Heritability of resting metabolic rate in a wild population of blue tits.

We report the first study with the aim to estimate heritability in a wild population, a nest box breeding population of blue tits. We estimated heritability as well as genetic and phenotypic correlations of resting metabolic rate (RMR), body mass and tarsus length with an animal model based on data from a split cross-fostering experiment with brood size manipulations. RMR and body mass, but not tarsus length, showed significant levels of explained variation but for different underlying reasons. In body mass, the contribution to the explained variation is mainly because of a strong brood effect, while in RMR it is mainly because of a high heritability. The additive variance in RMR was significant and the heritability was estimated to 0.59. The estimates of heritability of body mass (0.08) and tarsus length (0.00) were both low and based on nonsignificant additive variances. Thus, given the low heritability (and additive variances) in body mass and tarsus length the potential for direct selection on RMR independent of the two traits is high in this population. However, the strong phenotypic correlation between RMR and mass (0.643 +/- 0.079) was partly accounted for by a potentially strong, although highly uncertain, genetic correlation (1.178 +/- 0.456) between the two traits. This indicates that the additive variance of body mass, although low, might still somewhat constrain the independent evolvability of RMR

Changes in body composition after 2 years with rheumatoid arthritis

Objectives: Rheumatoid arthritis (RA) is associated with cardiovascular disease (CVD). Possible predictors for CVD are early changes in body composition. We therefore evaluated changes in lean body mass (LBM), lean mass of arms and legs (LMAL), total body fat mass (BFM), and truncal fat distribution (FD) after 2 years with RA and possible predictors. Methods: We registered 63 (45 women) RA patients with disease duration of <= 12 months at baseline and after 2 years. Disease Activity Score using 28 joint counts (DAS28), Health Assessment Questionnaire (HAQ) score, body mass index (BMI), comorbidities, smoking, and medications were recorded. Total and regional lean mass and fat mass were measured with dual energy X-ray absorptiometry (DXA). The data were compared with 63 age- and gender-matched controls. Results: LBM and LMAL at baseline in RA patients were significantly lower in men (p = 0.020 and 0.002, respectively) compared to matched controls. Truncal FD was non-significantly increased in RA patients (women p = 0.133, men p = 0.119). The age-related deterioration with decreased LBM after 2 years (p = 0.002 in women and men) and increased BFM (p < 0.001) and truncal FD (p = 0.020) in women were all significantly less pronounced in RA patients than in matched controls. Conclusions: In patients with early RA and after initiation of therapy, the age-related deterioration with decreasing LBM and increasing truncal FD was lower than in control subjects in this observational study. These potentially harmful alterations seem to be modifiable factors in patients with early RA

Risk factors for hip fractures in a middle-aged population: a study of 33,000 men and women.

Knowledge about subjects who sustain hip fractures in middle age is poor. This study prospectively investigated risk factors for hip fracture in middle age and compared risk factors for cervical and trochanteric hip fractures. The Malmo Preventive Project consists of 22,444 men, mean age 44 years, and 10,902 women, mean age 50 years at inclusion. Baseline assessment included multiple examinations and lifestyle information. Follow-up was up to 16 years with regard to occurrence of fracture. One hundred thirty-five women had one low-energy hip fracture each, 93 of which were cervical and 42 trochanteric. One hundred sixty-three men had 166 hip fractures, of which 81 were cervical and 85 trochanteric. In the final Cox regression model for women, the risk factors with the strongest associations with hip fracture were diabetes (risk ratio (RR) 3.89, 95% confidence interval (CI) 1.69-8.93, p=0.001) and poor self-rated health (RR 1.74, 95% CI 1.22-2.48, p=0.002). A history of previous fracture (RR 4.76, 95%CI 2.74-8.26, p=0.0001) was also a significant risk factor. In men, diabetes had the strongest association with hip fracture (RR 6.13, 95%CI 3.19-11.8, p=0.001). Smoking (RR 2.20, 95%CI 1.54-3.15, p=0.001), high serum gamma-glutamyl transferase (RR 1.84, 95%CI 1.50-2.26, p=0.001), poor self-rated health (RR 1.49, 95%CI 1.06-2.10, p=0.02) and reported sleep disturbances (RR 1.52, 95%CI 1.03-2.27, p=0.04) were other significant risk factors. The strongest risk factor for hip fracture for both women and men in middle age was diabetes. Many risk factors were similar for men and women, although the risk ratio differed. The risk factor pattern for cervical versus trochanteric fractures differed in both men and women. The findings indicate that those suffering a hip fracture before the age of 75 have a shorter life expectancy, suggesting that hip fractures affect the less healthy segment of the population

Changes in bone mineral density over 10 years in patients with early rheumatoid arthritis

Objectives To investigate changes in bone mineral density (BMD) in patients with early rheumatoid arthritis (RA) over a 10-year period. Methods Consecutive patients with early RA (symptom duration <12 months) were followed according to a structured programme and examined with dual-energy X-ray absorptiometry (DXA) at inclusion and after 2, 5 and 10 years. Mean Z-scores over the study period were estimated using mixed linear effect models. Changes in Z-scores between follow-up visits were analysed using paired T-tests. Results At inclusion, 220 patients were examined with DXA. At the femoral neck, the mean Z-score over 10 years was -0.33 (95 % CI -0.57 to -0.08) in men and -0.07 (-0.22 to 0.08) in women. Men had significantly lower BMD at the femoral neck than expected by age at inclusion (intercept Z-score value -0.35; 95 % CI -0.61 to -0.09), whereas there was no such difference in women. At the lumbar spine, the mean Z-score over the study period for men was -0.05 (-0.29 to 0.19) and for women 0.06 (-0.10 to 0.21). In paired comparisons of BMD at different follow-up visits, femoral neck Z-scores for men decreased significantly from inclusion to the 5-year follow-up. After 5 years, no further reduction was seen. Conclusions In this observational study of a limited sample, men with early RA had reduced femoral neck BMD at diagnosis, with a further significant but marginal decline during the first 5 years. Lumbar spine BMD Z-scores were not reduced in men or women with early RA. Data on 10-year follow-up were limited

Predictors of radiographic erosion and joint space narrowing progression in patients with early rheumatoid arthritis: a cohort study

Background: Radiographic damage in rheumatoid arthritis (RA) includes erosions and joint space narrowing (JSN). Different mechanisms may underlie their development. The objective of this study was to evaluate predictors of these entities separately. Methods: Consecutive early RA patients (symptom duration ≤12 months) from a defined area (Malmö, Sweden) recruited during 1995-2005 were investigated. Radiographs of hands and feet were scored by a trained reader according to the modified Sharp-van der Heijde score. Fat mass and lean mass distribution were measured at baseline using dual energy x-ray absorptiometry. Potential predictors of erosion and JSN progression from inclusion to the 5-year follow-up were evaluated. Results: Two hundred and thirty-three patients were included. Radiographs at baseline and 5 years were available for 162 patients. The median (interquartile) progression of erosion and JSN scores were 4 (0-8) and 8 (1-16), respectively. Rheumatoid factor (RF) was a robust significant predictor of both erosion and JSN score progression. In adjusted analyses, anti-CCP antibodies predicted erosions while the erythrocyte sedimentation rate was predictive of both outcomes. Smoking and high baseline disease activity (DAS28 > 5.1) predicted progression of erosions. Baseline erosion score was associated with progression of both erosion and JSN progression, while baseline JSN score was predictive only of the progression of JSN. Overweight/obesity (BMI ≥ 25 kg/m2) was a significant negative predictor of JSN score progression (β = - 0.14, p = 0.018, adjusted for RF, age, baseline JSN score) also when additionally adjusting for ever smoking (p = 0.041). Among female patients, this effect was observed in those of estimated post-menopausal age (> 51 years), but not in younger women. The truncal to peripheral fat ratio was associated with less JSN score progression in women, but not in men. Conclusions: Overweight RA patients had less JSN progression, independent of smoking status. This effect was seen in particular among older women (mainly post-menopausal), but not younger. Truncal fat was associated with less JSN progression in female patients. Smoking predicted erosion progression, and erosions may precede JSN. BMI and fat distribution may influence cartilage damage in early RA and might be related to hormonal factors

A synthesis of animal movement across scales

This chapter aims at synthesizing the knowledge presented in the chapters of the book’s three sections by addressing evolutionary compromises, dispersal, gene flow, and assisted movements. How climate change and other environmental changes at different scales may affect animal movement, migration, and dispersal in the future are also summarized here. Moreover, how the different senses are utilized for navigation and orientation and how these may lead to different movement and migration patterns are also discussed. Finally, how the recent technical revolution has affected animal movement research is addressed and the view on future perspectives of animal movement research is also provided