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C Christiansen

Publications and source records attributed to C Christiansen.

At least 289 records · Page 16Linked to original sources
PubMed1991

Dose-response bioactivity and bioavailability of salmon calcitonin in premenopausal and postmenopausal women.

We investigated the acute, dose-response to three intranasal doses of salmon calcitonin (sCT) (50 IU, 100 IU, and 200 IU) and one im dose (50 IU) in eight premenopausal and eight early postmenopausal women. Total serum calcium and serum beta-endorphin revealed significant changes after all four administrations (P less than 0.05). After the two highest intranasal and the im doses cAMP increased 10% and 35%, respectively (P less than 0.05). All administrations except the 50 IU intranasal dose produced significant increases in plasma sCT (P less than 0.05). The areas under the concentration-time curves, calculated for the period with the maximal changes (i.e. 120-240 min), illustrated a significant dose-related response in total serum calcium, beta-endorphin, and sCT (P less than 0.01-0.001). cAMP showed a dose-related tendency, the response to the im injection being significantly higher than that to the two lowest doses of intranasal sCT (P less than 0.05). We conclude that the doses administered produce a dose-related biological response and bioavailability. In women with normal and high bone turnover, sCT 100 IU intranasally seems as optimal as 50 IU im. The response to sCT should, furthermore, be assessed on bioactivity rather than on bioavailability.

Administration, Intranasal↗
PubMed1991

Effect of menopause and hormone replacement therapy on the urinary excretion of pyridinium cross-links.

Pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) are two cross-links of collagen molecules that are present in the extracellular matrix and released during its degradation. In contrast to the wide distribution of collagen, Pyr is present in bone and cartilage, but not in significant amounts in other connective tissues, and D-Pyr appears to be specific for bone tissue. Therefore, the urinary excretion of Pyr and D-Pyr might be a sensitive marker of bone matrix degradation. Using a specific high pressure liquid chromatography assay we have measured Pyr and D-Pyr cross-links in a 24-h and a fasting urine sample in 60 early postmenopausal women and 19 premenopausal women matched for age. Menopause induced a 62% increase in Fu Pyr (49.8 +/- 18.7 vs. 30.8 +/- 8.0 pmol/mumol creatinine; P less than 0.001) and an 82% increase in Fu D-Pyr (8.2 +/- 3.4 vs. 4.5 +/- 1.4 pmol/mumol creatinine; P less than 0.001). In 20 postmenopausal women on hormone replacement therapy, urinary Pyr and D-Pyr returned to premenopausal levels within 6 months, contrasting with unchanged levels during placebo treatment. The 24-h excretion of Pyr and D-Pyr was significantly lower than the fasting excretion, but was similarly decreased after hormone replacement therapy. Pyr and D-Pyr excretion measured in the same urinary sample were highly correlated (r = 0.85 for fasting and 0.83 for 24-h sampling), but correlations between fasting and 24-h values were weak (D-Pyr, r = 0.30; Pyr, r = 0.29; P less than 0.05 for both). Correlations between urinary cross-links and other markers of bone turnover (Fu hydroxyproline/creatinine and plasma osteocalcin) were significant but low (Pyr vs. osteocalcin, r = 0.29, P less than 0.05; Pyr vs. hydroxyproline, r = 0/.34; P less than 0.01; D-Pyr vs. osteocalcin, r = 0.39; P less than 0.01), except for D-Pyr vs. hydroxyproline (r = 0.24; P = 0.07), suggesting that these markers reflect different events of bone metabolism. Finally, a single measurement of the fasting excretion, but not of the 24-h excretion, of cross-links was significantly correlated (Pyr, r = 0.34; P less than 0.05; D-Pyr, r = -0.46; P less than 0.01), with the subsequent spontaneous rate of bone loss assessed by repeated measurements of the radial bone mineral content in 37 postmenopausal women.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1991

Serum lipids, lipoproteins, and apolipoproteins during postmenopausal estrogen replacement therapy combined with either 19-nortestosterone derivatives or 17-hydroxyprogesterone derivatives.

PURPOSE: To study the influence of combined hormone replacement therapy on levels of serum lipids, lipoproteins, and apolipoproteins. PATIENTS AND METHODS: One hundred thirty-nine healthy early postmenopausal women selected by means of a questionnaire, a medical examination, and a laboratory screening procedure to be a representative sample of postmenopausal Danish women aged 45 to 55 years old were randomized to four treatment and two placebo groups. The four groups receiving hormone replacement therapy were given 2 mg estradiol valerate equivalents (E), either sequentially combined with 75 micrograms levonorgestrel (E/LNG), 10 mg medroxyprogesterone acetate (E/MPA), or 150 micrograms desogestrel (E/DG), or continuously combined with 1 mg cyproterone acetate (E/CPA). Serum lipids, lipoproteins, and apolipoproteins were measured before institution of hormone replacement therapy and at nine well-defined times during the following 84 days. Total response and cyclical variations were calculated. RESULTS: All active treatment regimens reduced serum low-density lipoprotein cholesterol (LDL-C) significantly: E/CPA, 6% (95% confidence limits 0.3% to 11.3%); E/LNG, 10.9% (4.9% to 16.6%); E/MPA, 14.4% (7.4% to 20.9%); E/DG, 10.7% (3.3% to 17.6%). The changes in serum total cholesterol and apolipoprotein B were similar but smaller than those in LDL-C. None of these treatment regimens induced significant overall changes in serum high-density lipoprotein cholesterol (HDL-C) or apolipoprotein A1 (Apo A1). The sequentially combined hormone treatments induced significant cyclical variations in HDL-C, with an increase during estrogen therapy and a decrease during combined therapy: E/LNG, 13.3% (7.4% to 19.4%); E/MPA, 6.9% (1.6% to 12.6%); E/DG, 10.3% (5.8% to 14.9%). No cyclical changes in HDL-C were found in the group receiving continuously combined hormone replacement therapy (E/CPA). The changes in Apo A1 parallel those in HDL-C. CONCLUSION: All the treatment regimens produced changes in levels of serum lipids, lipoproteins, and apolipoproteins that may be considered favorable in terms of cardiovascular disease.

Androgen Antagonists↗
PubMed1991

[Consensus Development Conference. Prevention and treatment of osteoporosis].

A consensus development conference sponsored by the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the European Foundation for Osteoporosis and Bone Disease and the American National Osteoporosis Foundation was held in Copenhagen in October 1990. The consensus statement is presented (also published in Am J Med 1991; 90:107-10).

Absorptiometry, Photon↗
PubMed1990

Hormonal prevention and treatment of osteoporosis--state of the art 1990.

Osteoporosis is a growing disease, and attention should be directed to possible means of preventing and treating this disease. Osteoporosis may be caused by a number of diseases (secondary osteoporosis), but it most often occurs in otherwise healthy persons. The major risk factors are a low bone mass at skeletal maturity, and a rapid bone loss. Postmenopausal bone loss may be prevented by hormone replacement therapy. All types of oestrogens and all administration forms are effective, as long as a sufficient serum concentration is obtained. The greatest benefit of hormone replacement therapy is obtained if instituted right after the menopause, when the bone loss is most rapid. But oestrogen will also arrest the bone loss when instituted much later in life.

Estrogen Replacement Therapy↗
PubMed1990

Bone Gla protein (osteocalcin) assay standardization report.

The major conclusion of this study is that the different laboratory assays for serum BGP give a reasonably consistent picture of bone metabolism in the metabolic bone diseases examined only if the results are expressed as a percentage of serum BGP levels in normal individuals. This requires that all laboratories establish a mean control serum BGP value in an appropriate population of normal individuals. Since BGP levels determined by different laboratories on the same serum sample can vary by more than fourfold, the absolute serum BGP levels determined in one laboratory cannot be compared directly with the serum BGP levels determined in another. Although we cannot comment on the efficacy of different laboratory assays for serum BGP as measures of bone metabolism in disease states that were not examined, such as osteoporosis, it is clear that the large differences between laboratory assays make it imperative that all interlaboratory comparisons be based on values expressed as a percentage of serum BGP in an appropriate population of normal individuals.

Animals↗
PubMed1990

Screening procedure for women at risk of developing postmenopausal osteoporosis.

The present study includes 70 healthy, immediately postmenopausal women stratified according to future rate of bone loss. The stratification was performed by means of four parameters of bone turnover: serum alkaline phosphatase, fasting urinary calcium and hydroxyproline, and body weight, used in an equation developed in a previous study. After the stratification the women were followed without intervention for the next 24 months, with bone mass measurements every 3 months. The bone loss estimated at baseline by means of the equation correlated with the bone loss measured in the forearm (y = 0.72x - 1.52; r = 0.61; P less than 0.001). Plasma bone gla protein (BGP, osteocalcin), which is a new specific marker of bone formation, was now added to the model (replacing body weight). This increased the diagnostic validity (y = x; r = 0.76; P less than 0.001). From the present study we conclude that the postmenopausal bone loss can be predicted by means of four biochemical parameters determined in plasma and urine in women just after the menopause.

Biomarkers↗
PubMed1990

Does a single local absorptiometric bone measurement indicate the overall skeletal status? Implications for osteoporosis and osteoarthritis of the hip.

Regional bone mineral content (BMC) and density (BMD) (head, arms, chest, spine, pelvis, legs) of a total body dual photon 153Gd absorptiometry (DPA) scan were measured in 20 healthy postmenopausal women, 27 postmenopausal women with hip fracture, and 17 postmenopausal women with osteoarthritis of the hip. In addition, local BMC and BMD were measured in the proximal and distal regions of the distal forearm (BMCprox, BMDprox, BMCdist, BMDdist) by single photon absorptiometry (SPA); and in the lumbar spine (BMCL2-L4 and BMDL2-L4) by 153Gd DPA. The overall impression was a reduction of bone mass in hip fracture patients compared with healthy controls and an increase in the bone mass of osteoarthritic patients. These results were valid using both regional values of the total body scan, and local forearm and lumbar spine measurements, and statistically significant using one-way analysis of variance. There were, however, also significant within-group between-region differences (one-way analysis of variance), showing that the bone mass of the pelvis and legs in hip fracture patients was more reduced than in the remaining skeleton; in osteoarthritic patients it was not increased but rather unchanged or slightly reduced. The differences between the level of the three local measurements (BMDprox BMDdist BMDL2-L4), on the one hand, and the level of the six regional BMD values, on the other hand, were investigated by the two-way analysis of variance: local measurements = rows; regional values = columns. This analysis showed that none of the three local measurements was statistically better than the other two in predicting the overall level of skeletal bone mass as judged by the six regional values. We conclude that serious osteoporotic bone loss has a generalized nature, however, with a tendency towards lower values in the regions affected by fracture (viz: low bone mass in the legs of femoral neck fracture patients). Osteoarthritis may be associated with a high bone mass in most areas, but low values in the affected regions. Local lumbar spine measurement of bone mass by DPA is not superior to local forearm measurement of bone mass by SPA in predicting the nature of overall osteoporotic or osteoarthritic bone change.

Absorptiometry, Photon↗
PubMed1990

Comparison of vitamin D metabolism in early healthy and late osteoporotic postmenopausal women.

We studied 20 healthy premenopausal women aged 36.5 +/- 4.0 years (mean +/- 1 SD), 123 healthy postmenopausal women aged 50.0 +/- 2.4 years, and 103 postmenopausal women aged 65.1 +/- 5.6 years with symptomatic osteoporosis (forearm and spinal fracture). Serum levels of vitamin D metabolites [25(OH)D, 24,25(OH)2D3, and 1,25-(OH)2D] were compared with (1) bone mass in the forearm (single photon absorptiometry) and in the spine (dual photon absorptiometry); (2) biochemical indices of bone formation (serum alkaline phosphatase, plasma bone Gla protein), and bone resorption (fasting urinary hydroxyproline); and (3) other biochemical estimates of calcium metabolism (serum calcium, serum phosphate, 24-hour urinary calcium, intestinal absorption of calcium). The present study revealed no difference in any of the vitamin D metabolites between the premenopausal women, the healthy postmenopausal women and the osteoporotic women as a group. The concentrations of 1,25(OH)2D and 25(OH)D were significantly lower in patients with spinal fracture than in those with forearm fracture. In the early postmenopausal women serum 1,25(OH)D was related to forearm bone mass (r = -0.20; P less than 0.05), intestinal calcium absorption (r = 0.18; P less than 0.05), and 24-hour urinary calcium (r = 0.21; P less than 0.05); serum 25(OH)D was related to spinal bone mass (r = 0.23; P less than 0.01). In the osteoporotic women, serum vitamin D metabolites were not related to bone mass, but 1,25(OH)2D was related to bone Gla protein (r = 0.33; P less than 0.001), serum phosphate (r = -0.27; P less than 0.01), and 24-hour urinary calcium (r = 0.43; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

24,25-Dihydroxyvitamin D 3↗
PubMed1990

Discontinuous calcitonin treatment of established osteoporosis--effects of withdrawal of treatment.

PURPOSE: The purpose of this study was to examine the effects of discontinuous treatments with intranasal salmon calcitonin on bone and calcium metabolism in postmenopausal women and to establish the effects of withdrawing treatment. PATIENTS AND METHODS: This report presents data from 26 postmenopausal women with established osteoporosis (forearm fracture) 12 months after withdrawal of a 1-year double-blind, placebo-controlled therapy with intranasal calcitonin. The women then resumed treatment with calcitonin 200 IU plus calcium 500 mg daily in an open design for an additional 1-year period. A control group of 19 age-matched women (no forearm fracture) did not receive any treatment. RESULTS: At the end of the 3 years, the control group had lost significantly more bone in the forearm (single photon absorptiometry) and spine (dual photon absorptiometry) than had the group treated with intranasal calcitonin for 2 years, whereas the group receiving calcitonin for 1 year had intermediate values. During the year of withdrawal, the rate of bone loss was similar in the women who had received calcitonin and those who had received placebo. Calcitonin was especially effective in women with initially high bone turnover and low bone mass. The bone response in the spine could, furthermore, be estimated by the changes in bone turnover. CONCLUSION: Discontinuous treatment with intranasal calcitonin affects bone and calcium metabolism in established osteoporosis. In women with high-turnover osteoporosis, therapy results in a net gain of bone in both the peripheral and axial skeleton. Response to treatment may be monitored by changes in bone turnover.

Absorptiometry, Photon↗
PubMed1990

Influence of smoking, body fat distribution, and alcohol consumption on serum lipids, lipoproteins, and apolipoproteins in early postmenopausal women.

The impact of smoking, alcohol consumption, obesity, and body fat distribution (measured either directly by dual photon absorptiometry as abdominal fat% (AF%) or as the waist-to-hip ratio (WTH] on serum lipids, lipoproteins, and apolipoproteins was investigated in 148 early postmenopausal women. All the women were healthy and none were taking medication known to influence the parameters studied. Smokers had significantly higher levels of triglycerides, low density lipoprotein cholesterol (LDL-C), and apolipoprotein B (P less than 0.05), and higher ratios of LDL-C/HDL-C and apolipoprotein B/A-I (P less than 0.01), but lower levels of high density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (P less than 0.01). Moderate alcohol consumption was positively associated with HDL-C and apolipoprotein A-I (P less than 0.001). Body weight and body mass index (BMI) tended to be positively associated with an atherogenic lipoprotein and apolipoprotein profile. However, body fat distribution parameters (AF% and WTH) were stronger predictors of lipoproteins and apolipoproteins than were body weight and BMI, which did not seem to be independent predictors of lipoproteins and apolipoproteins. We conclude that cigarette smoking and a central fat distribution have a significant, independent, negative influence on lipids, lipoproteins, and apolipoproteins, whereas moderate alcohol consumption has a positive effect on these parameters in early postmenopausal women.

Adipose Tissue↗
PubMed1990

Time-dependent variations in bone turnover parameters during 2 months' cyclic treatment with different doses of combined estrogen and progestogen in postmenopausal women.

We determined the time-dependent variations in biochemical estimates of bone resorption and bone formation in 30 healthy postmenopausal women treated for two consecutive cycles of 28 days with a sequential estrogen/gestagen therapy. The women received either 1, 2, or 4 mg estradiol (E2) for 22 days and 1 mg norethisterone acetate (NETA) from day 13 to 22 of each cycle. Blood samples were drawn twice a week, ie, 16 blood samples in each woman. Biochemical estimates of bone resorption (fasting urinary hydroxyproline/creatinine, fasting urinary calcium/creatinine) decreased significantly during the two treatment cycles. In contrast, there was no overall decrease in bone formation parameters (plasma bone Gla protein [pBGP], serum alkaline phosphatase), and serum alkaline phosphatase decreased significantly during the estrogen-only phase, but increased during the E2 plus NETA phase. The present study supports our previous suggestion that NETA stimulates bone formation in early postmenopausal women.

Animals↗
PubMed1990

Collagen synthesis in postmenopausal women during therapy with anabolic steroid or female sex hormones.

The effect of anabolic steroid therapy and estrogen-progestogen substitution therapy on serum concentration of procollagen type III aminoterminal peptide (PIIINP), a measure of collagen synthesis, in postmenopausal women was studied in two double-blind studies: (1) 39 women allocated to treatment with either 50 mg nandrolone decanoate as an intramuscular depot or placebo injections every third week for 1 year, and (2) 40 women allocated to receive either 2 mg 17 beta-estradiol plus 1 mg norethisterone acetate daily or placebo tablets for 1 year. Serum PIIINP was measured every 3 months during the study. Anabolic steroid therapy resulted in a more than 50% increase (P less than .001) in serum PIIINP at 3 months, which thereafter decayed but remained significantly increased throughout the study period. Serum PIIINP showed the same pattern during estrogen-progestogen therapy, but to a lesser degree. We conclude that anabolic steroids stimulate type III collagen synthesis in postmenopausal women, while estrogen-progestogen therapy may have such an effect, but only to a lesser degree.

Aged↗
PubMed1990

Hormonal replacement therapy and the skeletal system.

The two most important risk factors for maintaining skeletal health are the bone mass obtained at skeletal maturity (peak bone mass) and the subsequent bone loss. Those women with a low peak bone mass and a rapid bone loss are thus at increased risk of developing osteoporosis in the future, and should be identified. This may be accomplished by determination of the bone mass combined with an estimate of the rate of the postmenopausal bone loss. The bone mass can be accurately assessed in the forearm by single photon absorptiometry. The postmenopausal bone loss can be estimated by three or four biochemical markers of bone turnover. The women at highest risk of developing osteoporosis should be offered preventive therapy, e.g., hormonal replacement therapy (HRT). HRT arrests the bone loss not only in early, but also in elderly postmenopausal women. The effect lasts as long as the therapy is continued. Several epidemiological studies have demonstrated that HRT decreases the number of osteoporotic fractures.

Bone and Bones↗