Relationship between trabecular bone score, bone mineral density and vertebral fractures in patients with axial spondyloarthritis.

BACKGROUND: In patients with axial spondyloarthritis, vertebral fracture risk is elevated and not always correlated with bone mineral density (BMD). Trabecular bone score (TBS) may offer some advantages in the assessment of vertebral fracture risk in these patients. The primary objective of this study was to compare TBS and BMD between axial spondyloarthritis patients depending on their vertebral fracture status. Secondary objectives were to estimate the prevalence of morphometric vertebral fractures, and to explore factors associated with fracture, as well as the interference of syndesmophytes on BMD and TBS. METHODS: A cross-sectional study was conducted. Data were collected on demographic and clinical characteristics, lab results, imaging findings and treatment. Statistical analysis was performed using SPSS v.13 statistical software. RESULTS: Eighty-four patients (60 men and 24 women; mean age of 59 years) were included. Nearly half (47.6%) of them had lumbar syndesmophytes. The rate of morphometric fracture was 11.9%. TBS showed a higher area under the curve (0.89) than total hip, femoral neck and lumbar BMD (0.80, 0.78, and 0.70 respectively) for classifying patients regarding their fracture status. Nonetheless, the differences did not reach statistical significance. Syndesmophytes affected lumbar spine BMD (p < 0.001), but not hip BMD or TBS. Fractures were associated with TBS, total hip BMD, erythrocyte sedimentation rate and C-reactive protein levels. CONCLUSIONS: We identified decreased TBS and total hip BMD, as well as increased erythrocyte sedimentation rate and C-reactive protein levels as factors associated with morphometric vertebral fractures. Unlike lumbar spine BMD, TBS is not affected by the presence of syndesmophytes.

Genetic diversity of HLA system in two populations from Campeche, Mexico: Campeche city and rural Campeche.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 81 Mexicans from the state of Campeche living in the city of Campeche (N = 34) and rural communities (N = 47), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Campeche include ten Native American, three European, one African and one Asian haplotype. Admixture estimates revealed that the main genetic components in the state of Campeche are Native American (65.56 ±â€¯0.96% by ML; 51.24% of Native American haplotypes), European (34.44 ±â€¯10.94% by ML; 30.25% of European haplotypes), and a virtually absent African genetic component (0.00 ±â€¯10.31% by ML; 9.26% of African haplotypes).

Genetic diversity of HLA system in two populations from Tabasco, Mexico: Villahermosa and rural Tabasco.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 224 Mexicans from the state of Tabasco living in the city of Villahermosa (N = 82) and rural communities (N = 142), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in Tabasco include 13 Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in Tabasco are Native American (67.79 ±â€¯1.59% by ML; 56.25% of Native American haplotypes) and European (27.21 ±â€¯3.97% by ML; 29.91% of European haplotypes), and a less prominent African genetic component (5.01 ±â€¯4.42% by ML; 8.93% of African haplotypes).

Genetic diversity of HLA system in two populations from Chiapas, Mexico: Tuxtla Gutiérrez and rural Chiapas.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 173 Mexicans from the state of Chiapas living in the city of Tuxtla Gutiérrez (N = 52) and rural communities (N = 121), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in Chiapas include 12 Native American and one European haplotype. Admixture estimates revealed that the main genetic components in Chiapas are Native American (71.61 ±â€¯0.58% by ML; 53.16% of Native American haplotypes) and European (26.39 ±â€¯5.05% by ML; 25.86% of European haplotypes), and a less prominent African genetic component (2.00 ±â€¯5.20% by ML; 9.77% of African haplotypes).

Genetic diversity of HLA system in seven populations from Veracruz, Mexico: Veracruz city, Coatzacoalcos, Córdoba, Orizaba, Poza Rica, Xalapa and rural Veracruz.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 1113 Mexicans from the state of Veracruz living in the cities of Coatzacoalcos (N = 55), Orizaba (N = 60), Córdoba (N = 56), Poza Rica (N = 45), Veracruz (N = 171), Xalapa (N = 187) and rural communities (N = 539) to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes include 12 Native American haplotypes. Admixture estimates revealed that the main genetic components are Native American (64.93 ±â€¯1.27% by ML; 55.10% of Native American haplotypes) and European (26.56 ±â€¯0.89% by ML; 28.38% of European haplotypes), and a relatively high African genetic component (8.52 ±â€¯1.82% by ML; 8.78% of African haplotypes).

Genetic diversity of HLA system in two populations from Morelos, Mexico: Cuernavaca and rural Morelos.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 112 Mexicans from the state of Morelos living in the city of Cuernavaca (N = 82) and rural communities (N = 30), to obtain information regarding allelic and haplotypic frequencies. The most frequent haplotypes in Morelos include seven Native American, one European, one African and one Asian haplotype. Admixture estimates revealed that the main genetic components in Morelos are Native American (60.43 ±â€¯2.22% by ML; 53.57% of Native American haplotypes) and European (39.58 ±â€¯3.70% by ML; 27.68% of European haplotypes), and a virtually absent African genetic component (0.00 ±â€¯4.93% by ML; but 11.16% of African haplotypes).

Genetic diversity of HLA system in a population from Guerrero, Mexico.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 144 Mexicans from the state of Guerrero to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes in the state of Guerrero include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Guerrero are Native American (61.36 ±â€¯2.69% by ML; 54.17% of Native American haplotypes) and European (35.01 ±â€¯4.59% by ML; 32.29% of European haplotypes), and a relatively low African genetic component (3.63 ±â€¯2.38% by ML; 5.90% of African haplotypes).

Genetic diversity of HLA system in two populations from Querétaro, Mexico: Querétaro city and rural Querétaro.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 88 Mexicans from the state of Querétaro living in the city of Querétaro (N = 45) and rural communities (N = 43), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Querétaro include seven Native American, two European and one Asian haplotype. Admixture estimates revealed that the main genetic components in the state of Querétaro are Native American (51.82 ±â€¯4.42% by ML; 42.61% of Native American haplotypes) and European (48.18 ±â€¯3.55% by ML; 46.02% of European haplotypes), with a virtually absent African genetic component (0.00 ±â€¯4.25% by ML; 4.55% of African haplotypes).

Genetic diversity of HLA system in two populations from Hidalgo, Mexico: Pachuca and rural Hidalgo.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 122 Mexicans from the state of Hidalgo living in the city of Pachuca (N = 41) and rural communities (N = 81), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in Hidalgo include eight Native American and one European haplotypes. Admixture estimates revealed that the main genetic components in Hidalgo are Native American (58.93 ±â€¯2.16% by ML; 54.51% of Native American haplotypes) and European (32.49 ±â€¯2.88% by ML; 28.69% of European haplotypes), and a relatively high African genetic component (8.58 ±â€¯0.93% by ML; 6.97% of African haplotypes).

Genetic diversity of HLA system in six populations from Mexico City Metropolitan Area, Mexico: Mexico City North, Mexico City South, Mexico City East, Mexico City West, Mexico City Center and rural Mexico City.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 1217 Mexicans from the Mexico City Metropolitan Area living in the northern (N = 751), southern (N = 52), eastern (N = 79), western (N = 33), and central (N = 152) Mexico City, and rural communities (N = 150), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes include 11 Native American haplotypes. Admixture estimates revealed that the main genetic components are Native American (63.85 ±â€¯1.55% by ML; 57.19% of Native American haplotypes) and European (28.53 ±â€¯3.13% by ML; 28.40% of European haplotypes), and a less apparent African genetic component (7.61 ±â€¯1.96% by ML; 7.17% of African haplotypes).

The immunogenetic diversity of the HLA system in Mexico correlates with underlying population genetic structure.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) allele groups and alleles by PCR-SSP based typing in a total of 15,318 mixed ancestry Mexicans from all the states of the country divided into 78 sample sets, providing information regarding allelic and haplotypic frequencies and their linkage disequilibrium, as well as admixture estimates and genetic substructure. We identified the presence of 4268 unique HLA extended haplotypes across Mexico and find that the ten most frequent (HF > 1%) HLA haplotypes with significant linkage disequilibrium (Δ'≥0.1) in Mexico (accounting for 20% of the haplotypic diversity of the country) are of primarily Native American ancestry (A*02~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*08~DQB1*04, A*68~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*14~DQB1*03:01, A*24~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*04~DQB1*03:02, A*02~B*40:02~DRB1*04~DQB1*03:02, A*68~B*35~DRB1*04~DQB1*03:02, A*02~B*15:01~DRB1*04~DQB1*03:02). Admixture estimates obtained by a maximum likelihood method using HLA-A/-B/-DRB1 as genetic estimators revealed that the main genetic components in Mexico as a whole are Native American (ranging from 37.8% in the northern part of the country to 81.5% in the southeastern region) and European (ranging from 11.5% in the southeast to 62.6% in northern Mexico). African admixture ranged from 0.0 to 12.7% not following any specific pattern. We were able to detect three major immunogenetic clusters correlating with genetic diversity and differential admixture within Mexico: North, Central and Southeast, which is in accordance with previous reports using genome-wide data. Our findings provide insights into the population immunogenetic substructure of the whole country and add to the knowledge of mixed ancestry Latin American population genetics, important for disease association studies, detection of demographic signatures on population variation and improved allocation of public health resources.

[Validity and reliability of the sense of coherence scale among nursing undergraduate students from a Spanish university]. / Validez y confiabilidad de la escala de sentido de coherencia en estudiantes de grado de enfermería de una universidad española.

OBJECTIVE: To analyze the factor structure of the OLQ-13 scale and to study the direct relationship between sense of coherence and lifestyles in university students of nursing. METHOD: Cross-sectional study. LOCATION: University of Jaén. Andalusia, Spain. PARTICIPANTS: 384 students from the first three years of the nursing degree in the University of Jaén. MAIN MEASUREMENT: Internal consistency was studied by Cronbach's alpha, reliability test-retest was measured by intraclass coefficient correlation (ICC) and construct validity was analysed by exploratory factor analysis, confirmatory factor analysis and known-groups technique. RESULTS: The internal consistency of the scale was adequate (Cronbach α = 0.809). The ICC for the reliability test-retest was 0.91. The exploratory factor analysis showed 3 factors explaining 50.13% of the variance. The confirmatory factor analysis showed f goodness-of-fit indexes for the proposed model CFI=0.965; RMSA=0.041; GFI=0.963; SRMR=0.041. Statistically significant differences in sense of coherence were found among the subgroups of students with healthy and unhealthy lifestyles (p <0.001). CONCLUSIONS: The study confirms the multidimensionality of the OLQ-13 scale, in which 3 factors were identified: external meaningful, comprehensibility and manageability, and internal comprehensibility and manageability. The OLQ-13 may be a valid and reliable scale for use in the Spanish university population.

The population-based prevalence of osteoporotic vertebral fracture and densitometric osteoporosis in postmenopausal women over 50 in Valencia, Spain (the FRAVO study).

PURPOSE: To estimate the prevalence of vertebral fracture and densitometric osteoporosis in postmenopausal women over the age of 50 in Valencia, Spain. METHODS: This cross-sectional study was conducted in 2006-2007. An age-stratified population-based random sample of 824 postmenopausal women over the age of 50 answered a questionnaire and received a densitometric examination of the lumbar spine and hip with dual-energy X-ray absorptiometry and a lateral X-ray of the thoracic spine and lumbar regions. Osteoporosis was defined as a T-score less than or equal to -2.5 compared to a population of young women, and the presence of vertebral fractures was classified according to Genant's semiquantitative method. RESULTS: The average age of the women was 64 years (range 50-87 years). The prevalence for all vertebral fractures was 21.4% (95% CI: 17.7%-25.1%) and 9.7% (95% CI: 6.7%-12.7%) for moderate-severe fractures. In women over the age of 75, the respective values were 46.3% (95% CI: 34.2%-58.3%) and 23.9% (95% CI:13.6%-34.2%). Only 1.5% of the women with vertebral fractures were aware of their condition. The prevalence of osteoporosis was estimated as 27.0% (95% CI:23.1%-30.8%) for the lumbar spine, 15.1% (95% CI:11.7%-18.5%) in the femoral neck, and 31.8% (95% CI:27.8%-35.7%) at either sites. CONCLUSIONS: The study confirms that osteoporosis (1 in 3 women over the age of 50) and vertebral fracture (1 in 5 for all fractures and 1 in 10 for moderate-severe fractures) constitute a major public health and healthcare challenge; measuring their real impact will depend in part on the criteria used to define a fracture.