Parental TB associated with offspring asthma and rhinitis.

BACKGROUND: Infections in early life are associated with asthma and allergies in one-generation settings; however, the link between parental infection and offspring phenotype is rarely investigated. We aim to study the association of parental TB before conception of the offspring with offspring asthma and rhinitis.METHODS: We included 2,965 offspring born in 1985-2004 and registered in the Norwegian prescription database to 1,790 parents born after 1960 with a history of TB, and included in the Norwegian TB registry. Offspring asthma (n = 582) and rhinitis (n = 929) were defined based on diagnosis, type of medication and prescribed medication ≥1 year. Associations of parental TB <8 years, ≥8 years but before offspring´s birth year and after birth (reference category) with offspring asthma and rhinitis were analysed using logistic regression.RESULTS: Asthma risk was higher in persons with parental TB in childhood (OR 1.73, 95% CI 1.20-2.50) or later preconception (OR 1.38, 95% CI 1.00-1.91) than in persons with parental TB after offspring´s birth; this was significant only in the maternal line (childhood: OR 1.95, 95% CI 1.13-3.37; later preconception: OR 1.74, 95% CI 1.08-2.80). Associations with rhinitis were not identified.CONCLUSIONS: Parental childhood TB was associated with higher asthma risk in future offspring. We speculate that TB impacts maternal immunity and dysregulates the offspring´s type 2 immunity, and that TB-induced epigenetic reprograming of immune defences are transferred to the offspring.

Measurement of cortical porosity of the proximal femur improves identification of women with nonvertebral fragility fractures.

UNLABELLED: We tested whether cortical porosity of the proximal femur measured using StrAx1.0 software provides additional information to areal bone mineral density (aBMD) or Fracture Risk Assessment Tool (FRAX) in differentiating women with and without fracture. Porosity was associated with fracture independent of aBMD and FRAX and identified additional women with fractures than by osteoporosis or FRAX thresholds. INTRODUCTION: Neither aBMD nor the FRAX captures cortical porosity, a major determinant of bone strength. We therefore tested whether combining porosity with aBMD or FRAX improves identification of women with fractures. METHODS: We quantified femoral neck (FN) aBMD using dual-energy X-ray absorptiometry, FRAX score, and femoral subtrochanteric cortical porosity using StrAx1.0 software in 211 postmenopausal women aged 54-94 years with nonvertebral fractures and 232 controls in Tromsø, Norway. Odds ratios (ORs) were calculated using logistic regression analysis. RESULTS: Women with fractures had lower FN aBMD, higher FRAX score, and higher cortical porosity than controls (all p < 0.001). Each standard deviation higher porosity was associated with fracture independent of FN aBMD (OR 1.39; 95% confidence interval 1.11-1.74) and FRAX score (OR 1.58; 1.27-1.97) in all women combined. Porosity was also associated with fracture independent of FRAX score in subgroups with normal FN aBMD (OR 1.88; 1.21-2.94), osteopenia (OR 1.40; 1.06-1.85), but not significantly in those with osteoporosis (OR 1.48; 0.68-3.23). Of the 211 fracture cases, only 18 women (9%) were identified using FN aBMD T-score < -2.5, 45 women (21%) using FRAX threshold >20%, whereas porosity >80th percentile identified 61 women (29%). Porosity identified 26% additional women with fractures than identified by the osteoporosis threshold and 21% additional women with fractures than by this FRAX threshold. CONCLUSIONS: Cortical porosity is a risk factor for fracture independent of aBMD and FRAX and improves identification of women with fracture.