M.J. Martinez de Osaba

Osteoporosis and bone mineral metabolism disorders in cirrhotic patients referred for orthotopic liver transplantation.

Abstract. The purpose of this study was to determine the prevalence of osteoporosis, to estimate the bone turnover and hormonal status, and to identify the factors associated with bone disease in patients with end-stage liver disease who were referred for orthotopic liver transplantation.A prospective study was performed on 58 cirrhotic patients (6 with primary biliary cirrhosis, 14 with alcoholic cirrhosis, and 38 with posthepatitic cirrhosis), who were referred for orthotopic liver transplantation. Patients, excluding those with primary biliary cirrhosis, were classified in Child-Pugh groups according to the severity of liver disease (class B [28 patients], class C [24 patients]). Biochemical parameters of bone mineral metabolism and standard liver function tests were measured in all patients. Additionally, serum osteocalcin, urinary hydroxyproline/creatinine ratio, serum intact parathyroid hormone, serum 25-hydroxyvitamin D, serum 1,25-dihydroxyvitamin D, folliclestimulating hormone, and luteinizing hormone levels were determined in patients and controls within the same age range. Plasma testosterone, sex hormone-binding globulin levels, and free testosterone index were obtained for all men included in the study.Bone mass of the lumbar spine and femur were measured by dual X-ray absorptiometry (DPX-L), and were expressed as a standard deviation of mean values (Z-score) from a sex and age-matched control group. Spinal X-rays were obtained to assess vertebral fractures. Osteoporosis was considered as a factor in spinal bone mineral density with a Z-score below 2 or at least one vertebral fracture.Twenty-five patients (43%) had osteoporosis, with lower bone mass measurements in the lumbar spine than in the femoral neck (P < 0.005). Alcoholic and Child-Pugh C patients showed the lowest femoral bone mineral density values. Cirrhotic patients showed lower osteocalcin levels than controls (14.3 ± 5.9 vs. 18.2 ± 8.1 ng/ml; P < 0.05) and showed increased urinary hydroxyproline (125.1 ± 51.5 vs. 107.9 ± 26.6 nM/mg creatinine; P < 0.05). Serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and parathyroid hormone levels were significantly lower in cirrhotic patients than in controls (10.3 ± 9.1 vs. 23.1 ± 26.6 ng/ml; P= 0.000), (12.9 ± 9.1 vs. 48.3 ± 11.5 pg/ml; P= 0.000), (16.6 ± 9.2 vs. 27.9 ± 8.2 pg/ml; P= 0.000), with no differences between Child-Pugh groups. Alcoholic Child-Pugh C patients showed the lowest 25-hydroxyvitamin D serum values (4.5 ± 2.2 ng/ml; P < 0.05). Male patients had lower testosterone levels than controls (302.5 ± 229.4 vs. 556.7 ± 146.5 ng/dl; P= 0.000), with increased sex hormone-binding globulin values. Levels of testosterone and gonadotropin were related to Child-Pugh classification. No correlation was found between bone mass and hormonal values.A significant decrease in bone mass, particularly in the lumbar spine, is seen in end-stage cirrhotic patients. Reduced bone formation and significant disorders of bone mineral metabolism, such as vitamin D deficiency, reduced parathyroid hormone levels, and hypogonadism are involved. Moreover, severity and etiology of the liver disease are the main risk factors for developing bone loss and mineral metabolism disorders in patients referred for orthotopic liver transplantation.

Bone Disease After Liver Transplantation: A Long-Term Prospective Study of Bone Mass Changes, Hormonal Status and Histomorphometric Characteristics

Abstract: After liver transplantation there is a high incidence of fractures, with important rates of bone loss during the first months. However, the long-term evolution of bone mass and metabolism parameters have been scarcely studied. In order to determine the incidence and risk factors involved in the development of skeletal fractures and to analyze the long-term evolution of bone mass, bone turnover and hormonal status after liver transplantation, a 3-year prospective study was performed in 45 patients following liver transplantation. Serum osteocalcin, parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH D) and testosterone levels (men), and bone mass at the lumbar spine and femur were measured before and sequentially at different time points during 3 years. Spinal X-rays were obtained during the first year. Histomorphometric analysis of bone biopsies obtained in 24 patients within the first 12 hours after surgery and 6 months after transplantation was performed. Fifteen patients (33%) developed fractures after liver transplantation, and pre- transplant risk factors for fractures were age and low bone mass (odd”s ratio for osteoporosis, 95% confidence interval: 5.69, 1.32–24.53). Serum PTH, osteocalcin, 25-OH D, testosterone and creatinine levels increased after transplantation. Moreover, PTH correlated with creatinine and osteocalcin values. Bone mass decreased during the first 6 months and reached baseline values at the lumbar spine the second year, with posterior significant recovery at the femoral neck. Long term evolution of femoral neck BMD correlated with PTH levels. Six months after transplantation bone histomorphometric data showed an increase in bone formation parameters. After liver transplantation there is a high incidence of fractures, specially in elderly patients and those with osteoporosis. Bone mass decreased in the short-term period and improved, initially at the lumbar spine and later at the femur, according to histomorphometric evidences of an increase in bone formation. The increase in creatinine values induces a secondary hyperparathyroidism that influences the changes in femoral bone mass. Treatment of osteoporosis shortly after liver transplantation may be important in the prevention of bone fractures, particularly in patients with low bone mass.

Bone mass and mineral metabolism in liver transplant patients treated with FK506 or cyclosporine A

The purpose of this study was to compare the effects of Cyclosporine A (CyA) and FK506 on bone mass and mineral metabolism in liver transplantation (LT) patients. A prospective study was performed on 18 male patients who underwent LT treated with CyA, and 7 LT patients who received FK506. Bone mineral density (BMD) of the lumbar spine and proximal femur (DPX-L) was measured before and at 6, 12, and 24 months after transplantation. Moreover, intact parathyroid hormone (PTH) and 25-hydroxyvitamin D (25OHD) levels were determined at the same time. The cumulative dose of glucocorticoids was calculated in all patients. At 6 months, lumbar BMD decreased 5.2 ± 1.2 % (P=0.0005) and 2.9 ± 2.1 % (p=ns) in CyA and FK506 groups, respectively. Lumbar BMD reached baseline values at 1 year in the FK506 group and 2 years after LT in the CyA group. Moreover, significant intergroup differences in femoral neck BMD changes after 2 years of transplant were observed (CyA: −5.2 ± 1.97 versus FK506: +1.55 ± 2.2 %;P=0.039). In the first year posttransplant both groups showed a marked increase in PTH and 25OHD levels. The mean cumulative dose of glucocorticoids was higher in the CyA group (CyA group 11.06 ± 0.46 g versus FK 506 group 6.71 ± 0.42 g;P<0.001), and multiple linear regression analysis showed a negative correlation between BMD changes at the lumbar spine and mean cumulative dose of glucocorticoids (P=0.022). In conclusion, our data suggest that after liver transplantation treatment with FK506 shows a more favorable long-term effect on bone mass evolution than CyA therapy. These differences seem to be associated with the lower dose of glucocorticoids used in the FK506 group.

Biochemical markers of bone turnover after surgical menopause and hormone replacement therapy

The objective of this study was to evaluate the effect of surgical menopause and hormone replacement therapy (HRT) on the new biochemical markers of bone turnover. Fourteen women who had undergone surgical menopause and began HRT 3 months after surgery were recruited for a 1-year study. Results were compared with a control group of 31 healthy premenopausal women of similar age. Serum samples were obtained to determine total alkaline phosphatase, bone alkaline phosphatase, propeptides carboxy- and amino-terminal of type I procollagen (PICP, PINP), osteocalcin, tartrate-resistant acid phosphatase, and carboxy-terminal telopeptides of type I collagen (ICTP and serum CTX). Urine samples were analyzed for hydroxyproline, pyridinoline, deoxypyridinoline, alpha- and beta-carboxy-terminal telopeptides of type I collagen (alpha-CTX and beta-CTX), and amino-terminal telopeptide of type I collagen (NTX). Determinations were performed after 3 months of surgical menopause and after 3 and 9 months of HRT. All biochemical markers increased after menopause, and most of them normalized after 9 months of HRT. Serum PINP showed the highest proportion of increased values after surgery among bone formation markers (62%), as well as the highest mean percent increase (101%). Among bone resorption markers in postmenopausal women, urinary beta-CTX, alpha-CTX, NTX, and serum CTX showed the highest proportion of increased values (100%, 67%, 58%, 58%, respectively) as well as the greatest mean percent increase. They were also the markers with the most marked response to HRT. In conclusion, serum PINP is the most sensitive marker of bone formation, whereas beta-CTX is the most sensitive marker of bone resorption after surgical menopause. In addition, both markers showed the highest response after HRT.

Prediction of depressive relapse in remitted bipolar patients using corticotrophin‐releasing hormone challenge test

Abnormalities in corticotrophin (ACTH) and Cortisol levels before and after corticotrophin‐releasing hormone (CRH) stimulation have been reported in depressed bipolar patients. The ACTH and free Cortisol response to the injection of 100 ug of synthetic human CRH and plasma cortisol‐binding globulin (CBG) levels were measured in 42 lithium‐treated patients suffering from RDC bipolar‐I disorder in remission, and in 21 age‐ and sex‐matched control subjects. A 1‐year follow‐up was conducted in order to assess any possible relationship between outcome and the hormonal response. Bipolar patients showed higher baseline and peak ACTH concentrations than controls. A lower net area under the ACTH concentration curve after CRH stimulation predicted depressive relapse within 6 months by multiple regression analysis. The CRH challenge test could be a potentially good predictor of depressive relapse in remitted bipolar patients.

Immunocytochemical evidence on the effects of glucocorticoids on type I collagen synthesis in human osteoblastic cells.

The effects of glucocorticoids on DNA synthesis and cellular function were assessed in cultures of human osteoblastic cells by using indirect immunoperoxidase staining with a type I antiprocollagen antibody and by measuring procollagen type I N and C propeptides (PINP, PICP) in the culture medium by radiometric methods. Likewise, we analyzed the correlation between intracellular immunostaining and procollagen propeptides released into the culture medium, as well as the correlation between PINP and PICP. Human osteoblasts were cultured with and without addition of dexamethasone (DEX) at two supraphysiological concentrations, 10−6 M and 10−7 M, for 24 and 48 h. Treatment with DEX at 10−6 M was associated with a significant decrease in the percentage of cells showing intracellular type I procollagen immunoreactivity at 24 and 48 h (P < 0.05). Similar effects were observed with 10−7 M DEX. Dexamethasone 10−6 M and 10−7 M also induced significant decreases in PINP and PICP values after 24 and 48 h of treatment (P < 0.05). The decrease in intracellular procollagen immunoreactivity and propeptide secretion was not associated with a reduction in DNA synthesis. A highly significant correlation was observed between the values of PINP and PICP in the culture medium as well as between the values of intracellular immunostaining and PINP and PICP (P < 0.001). In conclusion, our results suggest that supraphysiological doses of glucocorticoids produce a direct inhibition on osteoblastic function through their effect on type I procollagen synthesis. Immunoperoxidase detection of type I intracellular procollagen as well as the quantification of PINP and PICP in the culture medium are reliable methods of assessing osteoblast function.

Effects of oophorectomy and hormone replacement therapy on pituitary-gonadal function

The purpose of this study was to determine how oophorectomy and different hormone replacement therapy (HRT) regimens using low doses of medroxyprogesterone acetate (MPA, 2.5 mg/day) influence the pituitary-gonadal axis function. Ninety (90) women, who had had regular menses prior to surgery, completed a 1-year follow-up period. Patients were assigned to 5 groups. The first (n = 16) received 0.625 mg/day conjugated equine oestrogens (CEE) cyclically, the second (n = 20) 50 micrograms day transdermal oestradiol (E2) cyclically and the third (n = 15) 0.625 mg/day CEE continuously. These 3 groups also received 2.5 mg MPA sequentially for the last 12 days of HRT administration. The fourth group (n = 20) received 0.625 mg/day CEE and 2.5 mg/day of MPA continuously, while the fifth (n = 19) constituted a control group. After oophorectomy all patients showed increases in follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, and decreases in those of E2, oestrone (E1), prolactin (PRL), sex-hormone-binding globulin (SHBG), androstenedione (delta A4) and testosterone (T). No changes were detected in dehydroepiandrosterone sulphate (DHEA-S) levels. After HRT, decreases in FSH, LH and PRL levels and increases in those of E2, E1 and SHBG were observed, but no changes were seen in T, delta A4 or DHEA-S plasma levels. As the differences that were found cannot be attributed to the presence of ovaries, it is reasonable to assume that they were perhaps due to the treatment. All these changes, with the exception of a decrease in PRL levels, are therefore to be expected after HRT.

Evolution of Secondary Hyperparathyroidism After Kidney Transplantation in Patients Receiving Cinacalcet on Dialysis

BACKGROUND Secondary hyperparathyroidism (SHPT) is a relevant problem in patients undergoing dialysis, and cinacalcet hydrochloride seems to be the best option for controlling it. After kidney transplantation (KTx), moderate to severe SHPT may persist and cause hypercalcemia and hypophosphatemia, among other deleterious effects. The number of patients receiving cinacalcet before KTx is increasing. OBJECTIVE To evaluate the evolution of calcemia, phosphatemia, and intact parathyroid hormone (iPTH) after KTx in patients with SHPT receiving cinacalcet on dialysis. PATIENTS AND METHODS The study included 19 patients (15 men and 4 women; mean [SD] age, 52 [13] years) undergoing dialysis and receiving cinacalcet before KTx. Mean duration of dialysis before KTx was 33 (25) months, and cinacalcet dose was 45 (15) mg/d. Creatinine, calcium, phosphorus, alkaline phosphatase, and iPTH concentrations were evaluated at baseline (day of surgery), at 15 days after surgery, and then monthly for 6 months. In all patients, cinacalcet therapy was discontinued on the day of surgery. RESULTS After the first month post-KTx, mean (SD) serum creatinine concentration was 1.6 (0.4) mg/dL and remained stable during follow-up. Calcium and phosphorus concentrations were normal in 13 patients after KTx; however, in 6 patients, hypercalcemia (calcium concentration, 11 [1.3] mg/dL) or hypophosphatemia (phosphorus concentration, 1.7 [0.6] mg/dL) developed, with iPTH concentration of 557 (400) pg/mL and alkaline phosphatase concentration of 307 (114) IU/mL. Treatment with cinacalcet resulted in correction of calcium and phosphorus concentrations (10.1 [0.4] mg/dL and 1.7 [0.7] mg/dL, respectively). Patients in whom hypercalcemia or hypophosphatemia developed were receiving cinacalcet, 60 mg/d or more, during dialysis therapy. Patients who received cinacalcet, 30 mg/d, before KTx did not exhibit hypercalcemia or hypophosphatemia after KTx. CONCLUSION In patients with HPT undergoing dialysis and receiving cinacalcet, 60 mg/d or more, this drug therapy should be continued after KTx to avert development of hypercalcemia or hypophosphatemia.

Cortisol-binding globulin levels in bipolar disorder

Cortisol-binding globulin (CBG) is an alpha-1-glycoprotein with high affinity for cortiso that could be a potential biological marker of chronic stress, according to several previous studies. In order to examine CBG concentrations in bipolar disorder, we determined serum CBG levels by radioimmunoassay with monoclonal antibodies in a sample of 39 RDC bipolar I patients in remission and 21 healthy age-, sex- and weight-matched control subjects. Only lithium treatment was permitted. Plasma cortisol and serum lithium levels were also determined. Bipolar males showed statistically significant lower serum CBG levels than controls, whereas women showed very similar values. No correlation was found between CBG levels and cortisol or lithium concentrations. It is concluded that CBG levels are affected by chronic affective illness, even during remission periods, at least in bipolar males.

Antagonism of oestrogen-induced prolactin release by medroxyprogesterone acetate

Previous studies conducted at our clinic suggested that the administration of hormone replacement therapy (HRT) in postmenopausal women could result in the inhibition of oestrogen-induced prolactin (PRL) release. The aim of this study was to determine how the pituitary function is affected by the sequential addition of medroxyprogesterone acetate (MPA) to oestrogen replacement therapy. Twenty-one postmenopausal women receiving no other medication were treated with a standard dose (0.625 mg/day) of conjugated equine oestrogens (CEE) for a period of 24 days, plus 5 mg/day MPA added sequentially during the last 12 days of the oestrogen therapy. Blood samples were collected before treatment, during oestrogen and oestrogen-progestogen administration and after cessation of treatment. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17 beta-oestradiol (E2) and PRL levels were studied. During treatment gonadotrophin concentrations decreased significantly, while after cessation of HRT the levels of FSH and LH increased. These gonadotrophin fluctuations indicated a sharp rise in E2 levels during therapy and a significant decrease during the treatment-free period. PRL levels were found to be higher during CEE therapy, but they fell when patients received CEE in combination with MPA. These observations suggest that the role of progestogens in a variety of experimental and clinically relevant situations needs to be investigated not only as regards their direct action but also their modulation of the effect of oestrogen.