TBS correlates with bone density and microstructure at trabecular and cortical bone evaluated by HR-pQCT.

INTRODUCTION: Trabecular bone score (TBS) estimates bone microstructure, which is directly measured by high-resolution peripheral quantitative computed tomography (HRpQCT). We evaluated the correlation between these methods and TBS influence on fracture risk assessed by FRAX. MATERIALS AND METHODS: We evaluated 129 individuals (82 women, 43 postmenopausal) 20 to 82.3 years without prevalent clinical or non-clinical morphometric vertebral fractures, using DXA (spine and hip), HR-pQCT at distal radius (R) and tibia (T) and TBS which classifies bone microarchitecture as normal (TBS ≥ 1.350), partially degraded (1.200 < TBS < 1.350), or degraded (TBS ≤ 1.200). RESULTS: Spine and hip BMD and HR-pQCT parameters at cortical bone: area (T), density (R,T) thickness (T) and trabecular bone: density (R,T), number (T) and thickness (R) were significantly better in the 78 individuals with normal TBS (group 1) versus the 51 classified as partially degraded (n = 42) or degraded microarchitecture (n = 9) altogether (group 2). TBS values correlated with age (r = - 0.55), positively with spine and hip BMD and all cortical and trabecular bone density and microstructure parameters evaluated, p < 0.05 all tests. Binary logistic regression defined age (p = 0.008) and cortical thickness (p = 0.018) as main influences on TBS, while ANCOVA demonstrated that HR-pQCT data corrected for age were not different between TBS groups 1 and 2. TBS adjustment increased FRAX risk for major osteoporotic fractures and hip fractures. CONCLUSION: We describe significant association between TBS and both trabecular and cortical bone parameters measured by HR-pQCT, consistent with TBS influence on fracture risk estimation by FRAX, including hip fractures, where cortical bone predominates.

Hyperphosphatemia is associated with cardiac valve calcification in chronic hypoparathyroidism.

PURPOSE: To evaluate the association between metabolic abnormalities and cardiovascular risk factors in patients with chronic hypoparathyroidism (HPP). PATIENTS AND METHODS: Patients 18 years and older, glomerular filtration > 30 mL/min/1.73 m2 and no documented coronary artery disease were selected. Serum calcium, phosphorus, glucose, lipids, PTH, 25(OH)D and FGF23 were measured. Cardiovascular risk was estimated by the European Society of Cardiology (ESC) calculator. Transthoracic echocardiogram and carotid ultrasound were performed to detect carotid plaques (CP), carotid intima-media thickness (IMT), cardiac valve calcification (CVC), and left ventricular hypertrophy (LVH). RESULTS: Thirty-seven patients (94.6% female), aged 56.0 ± 13.5 years and HPP duration 7.0 (4.0; 11.3) years, were included. Fifteen were classified as low cardiovascular risk, 9 as intermediate risk, 9 as high risk and none as very high risk. The prevalence of CP, CVC and LVH was 24.3%, 24.3% and 13.5%, respectively. IMT values were within normal ranges in all cohort. FGF23 were not associated with CP, IMT, CVC or LVH. After logistic regression, phosphorus was the only significant metabolic variable impacting CVC in univariate analysis (OR 2.795; 95% CI 1.132-6.905; p = 0.026), as well as in the multivariate analysis (OR 3.572; 95% CI 1.094-11.665; p = 0.035). Analysis by ROC curve showed serum phosphorus > 5.05 mg/dL (AUC 0.748; CI 0.584-0.877; p = 0.05) as the best cutoff point associated with valve heart calcification (sensitivity 78%; negative predictive value 91.3%). CONCLUSION: Hyperphosphatemia was associated with CVC in HPP patients. Further studies are needed to investigate whether the control of hyperphosphatemia may reduce cardiovascular risk in this population.

Cortisol level after dexamethasone suppression test in patients with non-functioning adrenal incidentaloma is positively associated with the duration of reactive hyperemia response on microvascular bed.

PURPOSE: Data on endothelial derangements in patients with non-functioning adrenal incidentaloma (NFAI) are scarce. METHODS: We investigated if NFAI patients present clinical, biochemical and endothelial alterations compared to individuals without an adrenal lesion and also the associations among these variables. Forty-two NFAI and 40 controls were evaluated. NFAI diagnosis and controls were defined according to the current guidelines and based on a normal adrenal imaging exam, respectively. Body composition was evaluated by dual emission X-ray absorptiometry. Endothelial reactivity was assessed by two methods: tonometry (Endo-PAT®) and laser speckle contrast imaging (LSCI). RESULTS: There were no differences between groups regarding age, gender, ethnicity, smoking status, and statin use. The frequency of metabolic syndrome according to the International Diabetes Federation criteria was 69% and 57.9%, respectively in NFAI and controls (p = 0.36), whereas the atherosclerotic cardiovascular disease (ASCVD) risk was 63.4% and 66.7% (p = 0.81). The clinical, laboratory, and anthropometric characteristics, as well as body composition, were similar between the groups. Additionally, any differences between groups were observed on endothelial reactivity tests. Nevertheless, we noted an association between cortisol levels after 1 mg-dexamethosone suppression test (1 mg-DST) and the duration of post-occlusive reactive hyperemia tested on microcirculation (r = 0.30; p = 0.03). NFAI patients require more antihypertensive drugs to achieve blood pressure control (p = 0.04). The number of antihypertensive drugs used to control blood pressure correlated with cortisol levels after 1 mg-DST (r = 0.29; p = 0.03). CONCLUSIONS: Since both groups herein investigated had a high frequency of metabolic syndrome and ASCVD risk, it might explain similarities observed on endothelial reactivity. Nevertheless, prolonged reactive hyperemia response on microcirculation was correlated with cortisol levels under suppression.

Exon 3-deleted growth hormone receptor isoform is not related to worse bone mineral density or microarchitecture or to increased fracture risk in acromegaly.

PURPOSE: Acromegaly is a cause of secondary osteoporosis and is associated with increased risk of vertebral fractures (VFs). The influence of exon 3-deleted isoform of growth hormone receptor (d3-GHR) on bone microarchitecture has not been studied in acromegaly. AIM: The aim of this study was to analyze the associations between d3-GHR isoform and bone mineral density (BMD), bone microarchitecture, and VFs in acromegaly patients. METHODS: Consecutive acromegaly patients treated at a single reference center were included. BMD was analyzed using dual-energy X-ray absorptiometry (DXA) and bone microarchitecture was analyzed by high-resolution peripheral quantitative computed tomography (HR-pQCT). The presence of moderate to severe VFs was assessed by thoracic and lumbar X-ray. GHR genotyping was analyzed by PCR, and full-length isoform of GHR (fl-GHR) was represented by a 935-bp fragment and d3-GHR by a 532-bp fragment. RESULTS: Eighty-nine patients were included [56 females; median age at diagnosis: 43 years (17-78)]. Disease was uncontrolled in 63% of patients. At least one d3-GHR allele was present in 60% of patients. Frequency of active disease (p = 0.276) and hypogonadism (p = 1.000) was not different between patients with fl-GHR and those with at least one d3-GHR. There was no difference in any DXA or HR-pQCT parameters between patients with fl-GHR and those with d3-GHR. Significant VFs were observed in 14% of patients, but there was no difference in frequency between patients with fl-GHR and those with at least one d3-GHR allele (p = 0.578). CONCLUSIONS: Presence of d3-GHR was not associated with worse BMD or bone microarchitecture or with higher frequency of significant VFs.

Vitamin D deficiency is associated with cortical bone loss and fractures in the elderly.

INTRODUCTION: The role of vitamin D on bone microarchitecture and fragility is not clear. OBJECTIVE: To investigate whether vitamin D deficiency (25(OH)D <20 ng/mL) increases cortical bone loss and the severity of fractures. DESIGN: Cross-sectional study of 287 elderly women with at least one prevalent low-impact fracture. METHODS: Biochemistry, X-rays to identify vertebral fractures (VFs) and to confirm non-vertebral fractures (NonVFs), and high-resolution peripheral quantitative computed tomography (HR-pQCT) to evaluate bone microstructure. RESULTS: Serum 25(OH)D levels were associated with body mass index (BMI: r = -0.161, P = 0.006), PTH (r = -0.165; P = 0.005), CTX (r = -0.119; P = 0.043) and vBMD at cortical bone (Dcomp: r = 0.132; P = 0.033) and entire bone (D100: r = 0.162 P = 0.009) at the distal radius, but not at the tibia. Age and PTH levels were potential confounding variables, but in the multiple linear regressions only BMI (95% CI: 0.11-4.16; P < 0.01), 25(OH)D (95% CI: -0.007 to 1.70; P = 0.05) and CTX (95% CI: -149.04 to 21.80; P < 0.01) predicted Dcomp, while BMI (95% CI: 1.13-4.18; P < 0.01) and 25(OH)D (95% CI: 0.24-1.52; P < 0.01) predicted D100. NonVFs predominated in patients with 25(OH)D <20 ng/mL (P = 0.013). Logistic regression analysis showed a decrease in the likelihood of presenting grade 2-3 VFs/NonVFs for every increase in 25(OH)D (OR = 0.962, 95% CI: 0.940-0.984; P = 0.001), BMI (OR = 0.932, 95% CI: 0.885-0.981; P = 0.007) and D100 at radius (OR = 0.994, 95% CI: 0.990-0.998; P = 0.005). CONCLUSION: In elderly patients with prevalent fractures, vitamin D deficiency was associated with cortical bone loss and severity of fractures.

An investigation of the bidirectional link between osteoporosis and periodontitis.

This study investigated whether periodontitis affects systemic bone status and whether FRAX® is a screening tool for periodontal disease in elderly women. The findings showed that bone density was not influenced by periodontitis and highlighted that women with FRAX® score above the intervention threshold had greater chance to present severe periodontitis. PURPOSE: This study investigated whether periodontal disease is a predictor for systemic bone loss among elderly women. The utilization of FRAX® as a screening tool for severe periodontitis was also evaluated in this population. METHODS: Current bone mineral density (BMD) for lumbar spine and proximal femur was used as an indicator of "bone status." Number of interdental sites with severe clinical attachment loss, frequency of bleeding on probing, and percentage of tooth loss due to periodontitis represented "periodontal disease" that was tested as a predictor of bone loss in a structural equation modeling analysis involving 110 participants. The intake of antiosteoporosis medication was considered in the analysis. Four other different criteria for periodontitis classification were also tested. FRAX® for major fracture was calculated without BMD, and with intervention threshold set by age. Longitudinally, BMD changes up to 10 years were also obtained and checked for possible association with periodontitis. RESULTS: Periodontal disease was not a predictor for worse systemic bone status according to the different periodontal disease classifications, and was not associated with BMD changes. Antiosteoporosis medication directly predicted periodontal disease and systemic bone status. Women with FRAX® score above the intervention threshold had higher chance for periodontitis in more advanced stages: III/IV (OR = 1.13, 95% CI [1.04 to 1.22], p = 0.03). CONCLUSION: Periodontal disease did not constitute a predictor for reduced systemic bone density in the studied population of elderly women. On the other hand, FRAX® demonstrated to be a useful tool to suggest periodontal evaluation. Antiresorptive medication showed benefits on periodontal and bone status.

Evaluation of body composition using dual-energy X-ray absorptiometry in patients with non-functioning adrenal incidentalomas and an intermediate phenotype: Is there an association with metabolic syndrome?

PURPOSE: Metabolic syndrome (MS) and sarcopenia are associated with increased cardiovascular risk. No studies using dual-energy x-ray absorptiometry (DXA) have evaluated association between body composition (BC) changes and MS in adrenal incidentaloma (AI). Our aim was to analyse BC in non-functioning AI (NFAI) and intermediate phenotype (IP) relative to controls and to correlate with cortisol levels. METHODS: Cross-sectional study with 44 NFAI (serum cortisol ≤ 50 nmol/L after the overnight 1 mg dexamethasone suppression test), 27 IP (cortisol 51-138 nmol/L), and 41 controls (normal adrenal on imaging examination) using DXA. Autonomic cortisol secretion (cortisol > 138 nmol/L) was excluded from the study. BC data were compared using criteria for MS (World Health Organization, National Cholesterol Education Program-Adult Treatment Panel-III, American Association of Clinical Endocrinologists (AACE), and International Diabetes Federation). RESULTS: There was no significant difference in clinical data and body mass index (BMI) among the three groups. Waist circumference (WC) was larger in AI vs. controls (p < 0.01). Waist-to-hip ratio was higher in NFAI vs. controls and waist-to-height ratio was higher in IP vs. controls (p = 0.03 and p = 0.02, respectively). The frequency of MS was higher in AI vs. controls. BC was not different among the groups. Patients with AI there was a significant association of MS with both an increase in total fat and body fat index (all criteria), and a significant difference between MS and smaller BMI-adjusted lean mass (AACE, p = 0.036). No correlation of cortisol after 1 mg dexamethasone test with BC or MS. AI and WC were independently associated with MS. CONCLUSIONS: AI presented high frequency of MS and was independently associated with MS. Possible deleterious effects of cortisol secretion seem to initially affect the muscular system.

Effects of Bone Fragility and Antiresorptive Drugs on Periodontal Disease and Tooth Loss: A Longitudinal Study.

This longitudinal study aimed to elucidate whether systemic bone fragility predicts severe periodontal clinical attachment loss (CAL) and tooth loss over the years and to test the influence of bone medication and periodontal maintenance in these relationships. Elderly women were evaluated for bone mineral density (BMD) and for fracture risk assessment (FRAX) in a cross-sectional analysis and retrospective follow-up (6- and 10-y periods). Data on BMD and FRAX were used as indicators of bone fragility in structural equation modeling. Periodontal examination and data on postmenopausal tooth loss were recorded. Multivariate Poisson regression models with robust covariance were used to estimate relative risk (RR) and 95% CI of BMD and FRAX for sites with CAL ≥6 mm and for tooth loss. The cross-sectional analysis included 134 women aged 65 to 80 y, and from them 71 and 49 women had available data for analysis in the 6- and 10-y follow-up periods, respectively. Bone fragility predicted severe CAL over 10 y (e.g., femoral neck: 10-y analysis, ß = -0.389, P = 0.005; cross-sectional, ß = -0.190, P = 0.004); however, this association did not remain significant when the use of bone medication was evaluated. Poisson regression showed that a better skeletal condition was associated with a lower risk of severe periodontal disease and tooth loss (cross-sectional femoral neck: RR = 0.08, P < 0.001; RR = 0.03, P < 0.001, respectively) when not adjusted for bone medication and periodontal maintenance. The receiver operating characteristic curve suggested that women with osteoporosis should be referred for periodontal assessment (sensitivity = 71.0%, specificity = 70.0%). Bone fragility is a relevant longitudinal predictor of severe periodontal disease and tooth loss among elderly women. The use of bisphosphonates improved the bone condition as well as the periodontal status. Periodontal maintenance also minimized the negative impact of low BMD on teeth-supportive tissues in the studied population. Knowledge Transfer Statement: The results of this study present evidence that the management of bone fragility and osteoporosis may be important in the prevention of periodontal attachment loss and future tooth loss. Besides the antiresorptive effects of the antiosteoporosis drugs on systemic bone conditions, these medications may protect periodontal tissues. The interaction of health care professionals such as dentists and physicians represents a key role for the approach to women's health, especially in an aging world.

Association of osteoporosis and bone medication with the periodontal condition in elderly women.

UNLABELLED: This study investigated whether osteoporosis and its treatment may affect periodontal condition in elderly women. The findings highlighted that women with osteoporosis had a higher chance to present severe periodontitis than women with normal bone mineral density (BMD), particularly those who were not treated for osteoporosis. INTRODUCTION: This study investigated whether osteoporosis increases the frequency and severity of chronic periodontitis in elderly women and evaluated the influence of vitamin D and osteoporosis treatment in the periodontal condition. METHODS: In this cross-sectional study, elderly women were selected among 1266 subjects evaluated for lumbar spine and proximal femur bone mineral density (BMD) using dual energy X-ray absorptiometry. Sociodemographic, clinical characteristics, and complete periodontal examination were recorded. Serum 25-hydroxyvitamin D levels were measured by chemiluminescence. RESULTS: Forty-eight elderly women with normal BMD and 86 with osteoporosis were selected. Women with osteoporosis presented higher frequency of sites with clinical attachment level ≥6 mm (p = 0.003) and gingival recession ≥3 mm (p = 0.002) than those with normal BMD and were more than twice as likely to present severe periodontitis (odds ratio (OR) = 2.49, 95 % CI [1.14 to 5.43]). Osteoporotic women who were not treated for the condition had more chance to present severe periodontitis (OR = 3.16, 95 % CI [1.28 to 7.82]) than those who did use bisphosphonates (OR = 2.04, 95 % CI [0.85 to 4.89]). Among the participants who presented low levels of vitamin D, those with osteoporosis exhibited a higher chance to present severe periodontitis than those with normal BMD (p = 0.027), but the association between vitamin D levels and osteoporosis was not statistically significant after adjustment (p = 0.198). CONCLUSIONS: Elderly women with osteoporosis have a greater chance to present periodontitis, with higher severity than those with normal BMD. Osteoporosis treatment provides protection for periodontitis.

Effects of immunosuppressant FK-506 on tooth movement.

OBJECTIVE: To test the hypothesis that immunosuppressant tacrolimus treatment can interfere with bone turnover and rate of tooth movement. MATERIAL AND METHODS: One-hundred twenty Wistar male rats were divided into four groups: Group 1 (rats subjected to orthodontic movement plus treatment with saline solution vehicle), Group 2 (rats subjected to orthodontic movement plus treatment with FK506), Group 3 (rats treated with FK506 only), and Group 4 (rats treated with saline solution vehicle). The maxillary incisors were laterally moved with a reciprocal load of 35 cN. The dosage of FK506 was 2 mg/kg/day. Howship's lacunae, osteoclasts, and macrophages were counted. RESULTS: Tooth movement was found to be greater in Group 1 than in Group 2 for all time periods (on days 3, 7, and 14), although a significant difference was observed only on days 7 and 14 (p < 0.05). The number of osteoclasts was smaller in Group 1 than in Group 2, whereas the number of Howship's lacunae was greater. CONCLUSION: FK506 has the capacity of promoting osteoclasts inhibition with probable osteoclastic apoptosis of alveolar bone following tooth movement.

Effects of GH-IGF-I excess and gonadal status on bone mineral density and body composition in patients with acromegaly.

SUMMARY: Studies on body composition and bone mineral density in acromegaly have conflicting results. Our data point to an increase in lean mass, a decrease in adipose tissue, and that the anabolic effect of GH on bone is partially dependent on modifications in body composition. INTRODUCTION: The effects of growth hormone (GH) and insulin-like growth factor I (IGF-I) excess and gonadal status on bone mineral density (BMD) and body composition (BC) in acromegalic patients are uncertain. METHODS: Bone mineral density and BC were evaluated by dual-energy X-ray absorptiometry (Prodigy-GE) in 75 patients (22 men and 53 women) with acromegaly, mean age 48.9 ± 14.5 years. Acromegaly was considered "controlled" when serum IGF-I was within the specific age-adjusted reference range, and serum GH was lower than 2.5 ng/mL. Comparisons between groups were performed using unpaired t test or Mann-Whitney U test. Categorical variables were analyzed by chi-square (x (2)) test. In order to compare data of different subgroups stratified by disease activity and gonadal status, one-way analysis of variance (ANOVA) and Bonferroni post hoc analysis were performed. To evaluate the correlation between GH and IGF-I and densitometric parameters, Pearson and Spearman rank order correlation were performed, as appropriate. RESULTS: There were no differences in BMD when considering disease activity and gonadal status. Active disease and eugonadism were positively correlated to an increase in lean mass and a decrease in fat mass. After multiple linear regression, there were positive correlations between GH and Z-score at lumbar spine and between lean mass and BMD at proximal femur. CONCLUSION: Our data support that GH-IGF-I excess and eugonadism have great influence on BC modifications and that the anabolic effects of GH-IGF-I on bone are, at least in part, dependent on these alterations in body composition.

Low body mass index and declining sex steroids explain most age-related bone loss in Brazilian men.

SUMMARY: Osteoporosis in men is underestimated, but our data point to an increasing prevalence rate in those over 70 years old with body mass index (BMI) <25 kg/m(2), bioavailable testosterone <2.7 nmol/L, bioavailable estradiol <40 pmol/L, and high bone turnover, defined in this study as serum carboxyterminal cross-linked telopeptide of type I collagen (ICTP) >4.3 microg/L. INTRODUCTION: The association of sex steroids and osteoporosis was evaluated in 104 men, aged 50-93 years old. METHODS: Bone mineral density (BMD), bone turnover (ICTP), testosterone (T), and estradiol (E(2)) were measured; free and bioavailable hormones (free testosterone index [FTI], BioT, free estradiol index [FEI], and BioE(2)) were calculated from T, E(2), sex hormone-binding globulin (SHBG), and albumin. Nonparametric analysis and Poisson regression models were used. RESULTS: Significant increases in SHBG and ICTP and decreases in femoral neck BMD, FTI, FEI, BioT, and BioE(2) were observed with each additional decade of age. Femoral neck BMD was inversely correlated with ICTP, and both were significantly associated with SHBG, FTI, BioT, FEI, and BioE. There was a direct and graded association between age and osteoporosis prevalence rate (OP PR; p = 0.028). Compared to participants less than 70 years old, the crude OP PR of those 80 years and older was 3.2 (95%CI = 1.4-7.3). Adjusting sequentially for BMI and bioavailable sex hormones attenuated the association between age and osteoporosis prevalence by 55% and 77%, respectively. CONCLUSION: Our data support the view that low BMI and declining sex steroids explain most of the association between aging, increased bone turnover, and osteoporosis in men.

Evaluation of osteoporotic bone structure through synchrotron radiation X-ray microfluorescence images.

The abnormal accumulation or deficiency of trace elements may theoretically impair the formation of bone and contribute to osteoporosis. In this context, the knowledge of major and trace elements is very important in order to clarify many issues regarding diseases of the bone, such as osteoporosis, that remain unresolved. Several kinds of imaging techniques can be useful to access morphology and the minerals present in osteoporotic bones. In this work, synchrotron radiation X-ray microfluorescence was used as an X-ray imaging technique to investigate bone structures. Therefore, this research aims to improve the knowledge about some aspects of bone quality. The measurements were carried out at the Brazilian Synchrotron Laboratory Light Laboratory, in Brazil. A white beam with an energy range of 4-23 keV, a 45 degrees /45 degrees geometry and a capillary optics were used. It was demonstrated that bone quality can and must be evaluated not only by considering the architecture of bones but also by taking into account the concentration and the distribution of minerals. Our results showed that the elemental distributions in bone zones on a micron scale were very helpful to understand functions in those structures.

Bone diagnosis by X-ray techniques.

In this work, two X-ray techniques used were 3D microcomputed tomography (micro-CT) and X-ray microfluorescence (micro-XRF) in order to investigate the internal structure of the bone samples. Those two techniques work together, e.g. as a complement to each other, to characterize bones structure and composition. Initially, the specimens were used to do the scan procedure in the microcomputer tomography system and the second step consists of doing the X-ray microfluorescence analysis. The results show that both techniques are powerful methods for analyzing, inspecting and characterizing bone samples: they are alternative procedures for examining bone structures and compositions and they are complementary.

Prevalence of osteopenia in men with prolactinoma.

The aim of this cross-sectional study was to analyze bone mineral density (BMD) and prevalence of osteopenia and osteoporosis in 30 men with prolactinoma, and compare them to 22 control subjects. BMD of lumbar spine and femur was evaluated by dual-energy X-ray absorptiometry. PRL, testosterone, estradiol, sexual hormone-binding globulin and free androgen and estrogen indexes (FAI and FEI, respectively) were measured in all the subjects. In patients with prolactinoma, mean values of PRL and testosterone were calculated for the 12-month period that preceded the study. The mean T-score of the four sites analyzed by bone densitometry was lower in men with prolactinoma than in controls (p-values: lumbar spine=0.015, femoral neck <0.0001, trochanter=0.037, total femur=0.036), and 55.6% of the former presented osteopenia or osteoporosis at one or more sites (p =0.035). The lumbar spine was the most seriously affected site, where 29.6% had osteopenia and 14.8% had osteoporosis. By the time of BMD determination, significant associations were found between BMD and PRL, testosterone, FAI, estradiol, FEI, and duration of hypogonadism. Considering the period of 12 months that preceded BMD evaluation, trochanter BMD was associated with mean PRL levels, while there was an association between lumbar spine BMD and mean testosterone levels. However, the multiple regression analysis showed that estradiol was the main determinant of BMD. In conclusion, men with prolactinoma have high prevalence of osteopenia and osteoporosis. Bone loss in such patients is associated with hyperprolactinemia and hypogonadism, and mainly influenced by estrogen.

Ribavirin, but not interferon alpha-2b, is associated with impaired osteoblast proliferation and differentiation in vitro.

Hepatitis C treatment with interferon alpha-2b (IFN-alpha) and ribavirin has been related to decreased bone mineral density. The aim of this study was to investigate the in vitro effects of different concentrations of ribavirin and IFN-alpha on osteoblast-like cells. Human osteoblast-like cells obtained by the outgrowth of cells from bone chips were exposed to ribavirin (0.1-10 microg/mL) or IFN-alpha (0.1-1000 UI/mL). At regular time-points, cultures were harvested for posterior analysis. Alkaline phosphatase (ALP) activity was determined on days 7 and 14, and cell growth was accessed by C3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and cell count on days 1, 3, 5, and 7. Flow cytometry analysis was used for investigating cell death on days 1, 3, 5, and 7. IFN-alpha affected ALP expression only at the higher concentration (1000 UI/mL) after 7 days (P < 0.05). No effects were detected in cell growth. In ribavirin treated cultures, concentrations higher than 2.5 microg/mL were associated with a decrease in ALP activity within 7 and 14 days (P < 0.01 and P < 0.001, respectively). Furthermore, the reduction in cell growth was dose-dependent and was detected after the fifth day. This decrease can be explained by an increase in the number of dead cells and a decrease in cell proliferation. In conclusion, our experiments demonstrated that ribavirin reduced, in a time- and dose-dependent manner, the number of metabolically active cells through a decrease in proliferation and an increase in cell death, and induced an impairment in osteoblast differentiation. These negative effects of ribavirin on osteblast-like cells might contribute to the bone loss reported in vivo.

Effects of transdermal and oral estrogen replacement on lipids and glucose metabolism in postmenopausal women with type 2 diabetes mellitus.

OBJECTIVE: To compare the effects of oral and transdermal estrogen replacement on lipid and glucose metabolism in postmenopausal women with diabetes mellitus type 2. DESIGN AND METHODS: In an open, randomized, cross-over study, 21 diabetic postmenopausal women were treated with transdermal 17beta-estradiol 50 microg or oral conjugated equine estrogens (CEE) 0.625 mg daily, both associated with 300 mg/day of oral micronized progesterone for 12 days monthly during 6 months each. After a 12-h overnight fasting period, blood glucose, insulin, glycosylated hemoglobin (HbA1c) and lipoprotein profile were evaluated, at baseline and after 6 months of each schedule of hormone replacement therapy (HRT). Insulin sensitivity was determined by homeostasis model assessment (HOMA). RESULTS: HRT had no negative influence on glucose metabolism. After 6 months of CEE treatment, there was a significant increase in high-density lipoprotein (HDL) cholesterol, but also in triglycerides, of 9.0% and 20.7%, respectively (p = 0.04). The levels of total cholesterol and low-density lipoprotein (LDL) cholesterol were unaffected. Transdermal estradiol did not affect the lipid profile. CONCLUSIONS: Hormone replacement therapy with either oral or transdermal estrogen plus micronized progesterone has no harmful influence on glucose metabolism in type 2 diabetic postmenopausal women; whether the increase in HDL cholesterol, but also in triglyceride levels, makes oral CEE the better choice remains an open question.