Reproducibility of bone mineral density measurements using dual X-ray absorptiometry in daily clinical practice

Bone mineral density (BMD) measurements are frequently performed repeatedly for each patient. Subsequent BMD measurements allow reproducibility to be assessed. Previous studies have suggested that reproducibility may be influenced by age and clinical status. The purpose of the study was to examine the reproducibility of BMD by dual energy X-ray absorptiometry (DXA) and to investigate the practical value of different measures of reproducibility in three distinct groups of subjects: healthy young volunteers, postmenopausal women and patients with chronic rheumatic diseases. Two hundred twenty-two subjects underwent two subsequent BMD measurements of the spine and hip. There were 60 young healthy subjects, 102 postmenopausal women and 60 patients with chronic rheumatic diseases (33 rheumatoid arthritis, 10 ankylosing spondylitis and 10 other systemic diseases). Forty-five patients (75%) among the third group were receiving corticosteroids. Reproducibility was expressed as the smallest detectable difference (SDD), coefficient of variation (CV), least significant change (LSC) and intraclass correlation coefficient (ICC). Sources of variation were investigated by linear regression analysis. The median interval between measurements was 0 days (range 0–7). The mean difference (SD) between the measurements (g/cm²) was –0.0001 (±0.003) and –0.0004 (±0.002) at L1-L4 and the total hip, respectively. At L1-L4 and the total hip, SDD (g/cm²) was ±0.04 and ±0.02, CV (%) was 2.02 and 1.29, and LSC (%) 5.60 and 3.56, respectively. The ICC at the spine and hip was 0.99 and 0.99, respectively. Only a minimal difference existed between the groups. Reproducibility in the three groups studied was good. In a repeated DXA scan, a BMD change, the least significant change (LSC) or the SDD should be regarded as significant. Use of the SDD is preferable to use of the CV and LSC because of its independence from BMD and its expression in absolute units. Expressed as SDD, a BMD change of at least ±0.04 g/cm² at L1-L4 and ±0.02 g/cm² at the total hip should be considered significant. This reproducibility seems independent from age and clinical status and improved in the hips by measuring the dual femur.     

Psychometric evaluation of a Moroccan version of health assessment questionnaire for use in Moroccan patients with rheumatoid arthritis

Objective of the study is to test the reliability and validity of a translated version of health assessment questionnaire (HAQ) on Moroccan patients with rheumatoid arthritis (RA). We led a prospective study from July 2004 to September 2005. A total of 100 Moroccan patients were recruited. After translation to dialect Arabic, back translation, expert committee review and pretesting of the questionnaire, it was administered to the selected patients and tested for construct validity, reliability and internal consistency. The construct validity was evaluated by correlating the yield of the questionnaire with other disease activity and severity parameters. The questionnaire was administered again after a time interval of between 2 and 10 days for evaluation of the reliability of this test. All the items were tested for their loyalty to the principal component. The adapted questionnaire showed a good internal consistency. Cronbach's alpha test was 0.994. The test-retest showed a strong reliability with a kappa test ranging from 0.70 to 0.92 for all domains. Intraclass correlation coefficient for the total score was 0.987. The Moroccan HAQ showed a strong validity. It correlates significantly with disease activity and severity parameters. The unidimentionality has been demonstrated. About 71.5% of all variabilities was accounted for by the first principal component. The Moroccan Arabic dialect version of HAQ is a reliable and valid instrument that can be self-administered by Moroccan RA patients to assess their functional disability.     

Genotypic Correlation Between Six Common β-Thalassemia Mutations and the XmnI Polymorphism in the Moroccan Population

β-Thalassemia (thal) is the most common recessive inherited disorder in Mediterranean populations. It is estimated that the frequency of this disease in the Moroccan population is between 1.5 and 3.0%. Severe forms of homozygous thalassemia cases require expensive and technically demanding curative (bone marrow transplantation) or palliative (chronic transfusion/chelation) therapies. The ?158 (C→T) polymorphism of the ^Gγ-globin gene (XmnI polymorphism) is known to ameliorate the severity of the disease because of it strong association with an increased production of fetal hemoglobin (Hb F). Among the many known mutations in Morocco, six are common [codon 39 (C→T), frameshift codon (FSC) 8 (?AA), IVS-II-745 (C→G), FSC 6 (?A), ?29 (A→G) and IVS-I-1 (G→A)]. In this study, we have investigated, in 82 Moroccan β-thalassemic chromosomes, the correlation between the six common mutations and the XmnI polymorphism using the Fisher exact test. The XmnI polymorphism was divided into two categories, (XmnI [+] and XmnI [?]) and the six common Moroccan mutations into two groups (group I with FSC 8 and group II without FSC 8). Correlation was carried out between the XmnI [+] category and the six common mutations individually that showed that 68% of chromosomes in the XmnI [+] category had the FSC 8 (?AA) mutation. The results reported here show that there is a positive correlation between the XmnI polymorphism and FSC 8 mutation in linkage with haplotype IV [? + ? + + ? +] (p <10^?5). In conclusion, molecular determination of genetic markers in early childhood will help to identify candidates for pharmacological Hb F switching by hydroxyurea (HU). In the Moroccan population, a good response to HU treatment should be suspected in cases with the ?158 (C→T) polymorphism in linkage with haplotype IV and internal β-globin gene framework 3.     

The Rare Codon 24 (T>A) (β+) Mutation in Association with the Common Codon 39 (C> T) (β0) Mutation Causes Transfusion-Dependent β-Thalassemia in a Moroccan Patient

We present the rare codon 24 (T?>?A) (β⁺) mutation causing transfusion-dependent β-thalassemia (β-thal) in combination with the common codon 39 (C?>?T) (β⁰) defect in a Moroccan boy. We report the characterization of the mutation, phenotype, haplotype and possible origin of the first case in Morocco and discuss the significance of this genotype combination with a β⁰ defect.     

Autonomic profile of patients with migraine]

OBJECT: Dysfunction of autonomic nervous system (ANS) is implicated in the genesis and persistence of migraine. The objective of this study was to compare autonomic nervous system (ANS) profile of migraineurs during headache-free periods to a group of normal subjects based on cardio-vascular reactivity. METHODS: Patients with migraine according to the criteria of IHS 2004 were selected for the study. After a 30 min resting blood pressure (BP), the following standard tests were performed: deep-breathing (DB), hand grip (HG) of 15 s and 3 min, valsalva maneuver, echo stress, (ES) and tilt test (TT). Results were compared to 44 normal subjects, age similar, 37 female, (84.1%) using the Student test, with P < 0.005 as significant. RESULTS: Thirty-two patients (27 female (84.38%), 16-51 years, mean 40.41 +/- 7.8) were studied. Twenty-two patients (69%) had systolic blood pressure below 94 mmHg and 25 patients (78%) had diastolic blood pressure below 60 mmHg. Compared to normal, migraineurs exhibited a significantly higher vagal response (P < 0.001) and a significantly lower alpha sympathetic response, central by using ES as well as peripheral by using HG of 3 min (P < 0.001). CONCLUSIONS: Autonomic cardiovascular reactivity of patients with migraine showed a vagal hyperactivity and a deficiency of the alpha sympathetic system. This leads to further studies with new therapeutical approaches.