Phosphorus Supplementation Recovers the Blunted Diet-Induced Thermogenesis of Overweight and Obese Adults: A Pilot Study

Vitamin D status and its relationship with obesity indicators in Moroccan adult women

Background: Although vitamin D deficiency has been studied in various populations, there are few data on its prevalence and associated factors among Moroccan women. Aim: To determine the prevalence of vitamin D deficiency and investigate its association with body mass index (BMI), waist circumference, and serum concentrations of parathyroid hormone, calcium, and phosphorus in a sample of Moroccan adult women. Methods: This is a cross-sectional study conducted at Mohammed V Military Hospital of Instruction, Rabat. Anthropometric measurements and biochemical analyses were performed using standard procedures Results: A total of 714 women aged 18-65 years participated in this study. The overall prevalence of vitamin D deficiency was 74.4%. Approximately 24% and 51% of women had severe and moderate vitamin D deficiency, respectively. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were inversely correlated with BMI in vitamin D-deficient subjects (P = 0.036) and with parathyroid hormone 1-84 (PTH1-84) levels in the study sample (P = 0.010). PTH1-84 concentrations were greater among overweight/obese individuals compared to their non-overweight peers (P = 0.001) and tended to be higher among vitamin D-deficient women than vitamin D-sufficient women (P = 0.053). Conclusion: This study showed a very high prevalence of vitamin D deficiency in this sample of Moroccan women. Lower serum 25(OH)D levels were associated with increased BMI in vitamin D-deficient women and with elevated PTH1-84 levels among the study sample. Although these findings come from a convenience sample of women that attended a nutrition clinic, they underscore the urgent need to develop public health interventions to improve women's vitamin D status.

Eat like a Pig to Combat Obesity

Obesity and related metabolic health issues are a growing human threat, with many theories regarding its causes. In swine, physiologically alike to humans, considerable knowledge on obesity mechanisms has been accumulated. Calorie counting is the basis for managing swine diets and applied with great accuracy. Epigenetic programing predisposes pigs to insulin insensitivity, but pigs seem to sense this insensitivity and consequently eat less, preventing obesity. Pigs naturally prefer to eat small breakfasts and large dinners. Deviating from this eating pattern or providing diets with a high glycemic burden can trigger obesity; however, pigs will restrict food intake to prevent serious obesity. Interestingly, in practice, problems with obesity are rarely seen, even when pigs are fed poorly timed diets similar to junk food, likely because swine diets are balanced for every nutrient. Indeed, feeding pigs diets deficient in micronutrients does trigger obesity. For humans, several micronutrient requirements have not been set officially, and diets optimized for all micronutrients are rarely provided. In conclusion, various obesity triggers are being debated for humans, which have been proven in swine. Obesity problems in pigs are nevertheless less excessive, likely because pigs recognize unhealthy eating practices and consequently reduce food intake to avoid serious complications. Finally, swine diets are normally balanced for all nutrients, which may be an important practice to prevent obesity, from which human health could greatly benefit.

Serum TSH, 25(OH) D and phosphorus levels predict weight loss in individuals with diabetes/prediabetes and morbid obesity: a single-center retrospective cohort analysis

BACKGROUND

To evaluate the association of vitamin D and thyroid-stimulating hormone (TSH) with weight loss (WL) percentage (%) in patients with diabetes/prediabetes and Class II/III obesity.

METHODS

A retrospective cohort study was designed. Data were collected from a database of a referral endocrinology clinic that is prospectively and systematically generated. After exclusion of unavailable cases, the study enrolled 285 patients (51 ± 11 years old, female/male = 208/77; diabetes/prediabetes = 159/126; no/on levothyroxine replacement = 176/109; Class II/III obesity = 184/101, respectively) who maintained euthyroidism and were followed up for ≥6 months. The data were analyzed to determine the predictors of WL%.

RESULTS

Compared with baseline, in the median 22 months of follow-up, the whole study group lost 5.1% of their baseline body weight. As most obesity management trials define success as 'at least 10% of WL compared to baseline', we stratified the patients based on WL% extents. The distribution was as follow: Group 1 (n = 61) lost ≥10% body weight, Group 2 (n = 162) lost < 10% body weight, while Group 3 (n = 62) gained weight by the final visit. In groups 1 and 2 (weight losers), the serum thyroid stimulatig hormone (TSH) and parathyroid hormone (PTH) levels decreased and the free thyroxine (fT4), calcium, phosphorus, and 25-hydroxyvitamin D (25(OH)D) levels increased. In Group 3 (weight gainers), these changes were not observed (except for an increase in calcium levels). Regression analysis revealed that the final visit TSH (β = - 0.14, p < 0.05), 25(OH) D (β = 0.15, p < 0.05), and phosphorus (β = 0.20, p < 0.05) levels predicted WL%. However, if patients with autoimmune thyroiditis were excluded from the analysis, the decrease in TSH levels was not statistically significant.

CONCLUSIONS

Serum TSH, phosphorus, and 25(OH) D levels predict WL% in euthyroid patients with diabetes/prediabetes and morbid obesity. TSH predictivity seems to be a function of thyroid autoimmunity present with increased frequency in this cohort. Greater levels of phosphorus within the reference range and a sufficient vitamin D status are associated with a greater WL%.

Chronic High Phosphate Intake in Mice Affects Macronutrient Utilization and Body Composition

SCOPE

In the last decades, dietary phosphate intake has increased due to a higher consumption of processed food. This higher intake has an impact on body composition and health state. Recently, we found that a high chronic phosphate diet leads to no major renal alterations, but negatively affects parameters of bone health probably due to the chronic acid load. Here we assessed the effect of high phosphate consumption on parameters of energy metabolism.

METHODS AND RESULTS

Healthy mature adult mice were fed for 1 year or four months with either a standard (0.6 % w/w) or a high phosphate (1.2 % w/w) diet. Males and females of two different genetic backgrounds were investigated. Mice fed the high phosphate diet showed an attenuated body-weight gain, lower respiratory exchange ratio, decreased body fat mass and increased lean-to-fat mass ratio. Moreover, the high phosphate diet led to fasting hypoglycemia with no differences in the glucose response to an oral glucose tolerance test. Triglycerides and cholesterol in blood were similar independently of dietary phosphate content. However, 1-methylhistidine was lower in animals fed a chronic high phosphate intake.

CONCLUSIONS

High phosphate diet attenuates body weight gain, but induces hypoglycaemia and may alter muscle homeostasis. This article is protected by copyright. All rights reserved.

PiT2 deficiency prevents increase of bone marrow adipose tissue during skeletal maturation but not in OVX-induced osteoporosis

The common cellular origin between bone marrow adipocytes (BMAds) and osteoblasts contributes to the intimate link between bone marrow adipose tissue (BMAT) and skeletal health. An imbalance between the differentiation ability of BMSCs towards one of the two lineages occurs in conditions like aging or osteoporosis, where bone mass is decreased. Recently, we showed that the sodium-phosphate co-transporter PiT2/SLC20A2 is an important determinant for bone mineralization, strength and quality. Since bone mass is reduced in homozygous mutant mice, we investigated in this study whether the BMAT was also affected in PiT2^-/- mice by assessing the effect of the absence of PiT2 on BMAT volume between 3 and 16 weeks, as well as in an ovariectomy-induced bone loss model. Here we show that the absence of PiT2 in juveniles leads to an increase in the BMAT that does not originate from an increased adipogenic differentiation of bone marrow stromal cells. We show that although PiT2^-/- mice have higher BMAT volume than control PiT2^+/+ mice at 3 weeks of age, BMAT volume do not increase from 3 to 16 weeks of age, leading to a lower BMAT volume in 16-week-old PiT2^-/- compared to PiT2^+/+ mice. In contrast, the absence of PiT2 does not prevent the increase in BMAT volume in a model of ovariectomy-induced bone loss. Our data identify SLC20a2/PiT2 as a novel gene essential for the maintenance of the BMAd pool in adult mice, involving mechanisms of action that remain to be elucidated, but which appear to be independent of the balance between osteoblastic and adipogenic differentiation of BMSCs.

The Role of Mineral Deficiencies in Insulin Resistance and Obesity

Minerals are critical for maintaining overall health. These tiny chemical compounds are responsible for enzymatic activation, maintaining healthy teeth and bones, regulating energy metabolism, enhancing immunity, and aiding muscle and brain function. However, mineral deficiency in the form of inadequate or under nourished intake affects millions of people throughout the world, with well-documented adverse health consequences of malnutrition. Conversely, mineral deficiency may also be a risk factor for Insulin Resistance (IR) and obesity. This review focuses on another, more "less discussed" form of malnutrition, namely mineral deficiency and its contribution to metabolic disorders. At the cellular level, minerals maintain not only molecular communication but also trigger several key biochemical pathways. Disturbances in these processes due to mineral insufficiency may gradually lead to metabolic disorders such as insulin resistance, pre-diabetes, and central obesity, which might lead to renal failure, cardiac arrest, hepatic carcinoma, and various neurodegenerative diseases. Here we discuss the burden of disease promoted by mineral deficiencies and the medical, social, and economic consequences. Mineral deficiency-mediated IR and obesity have a considerable negative impact on individual well-being, physical consideration, and economic productivity. We discuss possible molecular mechanisms of mineral deficiency that may lead to IR and obesity and suggest strategies to counter these metabolic disorders. To protect mankind from mineral nutrient deficiencies, the key is to take a variety of foods in reasonable quantities, such as organic and pasture-raised eggs, low fat dairy, and grass-fed and finished meats, insecticide, and pesticide-free vegetables and fruits.

Phosphorus Supplementation Mitigates Perivascular Adipose Inflammation-Induced Cardiovascular Consequences in Early Metabolic Impairment

Background

The complexity of the interaction between metabolic dysfunction and cardiovascular complications has long been recognized to extend beyond simple perturbations of blood glucose levels. Yet, structured interventions targeting the root pathologies are not forthcoming. Growing evidence implicates the inflammatory changes occurring in perivascular adipose tissue (PVAT) as early instigators of cardiovascular deterioration.

Methods and Results

We used a nonobese prediabetic rat model with localized PVAT inflammation induced by hypercaloric diet feeding, which dilutes inorganic phosphorus (Pi) to energy ratio by 50%, to investigate whether Pi supplementation ameliorates the early metabolic impairment. A 12‐week Pi supplementation at concentrations equivalent to and twice as much as that in the control diet was performed. The localized PVAT inflammation was reversed in a dose‐dependent manner. The increased expression of UCP1 (uncoupling protein1), HIF‐1α (hypoxia inducible factor‐1α), and IL‐1β (interleukin‐1β), representing the hallmark of PVAT inflammation in this rat model, were reversed, with normalization of PVAT macrophage polarization. Pi supplementation restored the metabolic efficiency consistent with its putative role as an UCP1 inhibitor. Alongside, parasympathetic autonomic and cerebrovascular dysfunction function observed in the prediabetic model was reversed, together with the mitigation of multiple molecular and histological cardiovascular damage markers. Significantly, a Pi‐deficient control diet neither induced PVAT inflammation nor cardiovascular dysfunction, whereas Pi reinstatement in the diet after a 10‐week exposure to a hypercaloric low‐Pi diet ameliorated the dysfunction.

Conclusions

Our present results propose Pi supplementation as a simple intervention to reverse PVAT inflammation and its early cardiovascular consequences, possibly through the interference with hypercaloric‐induced increase in UCP1 expression/activity.

Daily energy expenditure in rats following structured exercise training is affected by dietary phosphorus content

P ingestion has been found to alter energy balance, while regular physical exercise (E) was reported to be associated with energy compensation. However, it is not clear whether dietary P would affect energy compensation following structured E. Two experiments were performed, low P (LP) (0·1, 0·2 and 0·3 %P) and high P (HP) (0·3 , 0·6 and 1·2 %P) diets. In each experiment, male rats were randomly divided into three groups (n 8), in which a sedentary or a moderate-intensity exercise routine (30 min 5 d a week) was implemented. Energy intake (EI); efficiency and stores; body measures and total energy expenditure (TEEx) were monitored for 6 weeks. In the LP experiment, EI and weight gain were the lowest in the 0·1 and 0·2 %P as compared with the 0·3 %P. In the HP experiment, EI was highest in the high P (0·6 and 1·2 %P) groups, while weight gain was reduced. In both experiments, exercise was able to reduce body fat accumulation and to maintain a higher % lean body mass. In the LP diets experiment, the similarity in TEEx between the sedentary and exercising groups suggests the probability of a reduction in normal daily activities, which indicates the presence of compensation for the energy expended during exercise by a subsequent reduction in EE. In contrast, the elevated TEEx in the HP exercising groups (0·6 and 1·2 %P) argue against the presence of energy compensation. In conclusion, high dietary P decreases the body's capability to compensate for the energy deficit induced by E, consequently maintaining an elevated TEEx.

Body composition and cardiometabolic health of pediatric patients with X-linked hypophosphatemia (XLH) under burosumab therapy

BACKGROUND

Burosumab, a recombinant anti-FGF23 monoclonal antibody, was recently introduced as a treatment for X-linked hypophosphatemia (XLH). Burosumab normalizes blood phosphate levels, thereby healing rickets, decreasing leg bowing, and reducing pain. We aimed to explore the body composition and cardiometabolic health of pediatric patients with XLH treated with burosumab.

METHODS

This observational real-life study was conducted on growing children and adolescents. The outcome measures included changes in sex- and age-adjusted anthropometric and body composition parameters [fat mass (FM), fat-free mass (FFM), appendicular skeletal muscle mass (ASMM), muscle-to-fat ratio (MFR)], blood pressure, laboratory evaluation, and radiographic rickets severity [Thacher Rickets Severity Score (TRSS)]. Body composition was assessed by bioelectrical impedance analysis (BIA). Percentiles for FFM% and ASMM% were calculated according to BIA pediatric reference curves. The delta variable was calculated as the variable at 12 months minus the variable at baseline.

RESULTS

A total of 15 pediatric patients with XLH are treated in our clinic; included in the analyses were 7 children and adolescents (3 males, mean age 8.7 ± 3.2 years) with XLH without comorbidities. Baseline BIA revealed an unfavorable physique, with increased body fat percentage in five patients and decreased muscle mass in six. Indices of lean body mass significantly increased after 6 and 12 months of treatment: FFM(kg) (p = 0.001, p = 0.046, respectively) and ASMM(kg) (p = 0.012, p = 0.034, respectively), without any significant change in FM(kg). The percentile of ASMM% increased significantly after 6 months of treatment (p = 0.006) and stabilized thereafter. TRSS improved significantly after 12 months of therapy (p = 0.005). Age was positively correlated with delta TRSS (r = 0.814, p = 0.026), and delta TRSS was negatively correlated with delta MFR (r = -0.826, p = 0.022).

CONCLUSIONS

There was a heretofore unrecognized improvement in body composition of growing children and adolescents with XLH who were treated with burosumab. These findings highlight the need to initiate burosumab treatment at a younger age when rickets is less severe.

Impact of a novel partial defatting technology on oxidative stability and sensory properties of peanut kernels

A novel process, 'mechanical expression preserving shape integrity', was conceived to prepare low-fat peanuts in response to health-conscious consumer demands. The main purpose of this study was to preserve the taste, aroma, and oxidative stability of the defatted product. Results generated from a central composite rotatable design showed that highest consumer sensory scores were reached at low pressures (4-6 MPa). Free fatty acid, peroxide, p-anisidine, and total oxidation values were mostly affected by water content [W] and pressure [P] with high correlation coefficients (82% < R² < 87%). Overall, lipid oxidation and flavor fade were associated with higher defatting ratios and greater physical damage. The latter plays a major role in increasing the surface area and facilitating the access of oxygen to the remaining oil, thus rendering the defatted product more prone to oxidation. However, oxidation was reduced significantly using a Response Surface Methodology to optimize conditions ([W] 12.2 ± 0.6%d.b., [P] 6 ± 0.3 MPa and time [t] 18.2 ± 0.6 min).

Increased prevalence of overweight and obesity in children with X-linked hypophosphatemia

BACKGROUND/AIM

X-linked hypophosphatemia (XLH) is a rare disease characterized by low phosphate levels. Scientific evidence points to a link between hypophosphatemia and obesity in general population. The aim of our longitudinal observational study was to investigate the prevalence of obesity and associated factors in a large cohort of children with XLH.

PATIENTS/METHODS

We studied 172 XLH-children 5-20 years of age (113 girls/59 boys). Anthropometric parameters (weight, height, and BMI) were collected at birth and during follow-up at mean ages of 5.3, 8.2, 11.3, and 15.9 years (groups 1, 2, 3, and 4, respectively). In each group, subjects were classified based on International Obesity Taskforce (IOTF) cut off values of BMI for age and sex as overweight or obese (IOTF 25-30 or ≥30 kg/m2, respectively).

RESULTS

In each age-group, almost 1/3 of XLH-patients were classified as overweight or obese (29.4, 28.7, 27.5, and 36.7% in groups 1, 2, 3, and 4, respectively). Children without a XLH-family history had higher BMI-IOTF at every point of follow-up, compared to those with positive XLH-family history. Similarly, higher BMI-IOTF was significantly associated with treatment duration (23.3 ± 4.4 vs 23.8 ± 3.8 vs 25.2 ± 4.5 kg/m2, for subjects with treatment duration of <5, 5-10 and >10 years, respectively, P for trend = 0.025). Multiple regression analysis confirmed an association of treatment duration and lack of XLH-family history with higher BMI-IOTF.

CONCLUSION

One out of three of XLH-children have phenotypically unfavourable metabolic profile expressed as increased prevalence of overweight or obesity in comparison to general population. Both the lack of XLH family history and the duration of treatment increase the risk of higher BMI-IOTF. BMI should be carefully monitored in children, and later in adults, with XLH.

Dietary Lead and Phosphate Interactions Affect Oral Bioavailability of Soil Lead in the Mouse

Effects of dietary P level on the oral bioavailability of Pb present in soil were examined in a mouse model. Adult female C57BL/6 mice had free access to AIN-93G purified rodent diet amended with Pb as a soluble salt, Pb acetate, or in a soil matrix (NIST SRM 2710a). In these studies, the basal diet contained P at a nutritionally sufficient level (0.3% w/w) and the modified diets contained P at a lower (0.15%) or a higher (1.2%) level. For either dietary Pb source (Pb acetate or NIST SRM 2710a), low dietary P level markedly increased accumulation of Pb in bone, blood, and kidney. Tissue Pb levels in mice fed a high P in diet were not different from mice fed the basal P diet. Dietary P and Pb interacted to affect body weight change and feed efficiency in mice. The relative contribution of different Pb species in diet and feces was also affected by dietary P level. Differences in Pb species between diet and feces indicated that transformation of Pb species can occur during gastrointestinal tract transit. These interactions between Pb and P that alter Pb speciation may be important determinants of the bioavailability of Pb ingested in soil.

High phosphate diet suppresses lipogenesis in white adipose tissue

Excessive phosphate intake has been positively associated with renal and vascular dysfunction, conversely negatively associated with body fat accumulation. We investigated the effect of a high-phosphate diet on the expression of lipid metabolic genes in white adipose tissue and liver. Male 8-week-old Sprague-Dawley rats were fed a control diet containing 0.6% phosphate or a high-phosphate diet containing 1.5% phosphate for 4 weeks. In comparison to the control group, the HP group showed a significantly lower body fat mass and fasting plasma insulin level alongside decreased lipogenic and increased lipolytic gene expression in visceral fat. Additionally, the expression of genes involved in hepatic lipogenesis, hepatic glycogenesis, and triglyceride accumulation decreased in the high-phosphate group. Exogenous phosphate, parathyroid hormone, and fibroblast growth factor 23 did not directly affect the expression of lipolytic or lipogenic genes in 3T3-L1 adipocytes and HepG2 hepatocytes. Thus, the high-phosphate diet suppressed the activity of white adipose tissue by increasing lipolytic gene expression and decreasing lipogenic gene expression. These effects could have been caused by the lowered fasting plasma insulin level that occurred in response to the high-phosphate diet, but were not directly caused by the increases in plasma phosphate or phosphaturic hormones.

High phosphate diet suppresses lipogenesis in white adipose tissue

Excessive phosphate intake has been positively associated with renal and vascular dysfunction, conversely negatively associated with body fat accumulation. We investigated the effect of a high-phosphate diet on the expression of lipid metabolic genes in white adipose tissue and liver. Male 8-week-old Sprague-Dawley rats were fed a control diet containing 0.6% phosphate or a high-phosphate diet containing 1.5% phosphate for 4 weeks. In comparison to the control group, the HP group showed a significantly lower body fat mass and fasting plasma insulin level alongside decreased lipogenic and increased lipolytic gene expression in visceral fat. Additionally, the expression of genes involved in hepatic lipogenesis, hepatic glycogenesis, and triglyceride accumulation decreased in the high-phosphate group. Exogenous phosphate, parathyroid hormone, and fibroblast growth factor 23 did not directly affect the expression of lipolytic or lipogenic genes in 3T3-L1 adipocytes and HepG2 hepatocytes. Thus, the high-phosphate diet suppressed the activity of white adipose tissue by increasing lipolytic gene expression and decreasing lipogenic gene expression. These effects could have been caused by the lowered fasting plasma insulin level that occurred in response to the high-phosphate diet, but were not directly caused by the increases in plasma phosphate or phosphaturic hormones.

Cardiac Autonomic Neuropathy as a Result of Mild Hypercaloric Challenge in Absence of Signs of Diabetes: Modulation by Antidiabetic Drugs

Cardiac autonomic neuropathy (CAN) is an early cardiovascular complication of diabetes occurring before metabolic derangement is evident. The cause of CAN remains elusive and cannot be directly linked to hyperglycemia. Recent clinical data report cardioprotective effects of some antidiabetic drugs independent of their hypoglycemic action. Here, we used a rat model receiving limited daily increase in calories from fat (HC diet) to assess whether mild metabolic challenge led to CAN in absence of interfering effects of hyperglycemia, glucose intolerance, or obesity. Rats receiving HC diet for 12 weeks showed reduction in baroreceptor sensitivity and heart rate variability despite lack of change in baseline hemodynamic and cardiovascular structural parameters. Impairment of cardiac autonomic control was accompanied with perivascular adipose inflammation observed as an increased inflammatory cytokine expression, together with increased cardiac oxidative stress, and signaling derangement characteristic of diabetic cardiomyopathy. Two-week treatment with metformin or pioglitazone rectified the autonomic derangement and corrected the molecular changes. Switching rats to normal chow but not to isocaloric amounts of HC for two weeks reversed CAN. As such, we conclude that adipose inflammation due to increased fat intake might underlie development of CAN and, hence, the beneficial effects of metformin and pioglitazone.