Evaluation of type traits in relation to production,and their importance in early selection for milk performance in dairy buffaloes

Type traits (TTs) can contribute to breeding animals with good economic traits such as production, longevity, fertility, and profitability. Dairy buffaloes are the second largest source of milk supply in the world, and their TTs should be taken into consideration in future dairy buffalo breeding programmes. However, the relationship between TTs and milk production traits in buffalo remains largely unknown. The study aimed to establish an early selection method for buffaloes with desirable milk performance by TTs. Using 1 908 records from 678 buffaloes, the relationship between TTs and milk production traits was analysed and the optimal growth curves of TTs related to milk production traits were constructed. We examined the correlations between 45 TTs (33 body structural, 12 udder and teat morphological traits) and three milk production traits (milk yield (MY), milk fat percentage (MF), and milk protein percentage (MP)). The results showed that the highest correlation was found between MY and udder circumference (r = 0.438), teat length (r = ?0.380) or heart girth (r = ?0.341). The teat distance and teat circumference exhibited a significant negative correlation with MF and MP. Rump length was the only trait that had a significant positive correlation with milk production traits, suggesting that milk performance could be comprehensively improved by including rump length in the selection procedure. Notably, we found that high milk production traits was obtained from the buffaloes with short teats (<6 cm), small heart girth (<200 cm), large udder circumference (>104 cm), long rump (>39 cm), and small distance between teats. Moreover, an early selection method for buffaloes with excellent milk performance was developed based on the non-linear models. Brody model exhibited the best fitting effect for heart girth and rump length, while the Logistic model displayed the best fitting effect for teat length. Our findings provide theoretical basis for the early selection of buffaloes with desirable milk performance.     

Analyses of the genetic relationships between lactose,somatic cell score,and growth traits in Simmental cattle

Lactose and somatic cell score (SCS) are major economic traits of milk. However, for many countries, they are typically not directly considered in the national genetic evaluation of Simmental cattle. This study aimed to estimate the genetic relationships between lactose, SCS, and growth traits of Simmental cattle to provide information for the national genetic evaluation of the selection of traits of this cattle population. The data of 1781 animals with 6519 records obtained over a period of 41 years (1975–2016) were collected from Xinjiang Hutubi Farm, China. The analyzed traits included 305 days of milk yield (305MY), milk fat percentage (MFP), milk protein percentage (MPP), milk lactose percentage (MLP), total solids (TS), SCS, body height (BH), body length (BL), chest girth (CG), abdominal circumference (AC), rump width (RW), rump length (RL), leg circumference (LC), and cannon circumference (CC). The multiple-trait repeatability model was adopted to estimate (co)variance components using the average information-restricted maximum likelihood method implemented using the DMU statistical package. The heritability estimates for milk components and growth traits ranged from 0.09 (SCS) to 0.51 (BH). Genetic correlations for milk components ranged from 0.03 ± 0.14 (MFP and MLP) to 0.81 ± 0.08 (MFP and MPP). Genetic correlation between MLP and SCS was moderate and negative (− 0.50 ± 0.15) compared with that among other traits. Genetic correlations between the milk components and growth traits ranged from 0.00 ± 0.07 (305MY and RW) to − 0.64 ± 0.15 (MLP and BL). Genetic correlations of BL, LC, RW, and RL with MLP were moderate to high and negative ranging from − 0.39 to − 0.64. Somatic cell score showed the highest correlation with BL (0.41) followed by LC (0.21). An increase in MLP would result in an increase in 305MY or TS and a decrease in BL, LC, RW, and RL. Additionally, a decrease in SCS would occur with the selection of increased MLP and reduced BL. We conclude that selection based on easily and inexpensively measured growth traits could improve the milk quality from Simmental cattle.     

The Quételet index revisited in children and adults

BackgroundThe body mass index (BMI) is based on the original concept that body weight increases as a function of height squared. As an indicator of obesity the modern BMI assumption postulates that adiposity also increases as a function of height in states of positive energy balance.ObjectiveTo evaluate the BMI concept across different adiposity magnitudes, in both children and adults.MethodsWe studied 975 individuals who underwent anthropometric evaluation: 474 children and 501 adults. Tetrapolar bioimpedance analysis was used to assess body fat and lean mass.ResultsBMI significantly correlated with percentage of body fat (%BF; children: r = 0.893; adults: r = 0.878) and with total fat mass (children: r = 0.967; adults: r = 0.953). In children, body weight, fat mass, %BF and waist circumference progressively increased as a function of height squared. In adults body weight increased as a function of height squared, but %BF actually decreased with increasing height both in men (r = −0.406; p < 0.001) and women (r = −0.413; p < 0.001). Most of the BMI variance in adults was explained by a positive correlation of total lean mass with height squared (r² = 0.709), and by a negative correlation of BMI with total fat mass (r = −0.193).ConclusionsBody weight increases as a function of height squared. However, adiposity progressively increases as a function of height only in children. BMI is not an ideal indicator of obesity in adults since it is significantly influenced by the lean mass, even in obese individuals.     

Phenotypic and genetic relationships between udder morphology and udder health in dairy ewes

The aim of this paper was studying the phenotypic and genetic relationships between udder morphology traits and udder health in dairy sheep. From 2000 to 2008 udder traits, somatic cell count (SCC) and clinical mastitis cases were recorded in an experimental flock consisting each year of around 900 ewes. A logistic regression was performed to evaluate the risk for a ewe of showing either a mastitis or at least 2 daily SCC records greater than 1 × 10⁶ cells/ml in one of its lactations as function of udder traits scored in 1st lactation. 1587 individual udder scores and 39,950 SCC daily records were used for the analysis. Secondly, genetic correlation between lactation mean of somatic cell score and udder traits were estimated by a REML method applied to four bi-trait animal models, using data from 2251 primiparous ewes. Logistic regression results indicated that the risk of mastitis or high SCC values during the productive life increased as the cistern height increased and the degree of udder suspension and udder depth decreased. This suggests that the appraisal of the udder is a useful tool for culling decision aimed at increasing the sanitary status of the flock. The genetic correlation between lactation SCS and udder traits were favourable for udder depth (−0.50 ± 0.12), teat placement (0.39 ± 0.011) and degree of udder suspension (−0.42 ± 0.011) and closed to zero for the degree of separation of the two halves. Thus selection for udder morphology, already implemented in some dairy sheep breeds with the aim of improving machine milkability, will lead to a favourable correlated genetic response on SCC.     

Determination of prediction equations for estimating body weight of Zulu (Nguni) sheep

Data on linear body measurements (LBM) of 403 sheep collected in three areas of KwaZulu-Natal were utilized to develop a prediction equation for live body weight of Zulu sheep. Data were collected on live weight (LW), heart girth (HG), wither height (WH) and scrotum circumference (SC) on sheep of all ages. The age of sheep was estimated by dentition. The analysis of variance showed that age and sex were important factors contributing to variation in LW of Zulu sheep. Phenotypic correlation coefficients and regression equations of LW on HG, WH and SC were computed within different age groups (milk set of teeth, one pair, two pairs and the three and four pairs of incisors). Low correlation coefficients (r = 0.21–0.48) between LW, HG and WH were found among the pregnant ewes. The relationship between LBM and LW was stronger (r = 0.66–0.86) for males than among females (r = 0.42–0.75). The cubic polynomial of HG was the best fit (R² = 0.76) for the live weight prediction of young sheep with milk set of teeth. The combination of HG and WH produced the best fit for the two tooth and above males and non-pregnant females. The LW prediction equations for pregnant females were not reliable (R² = 0.05–0.26). The SC was more precise (R² = 0.61–0.80) when estimating the live weight of young males (<15–22-month-old) than of the older rams (R² = 0.23–0.56). It was concluded that LW of Zulu sheep can be reasonably estimated using the HG and WH. A table could be constructed for the farmers to estimate the LW of their animals.     

Comparison of four techniques to estimate milk production in singleton-rearing non-dairy ewes

Accurate estimates of milk production or milk intake are difficult, as all methods interfere to some degree with the natural behaviour of the dam and her young, and potentially alter milk yield itself. The present study compared milk yield obtained by the “oxytocin” method, udder dimensions (UD), the isotope dilution method, and live weight change of the lamb, in an attempt to select the most accurate and convenient way of measuring milk production in non-dairy sheep. In addition, the study investigated which of the three milk-estimation techniques was an accurate predictor of growth rates of lambs. Thirty-seven singleton-bearing and rearing ewes were milked once a week, for seven consecutive weeks, using the “oxytocin” method. Prior to each afternoon milking, the external dimensions of the ewe's udder were measured. Lambs were weighed weekly for the first seven weeks of life and live weight change was calculated. The deuterium oxide (D₂O) dilution technique was used to estimate milk intake of the lambs and performed at approximately 7 days post-partum and finishing on approximately day 14. Pearson's correlation coefficients and multiple regression coefficients among techniques were calculated. The UD-models at d7 (R² = 0.35), d35 (R² = 0.36) and d42 (R² = 0.34), were the best models explaining variation in milk yield (concordance correlation coefficient (CCC) = 0.49; 0.53; 0.51; for d7, d35 and d42, respectively). The lamb live weight-change model explained the variation in milk yield best at d28 (R² = 0.32; CCC = 0.49), at d35 (R² = 0.22; CCC = 0.36) and at d42 (R² = 0.28; CCC = 0.44). At d14, the intake of milk by lambs as measured by the D₂O technique, did not explain the variation in milk yield. In conclusion, udder dimensions, lamb live weight change and lamb milk intake are relatively poor estimators of the milk yield of singleton-rearing ewes obtained by the “oxytocin” method. Additionally, udder dimensions, milk yield and lamb milk intake do not give an accurate prediction of growth rates of singleton lambs. These results emphasize that there is a difference between ewe milk production potential and lamb milk intake, which need to be considered when estimating milk production in non-dairy animals.     

Physical properties of extruded fish feed with inclusion of different plant (legumes,oilseeds, or cereals) meals

A study was undertaken to evaluate the effect of various ingredients on the physical quality of fish feeds. Eleven fish meal-based diets, formulated to have the same levels of macronutrients, differing in either starch or protein source, were processed in a five section twin-screw extruder. The purified starch, added to reach the nutritional specifications of the diets, was significantly correlated to expansion (r = 0.405, P<0.001), durability (r = 0.276, P=0.012), and hardness (r = 0.494, P<0.001), while such correlations were not seen for the total starch level in the diets. Cellulose, added as filler to reach the same level of NSP in the diets, was negatively correlated to the expansion (r = ?0.603, P<0.001). The specific mechanical energy of the extrusion process was weakly correlated to starch gelatinisation (r = 0.220, P<0.019). The present study showed that traditional parameters and classifications such as chemical composition of plant ingredients are inadequate indicators of processing effects when used in fish diets. The overall conclusion is that processing parameters needed to achieve the desired physical properties of diets, should be based on specific knowledge of each ingredient in the feed.     

Distal skeletal tibia assessed by HR-pQCT is highly correlated with femoral and lumbar vertebra failure loads

Dual energy X-ray absorptiometry (DXA) is the standard for assessing fragility fracture risk using areal bone mineral density (aBMD), but only explains 60–70% of the variation in bone strength. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides 3D-measures of bone microarchitecture and volumetric bone mineral density (vBMD), but only at the wrist and ankle. Finite element (FE) models can estimate bone strength with 86–95% precision. The purpose of this study is to determine how well vBMD and FE bone strength at the wrist and ankle relate to fracture strength at the hip and spine, and to compare these relationships with DXA measured directly at those axial sites. Cadaveric samples (radius, tibia, femur and L4 vertebra) were compared within the same body. The radius and tibia specimens were assessed using HR-pQCT to determine vBMD and FE failure load. aBMD from DXA was measured at the femur and L4 vertebra. The femur and L4 vertebra specimens were biomechanically tested to determine failure load. aBMD measures of the axial skeletal sites strongly correlated with the biomechanical strength for the L4 vertebra (r = 0.77) and proximal femur (r = 0.89). The radius correlated significantly with biomechanical strength of the L4 vertebra for vBMD (r = 0.85) and FE-derived strength (r = 0.72), but not with femur strength. vBMD at the tibia correlated significantly with femoral biomechanical strength (r = 0.74) and FE-estimated strength (r = 0.83), and vertebral biomechanical strength for vBMD (r = 0.97) and FE-estimated strength (r = 0.91). The higher correlations at the tibia compared to radius are likely due to the tibia’s weight-bearing function.     

Comparison of clinical findings,microbiological results,and farming parameters in goat herds affected by recurrent infectious mastitis

A total of 1388 goats from 31 farms distributed throughout Sardinia, Italy, were investigated in this study. The goat population of Sardinia accounts for a quarter of the entire goat population of Italy. In this work, data and information concerning each farming site were collected, a detailed clinical examination of the udder of lactating animals was carried out, and microbiological examination of milk was performed. Results were then subjected to statistical analysis in order to highlight possible correlations among all findings. Significant results were obtained by comparing clinical findings with bacteriological positivity of milk.Intra-mammary infections were detected in 22.7% of all goats examined. Staphylococcus spp., Streptococcus spp., and Mycoplasma spp. were detected in 73.5%, 9.7%, and 4.7% of positive milk cultures, respectively. Other bacterial genera showed a prevalence lower than 3%. Milk positivity to Staphylococcus aureus was significantly associated to presence in the udder of pustules, ulcers, nodules, and rubor (p < 0.05). Staphylococcus caprae was associated to manual vs mechanical milking, age, udder edema, and absence of mammary secretions (p < 0.05). Staphylococcus epidermidis was positively associated to age (p < 0.05). Streptococcus uberis was associated to mechanical milking, atrophic udder texture, and reactive mammary lymph nodes (p < 0.05). Several other factors showed statistically significant correlations. Taken together, the results presented in this work highlight the specificity, the usefulness, and the practical value of performing a clinical examination of the udder, and suggest its relevance as the most important diagnostic tool for complementing microbiological examination of milk.     

Feeding soybean meal increases the blood level of isoflavones and reduces the steroidogenic capacity in bovine corpora lutea,without affecting peripheral progesterone concentrations

Thirty-three Holstein-Friesian cows were followed from 14 days pre partum until the fourth ovulation post partum. Housing conditions and basic ration were identical for all animals. Concentrates were individually supplemented according to the daily milk production level, using two different types of protein rich concentrates: soybean meal and rapeseed meal. Soybean and rapeseed meal are known to be respectively high and low in isoflavones. Cows were randomly divided into three groups and blocked for parity. Group I (n = 11) was supplemented with soybean meal and acted as control group. Groups II (n = 11) and III (n = 11) were respectively supplemented with soybean and rapeseed meal and were subjected to a biopsy sampling of the corpus luteum at day 9 of the first three postpartal estrous cycles.Soybean meal supplementation to lactating dairy cows (1.72 kg on average) induced an increase in the blood concentration of equol, dihydrodaidzein, o-desmethylangolensin in both soy groups and resulted in a reduced area occupied by steroidogenic (P = 0.012) and endothelial cells (P = 0.0007) in the luteal biopsies. Blood concentrations of equol and glycitein were negatively correlated with the areas occupied by steroidogenic (r = −0.410 with P = 0.0002, respectively r = −0.351 with P = 0.008) and endothelial cells (r = −0.337 with P = 0.01, respectively r = −0.233 with P = 0.085) in the 3 first estrous cycles. The latter however did not affect the diestrous peripheral blood progesterone concentration.     

Oral morphology and dietary choices of goats on rangeland

The morphometrics of mandible and teeth of mixed-breed goats on rangeland were analyzed to investigate the association between the oral apparatus and diet type. Canonical relationship between sets of mandible measurements (7) and main plants ingested (17) indicated that, overall, oral characteristics tended to modify ingestive behavior (canonical correlation = 0.81). In general, incisor length had a greater effect (absolute value of standardized coefficient: AVSC = 0.56) on ingestion of Nolina cespitifera than did other mandible variables. Incisor width influenced the ingestion of Parthenium incanum (AVSC = 0.47) and Flourensia cernua (AVSC = 0.43). Distance between the bases of the last most lateral incisors (I₄ or corners) was associated with the ingestion of Atriplex canescens (AVSC = 0.54) and Florensia cernua (AVSC = 0.69). Incisor breath was important for the consumption of Larrea tridentata (AVSC = 0.68) and Cowania plicata (AVSC = 0.50). The ingestion of Agave lechuguilla (AVSC = 0.51) and Sphaeralcea angustifolia (AVSC = 0.43) were influenced principally by muzzle width. Distance between first molars was the variable most closely associated to the ingestion of Buchloe dactyloides (AVSC = 0.51) and Croton dioicus (AVSC = 0.62). Mandible length had a greater effect on the ingestion of F. cernua and Atriplex canescens than did other oral traits. Variation in the oral apparatus did not affect percentage of grasses, forbs and shrubs of goat diets. Fecal nitrogen, fecal phosphorous and number of species consumed were not related to oral traits. These results suggest that different dimensions in the oral apparatus of grazing goats lead to divergent selection of range plants, without altering the quality of their diet.     

Relationship between zinc levels and plasma leptin in hemodialysis patients

Recent evidences suggested a possible relationship between zinc deficiency and leptin levels in pathogenesis of anorexia in chronic kidney disease. The present study addressed the relationship between zinc and leptin in hemodialysis (HD) patients.MethodsFifty HD patients (54.3 ± 12.7 years old, 62% men) were studied and compared to 21 healthy volunteers (50.7 ± 15.7 years old, 43% men). Biochemical data, serum zinc, plasma leptin, IL-6, TNF-α and C-Reactive Protein levels were determined. Anthropometric parameters, food intake and appetite score were also assessed.ResultsThe leptin levels were higher in HD patients (16.1 μg/mL (0.21–118.25) vs 6.0 μg/mL (0.50–23.10)) in healthy volunteers (p = 0.04), whereas serum zinc levels were lower (54.5 ± 16.3 μg/dL) compared to healthy volunteers (78.4 ± 9.4 μg/dL) (p = 0.0001). The plasma leptin was correlated negatively with plasma zinc (r = ?0.33; p = 0.007), energy (r = ?0.38; p = 0.002) and protein intake (r = ?0.34; p = 0.006) and, positively correlated with BMI (r = 0.54; p = 0.0001), % body fat (r = 0.70; p = 0.0001) and conicity index (r = 0.46; p = 0.001). Plasma zinc was associated with hemoglobin (r = 0.30; p = 0.04) and negatively associated with TNF-α (r = ?0.37; p = 0.002) and C-Reactive Protein (r = ?0.37; p = 0.004). There was no correlation among Zn, leptin and appetite score in these patients.ConclusionThis study showed that low plasma zinc levels are negatively associated with high leptin levels in HD patients.     

Medial gastrocnemius muscle-tendon interaction and architecture change during exhaustive hopping exercise

Background: Previous literature has shown in vivo changes in muscle-tendon interaction during exhaustive stretch-shortening cycle (SSC) exercise. It is unclear whether these changes in muscle-tendon length during exhaustive SSC exercise are associated with changes in mechanical efficiency (ME). The purpose of the study was to investigate whether changes in platarflexor contractile component (CC) length, tendon length, and changes in plantarflexor muscle activity could explain reduction in ME during exhaustive SSC exercise. Methods: Eight males participated in an exhaustive hopping task to fatigue. Mechanical work and energy expenditure were calculated at different time-points during the hopping task. Furthermore, hopping kinetics and kinematics, medial gastrocnemius (MG) muscle activity, and in vivo ultrasound of the MG were also collected at different time-points throughout the hopping task. Results: ME did not change during the hopping protocol despite shorter tendon and longer CC lengths as subjects approached exhaustion. Percent decreases in pennation angle and muscle thickness were most strongly correlated to time to exhaustion (r = 0.94, p ⩽ 0.05; r = 0.87, p ⩽ 0.05; respectively). Percent changes in CC length change and pennation angle were strongly correlated to percent decrease in maximal voluntary isometric plantarflexion (MVIP) force (r = −0.71, p ⩽ 0.04; r = 0.70, p ⩽ 0.05; respectively). Braking/push-off EMG ratio increased from initial pre-fatigue values to all other time points showing neuromuscular adaptations to altered muscle lengths. Conclusion: Findings from the current study suggest that changes in CC and tendon lengths occur during repetitive hopping to exhaustion, with the amount change strongly related to time to exhaustion. ME of hopping remained unchanged in the presence of altered CC and tendon lengths.     

Association between selenium nutritional status and metabolic risk factors in men with visceral obesity

Background and aimPrevious evidence has suggested an association between selenium and cardiovascular disease, which is main outcome of metabolic syndrome. The aim of this study was to examine possible correlation between selenium nutritional status and metabolic risk factors in men with visceral obesity.MethodsPlasma samples were collected from 123 Indonesian men with visceral obesity. Their metabolic risk factors and selenium nutritional status were analyzed. The eligible subjects (n = 78) were stratified according to the International Diabetes Federation: obese, obese plus one component, and obese plus two components or more. Obese plus two components or more were diagnostic criteria of metabolic syndrome. Pearson's correlation was performed to examine the correlation in each group.ResultsIn the obese group, selenium positively correlated with high-density lipoprotein (HDL) cholesterol (r = 0.390, P < 0.05) and with fatty acid binding protein-4 (FABP4) (r = 0.474, P < 0.05); glutathione peroxidase-3 (GPx3) activity was inversely correlated with FABP4 (r = ?467, P < 0.05). In the obese plus one component group, GPx3 activity positively correlated with HDL cholesterol (r = 0.413, P < 0.05). In the metabolic syndrome group, selenium negatively correlated with monocytes chemoattractant protein (MCP)-1 (r = ?0.429, P < 0.05).ConclusionsThese results show that the association between selenium nutritional status and metabolic risk factors is limited to particular group of obese men with or without metabolic syndrome.     

Asociación de la fuerza muscular con marcadores tempranos de riesgo cardiovascular en adultos sedentarios

ObjectiveTo assess the association between muscle strength and early cardiovascular risk (CVR) markers in sedentary adults.Materials and methodsA total of 176 sedentary subjects aged 18-30 years were enrolled. Body mass index and fat percentage were calculated, and waist circumference, grip strength by dynamometry, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and maximal oxygen uptake by VO_2max were measured as CVR markers. A multivariate logistic regression analysis was used to assess associations between muscle strength and CVR markers.ResultsInverse correlations were found between muscle strength and adiposity (r = -.317; P = .001), waist circumference (r = -.309; P = .001), systolic blood pressure (r = -.401; P = .001), and mean arterial pressure (r = -.256; P = .001). Subjects with lower levels of muscle strength had a 5.79-fold (95% CI 1.57 to 9.34; P = .008) risk of having higher adiposity levels (≥ 25%) and a 9.67-fold (95% CI = 3.86 to 19.22; P < .001) risk of having lower physical capacity values for VO_2max (≤ 31.5 mL/kg/min^-1).ConclusionsIn sedentary adults, muscle strength is associated to early manifestations of CVR. It is suggested that muscle strength testing is added to routine measurement of VO_2max and traditional risk factors for prevention and treatment of cardiovascular risk.     

Age and sex affect protein metabolism at protein intakes that span the range of adequacy: comparison of leucine kinetics and nitrogen balance data

Research suggests that changes in leucine oxidation (leu_ox) with feeding may reflect adult protein requirements. We evaluated this possibility by assessing the effects of age, sex, and different protein intakes on whole-body leucine kinetics and nitrogen balance. Thirty-four young (n= 18, 22–46 years) and old (n= 16, 63–81 years) men and women completed three 18-day trials with protein intakes of 0.50, 0.75 and 1.00 g protein·kg body weight^? 1·d^? 1. Fasting and fed-state leucine kinetics were quantified on day 12 of each trial using a primed, constant infusion of L-[1-13C]leucine. Protein requirement was estimated using classical nitrogen balance measurements and calculations. Leucine kinetics parameters were influenced by age and sex across all protein intakes. With feeding, leu_ox increased more in old vs. young adults. Independent of age, fasting and fed-state leu_ox were lower, and net leucine balance (fasting+fed-state) was higher in women vs. men. Among all subjects and protein intakes, nitrogen balance was correlated with fed-state leu_ox (r= 0.39), fed-state leucine balance (r= 0.60), net leucine balance (r= 0.49) and the change in leu_ox from the fasting to fed state (r= 0.49) (P<.05 for all results). At the highest protein intake, the change in leu_ox with feeding was inversely correlated with protein requirement (r=?0.39). These findings indicate that leucine kinetics, especially leu_ox, reflect nitrogen balance-based estimates of the need for dietary protein and generally support the view that protein requirement is comparable between young and old adults.     

Circulating levels of irisin in patients with anorexia nervosa and different stages of obesity – Correlation with body mass index

Irisin was recently identified as cleavage product of fibronectin type III domain containing 5 (FNDC5) and shown to increase energy expenditure in mice and humans and therefore was discussed as potential treatment option in obesity. However, the regulation of irisin under conditions of severely altered body weight such as anorexia nervosa and obesity remains to be investigated. We analyzed circulating irisin levels over a broad spectrum of body weight in 40 patients with anorexia nervosa (mean body mass index, BMI 12.6 ± 0.7 kg/m²), normal weight controls (22.6 ± 0.9 kg/m²) and obese patients with BMI of 30–40 (36.9 ± 1.2 kg/m²), 40–50 (44.9 ± 1.1 kg/m²) and >50 (70.1 ± 2.7 kg/m², n = 8/group). Correlation analyses were performed between irisin and different body indices, parameters of body composition and hormones involved in various homeostatic processes. Obese patients showed higher circulating irisin levels compared to normal weight and anorexic patients (p < 0.05) resulting in a correlation of irisin with body weight (r = 0.47, p < 0.01) and BMI (r = 0.50, p < 0.001). Plasma irisin was also positively correlated with fat mass (r = 0.48, p < 0.01), body cell mass (r = 0.45, p < 0.01) and fat free mass (r = 0.40, p < 0.05). Insulin levels were positively correlated with irisin (r = 0.45, p < 0.01), whereas circulating ghrelin, cortisol, thyroid-stimulating hormone or C-reactive protein were not (p > 0.05). These data indicate that circulating irisin is affected under conditions of altered BMI with highest levels in severely obese patients. The increase of irisin under conditions of obesity may indicate a physiological function to improve glucose tolerance which is often impaired in obese subjects.     

Do adipokines underlie the association between known risk factors and breast cancer among a cohort of United States women?

Introduction: Obesity is a well-established risk factor for postmenopausal breast cancer, but mechanisms underlying the association are unclear. Adipocyte-derived, cytokine-like adipokines have been suggested as contributory factors. To evaluate their association with breast cancer risk factors and breast cancer risk, we conducted a nested case-control study of 234 postmenopausal breast cancer cases and 234 controls in a cohort of U.S. women with prospectively-collected serum samples obtained in the mid 1970s and followed for up to 25 years. Methods: Adiponectin, absolute plasminogen activator inhibitor-1 (aPAI-1), and resistin were measured by a multiplex immunoassay. Sex hormones were available for 67 cases and 67 controls. Results: Among controls, we found that lower levels of adiponectin and higher levels of aPAI-1 were correlated with increasing levels of estradiol (Spearman r = ?0.26, p-value = 0.033; r = 0.42, p = 0.0003), decreasing levels of sex hormone binding globulin (r = 0.38, p = 0.0013; r = ?0.32, p = 0.0076), and increasing body mass index (BMI) (r = ?0.31, p =  < 0.0001; r = 0.39, p =  < 0.0001). Hormones were not associated with resistin. Among the relatively small percentage of women using postmenopausal hormones at the time of blood collection (13.7%), aPAI-1 levels were higher than in non-users (p = 0.0054). Breast cancer risk was not associated with circulating levels of adiponectin (age-adjusted p for linear trend = 0.43), aPAI-1 (p = 0.78), or resistin (p = 0.91). The association was not confounded by BMI, parity, age at first full-term birth, age at menopause, current postmenopausal hormone use, and circulating sex steroid hormones. Furthermore, adipokine associations were not modified by BMI (p > 0.05). The lack of association with risk may be due to measurement error of the laboratory assays. Discussion: lower levels of adiponectin and higher levels of aPAI-1 measured in prospectively-collected serum from postmenopausal women were associated with increasing BMI but not breast cancer risk.