The impact of bariatric surgery on calcium homeostasis and bone metabolism

The increasing prevalence of obesity poses a health thread for individuals and a major economic burden. Besides other important obesity related diseases such as type 2 diabetes (T2D), it has become clear that obesity is also associated with an increased fracture risk. Bariatric surgery or weight loss surgery has proven to be a valuable treatment option for morbid obesity and improvement of obesity related conditions. Roux-en-Y gastric bypass (RYGB) is regarded as the gold standard, but Sleeve Gastrectomy (SG) is gaining territory as it is believed to lead to less malabsorption, but absorption data on this procedure is currently limited. Both procedures adapt the intestinal anatomy and physiology, and subsequently can cause nutritional deficiencies, in particular of calcium, which at long term can lead to metabolic bone diseases. In this project, the impact of RYGB and SG on calcium homeostasis and bone metabolism will be investigated in detail in mice. Calcium transport will be characterized in the intestines and kidneys and the effects on the bones will be thoroughly phenotyped.status: publishe

Jodium, moeten we ons zorgen maken?

De jodiuminname lijkt een zorgenkind. De gebruikelijke inname, ook in België, is suboptimaal en vergt bijkomende maatregelen, zoals jodiumverrijking. Daarnaast moeten ook de algemene voedingsaanbevelingen zowel in de theorie als in de praktijk goed worden opgevolgd, zeker in tijden waarin het publiek gevoelig is voor hippe voedingstrends die onder meer oproepen om geen brood en melkproducten meer te eten. Goede bronnen van jodium mogen niet ondoordacht uit de voeding worden geschrapt of inadequaat worden vervangen.no ISSNstatus: publishe

Alteration of the Condylar Oral Bone in Obese and Gastric Bypass Mice

Obesity is the main cause of type 2 diabetes mellitus (T2DM). Roux-en-Y gastric bypass (RYGB) surgery is an effective treatment for this obesity-related health problem. However, the adverse effects of T2DM on bone tissue persist or even aggravate after this surgical procedure. As studies on the mandibular condyle bone are scarce, the aim of the present study was to assess its compositional characteristics in T2DM and RYGB conditions. Thirty-two male C57BL/6 mice at 8 weeks of age were randomly assigned to receive either a high-fat or low-fat diet. After 14 weeks of high-fat diet intake, seven obese mice were subjected to RYGB surgery. All animals were euthanized at the age of 30 weeks. Mandibular bones were removed and the trabecular condyle region was assessed using Raman spectroscopy. A decreased mineralization was observed for both T2DM and RYGB condyle bones when compared to controls, with elevated carbonate substitutions for the RYGB group. No compositional differences in crystallinity and presence of advanced glycation end products were found between the groups, with the exception of an increased presence of N-carboxymethyl-lysine in RYGB bone compared to their T2DM counterpart. Site-specific measurements revealed a non-uniform bone composition, with increasing mineralization and carbonate substitutions towards the centre of the mandibular condyle. T2DM and RYGB surgery affect the mandibular condyle bone quality, as investigated at compositional level. Assessment of bone structural properties and remodelling should be carried out to further explore the effects of T2DM and RYGB surgery on this skeleton area

Alteration of the Condylar Oral Bone in Obese and Gastric Bypass Mice

Obesity is the main cause of type 2 diabetes mellitus (T2DM). Roux-en-Y gastric bypass (RYGB) surgery is an effective treatment for this obesity-related health problem. However, the adverse effects of T2DM on bone tissue persist or even aggravate after this surgical procedure. As studies on the mandibular condyle bone are scarce, the aim of the present study was to assess its compositional characteristics in T2DM and RYGB conditions. Thirty-two male C57BL/6 mice at 8 weeks of age were randomly assigned to receive either a high-fat or low-fat diet. After 14 weeks of high-fat diet intake, seven obese mice were subjected to RYGB surgery. All animals were euthanized at the age of 30 weeks. Mandibular bones were removed and the trabecular condyle region was assessed using Raman spectroscopy. A decreased mineralization was observed for both T2DM and RYGB condyle bones when compared to controls, with elevated carbonate substitutions for the RYGB group. No compositional differences in crystallinity and presence of advanced glycation end products were found between the groups, with the exception of an increased presence of N-carboxymethyl-lysine in RYGB bone compared to their T2DM counterpart. Site-specific measurements revealed a non-uniform bone composition, with increasing mineralization and carbonate substitutions towards the centre of the mandibular condyle. T2DM and RYGB surgery affect the mandibular condyle bone quality, as investigated at compositional level. Assessment of bone structural properties and remodelling should be carried out to further explore the effects of T2DM and RYGB surgery on this skeleton area.status: publishe

Modelling cereal crops to assess future climate risk for family food self-sufficiency in southern Mali

Future climate change will have far reaching consequences for smallholder farmers in sub-Saharan Africa, the majority of whom depend on agriculture for their livelihoods. Here we assessed the farm-level impact of climate change on family food self-sufficiency and evaluated potential adaptation options of crop management. Using three years of experimental data on maize and millet from an area in southern Mali representing the Sudano-Sahelian zone of West Africa we calibrated and tested the Agricultural Production Systems sIMulator (APSIM) model. Changes in future rainfall, maximum and minimum temperature and their simulated effects on maize and millet yield were analysed for climate change predictions of five Global Circulation Models (GCMs) for the 4.5 Wm−2 and 8.5 Wm−2 radiative forcing scenario (rcp4.5 and rcp8.5). In southern Mali, annual maximum and minimum temperatures will increase by 2.9 °C and 3.3 °C by the mid-century (2040–2069) as compared with the baseline (1980–2009) under the rcp4.5 and rcp8.5 scenario respectively. Predicted changes in the total seasonal rainfall differed between the GCMs, but on average, seasonal rainfall was predicted not to change. By mid-century maize grain yields were predicted to decrease by 51% and 57% under current farmer’s fertilizer practices in the rcp4.5 and rcp8.5 scenarios respectively. APSIM model predictions indicated that the use of mineral fertilizer at recommended rates cannot fully offset the impact of climate change but can buffer the losses in maize yield up to 46% and 51% of the baseline yield. Millet yield losses were predicted to be less severe under current farmer’s fertilizer practices by mid-century i.e. 7% and 12% in the rcp4.5 and rcp8.5 scenario respectively. Use of mineral fertilizer on millet can offset the predicted yield losses resulting in yield increases under both emission scenarios. Under future climate and current cropping practices, food availability is expected to reduce for all farm types in southern Mali. However, large and medium-sized farms can still achieve food self–sufficiency if early planting and recommended rates of fertilizer are applied. Small farms, which are already food insecure, will experience a further decrease in food self-sufficiency, with adaptive measures of early planting and fertilizer use unable to help them achieve food self-sufficiency. By taking into account the diversity in farm households that is typical for the region, we illustrated that crop management strategies must be tailored to the capacity and resource endowment of local farmers. Our place-based findings can support decision making by extension and development agents and policy makers in the Sudano-Sahelian zone of West Africa

Involvement of the GHSR in the developmental programming and metabolic disturbances induced by maternal undernutrition

The mismatch between maternal undernutrition and adequate nutrition after birth increases the risk of developing metabolic diseases. We aimed to investigate whether the hyperghrelinemia during maternal undernourishment rewires the hypothalamic development of the offspring and contributes to the conversion to an obese phenotype when fed a high-fat diet (HFD). Pregnant C57BL/6 J, wild type (WT) and ghrelin receptor (GHSR)-/- mice were assigned to either a normal nourished (NN) group, or an undernutrition (UN) (30% food restricted) group. All pups were fostered by NN Swiss mice. After weaning, pups were fed a normal diet, followed by a HFD from week 9. Plasma ghrelin levels peaked at postnatal day 15 (P15) in both C57BL/6 J UN and NN pups. Hypothalamic Ghsr mRNA expression was upregulated at P15 in UN pups compared to NN pups and inhibited agouti-related peptide (AgRP) projections. Adequate lactation increased body weight of UN WT but not of GHSR-/- pups compared to NN littermates. After weaning with a HFD, body weight and food intake was higher in WT UN pups but lower in GHSR-/- UN pups than in NN controls. The GHSR prevented a decrease in ambulatory activity and oxygen consumption in UN offspring during ad libitum feeding. Maternal undernutrition triggers developmental changes in the hypothalamus in utero which were further affected by adequate feeding after birth during the postnatal period by affecting GHSR signaling. The GHSR contributes to the hyperphagia and the increase in body weight when maternal undernutrition is followed by an obesity prone life environment.status: publishe

Evaluation of climate adaptation options for Sudano-Sahelian cropping systems

In the Sudano-Sahelian region, smallholder agricultural production is dominated by rain-fed production of millet, sorghum and maize for food consumption and of cotton for the market. A major constraint for crop production is the amount of rainfall and its intra and inter-annual variability. We evaluated the effects of planting date on the yield of different varieties of four major crops (maize, millet, sorghum and cotton) over three contrasting growing seasons in 2009-2011 (with 842. mm, 1248. mm and 685. mm of rainfall respectively) with the aim of identifying climate adaptation options in the Sudano-Sahelian region. Three planting dates (early, medium, and late) and three varieties of long, medium, and short duration of each crop were compared. For fertilized cereal crops, maize out yielded millet and sorghum by respectively 57% and 45% across the three seasons. Analysis of 40 years of weather data indicates that this finding holds for the longer time periods than the length of this trial. Late planting resulted in significant yield decreases for maize, sorghum and cotton, but not for millet. However, a short duration variety of millet was better adapted for late planting. When the rainy season starts late, sorghum planting can be delayed from the beginning of June to early July without substantial reductions in grain yield. Cotton yield at early planting was 28% larger than yield at medium planting and late planting gave the lowest yield with all three varieties. For all four crops the largest stover yields were obtained with early planting and the longer planting was delayed, the less stover was produced. There was an interaction between planting date and variety for millet and sorghum, while for maize and cotton the best planting date was more affected by the weather conditions. The findings of this study can support simple adaptation decisions: priority should be given to planting cotton early; maize is the best option if fertilizer is available; planting of maize and sorghum can be delayed by up to a month without strong yield penalties; and millet should be planted last. © 2013 Elsevier B.V