Prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age: the HunMen Study

Summary

This study reports a high prevalence of hypovitaminosis D and low bone mineral density (BMD) in a healthy Hungarian male cohort over 50 years of age. Men with 25-hydroxyvitamin D levels of <75 nmol/L had a significantly higher 10-year hip and major osteoporotic fracture probability using the country-specific fracture risk assessment (FRAX) algorithm.

Introduction

The aim of this study is to characterize the prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age.

Methods

We determined levels of 25-hydroxyvitamin D (25-OH-D), PTH, osteocalcin (OC), C-terminal telopeptides of type-I collagen (CTX-I), procollagen type 1 amino-terminal propeptide (PINP), BMD at L1–L4 (LS) and femur neck (FN), daily dietary calcium intake, and the 10-year probability of hip fracture and a major osteoporotic fracture using the country-specific FRAX algorithm in 206 randomly selected ambulatory men.

Results

The mean (range) age of the volunteers was 60 (51–81) years. The prevalence of hypovitaminosis D (25-OH-D, <75 nmol/L) was 52.9%. The prevalence of low (T-score?<??1.0) BMD at the FN and LS was 45% and 35.4%, respectively. The mean (range) FRAX hip fracture and FRAX major osteoporotic fracture was 0.8% (0–9.4%) and 3.8% (1.7–16%), respectively. On comparing the vitamin D sufficient to the insufficient group, there was a statistically significant difference between the FRAX hip fracture and FRAX major osteoporotic fracture indexes. There was significant seasonal variation in the vitamin D levels; the lowest levels were measured in winter and the highest in summer.

Conclusions

A high prevalence of hypovitaminosis D and low BMD were observed in the studied Hungarian male population. This is the first study reporting higher 10-year hip and major osteoporotic fracture probability using the country-specific FRAX algorithm in individuals with hypovitaminosis D.     

Single acute stress-induced progesterone and ovariectomy alter cardiomyocyte contractile function in female rats

Aim

To assess how ovarian-derived sex hormones (in particular progesterone) modify the effects of single acute stress on the mechanical and biochemical properties of left ventricular cardiomyocytes in the rat.

Methods

Non-ovariectomized (control, n = 8) and ovariectomized (OVX, n = 8) female rats were kept under normal conditions or were exposed to stress (control-S, n = 8 and OVX-S, n = 8). Serum progesterone levels were measured using a chemiluminescent immunoassay. Left ventricular myocardial samples were used for isometric force measurements and protein analysis. Ca²⁺-dependent active force (F_active), Ca²⁺-independent passive force (F_passive), and Ca²⁺-sensitivity of force production were determined in single, mechanically isolated, permeabilized cardiomyocytes. Stress- and ovariectomy-induced alterations in myofilament proteins (myosin-binding protein C [MyBP-C], troponin I [TnI], and titin) were analyzed by sodium dodecyl sulfate gel electrophoresis using protein and phosphoprotein stainings.

Results

Serum progesterone levels were significantly increased in stressed rats (control-S, 35.6 ± 4.8 ng/mL and OVX-S, 21.9 ± 4.0 ng/mL) compared to control (10 ± 2.9 ng/mL) and OVX (2.8 ± 0.5 ng/mL) groups. F_active was higher in the OVX groups (OVX, 25.9 ± 3.4 kN/m² and OVX-S, 26.3 ± 3.0 kN/m²) than in control groups (control, 16.4 ± 1.2 kN/m² and control-S, 14.4 ± 0.9 kN/m²). Regarding the potential molecular mechanisms, F_active correlated with MyBP-C phosphorylation, while myofilament Ca²⁺-sensitivity inversely correlated with serum progesterone levels when the mean values were plotted for all animal groups. F_passive was unaffected by any treatment.Conclusion Stress increases ovary-independent synthesis and release of progesterone, which may regulate Ca²⁺-sensitivity of force production in left ventricular cardiomyocytes. Stress and female hormones differently alter Ca²⁺-dependent cardiomyocyte contractile force production, which may have pathophysiological importance during stress conditions affecting postmenopausal women.The relation between stress, gender, and cardiovascular diseases is well established (1-4). Some of the known risk factors for cardiovascular disease such as smoking, unhealthy diet, and behavioral and psychosocial stress have deleterious effects on the cardiovascular system via activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis (5-8). Acute restraint stress is a preferred and widely used method to induce physical stress in animal models (9). Moreover, restraint and immobilization are important as models for psychological stress, which was shown to adversely affect ovarian function (10) and to play a pivotal role in the pathomechmanism of Takotsubo (stress) cardiomyopathy in postmenopausal women (11).Gender is a very important factor in the development of cardiovascular diseases. Premenopausal women have better lipid profile, endothelial function (12), and a lower risk to develop coronary artery disease and myocardial infarction (MI) than men. These advantages of female gender, however, are abolished after menopause, which is associated with increased prevalence of left ventricular (LV) hypertrophy, decreased LV ejection fraction, and LV contractility (13). One of the explanations for the distinct myocardial responses is the cardioprotective effect of female sex hormones (eg, estrogens) (14,15).Progesterone performs several actions on the heart: it exerts an antiarrhythmic effect by accelerating cardiac repolarization (16) and has a preventive role in ischemia-reperfusion injury via reducing inflammatory response (17). It has been shown to inhibit cardiomyocyte apoptosis (18), induce vasodilation, and reduce blood pressure via increasing nitric oxide (NO) levels in normotensive and hypertensive patients (19). Importantly, progesterone is produced by the both ovaries and the adrenal gland: Moreover, the adrenal progesterone content is similar or even larger than that in the ovaries (20). Adrenal progesterone production and secretion increase along with corticosterone regardless of gender and estradiol under stress conditions (21). Progesterone, being an indirect precursor of cortisol (22), increases in response to adrenocorticotrophic hormone (ACTH) stimulation (23).In the heart, there are multiple estrogen hormone receptor types (24). The expression of aromatase in the heart suggests that estrogen may be synthesized also within the cardiomyocyte to exert autocrine/paracrine actions (25). Myocyte contractility seems to be modulated by systemic estrogen levels and altered in cardiomyocytes derived from ovariectomized (OVX) rats (26). In particular, myofilament Ca²⁺-sensitivity is increased in isolated myofibrillar preparations from OVX rats, and restored to the basal levels with estrogen supplementation (27,28).Activation of the sympathetic nervous system plays a central role in the regulation of cardiomyocyte contractile function and myofilament Ca²⁺-sensitivity through beta-adrenergic receptor stimulation, activating the protein kinase A (PKA). PKA-mediated phosphorylation of Ca²⁺-handling and myofilament proteins (myosin binding protein-C [MyBP-C], troponin I [TnI], titin) were shown to alter cardiomyocyte contractile function (29,30). It has been suggested that female cardiomyocytes operate at lower levels of intracellular Ca²⁺ than those of males, particularly under inotropic conditions (31). This difference in Ca²⁺ homeostasis may be related to the fact that estrogen suppresses the L-type Ca²⁺ current (32,33) and may reduce the amount of Ca²⁺ released from the sarcoplasmic reticulum (SR) (34), which was shown to be larger in myocytes from OVX rats (35). Not only cardiomyocyte contraction, but relaxation may also be affected by estrogen via altered Ca²⁺ re-uptake into the SR and modified Ca²⁺ efflux via increased sarcolemmal Na⁺/Ca²⁺ exchange (36). Interestingly, despite similar SR Ca²⁺ content in males and females (37), studies using OVX models report conflicting results concerning changes in the expression and activity of the SR Ca²⁺-ATPase and its regulator protein phospholamban (38-41). Much less is known about the possible effect of progesterone on cardiomyocyte contractile function. We hypothesized that progesterone affected force production of single isolated cardiomyocytes. Therefore, in the present study we aimed to investigate how sex hormones (particularly progesterone) and single acute restraint stress altered cardiomyocyte contractile function and to identify the consequent posttranslational myofilament protein modifications in OVX rats.     

Bone mineral density in women with systemic lupus erythematosus

The aim of this cross-sectional study was to determine the prevalence of reduced bone mineral density (BMD) in a group of female SLE patients and to identify factors predictive of reduced BMD. Femoral neck (FN) and lumbar spine (LS) dual-energy X-ray absorptiometry results were evaluated in 79 pre- and postmenopausal women with SLE aged (mean, range) 49 (22–73) years). Variables evaluated were disease duration, SLEDAI, current and cumulative corticosteroid dose, Steinbrocker’s functional classification, use of immunosuppressive agents, and history of fracture due to minor trauma. A T-score of ≤1.0 was found in 61.9% at the LS and 48.3% at the FN, and 18 (23.7%) patients belonged to the category of osteoporosis at LS, compared to only three (5.4%) patients at FN. A statistical difference (P= 0.014) was found when comparing LS BMD in pre- and postmenopausal patients. LS BMD had a significant correlation with daily and cumulative steroid dose (P= 0.016 and 0.031, respectively). There was a significant difference in LS BMD between the daily steroid dose group receiving ≤7.5 and those receiving >7.5 mg/day (P= 0.008), and also in FN BMD comparing groups on 0 and >7.5 mg/day (P= 0.022). There was significant difference in LS and FN BMD between patients in Steinbrocker classes I and III (P= 0.016 and 0.005, respectively). No significant correlation was found in either subgroup between BMD and other studied parameters. We concluded that the prevalence of reduced bone mass at LS is pronounced among postmenopausal women with SLE, in those with a high Steinbrocker functional classification and those on a high daily steroid dose. Therefore, these patients should be considered as a high-risk group deserving regular spinal BMD scans and therapy in time to prevent vertebral fractures. Received: 26 March 2000 / Accepted: 18 September 2001     

Prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in community dwelling postmenopausal Hungarian women

Hypovitaminosis D can result in low bone mass. The prevalence of hypovitaminosis D has public health implications, especially where data are lacking. Since diet and sunlight are the two souces of vitamin D, the results obtained in one geographical region may not be universally applicable. The aim of this study is to characterize the prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in community dwelling postmenopausal Hungarian women. We determined serum levels of 25-hydroxyvitamin D (25-OH-D), PTH, osteocalcin (OC), degradation products of C-terminal telopeptides of type-I collagen (CTx), dietary calcium intake and BMD at L2–L4 lumbar spine (LS) and femur neck (FN) in 319 randomly selected ambulatory postmenopausal women. The prevalence of hypovitaminosis D (serum 25-OH-D50 nmol/l) was 56.7%. On comparing patients with normal and low 25-OH-D, a significant difference was found in age (61.6±8.5 years versus 67.3±9.9 years; P<0.001), PTH (3.9±1.9 pmol/l versus 4.3±2.7 pmol/l; P<0.05), FN BMD (0.802±0.123 g/cm² versus 0.744±0.125 g/cm²; P<0.001) and dietary calcium intake (714.4±199.4 g/day versus 607.9±233 g/day; P<0.001). Osteoporotic patients had a significantly lower 25-OH-D (37.6±19.8 nmol/l versus 56.4±24 nmol/l; P<0.001) and dietary calcium intake (519.2±244.5 mg/day versus 718.2±164.3 mg/day; P<0.001). After controlling for all other variables, 25-OH-D was found to be significantly associated with age, the average hours of sunshine in the 3 months prior to 25-OH-D level determination and dietary calcium intake (r ²=0.190; P<0.001). For FN BMD, significant independent predictors were age, body mass index, 25-OH-D and dietary calcium intake (r ²=0.435; P<0.001). The prevalence of hypovitaminosis D during spring, summer, autumn and winter was 71%, 46.3%, 49.4% and 56.7%, respectively. There was significant seasonal variation in 25-OH-D, PTH, OC, calcium intake and FN BMD. There is a high prevalence of hypovitaminosis D in healthy postmenopausal Hungarian women, and FN BMD is associated with serum 25-OH-D and dietary calcium intake.     

A decade of experience with TCu200

This paper summarizes ten years of experience with 2766 interval insertions of the TCu200 device. One hundred and twenty months of use were completed by 572 patients and the cumulative woman-months of use were 159 664. For evaluating the overall performance, gross cumulative and yearly specific life-table termination and continuation rates were calculated as suggested by Tietze [2]. The cumulative pertinent rates at the end of the ten-year follow-up period were as follows: pregnancy 10.2; expulsion 6.3; bleeding/pain 32.3; and removal for other medical reasons 19.4. The gross annual rates for the same conditions at the end of the first year of use were: 1.8, 2.4, 4.2, and 2.0, while in the tenth year they were: 0.6, 0.1, 4.4, and 2.8, respectively. The continuation rate was 89.1 at the end of the 12th month and 33.2 at the end of the 10th year. Based on this evaluation, the TCu200 IUD has a good overall performance and a longer lifespan than was previously expected.     

Laser-induced plasma spectroscopy (LIPS): use of a geological tool in assessing bone mineral content

Bone may be similar to geological formulations in many ways. Therefore, it may be logical to apply laser-based geological techniques in bone research. The mineral and element oxide composition of bioapatite can be estimated by mathematical models. Laser-induced plasma spectrometry (LIPS) has long been used in geology. This method may provide a possibility to determine the composition and concentration of element oxides forming the inorganic part of bones. In this study, we wished to standardize the LIPS technique and use mathematical calculations and models in order to determine CaO distribution and bone homogeneity using bovine shin bone samples. We used polished slices of five bovine shin bones. A portable LIPS instrument using high-power Nd++YAG laser pulses has been developed (OpLab, Budapest). Analysis of CaO distribution was carried out in a 10?×?10 sampling matrix applying 300-μm sampling intervals. We assessed both cortical and trabecular bone areas. Regions of interest (ROI) were determined under microscope. CaO peaks were identified in the 200–500 nm wavelength range. A mathematical formula was used to calculate the element oxide composition (wt%) of inorganic bone. We also applied two accepted mathematical approaches, the Bartlett’s test and frequency distribution curve-based analysis, to determine the homogeneity of CaO distribution in bones. We were able to standardize the LIPS technique for bone research. CaO concentrations in the cortical and trabecular regions of B1–5 bones were 33.11?±?3.99% (range 24.02–40.43%) and 27.60?±?7.44% (range 3.58–39.51%), respectively. CaO concentrations highly corresponded to those routinely determined by ICP-OES. We were able to graphically demonstrate CaO distribution in both 2D and 3D. We also determined possible interrelations between laser-induced craters and bone structure units, which may reflect the bone structure and may influence the heterogeneity of CaO distributions. By using two different statistical methods, we could confirm if bone samples were homogeneous or not with respect to CaO concentration distribution. LIPS, a technique previously used in geology, may be included in bone research. Assessment of element oxide concentrations in the inorganic part of bone, as well as mathematical calculations may be useful to determine the content of CaO and other element oxides in bone, further analyze bone structure and homogeneity and possibly apply this research to normal, as well as diseased bones.     

Investigation of Thr715Pro P-selectin gene polymorphism and soluble P-selectin levels in type 2 diabetes mellitus

Increased levels of soluble P-selectin (sP-selectin) have been shown in a number of different disorders, e.g. diabetes mellitus (DM) and cardiovascular disease (CVD). Several studies have attempted to demonstrate the association of the most intensively examined variant of P-selectin gene polymorphism (Thr715Pro) with sP-selectin levels in healthy subjects and in CVD, but contradictory data have been reported. To clarify the effect of Pro715 allele on the sP-selectin levels in type 2 DM, we analysed this polymorphism in diabetic patients and compared these data with sP-selectin levels. Type 2 DM patients (n = 119), 48 BMImatched non diabetic individuals - consisting mostly of overweight subjects - and 57 healthy volunteers were included in the study. TheThr715Pro polymorphism was analysed by PCR-RFLP, while sP-selectin levels were measured by ELISA. Significantly elevated sP-selectin levels were found in both DM and in overweight subjects compared to healthy controls. We confirmed previous reports that in healthy Pro715 allele carriers lower sPselectin levels could be measured; however, this difference was only significant in case of lean subjects. No significant difference was detected in sP-selectin level among DM and overweight individuals according to this genotype. However, significant difference was observed in sP-selectin levels in older DM patients compared to younger ones, but these levels were not accounted for by the Thr715Pro polymorphism. We suggest that in type 2 DM individuals, the significantly elevated sP-selectin levels are not due to the Thr715Pro P-selectin gene polymorphism.     

Analytical Performance Specifications for 25-Hydroxyvitamin D Examinations

Currently the 25-hydroxy vitamin D (25(OH)D) concentration is thought to be the best estimate of the vitamin D status of an individual. Unfortunately, its measurement remains complex, despite recent technological advances. We evaluated the biological variation (BV) of 25(OH)D in order to set analytical performance specifications (APS) for measurement uncertainty (MU). Six European laboratories recruited 91 healthy participants. The 25(OH)D concentrations in K₃-EDTA plasma were examined weekly for up to 10 weeks in duplicate on a Lumipulse G1200 (Fujirebio, Tokyo, Japan). The linear regression of the mean 25(OH)D concentrations at each blood collection showed that participants were not in a steady state. The dissection of the 10-sample collection into two subsets, namely collections 1–5 and 6–10, did not allow for correction of the lack of homogeneity: estimates of the within-subject BV ranged from 5.8% to 7.1% and the between-subject BV ranged from 25.0% to 39.2%. Methods that would differentiate a difference induced by 25(OH)D supplementation at p < 0.05 should have MU < 13.6%, while at p < 0.01, the MU should be <9.6%. The development of APS using BV assumes a steady state of patients. The findings in this study suggest that patients are not in steady state. Therefore, APS that are based on MU appear to be more appropriate.     

Pre-malignant and malignant cervical pathologies among inert and copper-bearing intrauterine contraceptive device users: a 10-year follow-up study.

OBJECTIVES: The aim of the study was to compare the incidence of pre-malignant and malignant cervical conditions during a period of 10 years of use of inert (Szontagh) and copper-bearing IUCDs. METHODS: Candidates were parous women requesting intrauterine contraception regardless of the previous IUCD use and having no contraindications. Follow-ups were scheduled at 1, 6, and 12 months after insertion, and annually thereafter. Colposcopy and cytological evaluation were performed at insertion and at yearly follow-ups. For comparison of the two groups and the different follow-up periods (at the end of each ordinal year), net and gross cumulative lifetable rates were calculated. Statistical differences were measured by chi-squared test, and were regarded as significant at P 相似文献   

Analysis of risk factors for the development of thrombotic complications in antiphospholipid antibody positive lupus patients

The objective of this study was to characterize risk factors for thrombotic events in lupus patients. A total of 272 lupus patients were followed up for five years during which the presence of aPL antibodies [anticardiolipin (aCL), anti-beta2-glycoprotein I (abeta2GPI) and lupus anticoagulant (LAC)] were determined, and all thrombotic incidents and antithrombotic therapy-related data were collected. At baseline, three groups were constituted, an aPL- group with 107 aPL negative patients, an aPL+ group with 81 aPL positive patients without clinical thrombosis and a secondary antiphospholipid syndrome (APS) group with 84 aPL+ patients who met the Sapporo criteria. LAC was more common in the APS than the aPL+ group (32.1% versus 9.9%, P < 0.001). The prevalence of clinical thrombotic events was significantly higher when all three types of aPL were present compared to only aCL positive cases. During follow up, aPL appeared in 7.5% of the aPL- group, and 2.8% of this group had thrombotic complications. In the aPL+ group, thrombotic events reoccurred in 1.9% of those receiving antithrombotic prophylaxis and 6.9% of those without primary prophylaxis. Despite anticoagulant therapy, thrombotic events reoccurred in 8.3% of the APS group. These findings indicate that LAC, constant and cumulative presence of aPL and previous thrombosis are positive predictors for the development of thrombotic complication in lupus patients.