Biochemical markers of bone mineral density

Table 4 Biochemical markers of bone mineral density...

The use of glucocorticoids is associated with reduced bone mineral density, bone loss, osteoporosis, and fractures. This has been described during the long-term use of glucocorticoid by any route of administration (SEDA-19, 377) (SEDA-20, 374). The effects of glucocorticoids on bone have been reviewed (SEDA-21, 417) (165). Biochemical markers of bone mineral density are listed in Table 4. In patients with secondary hypoadrenaUsm, hydrocortisone 30 mg/day for replacement produced a significant fall in osteocalcin, indicating bone loss. Lower doses of hydrocortisone (10 mg and 20 mg) produced similar efficacy in terms of quality of life but smaller effects on osteocalcin concentrations and therefore a reduction in bone loss (166). 

Glucocorticoids can even cause osteoporosis when they are used for long-term replacement therapy in the Addison s disease, as has been shown by a study of 91 patients who had taken glucocorticoids for a mean of 10.6 years, in whom bone mineral density was reduced by 32% compared with age-matched controls (SEDA-19, 377 198). However, these results contrasted with the results of a Spanish study in patients with Addison s disease, in which no direct relation was found between replacement therapy and either bone density or biochemical markers of bone turnover of calcium metabolism (alkaline phosphatase, osteocalcin, procollagen I type, parathormone, and 1,25-dihydroxycolecalciferol) (SEDA-19, 377 199). 

Studies of the effects of inhaled glucocorticoids have used biochemical markers of bone function and imaging techniques to assess bone mineral density. Some of the biochemical markers are summarized in Table 1. Initial, short-term studies caused concern about the effect of inhaled glucocorticoids on bone metabolism. 

While biochemical markers of bone metabolism may be sensitive to the effects of glucocorticoids in the short term, the relation between changes in these markers and intermediate measures, such as bone mineral density, and the more important clinical outcomes of fractures, is unknown. In a random stratified sample of 3222 women in the perimenopausal age range (47-56 years), including 119 women with asthma, bone mineral density was measured to determine whether asthma was a risk factor of osteoporosis and to investigate the effect of inhaled glucocorticoids (102). The subjects had predominantly adult-onset asthma, as the age at diagnosis was over 40 years. There were 26 patients who were treated mainly with... 

Although studies in which biochemical markers of bone turnover are measured for periods of 1-2 months do not predict the development of bone thinning, osteoporosis, or fracture, they can be useful in comparing the potential effects on bone of different glucocorticoids. Studies of bone mineral density over longer time periods relate more directly to osteoporosis and fracture risk. 

While biochemical markers of bone metabolism may be sensitive to the effects of glucocorticoids in the short term, the relation between changes in these markers and intermediate measures, such as bone mineral density, and... 

An estimated 75 million people are affected by osteoporosis to some degree in the United States, Europe, and Japan. Osteoporosis is a systematic skeletal disease characterized by bone mass and microarchitectural deterioration with a consequent increase in bone fragility and susceptibility to fracture. Operationally, osteoporosis can be defined as a certain level of bone mineral density. The definition of osteoporosis is somewhat arbitrary and is based on epidemiological data relating fracture incidence to bone mass. Uncertainty also is introduced due to variability in bone densitometry measurements. Other clinical measures to assess the skeleton include collagen cross-links (measure of bone resorption) and levels of bone-specific alkaline phosphatase and osteocalcin (bone formation). A list of biochemical markers of bone remodeling is provided in Table 37-3. Measurement of total serum alkaline phosphatase level and urinary hydroxyproline or calcium levels is of limited value. 

Rix M, et al. Bone mineral density and biochemical markers of bone turnover in patients with predialysis chronic renal failure. Kidney Int 1999 56 1084-1093. 

Donath, J., Speer, G., Poor, G., Gergely, P., Tabak, A., and Lakatos, P. (2004) Vitamin D receptor, oestrogen receptor-alpha and calcium-sensing receptor genotypes, bone mineral density and biochemical markers in Paget s disease of bone. Rheumatology. 43, 692-695. 

Kaskani E, Lyritis GP, Kosmidis C, et al. Effect of intermittent administration of 200 IU intranasal salmon calcitonin and low doses of 1 alpha(OH) vitamin D3 on bone mineral density of the lumbar spine and hip region and biochemical bone markers in women with postmenopausal osteoporosis a pilot study. Clin Rheumatol. 2005 24 232-238. 

P6. Papadaki, H. A., Margioris, A. N., Miliaki, M., Steriopoulos, C., Valatas, W., and Eliopoulos, G. D., Chronic idiopathic neutropenia of adults is associated with decreased bone mineral density and alterations in bone turnover biochemical markers. Eur. J. Haematol. 62, 3111—3116 (1999). 

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