Abstract：
BACKGROUND:Whether low plasma 25-hydroxyvitamin D concentrations cause osteoporotic fractures is unclear. We tested the hypothesis that low plasma 25-hydroxyvitamin D concentrations are associated with increased risk of osteoporotic fractures using a Mendelian randomization analysis. METHODS:We genotyped 116 335 randomly chosen white Danish persons aged 20-100 years in 2 population-based cohort studies for plasma 25-hydroxyvitamin D decreasing genotypes in CYP2R1 (rs117913124 and rs12794714), DHCR7 (rs7944926 and rs11234027), GEMIN2 (rs2277458), and HAL (rs3819817); 35 833 had information on plasma 25-hydroxyvitamin D. We assessed risk of total, osteoporotic, and anatomically localized fractures from 1981 through 2017. Information on fractures and vital status was obtained from nationwide registries. RESULTS:During up to 36 years of follow-up, we observed 17 820 total fractures, 10 861 osteoporotic fractures, and 3472 fractures of hip or femur. Compared with individuals with 25-hydroxyvitamin D ≥ 50nmol/L, multivariable adjusted hazard ratios (95% CIs) for total fractures were 1.03 (0.97-1.09) for individuals with 25-49.9 nmol/L, 1.19 (1.10-1.28) for individuals with 12.5-24.9 nmol/L, and 1.39 (1.21-1.60) for individuals with 25-hydroxyvitamin D < 12.5 nmol/L. Corresponding hazard ratios were 1.07 (1.00-1.15), 1.25 (1.13-1.37), and 1.49 (1.25-1.77) for osteoporotic fractures and 1.09 (0.98-1.22), 1.37 (1.18-1.57), and 1.41 (1.09-1.81) for fractures of hip or femur, respectively. Hazard ratios per 1 increase in vitamin D allele score, corresponding to 3.0% (approximately 1.6 nmol/L) lower 25-hydroxyvitamin D concentrations, were 0.99 (0.98-1.00) for total fractures, 0.99 (0.97-1.00) for osteoporotic fractures, and 0.98 (0.95-1.00) for fractures of hip or femur. CONCLUSIONS:Low plasma 25-hydroxyvitamin D concentrations were associated with osteoporotic fractures; however, Mendelian randomization analysis provided no evidence supporting a causal role for vitamin D in the risk for osteoporotic fractures.
journal_name
Clin Chemjournal_title
Clinical chemistryauthors
Çolak Y,Afzal S,Nordestgaard BGdoi
10.1093/clinchem/hvaa049subject
Has Abstractpub_date
2020-05-01 00:00:00pages
676-685issue
5eissn
0009-9147issn
1530-8561pii
5814346journal_volume
66pub_type
杂志文章abstract：:We have developed an HPLC method for measuring carbamylated hemoglobin (CarHb), based on the quantification of valine hydantoin formed from the released NH2-terminal carbamyl valine residue after acid hydrolysis of hemoglobin. In uremia, CarHb is produced by nonenzymatic post-translational modification of the terminal...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1990-04-01 00:00:00
abstract：BACKGROUND:Insulin, growth hormone (GH), and growth factors (insulin-like growth factors [IGFs] and their binding proteins [IGFBPs]) are known to influence fetal growth and also the synthesis/secretion of the recently discovered hormones leptin and ghrelin. METHODS:In 153 delivering mothers and their offspring at birt...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2007.095299
更新日期：2008-03-01 00:00:00
abstract：:Unsaturated cobalamin-binding capacity in plasma (P-UBBC) is determined by use of a silica gel (QUSO G32) to separate haptocorrin (P-ApoHC) and transcobalamin (P-ApoTC). The method is sensitive and precise: detection limit 13 pmol/L, interassay coefficients of variation 3% for P-UBBC (mean = 1080 pmol/L), 4% for P-Apo...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-07-01 00:00:00
abstract：:To evaluate their potential usefulness in the differential diagnosis of Cushing's syndrome, we estimated the urinary excretion rates of the following non-metabolized, unbound steroid hormones: pregnenolone, progesterone, 17-OH-pregnenolone, 17-OH-progesterone, dehydroepiandrosterone (DHEA), androstenedione, testostero...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1986-01-01 00:00:00
abstract：:We describe modifications to two cartridges, those for alkaline phosphatase and creatinine, on an 18-channel SMAC (Sequential Multichannel Analyzer Computerized), which allow all 18 tests to be run with a commonly prediluted sample. This decreases the required sample size and eliminates the problem of fibrin clots in ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-05-01 00:00:00
abstract：:Circulating prostate cells can be detected in cancer patients by using reverse transcriptase-PCR (RT-PCR) assay for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) mRNA. A quality-control study involving a conventional RT-PCR assay was performed and, surprisingly, detected both transcripts...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1998-03-01 00:00:00
abstract：BACKGROUND:Current noninvasive assays for urothelial carcinoma (UC) lack clinical sensitivity and specificity. Given the utility of plasma cell-free DNA (cfDNA) biomarkers, the development of urinary cfDNA biomarkers may improve the diagnostic sensitivity. METHODS:We assessed copy number alterations (CNAs) by shallow ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2019.309633
更新日期：2020-01-01 00:00:00
abstract：:This rapid radioimmunoassay for aldosterone is performed directly on 100 microL of unprocessed plasma, with 125I-labeled aldosterone as the labeled antigen. Our use of steroid-free plasma in preparing the standard curve resulted in an overestimate of aldosterone; this problem was overcome by adding to such plasma a mi...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1983-02-01 00:00:00
abstract：:Estrogen receptor (ER) and progestin receptor (PR) concentrations in tumor biopsies are important predictive indicators of a clinical response to endocrine therapy of breast cancer. To assess interference of O.C.T. (optimum cutting temperature) embedding compound in assays of ER and PR by radioligand binding, we deter...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1989-12-01 00:00:00
abstract：:We examined the comparative behavior of subject-specific multivariate and univariate reference regions, using both computer-generated data and serial (semi-annual) measurements of selected analytes in subjects from a large health-maintenance program. Univariate studies under both homeostatic and random-walk time-serie...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-03-01 00:00:00
abstract：:Lactate dehydrogenase (LD) isoenzymes 1 and 2 in human serum were separated on a column of diethylaminoethyl-Sephadex. Samples layered on mini-columns were eluted with buffered sodium chloride (100, 150, and 200 mmol/liter). Lactate dehydrogenase activity in column effluents was measured by the Wacker method, and thei...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-03-01 00:00:00
abstract：BACKGROUND:Although microRNAs (miRNAs) play essential roles in spermatogenesis, little is known about seminal plasma miRNAs in infertile men. We investigated the profile of seminal plasma miRNAs in infertile men to identify miRNAs that are altered in infertility; we then evaluated their diagnostic value. METHODS:Semin...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2011.169714
更新日期：2011-12-01 00:00:00
abstract：BACKGROUND:The fibroblast growth factor (FGF) and FGF receptor (FGFR) axis plays a critical role in tumorigenesis, but little is known of its influence in ovarian cancer. We sought to determine the association of genetic variants in the FGF pathway with risk, therapeutic response, and survival of patients with ovarian ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2013.211490
更新日期：2014-01-01 00:00:00
abstract：BACKGROUND:Mutations in the retina-specific ABC transporter (ABCA4) gene have been associated with several forms of macular degenerations. Because the high complexity of the molecular genotype makes scanning of the ABCA4 gene cumbersome, we describe here the first use of denaturing HPLC (DHPLC) to screen for ABCA4 muta...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.033241
更新日期：2004-08-01 00:00:00
abstract：BACKGROUND:The applicability of microarray-based transcriptome massive analysis is often limited by the need for large amounts of high-quality RNA. RNA arbitrarily primed PCR (RAP-PCR) is an unbiased fingerprinting PCR technique that reduces both the amount of initial material needed and the complexity of the transcrip...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2004.036236
更新日期：2005-01-01 00:00:00
abstract：BACKGROUND:Meconium analysis is a diagnostically sensitive and objective alternative to maternal self-report for detecting prenatal tobacco exposure. Nicotine and metabolite disposition in meconium is poorly characterized, and correlation of analytes' concentrations with neonatal outcomes is unexplored. Our objectives ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.109173
更新日期：2008-12-01 00:00:00
abstract：BACKGROUND:The B-type natriuretic peptides (BNP and N-terminal pro-BNP) are secreted by the heart and, in the case of BNP, serve to maintain circulatory homeostasis through renal and vascular actions and oppose many effects of the renin-angiotensin system. Recent evidence suggests that in patients with severe heart fai...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2013.210435
更新日期：2014-03-01 00:00:00
abstract：BACKGROUND:Serial measurements of neurohormones have been shown to improve prognostication in the setting of acute heart failure (HF) or chronic HF without therapeutic intervention. We investigated the prognostic role of serial measurements of emerging neurohormones and BNP in a cohort of chronic HF patients undergoing...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2009.125856
更新日期：2010-01-01 00:00:00
abstract：:This enzyme immunoassay detects adenosine deaminase binding protein (ABP), a glycoprotein that is shed from the brush border of the proximal tubule in kidney damage. Two monoclonal antibodies, URO-4 and URO-4a, each react with different epitopes on ABP and are used as the "sandwich" pair of antibodies. A linear standa...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1985-05-01 00:00:00
abstract：:We developed an automated method for measurement of alpha-amylase isoenzymes in serum by a single kinetic assay (SKA) and a double kinetic assay (DKA) with 2-chloro-4-nitrophenyl-6(5)-azido-6(5)-deoxy-beta-maltopentaoside as a substrate and 6(3)-deoxymaltotriose (DOG3) as a novel selective amylase inhibitor. DOG3 show...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-04-01 00:00:00
abstract：:This time-resolved immunofluorometric assay (IFMA) developed for measurement of placental protein 5 (PP5) involves two antibodies: a monoclonal anti-PP5 antibody attached to a solid phase and an europium(III) chelate-labeled polyclonal anti-PP5 antibody as a tracer. The measuring range is 0.05-100 micrograms/L and the...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1988-08-01 00:00:00
abstract：:9-(2-Phosphonylmethoxyethyl)adenine (PMEA), (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA), and (R,S)-9-(3-fluoro-2-phosphonylmethoxypropyl)adenine (FPMPA) are selective antiviral agents with activity against a broad spectrum of DNA viruses and retroviruses. A highly sensitive method has been developed to ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1992-04-01 00:00:00
abstract：:Each of 65 laboratories analyzed 10 whole-blood samples for erythrocyte protoporphyrin by one or more of several analytical procedures. These procedures were of two types: (a) extraction of protoporphyrin from the erythrocytes into ethyl acetate/acetic acid, re-extraction into hydrochloric acid, and fluorometric measu...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1978-12-01 00:00:00
abstract：:We describe a mechanized chromogenic assay for factor X, the results of which correlate well with those for the one-stage clotting assays for factor X in which it is activated either via the extrinsic pathway by thromboplastin or directly by Russell's viper venom. We purified human factor X and raised monospecific ant...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1980-06-01 00:00:00
abstract：BACKGROUND:Increased plasma lipoprotein(a) [Lp(a)] concentrations have been reported to be an independent risk factor for coronary heart disease (CHD) in some prospective studies, but not in others. These inconsistencies may relate to a lack of standardization and the failure of some immunoassays to measure all apolipo...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1999-07-01 00:00:00
abstract：:Using 123 specimens, we compared the concordance of three different methods for determining glycohemoglobin (GHb): the Diamat (Bio-Rad Laboratories), an automated analyzer measuring HbA1c by cation-exchange chromatography; an assay with the IMx analyzer (Abbott Laboratories), based on boronate affinity binding; and an...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1995-02-01 00:00:00
abstract：:We followed the "abbreviated precision protocol" of the National Committee for Clinical Laboratory Standards for the evaluation of precision, accuracy, and carryover in analyses for glucose with the "Ektachem." We analyzed 760 clinical samples by this technique, by the FDA Proposed Class Standard glucose reference met...
journal_title：Clinical chemistry
pub_type： 临床试验,杂志文章
doi：
更新日期：1981-01-01 00:00:00
abstract：BACKGROUND:Adiponectin is an adipocyte-derived hormone circulating in different multimer complexes. The high-molecular-weight (HMW) complex is likely the active form of this protein and has been recognized as a risk marker for type 2 diabetes and coronary artery disease (CAD). Because quantification of HMW adiponectin ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：10.1373/clinchem.2008.112425
更新日期：2009-03-01 00:00:00
abstract：:The isoenzymes of lactate dehydrogenase (EC 1.1.1.27) were separated with excellent resolution in less than 1 h by high-pressure anion-exchange chromatography. These isoenzymes were determined in some tissue extracts and high-activity serum samples by this technique. ...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1976-04-01 00:00:00
abstract：:We compared three radioligands for use in a cytoplasmic estrogen-receptor assay, using pooled cytosol from human breast adenocarcinomas. The estrogen receptor content was determined in vitro by a dextran-coated charcoal method involving a 4-h incubation with and without diethylstilbestrol. Tritiated moxestrol failed t...
journal_title：Clinical chemistry
pub_type： 杂志文章
doi：
更新日期：1982-03-01 00:00:00
