Changes of inflammation in patients with psoriatic arthritis after high intensity interval training assessed by ultrasound and MRI, a randomized controlled trial.

BACKGROUND: In psoriatic arthritis (PsA) there is a theoretical risk of increased disease activity related to strenuous physical activity, including exercise. We evaluated the effect of high intensity interval training (HIIT) on objective measures of inflammation in PsA assessed by ultrasound (US) of peripheral joints and entheses, and by bone marrow edema (BME) on MRI of the sacroiliac joints (SIJ) and spine. METHODS: We randomly assigned 67 PsA patients to an intervention group that performed structured HIIT for 11 weeks, or to a control group instructed not to change their physical exercise habits. Outcome measures included US evaluation of the total cohort and MRI in a subgroup of 41; both assessed at 3 months. We calculated the proportions with an increased US B-mode and power-doppler (PD) signal of joints and entheses and Spondyloarthritis-Research-Consortium-of-Canada (SPARCC)-BME score of the SIJ and spine for both groups. RESULTS: Proportions with an increased US B-mode score of the joints were 32% and 28% in HIIT and control groups, respectively. Corresponding proportions of PD scores of the joints were 7% and 10% and PD scores of entheses were 32% and 31%. The proportions with increased MRI BME of the SIJ were 6% in the HIIT group and 10% in the control group. Corresponding proportions were 6% and 5% for the MRI BME of the spine. CONCLUSION: In PsA patients with a low to moderate disease activity, there was no clear evidence of objectively measured increased inflammation after HIIT, as evaluated by US and MRI. TRIAL REGISTRATION: ClinicalTrials.gov NCT02995460 (16/12/2016).

The evolution of masturbation is associated with postcopulatory selection and pathogen avoidance in primates.

Masturbation occurs throughout the animal kingdom. At first glance, however, the fitness benefits of this self-directed behaviour are unclear. Regardless, several drivers have been proposed. Non-functional hypotheses posit that masturbation is either a pathology, or a byproduct of high underlying sexual arousal, whereas functional hypotheses argue an adaptive benefit. The Postcopulatory Selection Hypothesis states that masturbation aids the chances of fertilization, while the Pathogen Avoidance Hypothesis states that masturbation helps reduce host infection by flushing pathogens from the genital tract. Here, we present comprehensive new data documenting masturbation across the primate order and use these, in conjunction with phylogenetic comparative methods, to reconstruct the evolutionary pathways and correlates of masturbation. We find that masturbation is an ancient trait within the primate order, becoming a more common aspect of the haplorrhine behavioural repertoire after the split from tarsiers. Our analyses provide support for both the Postcopulatory Selection and Pathogen Avoidance Hypotheses in male primates, suggesting that masturbation may be an adaptive trait, functioning at a macroevolutionary scale.

Evaluating the Impact of High Intensity Interval Training on Axial Psoriatic Arthritis Based on MR Images.

High intensity interval training (HIIT) has been shown to benefit patients with psoriatic arthritis (PsA). However, magnetic resonance (MR) imaging has uncovered bone marrow edema (BME) in healthy volunteers after vigorous exercise. The purpose of this study was to investigate MR images of the spine of PsA patients for changes in BME after HIIT. PsA patients went through 11 weeks of HIIT (N = 19, 4 men, median age 52 years) or no change in physical exercise habits (N = 20, 8 men, median age 45 years). We acquired scores for joint affection and pain and short tau inversion recovery (STIR) and T1-weighted MR images of the spine at baseline and after 11 weeks. MR images were evaluated for BME by a trained radiologist, by SpondyloArthritis Research Consortium of Canada (SPARCC) scoring, and by extraction of textural features. No significant changes of BME were detected in MR images of the spine after HIIT. This was consistent for MR image evaluation by a radiologist, by SPARCC, and by texture analysis. Values of textural features were significantly different in BME compared to healthy bone marrow. In conclusion, BME in spine was not changed after HIIT, supporting that HIIT is safe for PsA patients.

Physical and Psychosocial Burden of Psoriatic Arthritis: Longitudinal Data From a Population-Based Study in Norway.

OBJECTIVE: Psoriatic arthritis (PsA) can have a significant impact on health-related quality of life (HRQoL). Data on the timing of changes in the HRQoL of patients with PsA are limited. The present study was undertaken to explore associations between sleep disturbance, fatigue, pain, anxiety, depression, general health status, and satisfaction with life before and after a diagnosis of PsA compared to the general population. METHODS: Patients diagnosed with PsA between the Nord-Trøndelag Health Study (HUNT2 [1995-1997] and HUNT3 [2006-2008]) surveys were compared to the general population. The adjusted odds ratio (ORadj ) with 95% confidence interval (95% CI) was estimated at both time points. RESULTS: Among 36,507 individuals participating in both the HUNT2 and HUNT3 surveys, 160 were diagnosed with PsA between the surveys. The prevalence of sleep disturbances and fatigue was higher in PsA patients after diagnosis compared to the general population (ORadj 2.24 [95% CI 1.55-3.25] and ORadj 1.94 [95% CI 1.27-2.98], respectively). The prevalence of pain and poor health status were higher in patients with PsA compared with the general population even before PsA was diagnosed (ORadj 2.81 [95% CI 1.96-4.02] and ORadj 3.08 [95% CI 2.19-4.35], respectively) and increased after diagnosis of PsA (ORadj 12.87 [95% CI 6.27-26.40] and ORadj 5.63 [95% CI 3.99-7.95], respectively). For anxiety, depression, and life satisfaction, patients who developed PsA were comparable to the general population both before and after the diagnosis of PsA. CONCLUSION: Compared to the general population, PsA patients reported a higher prevalence of pain and poorer health status before diagnosis. Increased prevalence of sleep disturbances and fatigue in PsA patients was only found after the PsA diagnosis, and no differences between patients with PsA and the control group were found for anxiety and depression.

Adiposity and Physical Activity as Risk Factors for Developing Psoriatic Arthritis: Longitudinal Data From a Population-Based Study in Norway.

OBJECTIVE: Adiposity is prevalent among patients with psoriatic arthritis (PsA). However, the temporal relation is unclear. The present study was undertaken to investigate whether adiposity and body fat distribution are related to the risk of developing PsA, and whether physical activity could modify the possible risk. METHODS: We included 36,626 women and men from the Norwegian Nord-Trøndelag Health Study without diagnosed PsA at baseline from 1995 to 1997. Cox regression analysis was used to estimate adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) of incident PsA at follow-up from 2006 to 2008. RESULTS: During follow-up, 185 new cases of PsA were reported. Increases of 1 SD in body mass index (BMI) (4.2 and 3.5 kg/m2 for women and men, respectively) and waist circumference (10.8 and 8.6 cm, respectively) were associated with HRs of 1.40 (95% CI 1.24, 1.58) and 1.48 (95% CI 1.31, 1.68), respectively. Compared to individuals of normal weight, obese individuals had an HR of 2.46 (95% CI 1.65, 3.68), and overweight individuals had an HR of 1.41 (95% CI 1.00, 1.99). Comparing extreme quartiles of waist circumference yielded an HR of 2.63 (95% CI 1.73, 3.99). In analyses of combined effects using a BMI of <25 kg/m2 and high physical activity as reference, a BMI of ≥25 kg/m2 was associated with HRs of 2.06 (95% CI 1.18, 3.58) and 1.53 (95% CI 0.80, 2.91) among those with low and high physical activity levels, respectively. Corresponding HRs for high waist circumference and physical activity were 2.25 (95% CI 1.40, 1.63) and 1.85 (95% CI 0.95, 3.50). CONCLUSION: The results suggest that adiposity, particularly central obesity, is associated with increased risk of incident PsA. Although there was no clear modifying effect of physical activity, high levels of physical activity reduced the risk of PsA, regardless of BMI.

Impact of High-Intensity Interval Training on Disease Activity and Disease in Patients With Psoriatic Arthritis: A Randomized Controlled Trial.

OBJECTIVE: To evaluate the impact of high-intensity interval training (HIIT) on disease activity and disease perception in patients with psoriatic arthritis (PsA) and to evaluate whether a potential effect could be sustained for a longer period of time. METHODS: We randomly assigned 67 patients with PsA (43 women and 24 men) to an intervention group in which patients performed HIIT for 11 weeks or a control group of patients who were instructed not to change their physical exercise habits. Outcomes were assessed at 3 months and 9 months with the patient's global assessment (PGA), fatigue, and pain scores measured on a 100-mm visual analog scale (VAS), and the composite Disease Activity Score in 44 joints (DAS44) was calculated. We used linear mixed models to calculate the mean difference (95% confidence interval [95% CI]) between groups according to the intent-to-treat principle. RESULTS: At 3 months, there was no clear difference in the PGA score (-0.49 [95% CI -10.91, 9.94]), DAS44 (-0.08 [95% CI -0.36, 0.20]), or pain intensity (5.45 [95% CI -4.36, 15.26]) between the groups. However, patients in the intervention group reported less fatigue (-12.83 [95% CI -25.88, 0.23]) than those in the control group. There was no evidence of long-term effects of HIIT on outcomes measured at 9 months. CONCLUSION: HIIT showed no clear effects on disease activity markers in patients with PsA, but the intervention (exercise) group reported meaningfully less fatigue after the intervention period. The results of this study suggest that patients with PsA tolerate HIIT without deterioration of disease activity and with improvement in fatigue.

Effect of high-intensity interval training on cardiovascular disease risk factors and body composition in psoriatic arthritis: a randomised controlled trial.

BACKGROUND: Psoriatic arthritis (PsA) is associated with an accumulation of cardiovascular disease (CVD) risk factors. The aim of this study was to evaluate the effect of high-intensity interval training (HIIT) on CVD risk factors in patients with PsA. METHODS: We randomly assigned 61 patients with PsA (41 women and 20 men) to an intervention group performing HIIT for 11 weeks or a control group who were instructed to not change their physical exercise habits. Outcomes were assessed at 3 and 9 months with measures on maximal oxygen uptake (VO2max), fat percentage and Body Mass Index (BMI). We used linear mixed models to calculate mean difference with 95% CI between the groups according to the intention-to-treat principle. RESULTS: At 3 months, the HIIT group had a 3.72 mL/kg/min (95% CI 2.38 to 5.06) higher VO2max and a 1.28 (95% CI -2.51 to -0.05) lower truncal fat percentage than controls. There was also some evidence that the HIIT group had lower total fat percentage (-0.80; 95% CI -1.71 to 0.10) and slightly lower BMI (-0.31; 95% CI -0.78 to 0.17) than the control group. At 9 months, the HIIT group had still a higher VO2max (3.08; 95% CI 1.63 to 4.53) than the control group, whereas the difference in other factors were small. CONCLUSION: In patients with PsA, 3 months with HIIT was associated with a substantial increase in VO2max and a reduction in truncal fat percentage compared with controls. The beneficial effect on VO2max was also sustained through 9 months. TRIAL REGISTRATION NUMBER: NCT02995460.

Chemical composition of axillary odorants reflects social and individual attributes in rhesus macaques.

ABSTRACT: Scents play an important role in the life of most terrestrial mammals and may transmit valuable information about conspecifics. Olfaction was long considered of low importance in Old World monkeys due to their relative reduction of olfactory structures and low incidence of scent-marking behavior but has been increasingly recognized for mediating social relationships in recent years. Yet, studies investigating the composition of their chemical cues remain scarce. In the present study, we analyzed the potential information content of chemicals present on the skin of rhesus macaques (Macaca mulatta). We collected axillary secretions from 60 animals of the semifree-ranging population on Cayo Santiago (Puerto Rico, USA) with precleaned cotton swabs from which the secretions were subsequently extracted and analyzed by gas chromatography-mass spectrometry. Rhesus macaque axillary odorants varied in their overall similarity and composition. This variation was attributable to differences in sex, group membership, and kinship and further appeared to reflect age and rank in parts of our sample. The compounds most strongly associated with this variation primarily comprised larger molecular weight aldehydes and steroids. Such compounds are considered to be perceivable by the primate olfactory system through close-range interactions or through breakdown into smaller molecules by bacterial fermentation. Overall, our results provide additional evidence that odors of Old World monkeys reflect a wealth of potential information about their carrier, which provides the basis for chemical communication via body odors; however, its use by conspecifics needs to be confirmed in bioassays. SIGNIFICANCE STATEMENT: One prerequisite for olfactory communication is the presence of systematic variation in animal odors that is related to attributes such as age, sex, or kinship. The composition of odors has been examined in numerous mammals but, with the exception of humans, remains poorly understood in Old World monkeys and apes, taxonomic groups in which most species do not show scent-marking behavior. In the present study, we show that the composition of axillary secretions of an Old World monkey, the rhesus macaque, reflects sex, group membership, relatedness, and possibly also age and rank. This variation thus provides a basis for olfactory communication in Old World monkeys.

Change in cardiovascular risk factors in patients who develop psoriatic arthritis: longitudinal data from the Nord-Trøndelag Health Study (HUNT).

OBJECTIVES: The aim of this population-based study was to compare changes in cardiovascular (CV) risk factors over a decade-long period in patients who developed psoriatic arthritis (PsA) and the background population. METHODS: Patients diagnosed with PsA (n=151) between 1998 and 2008 and matched controls (n=755) who participated in both the Nord-Trøndelag Health Study (HUNT) 2 (1995-1997) and HUNT3 (2006-2008) were included. Mixed linear and logistic models were used to analyse the difference in mean change between HUNT2 and HUNT3 in patients and controls for body mass index (BMI), total cholesterol (TC), triglycerides, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c) and blood pressure (BP). RESULTS: At baseline (HUNT2), the patients who developed PsA compared with controls had higher BMI (27.2 vs 25.9 kg/m2, p<0.001) and lower HDL-c (1.32 vs 1.40 mmol/L, p<0.03) and more were smokers (41.1 vs 28.5%, p<0.01). Seventy-eight per cent had skin psoriasis. The mean PsA disease duration at HUNT3 was 4.8 (+/-3.0) years. The patients who developed PsA gained less weight from HUNT2 to HUNT3 compared with the control group (2.1 vs 3.9 kg, difference in mean change -1.8 kg, 95% CI -3.9 to -0.5, p<0.01). TC, triglycerides, LDL-c or HDL-c values and BP declined in both groups, with no significant differences between groups. CONCLUSION: Longitudinal 10-year data did not show an increase in CV risk factors in patients who developed PsA compared with controls. This study implies that unfavourable CV risk factors in PsA were present before the diagnosis was established.

Quantifying bone marrow inflammatory edema in the spine and sacroiliac joints with thresholding.

BACKGROUND: Psoriatic Arthritis (PsA) is a chronic inflammatory arthritis that develops in patients with psoriasis. Inflammatory edema in the spine may reflect subclinical disease activity and be a predictor of radiographic progression. A semi-quantitative method established by the spondyloarthritis research consortium of Canada (SPARCC) is commonly used to assess the disease activity in MR images of the spine. This study aims to evaluate thresholding for quantification of subtle bone marrow inflammation in the spine and the sacroiliac (SI) joints of patients with PsA and compare it with the SPARCC scoring system. METHODS: Short tau inversion recovery (STIR) MR images of the spine (N = 85) and the SI joints (N = 95) of patients with PsA (N = 41) were analyzed. A threshold was applied to visible bone marrow in order to mask areas with higher signal intensity, which are consistent with inflammation. These areas were considered as inflammatory lesions. The volume and relative signal intensity of the lesions were calculated. Results from thresholding were compared to SPARCC scores using linear mixed-effects models. The specificity and sensitivity of thresholding were also calculated. RESULTS: A significant positive correlation between the volumes and mean relative signal intensities, which were calculated by thresholding analysis, and the SPARCC scores was detected for both spine (p < 0.001) and SI joints (p < 0.001). For the spine, thresholding had sensitivity and specificity of 83% and 76% respectively, while for the SI joints the values were 51% and 88% respectively. CONCLUSIONS: Thresholding allows quantification of subtle bone marrow inflammatory edema in patients with psoriatic arthritis, and could support SPARCC scoring of the spine. Improved image processing and inclusion of automatic segmentation are required for thresholding of STIR images to become a rapid and reliable method for quantitative measures of inflammation. TRIAL REGISTRATION: NCT02995460 (December 14, 2016) - Retrospectively registered.

Sampling the Body Odor of Primates: Cotton Swabs Sample Semivolatiles Rather Than Volatiles.

We assessed the suitability of a frequently used sampling method employing cotton swabs for collecting animal body odor for gas chromatography-mass spectrometry (GC-MS) analysis of volatile organic compounds (VOCs). Our method validation showed that both sampling material and sampling protocols affect the outcome of the analyses. Thus, among the tested protocols swabs of pure viscose baked before use and extracted with hexane had the least blank interferences in GC-MS analysis. Most critical for the recovery of VOCs was the handling time: the significant recovery losses of volatiles experienced with this sampling procedure suggest that a rapid processing of such samples is required. In a second part, we used swab sampling to sample the body odor of rhesus macaques (Macaca mulatta), which lack scent glands. First results after GC-MS analysis of the samples collected from these nonhuman primates emphasize that proper analytical performance is an indispensable prerequisite for successful automated data evaluation of the complex GC-MS profiles. Moreover, the retention times and the nature of the identified chemical compounds in our samples suggest that the use of swabs is generally more appropriate for collecting semivolatile rather than VOCs.

Earlier breeding, lower success: does the spatial scale of climatic conditions matter in a migratory passerine bird?

Following over 20 years of research on the climatic effects on biodiversity we now have strong evidence that climate change affects phenology, fitness, and distribution ranges of different taxa, including birds. Bird phenology likely responds to changes in local weather. It is also affected by climatic year-to-year variations on larger scales. Although such scale-related effects are common in ecology, most studies analyzing the effects of climate change were accomplished using climatic information on a single spatial scale. In this study, we aimed at determining the scale-dependent sensitivity of breeding phenology and success to climate change in a migratory passerine bird, the barn swallow (Hirundo rustica). For both annual broods, we investigated effects of local weather (local scale) and the North Atlantic Oscillation (NAO, large scale) on the timing of breeding and breeding success. Consistent with previous studies in migratory birds we found that barn swallows in Eastern Germany bred progressively earlier. At the same time, they showed reduced breeding success over time in response to recent climatic changes. Responses to climatic variation were observed on both local and large climatic scales, but they differed with respect to the ecological process considered. Specifically, we found that the timing of breeding was primarily influenced by large-scale NAO variations and to a lesser extent by local weather on the breeding grounds. Conversely, climatic conditions on the local scale affected breeding success, exclusively. The observed decrease in breeding success over years is likely a consequence of scale-related mismatches between climatic conditions during different breeding phases. This provides further evidence that a species' response of earlier breeding may not be enough to cope with climate change. Our results emphasize the importance of considering the response of ecological processes along different climatic scales in order to better understand the complexity of climate change effects on biodiversity.

Sniffing behaviours in guenons.

In Old World monkeys (OWM), the olfactory sense is thought to be less important than in other primate taxa. However, during the last decade experimental studies have shown that OWM possess much better olfactory capabilities than suspected. Here, we investigate for the very first time sniffing behaviours in three guenon species (Diana, de Brazza's and owl-faced monkeys) held in the Leipzig Zoo, Germany. We recorded frequencies and contexts of sniffing. The sniff index was used to allow comparisons across species. It was found that individuals sniffed 6.12 ± 7.69 times per hour. Most sniffing occurred in food-related contexts. Furthermore, Diana monkeys sniffed less often than de Brazza's and owl-faced monkeys. Thus, natural selection may drive the differences in using the olfactory sense in closely related primate species.

Non-invasive collection and analysis of semen in wild macaques.

Assessments of primate male fertility via semen analyses are so far restricted to captivity. This study describes a non-invasive method to collect and analyse semen in wild primates, based on fieldwork with Yakushima macaques (Macaca fuscata yakui). Over nine mating seasons between 1993 and 2010, 128 masturbatory ejaculations were recorded in 21 males of 5 study troops, and in 11 non-troop males. In 55%, ejaculate volume was directly estimated, and in 37%, pH-value, sperm vitality, numbers, morphology and swimming velocity could also be determined. This approach of assessing semen production rates and individual male fertility can be applied to other primate taxa, in particular to largely terrestrial populations where males masturbate frequently, such as macaques and baboons. Furthermore, since explanations of male reproductive skew in non-human primate populations have until now ignored the potential role of semen quality, the method presented here will also help to answer this question.

Non-invasive blood sampling from primates using laboratory-bred blood-sucking bugs (Dipetalogaster maximus; Reduviidae, Heteroptera).

Primates are easily stressed by the conventional veterinary blood sampling routine and consequently, measured blood parameters may be biased. In this study, we tested blood-sucking bugs (Dipetalogaster maximus) on one lemur and two ape species (Microcebus murinus, Pongo abelii, Pan paniscus) as an alternative, non-invasive technique for bleeding primates. Within time periods of between 6 and 62 min we obtained blood volumes of 0.01-2.4 ml in 11 out of 12 trials from all three species. Therefore, we conclude that these bugs represent a new, gentle and effective tool for bleeding captive primates without stress.

How costly are ejaculates for Japanese macaques?

Much sexual selection theory is based on the idea that ejaculate is cheap. Since further details are unknown our aim was to determine the energy that primate males require for ejaculate production. We addressed this problem by measuring the energy content (in kJ) of ejaculates from Japanese macaques (Macaca fuscata) using standard bomb calorimetry. Then, we estimated the relative amount of energy that individuals require for ejaculate production by relating the net energy content of ejaculates to males' daily basal metabolic rate (BMR). Fresh macaque ejaculate contains 3.0 kJ ml(-1). Assuming a mean volume of 2.7 ml an average macaque ejaculate contains 8.1 kJ. Depending on the individuals' body mass (6-13 kg) and the number and volume of the ejaculates, macaque males are assumed to use between at least 0.8% and at most 6.0% of their BMR for ejaculate production per day during the breeding season. Even when regarding only the minimal energy investment of 0.8% of daily BMR for ejaculate production, clearly ejaculates come with some cost for primate males.