2.5 mg or 10 mg DHT administered by controlled-release pellets for 2 months. Body weights decreased with estrogen treatment but increased with DHT. Bone mineral density increased with the highest dose of DHT relative to OVX controls and the estrogen treated group. Dry and ashed bone weights and ash/dry weight ratios increased in the estrogen and DHT treated animals compared to the baseline OVX controls. Total bone calcium was greater with DHT and estrogen combined with DHT. The percent of calcium in the ash increased in all DHT treated groups. When normalized to final body weight, the total femur calcium content was significantly increased in the estrogen and estrogen with DHT groups, but not in the DHT groups compared with the baseline OVX and OVX control groups. The periosteal bone formation rates were increased with the high dose DHT alone and combined with estrogen. OVX rats had increased endochondral bone elongation rates relative to controls but this was decreased with estrogen treatment. DHT combined with estrogen increased endochondral growth rates relative to the estrogen treated group. Trabecular bone volume was decreased in all OVX groups relative to the base line group, but there were no significant effects observed with any treatments. Cancellous bone formation rates were suppressed with estrogen treatment but were partially reversed when combined with DHT. DHT treatments also increased most cancellous bone formation indices over OVX controls. While estrogen is known to preserve skeletal mass by reducing bone turnover, DHT increased skeletal mass by promoting bone growth and formation with concomitant increases in total body mass. DHT had greater effects on cortical bone and partially mitigated the suppressive effects of estrogen on bone growth and formation in the female skeleton.
ncbi.nlm.nih.gov/pubmed/8853853
Just another reason why you should not use finasteride, although taking a dual inhibitor would probably make this far worse.