Effects of dehydroepiandrosterone replacement therapy on bone mineral density in older adults: a randomized, controlled trial

Increases in bone mineral density in response to oral dehydroepiandrosterone replacement in older adults appear to be mediated by serum estrogens

CONTEXT

The mechanisms by which dehydroepiandrosterone (DHEA) replacement increases bone mineral density (BMD) in older adults are not known.

OBJECTIVE

The aims were to determine the effects of DHEA therapy on changes in sex hormones and IGF-I and their associations with changes in BMD.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blinded, placebo-controlled trial was conducted at an academic research institution. Participants were 58 women and 61 men, aged 60-88 yr, with low serum DHEA sulfate (DHEAS) levels.

INTERVENTION

The intervention was oral DHEA 50 mg/d or placebo for 12 months.

MAIN OUTCOME MEASURES

BMD and serum DHEAS, testosterone, estradiol (E(2)), estrone (E(1)), SHBG, IGF-I, and IGF binding protein 3 were measured before and after intervention. Free testosterone and estrogen (FEI) indices were calculated.

RESULTS

The average changes in hip and spine BMD (DHEA vs. placebo) ranged from 1.1 to 1.6%. Compared with placebo, DHEA replacement increased serum DHEAS, testosterone, free testosterone index, E(1), E(2), FEI, and IGF-I (all P < 0.001) and decreased SHBG (P = 0.02) in women and, in men, increased DHEAS, E(1), FEI (all P < 0.001), and E(2) (P = 0.02) and decreased SHBG (P = 0.037). The changes in total and regional hip BMD were associated with 12-month E(2) (all P <or= 0.001) and FEI (all P <or= 0.013). The effects of DHEA treatment were eliminated by adjustment for 12-month E(2).

CONCLUSIONS

The significant increases in hip BMD in older adults undergoing DHEA replacement were mediated primarily by increases in serum E(2) rather than direct effects of DHEAS.

[Hormone therapy and anti-aging: is there an indication?]

The desire for a long life is deeply embedded in nearly all men. Fortunately life expectancy has remarkably increased over the past decades, on the other hand advancing age is frequently associated with a rise in morbidity. Above simply prolonging life there is a need to search for strategies to improve the quality of life in the elderly. Different substances to prevent premature aging, cancer and degenerative disorders appear to be promising candidates. Since it has been suggested that the decline of different hormones over the lifespan is closely related to the aging process replacement of these hormones may be a strategy against aging. Especially hormones like growth hormone, DHEA, testosterone and melatonin were considered as anti-aging agents. This review is focusing on the theoretical background and the previously known effects of different hormones to slow aging processes. Despite some promising results in a variety of studies conducted over the past years presently available data do not justify the broad use of hormones for anti-aging purposes. However, although no single hormone can be recognized as a 'rejuvenating' and life extending agent, some of their actions may be beneficial for the aging process.

Bone mass and bone resorption in postmenopausal women with type 2 diabetes mellitus

The aim of the present study was to examine the relationships between bone mass or bone resorption evaluated by urinary cross-linked N-telopeptides of type I collagen (NTx) concentration and known and potential contributors to bone mass or bone resorption such as sex hormones, age, duration of diabetes, glycemic control (hemoglobin A(1c) [HbA(1c)]), body mass index (BMI), severity of diabetic complications, smoking status, and current treatment of diabetes in postmenopausal women with type 2 diabetes mellitus (n = 196). In addition, the relationship of bone mass to pulse wave velocity, which is an earlier indicator of cardiovascular disease, was investigated in a subgroup of patients (n = 120). Bone mass was evaluated by the quantitative ultrasound method. A higher stiffness index indicates higher bone mass. Inverse correlations were found between the stiffness index and age (r = -0.374, P < .0001) and between the stiffness index and log (urinary albumin excretion) (r = -0.170, P = .0398), and a positive correlation was found between the stiffness index and serum dehydroepiandrosterone sulfate (DHEA-S) concentration (r = 0.201, P = .0136). No significant correlations were found between the stiffness index and duration of diabetes, HbA(1c), BMI, or serum estradiol concentration. No significant correlations were found between urinary NTx concentration and age, duration of diabetes, HbA(1c), BMI, serum estradiol concentration, or serum DHEA-S concentration. The stiffness index correlated inversely with urinary NTx concentration (r = -0.262, P = .0002). No significant correlation was found between the stiffness index and pulse wave velocity (r = -0.165, P = .0714). Multiple regression analysis demonstrated that serum DHEA-S concentration was an independent determinant of the stiffness index (beta = .207, P = .0428). In conclusion, serum DHEA-S concentration correlated positively with bone mass, whereas glycemic control, BMI, or duration of diabetes did not correlate with bone mass or urinary NTx concentration in postmenopausal women with type 2 diabetes mellitus.

Dehydroepiandrosterone in adrenal insufficiency and ageing

PURPOSE OF REVIEW

The physiological role of dehydroepiandrosterone remains unclear, and there is continuing controversy on whether dehydroepiandrosterone treatment benefits adrenal-deficient and elderly people with an age-related decline in dehydroepiandrosterone. The objective of this study is to critically review published results and determine whether there is a valid case for dehydroepiandrosterone treatment with advancing age and hypoadrenalism.

RECENT FINDINGS

Oral dehydroepiandrosterone therapy in both elderly and hypoadrenal subjects achieves dehydroepiandrosterone levels comparable to young subjects. Long-term dehydroepiandrosterone replacement in elderly people demonstrated no improvement in body composition, physical performance or any metabolic parameters; however, a modest but inconsistent improvement in bone mineral density occurred at certain sites. Dehydroepiandrosterone replacement in hypoadrenalism modestly improved insulin sensitivity and altered the lipid profile, but it remains uncertain whether these changes improve any patient-important outcomes. Dehydroepiandrosterone replacement in adrenal deficiency inconsistently improves some aspects of mental health.

SUMMARY

Dehydroepiandrosterone replacement increases bone mineral density in elderly subjects; however, the effect is relatively small compared with established therapies for osteoporosis. No additional benefits have been identified for long-term dehydroepiandrosterone replacement, when used in the elderly to prevent or delay ageing. Dehydroepiandrosterone replacement may improve some metabolic variables and measures of psychological well-being in adrenal deficiency, but these benefits are not consistently sustained in long-term therapy. Long-term studies are needed to confirm sustained benefits in adrenal deficiency and establish long-term safety.

Relative contributions of adiposity and muscularity to physical function in community-dwelling older adults

OBJECTIVE

To determine the relative contributions of adiposity and muscularity to multi-dimensional performance-based and perceived physical function in older adults living independently.

METHODS AND PROCEDURES

Data from 109 women and men, aged 60 or older, with low serum dehydroepiandrosterone (DHEA) sulfate levels were included in this cross-sectional analysis of baseline measures from a single-site, randomized, controlled trial of DHEA replacement therapy. Physical function was determined by means of performance on the 100-point Continuous Scale-Physical Functional Performance (CS-PFP) test and by self-reporting using the physical function subscale of the Medical Outcomes Short Form-36 (SF36PF). Body composition was measured by dual-energy X-ray absorptiometry (DXA). Linear regression analyses were used to determine the contributions of body mass index (BMI; kg body mass/m2), fat index (FI; kg fat/m2), and appendicular skeletal muscle index (ASMI; kg muscle/m2) to the CS-PFP and SF36PF scores, adjusted for age and sex.

RESULTS

Age-adjusted regression analyses indicated that FI, but not ASMI, was a significant (P<0.001) determinant of CS-PFP (R2=0.54) and SF36PF (R2=0.37). When adjusted for age and sex, BMI was nearly as good a predictor of CS-PFP (R2=0.50) and SF36PF (R2=0.34) as FI.

DISCUSSION

Adiposity was a stronger predictor of measured and self-reported physical function than was muscularity in older adults living independently. BMI, adjusted for sex, is a reasonable substitute for adiposity in the prediction of physical function.

Effect of dehydroepiandrosterone supplementation on bone mineral density, bone markers, and body composition in older adults: the DAWN trial

We present results of a randomized, placebo-controlled trial to examine the effect of 50 mg daily oral DHEA supplementation for one year on bone mineral density (BMD), bone metabolism and body composition in 225 healthy adults aged 55 to 85 years.

INTRODUCTION

Dehydroepiandrosterone (DHEA) levels decline dramatically with age, concurrent with the onset of osteoporosis, suggesting a role for DHEA supplementation in preventing age-related bone loss.

METHODS

We conducted a randomized, placebo-controlled trial to examine the effect of 50 mg daily oral DHEA supplementation for one year on bone mineral density (BMD), bone metabolism and body composition in 225 healthy adults aged 55 to 85 years.

RESULTS

DHEA treatment increased serum DHEA and DHEA sulfate levels to concentrations seen in young adults. Testosterone, estradiol and insulin-like growth factor (IGF-1) levels increased in women (all p < 0.001), but not men, receiving DHEA. Serum C-terminal telopeptide of type-1 collagen levels decreased in women (p = 0.03), but not men, whereas bone-specific alkaline phosphatase levels were not significantly altered in either sex. After 12 months, there was a positive effect of DHEA on lumbar spine BMD in women (p = 0.03), but no effect was observed for hip, femoral neck or total body BMD, and no significant changes were observed at any site among men. Body composition was not affected by DHEA treatment in either sex.

CONCLUSION

Among older healthy adults, daily administration of 50 mg of DHEA has a modest and selective beneficial effect on BMD and bone resorption in women, but provides no bone benefit for men.

Drug Insight: breast cancer prevention and tissue-targeted hormone replacement therapy

The first-generation selective estrogen receptor modulator (SERM) tamoxifen has been the mainstream hormone therapy in breast cancer. Tamoxifen benefits all stages of the disease, but its use increases the risk of uterine cancer and thromboembolic events and it can only be administered for 5 years. Aromatase inhibitors are superior to tamoxifen at advanced stages of disease and as adjuvants; however, because they increase fractures, aromatase inhibitors are unlikely to be used to prevent disease. Raloxifene, a second-generation SERM, leads, like tamoxifen, to approximately 50% fewer cases of invasive breast cancer in high risk women, with a lower incidence of thromboembolic events. Several other SERMs are in development to improve tissue specificity, efficacy and tolerance. Raloxifene shows protection against vertebral fractures similar to bisphosphonates; however, no significant effect has been observed on nonvertebral fractures. Many SERMs are in development for prevention and treatment of osteoporosis. As breast cancer metastasizes early and advanced disease cannot be cured, prevention is essential. To avoid the concerns about the use of traditional hormone replacement therapy, dehydroepiandrosterone--a tissue-targeted precursor of sex steroid formation--offers hope of a physiological tissue-targeted hormone replacement that, combined with a SERM, would simultaneously prevent breast and uterine cancer.

Gonadal steroids and bone metabolism in men

PURPOSE OF REVIEW

Over the past decade, our increasing awareness of the clinical importance of osteoporosis in men has stimulated intense interest in trying to better understand male skeletal physiology and pathophysiology. The present review focuses on a major focus of research in this area, namely the attempt to define the influence and therapeutic potential of gonadal steroids in male bone metabolism.

RECENT FINDINGS

Building on previous work defining the relative roles of androgens and estrogens in the developing male skeleton and in maintaining normal bone turnover, recent studies have begun to define these issues from epidemiologic, physiologic and therapeutic perspectives. With access to data from large prospectively defined populations of men, investigators are confirming and challenging existing hypotheses and forwarding new concepts. Clinical trials have expanded beyond standard androgen replacement studies to explore more complex hormonal interventions. Physiologic investigation has continued to probe the mechanisms underlying the differential and independent roles of androgens and estrogens in male bone metabolism.

SUMMARY

Recent work has added significantly to our understanding of the role of gonadal steroids in male skeletal physiology. Nonetheless, further research is necessary to build on these initial human studies and to capitalize on rapidly emerging advances in our understanding of the basic biology of bone metabolism.

Acute effects of 2 hours of moderate-intensity cycling on serum parathyroid hormone and calcium

Previous studies have found that serum parathyroid hormone (PTH) increases in response to relatively short (<60 minutes), intense bouts of exercise, possibly as a result of decreases in serum calcium. Whether longer, less intense exercise also stimulates an increase in PTH is not known. The effects of 2 hours of moderate-intensity cycling on serum PTH and calcium were investigated in 20 competitive male cyclists, aged 22-45 years. Serum concentrations of PTH and calcium were measured before and after exercise. Dermal calcium loss was estimated using patch collections and loss of sweat. There were increases in PTH from 40.6 +/- 15.6 to 69.5 +/- 25.5 pg/mL (P < 0.001) and in serum calcium from 9.3 +/- 0.3 to 9.6 +/- 0.5 mg/dL (mean +/- standard deviation, P = 0.001) in response to exercise. Contraction of plasma volume explained the rise in calcium but not PTH. Dermal calcium loss was estimated at 138.0 +/- 71.9 mg for the 2-hour exercise bout. Neither the change in serum calcium nor the dermal calcium loss was significantly related to the increase in PTH. The study demonstrated that prolonged exercise stimulates PTH secretion. The effects of such transient increases in PTH on bone metabolism are not known.

Research on the Age-Related Changes in the Nitric Oxide Pathway in the Arteries of Rats and the Intervention Effect of Dehydroepiandrosterone

BACKGROUND

Aging, especially the aging of blood vessels, is a dangerous independent factor in the occurrence and development of cardiovascular and cerebrovascular diseases. However, the cellular and molecular pathologic mechanisms underlying the aging of blood vessels remain unclear.

PURPOSE

To observe changes in the nitric oxide (NO) pathway and the interventional effects of dehydroepiandrosterone (DHEA) in the artery during the aging process.

METHODS

Male Wistar rats were divided into 3 experimental groups of 6 rats each: group 1, adult control 12-month-old rats fed conventional fodder; group 2, 18-month-old rats fed conventional fodder, and group 3, 18-month-old rats that received 1 mg/kg/ DHEA in their fundamental fodder when they were 12 months old. The thoracic aorta was chosen. Endothelial NO synthase protein was measured using the Western blot method, the amount of NO using the Griess method, the amount of cGMP using radioimmunoassay, and the activity of superoxide dismutase (SOD) and the amount of malonyldialdehyde (MDA) using colorimetry.

RESULT

Compared with the adult group, in the aortas of 18-month-old rats the protein expression of endothelial NO synthase (eNOS) is lower; the activity of SOD is lower but the amount of MDA is higher; the amounts of NO and cGMP are lower, but after DHEA intervention these changes are apparently ameliorated in the aged group.

CONCLUSION

During the aging process in rat arteries, the expression of eNOS is lowered, the function of oxidation resistance is weakened, and the response of the vascular smooth muscle to NO is apparently decreased. DHEA is able to ameliorate the function of NO-related signal pathways and delay the aging process of the blood vessels.