Post-weaning protein malnutrition increases blood pressure and induces endothelial dysfunctions in rats

Meta-analysis and moderator analysis of the prevalence of malnutrition and malnutrition risk among older adults with dementia

BACKGROUND

Aging and dementia are common and closely related health problems in older adults, affecting their ability to maintain a healthy diet and ultimately resulting in malnutrition.

OBJECTIVE

In this study, we estimated the global prevalence of malnutrition and malnutrition risk in older adults with dementia.

DESIGN

Meta-analysis.

DATA SOURCES

Embase, Ovid MEDLINE, PubMed, CINAHL, Scopus, and Web of Science were comprehensively searched for articles published from database inception to October 2022.

METHODS

Pooled prevalence analysis was conducted using a generalized linear mixed model and a random-effects model. I2 and Cochran's Q statistics were used for identifying heterogeneity. Publication bias was evaluated using Peters' regression test and a funnel plot. Moderator analyses were conducted to investigate variations in the prevalence estimates of the included studies. All statistical analyses were conducted using R software.

RESULTS

A total of 16 studies involving a total of 6513 older adults with dementia were included in the analysis. The results indicated that 32.52 % (95 % confidence interval: 19.55-45.49) of all included older adults with dementia had malnutrition, whereas 46.80 % (95 % confidence interval: 38.90-54.70) had a risk of malnutrition. The prevalence of malnutrition was found to be high among older patients living in institutionalized settings (46.59 %) and those with Alzheimer's disease (12.26 %). The factors moderating the prevalence of malnutrition included adequate vitamin B12 consumption, risk behaviors, medical comorbidities, and certain neuropsychiatric symptoms. The prevalence of malnutrition risk was high among women (29.84 %) and patients with Alzheimer's disease (26.29 %). The factors moderating the prevalence of malnutrition risk included total cholesterol level, vitamin B12 consumption, risk behaviors, medical comorbidities, and certain neuropsychiatric symptoms.

CONCLUSIONS

Approximately one-third of older adults with dementia are malnourished and nearly half of older adults are at a risk of malnutrition. Encouraging collaboration among health-care professionals and ensuring early assessment and effective management of malnutrition are crucial for maintaining a favorable nutritional status in older adults with dementia.

REGISTRATION

This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO: CRD42022369329).

TWEETABLE ABSTRACT

Globally, approximately 32.52 % of older adults with dementia are malnourished and approximately 46.80 % are at a risk of malnutrition.

Effect of Moderate Malnutrition on the Pharmacokinetics of Etoposide and Vincristine in Freshly Weaned Rats

BACKGROUND

Moderate malnutrition is a common problem in young children. It is observed that severe malnutrition affects the pharmacokinetics of chemotherapy drugs in pediatric cancer patients, but moderate malnutrition is not well studied in this context.

OBJECTIVES

In this study, we aimed to understand how moderate malnutrition affects the pharmacokinetics of two chemotherapy drugs, etoposide and vincristine, using a murine model of early age moderate malnutrition.

METHODS

We developed a murine model of moderate childhood malnutrition by subjecting freshly weaned Sprague-Dawley rats to 8% protein diet for 8 weeks. In two separate experiments, we administered etoposide and vincristine (N = 8 for etoposide and N = 12 for vincristine each in protein deficient and control groups) through tail vein injection for pharmacokinetics study.

RESULTS

We found ~ 60% increase in area under the concentration-time curve (AUC) of etoposide in malnourished animals as compared to well-nourished animals. Furthermore, clearance, volume of distribution, and half-life were decreased by ~ 37, 53, and 24%, respectively, in malnourished animals. Pharmacokinetic parameters of vincristine showed only marginal differences between well-nourished and malnourished groups.

CONCLUSIONS

Our results suggest that while moderate malnutrition significantly affects the pharmacokinetics of etoposide, pharmacokinetics of vincristine remain unchanged. Since chemotherapy drugs have a narrow therapeutic index, the difference in AUC observed in our study might explain the increased toxicity of etoposide in malnourished pediatric cancer patients. This brings forth a need for robust clinical studies to validate our findings and optimize dose for malnourished patients.

Protein restriction during peripubertal period impairs endothelial aortic function in adult male Wistar rats

Protein restriction during early phases of body development, such as intrauterine life can favor the development of vascular disorders. However, it is not known if peripubertal protein restriction can favor vascular dysfunction in adulthood. The present study aimed to evaluated whether a protein restriction diet during peripubertal period favors endothelial dysfunction in adulthood. Male Wistar rats from postnatal day (PND) 30 until 60 received a diet with either 23% protein (CTR group) or with 4% protein (LP group). At PND 120, the thoracic aorta reactivity to phenylephrine, acetylcholine, and sodium nitroprusside was evaluated in the presence or absence of: endothelium, indomethacin, apocynin and tempol. The maximum response (Rmax) and pD2 (-log of the concentration of the drug that causes 50% of the Rmax) were calculated. The lipid peroxidation and catalase activity were also evaluated in the aorta. The data were analyzed by ANOVA (one or two-ways and Tukey's) or independent t-test; the results were expressed as mean ± S.E.M., p < 0.05. The Rmax to phenylephrine in aortic rings with endothelium were increased in LP rats when compared with the Rmax in CTR rats. Apocynin and tempol reduced Rmax to phenylephrine in LP aortic rings but not in CTR. The aortic response to the vasodilators was similar between the groups. Aortic catalase activity was lower and lipid peroxidation was greater in LP compared to CTR rats. Therefore, protein restriction during the peripubertal period causes endothelial dysfunction in adulthood through a mechanism related to oxidative stress.

Undernutrition - thirty years of the Regional Basic Diet: the legacy of Naíde Teodósio in different fields of knowledge

Undernutrition is characterized by an imbalance of essential nutrients with an insufficient nutritional intake, a disorder in which the clinical manifestations in most cases are the result of the economic and social context in which the individual lives. In 1990, the study by the medical and humanitarian Naíde Teodósio (1915-2005) and coworkers, which formulated the Regional Basic Diet (RBD) model for inducing undernutrition, was published. This diet model took its origin from the observation of the dietary habits of families that inhabited impoverished areas from the Pernambuco State. RBD mimics an undernutrition framework that extends not only to the Brazilian population, but to populations in different regions worldwide. The studies based on RBD-induced deficiencies provide a better understanding of the impact of undernutrition on the pathophysiological mechanisms underlying the most diverse prevalent diseases. Indexed papers that are analyzed in this review focus on the importance of using RBD in different areas of knowledge. These papers reflect a new paradigm in translational medicine: they show how the study of pathology using the RBD model in animals over the past 30 years has and still can help scientists today, shedding light on the mechanisms of prevalent diseases that affect impoverished populations.

Post-weaning protein malnutrition induces myocardial dysfunction associated with oxidative stress and altered calcium handling proteins in adult rats

Hypercaloric low-protein diet may lead to a state of malnutrition found in the low-income population of Northeastern Brazil. Although malnutrition during critical periods in the early life is associated with cardiovascular diseases in adulthood, the mechanisms of cardiac dysfunction are still unclear. Here we studied the effects of post-weaning malnutrition due to low protein intake induced by a regional basic diet on the cardiac contractility of young adult rats. In vivo arterial hemodynamic and in vitro myocardial contractility were evaluated in 3-month-old rats. Additionally, protein content of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), total phospholamban (PLB) and phosphorylated at serine 16 (p-Ser(16)-PLB), α2-subunit of the Na(+)/K(+)-ATPase (α2-NKA), and Na(+)/Ca(2+) exchanger (NXC) and in situ production of superoxide anion (O2(-)) were measured in the heart. Blood pressure and heart rate increased in the post-weaning malnourished (PWM) rats. Moreover, malnutrition decreased twitch force and inotropic responses of the isolated cardiac muscle. Protein expression of SERCA, PLB/SERCA, and p-Ser(16)-PLB/PLB ratios and α2-NKA were decreased without changing NCX. The contraction dependent on transsarcolemmal calcium influx was unchanged but responsiveness to Ca(2+) and tetanic peak contractions were impaired in the PWM group. Myocardial O2(-) production was significantly increased by PWM. Our data demonstrated that this hypercaloric low-protein diet in rats is associated with myocardial dysfunction, altered expression of major calcium handling proteins, and increased local oxidative stress. These findings reinforce the attention needed for pediatric care, since chronic malnutrition in early life is related to increased cardiovascular risk in adulthood. Graphical Abstract.

Perinatal programming of metabolic diseases: The role of glucocorticoids

The worldwide increase in metabolic diseases has urged the scientific community to improve our understanding about the mechanisms underlying its cause and effects. A well supported area of studies had related maternal stress with early programming to the later metabolic diseases. Mechanisms upon origins of metabolic disturbances are not yet fully understood, even though stressful factors rising glucocorticoids have been put out as pivotal trigger by programming metabolic diseases as long-term consequence. Considering energy balance and glucose homeostasis, by producing and/or sensing regulator signals, hypothalamus-pituitary-adrenal axis and endocrine pancreas are directly affected by glucocorticoids excess. We focus on the evidences reporting the role of increased glucocorticoids due to perinatal insults on the physiological systems involved in the metabolic homeostasis and in the target organs such as endocrine pancreas, white adipose tissue and blood vessels. Besides, we review some mechanisms underlining the malprogramming of type 2 diabetes, obesity and hypertension. Studies on this field are currently ongoing and even there is a good understanding regarding the effects of glucocorticoids addressing metabolic diseases, few is known about the relationship between maternal insults rising glucocorticoids to pups' metabolic disturbances, a thorough understanding about that may provide pivotal clinical clues regarding those disorders.

Impact of malnutrition on cardiac autonomic modulation in children

OBJECTIVE

To compare the autonomic behavior between malnourished children and a control group using analysis of heart rate variability (HRV).

METHOD

Data were analyzed from 70 children who were divided into two groups: malnourished and eutrophic, according to the Z-score nutritional status for height and age. For analysis of HRV indices, heart rate was recorded beat to beat with the child in the supine position for 20min. The analysis of these indices was performed using linear methods, analyzed in the time and frequency domains. Student's t-test for unpaired data and the Mann-Whitney test were used to compare variables between groups, with a significance level of 5%.

RESULTS

A reduction in systolic and diastolic blood pressure and an increase in heart rate were found in malnourished children compared to eutrophic children. The HRV indices suggested that malnourished children present reductions in both sympathetic and parasympathetic autonomic nervous system activity. The SDNN, rMSSD, NN50, pNN50, SD1, SD2, TINN, LF (ms²), and HF (ms²) indices were lower in malnourished children.

CONCLUSION

Malnourished children present changes in cardiac autonomic modulation, characterized by reductions in both sympathetic and parasympathetic activity, as well as increased heart rate and decreased blood pressure.

Slow Physical Growth, Delayed Reflex Ontogeny, and Permanent Behavioral as Well as Cognitive Impairments in Rats Following Intra-generational Protein Malnutrition

Environmental stressors including protein malnutrition (PMN) during pre-, neo- and post-natal age have been documented to affect cognitive development and cause increased susceptibility to neuropsychiatric disorders. Most studies have addressed either of the three windows and that does not emulate the clinical conditions of intra-uterine growth restriction (IUGR). Such data fail to provide a complete picture of the behavioral alterations in the F1 generation. The present study thus addresses the larger window from gestation to F1 generation, a new model of intra-generational PMN. Naive Sprague Dawley (SD) dams pre-gestationally switched to LP (8% protein) or HP (20% protein) diets for 45 days were bred and maintained throughout gestation on same diets. Pups born (HP/LP dams) were maintained on the respective diets post-weaningly. The present study aimed to show the sex specific differences in the neurobehavioral evolution and behavioral phenotype of the HP/LP F1 generation pups. A battery of neurodevelopmental reflex tests, behavioral (Open field and forelimb gripstrength test), and cognitive [Elevated plus maze (EPM) and Morris water maze (MWM)] assays were performed. A decelerated growth curve with significantly restricted body and brain weight, delays in apparition of neuro-reflexes and poor performance in the LP group rats was recorded. Intra-generational PMN induced poor habituation-with-time in novel environment exploration, low anxiety and hyperactive like profile in open field test in young and adult rats. The study revealed poor forelimb neuromuscular strength in LP F1 pups till adulthood. Group occupancy plots in MWM test revealed hyperactivity with poor learning, impaired memory retention and integration, thus modeling the signs of early onset Alzehemier phenotype. In addition, a gender specific effect of LP diet with severity in males and favoring female sex was also noticed.

Maternal protein restriction compromises myocardial contractility in the young adult rat by changing proteins involved in calcium handling

Maternal protein restriction (MPR) during pregnancy is associated with increased cardiovascular risk in the offspring in adulthood. In this study we evaluated the cardiac function of young male rats born from mothers subjected to MPR during pregnancy, focusing on the myocardial mechanics and calcium-handling proteins. After weaning, rats received normal diet until 3 mo old, when the following parameters were assessed: arterial and left ventricular hemodynamics and in vitro cardiac contractility in isolated papillary muscles. The body weight was lower and arterial pressure higher in the MPR group compared with young adult offspring of female rats that received standard diet (controls); and left ventricle time derivatives increased in the MPR group. The force developed by the cardiac muscle was similar; but time to peak and relaxation time were longer, and the derivatives of force were depressed in the MPR. In addition, MPR group exhibited decreased post-pause potentiation of force, suggesting reduced reuptake function of the sarcoplasmic reticulum. Corroborating, the myocardial content of SERCA-2a and phosphorylated PLB-Ser16/total PLB ratio was decreased and sodium-calcium exchanger was increased in the MPR group. The contraction dependent on transsarcolemmal influx of calcium was higher in MPR if compared with the control group. In summary, young rats born from mothers subjected to protein restriction during pregnancy exhibit changes in the myocardial mechanics with altered expression of calcium-handling proteins, reinforcing the hypothesis that maternal malnutrition is related to increased cardiovascular risk in the offspring, not only for hypertension, but also cardiac dysfunction.

The implication of protein malnutrition on cardiovascular control systems in rats

The malnutrition in early life is associated with metabolic changes and cardiovascular impairment in adulthood. Deficient protein intake-mediated hypertension has been observed in clinical and experimental studies. In rats, protein malnutrition also increases the blood pressure and enhances heart rate and sympathetic activity. In this review, we discuss the effects of post-weaning protein malnutrition on the resting mean arterial pressure and heart rate and their variabilities, cardiovascular reflexes sensitivity, cardiac autonomic balance, sympathetic and renin-angiotensin activities and neural plasticity during adult life. These insights reveal an interesting prospect on the autonomic modulation underlying the cardiovascular imbalance and provide relevant information on preventing cardiovascular diseases.

The influence of vitamin B12 supplementation on the level of white blood cells and lymphocytes phenotype in rats fed a low-protein diet

Protein malnutrition has a negative effect on body composition and some blood parameters, especially in the young growing organism. One of nutritional factors which could protect against negative consequences of protein deficiency may be B group vitamins. The aim of the study was to investigate the effect of vitamin B12 supplementation on the immune system in rats fed a standard and a low-protein diet. Rats were fed a control (20% of energy from protein) or a protein-deficient diet (4.5% of energy from protein). Half of animals in each group were additionally supplemented with vitamin B12 (300% of the daily intake). The white blood cells analysis and lymphocytes immunophenotyping (number and percentage) were performed. Low-protein diets caused disturbances in WBC and lymphocyte subpopulations in both short- (30-day) as well as long-term periods (90-day). Vitamin B12 supplementation significantly reduced the negative impact of protein malnutrition after 30 days, however had no effect on long-term malnutrition. Furthermore, vitamin B12 addition in rats fed a control diet did not affect the studied parameters. This observation opens the promise of use of vitamin B12 supplementation to improve immune system parameters in protein malnourished organisms.

Taurine supplementation reduces blood pressure and prevents endothelial dysfunction and oxidative stress in post-weaning protein-restricted rats

INTRODUCTION

Taurine is a sulfur-containing amino acid that exerts protective effects on vascular function and structure in several models of cardiovascular diseases through its antioxidant and anti-inflammatory properties. Early protein malnutrition reprograms the cardiovascular system and is linked to hypertension in adulthood. This study assessed the effects of taurine supplementation in vascular alterations induced by protein restriction in post-weaning rats.

METHODS AND RESULTS

Weaned male Wistar rats were fed normal- (12%, NP) or low-protein (6%, LP) diets for 90 days. Half of the NP and LP rats concomitantly received 2.5% taurine supplementation in the drinking water (NPT and LPT, respectively). LP rats showed elevated systolic, diastolic and mean arterial blood pressure versus NP rats; taurine supplementation partially prevented this increase. There was a reduced relaxation response to acetylcholine in isolated thoracic aortic rings from the LP group that was reversed by superoxide dismutase (SOD) or apocynin incubation. Protein expression of p47phox NADPH oxidase subunit was enhanced, whereas extracellular (EC)-SOD and endothelial nitric oxide synthase phosphorylation at Ser 1177 (p-eNOS) were reduced in aortas from LP rats. Furthermore, ROS production was enhanced while acetylcholine-induced NO release was reduced in aortas from the LP group. Taurine supplementation improved the relaxation response to acetylcholine and eNOS-derived NO production, increased EC-SOD and p-eNOS protein expression, as well as reduced ROS generation and p47phox expression in the aortas from LPT rats. LP rats showed an increased aortic wall/lumen ratio and taurine prevented this remodeling through a reduction in wall media thickness.

CONCLUSION

Our data indicate a protective role of taurine supplementation on the high blood pressure, endothelial dysfunction and vascular remodeling induced by post-weaning protein restriction. The beneficial vascular effect of taurine was associated with restoration of vascular redox homeostasis and improvement of NO bioavailability.

The role of nodose ganglia in the regulation of cardiovascular function following pulmonary exposure to ultrafine titanium dioxide

The inhalation of nanosized air pollutant particles is a recognised risk factor for cardiovascular disease; however, the link between occupational exposure to engineered nanoparticles and adverse cardiovascular events remains unclear. In the present study, the authors demonstrated that pulmonary exposure of rats to ultrafine titanium dioxide (UFTiO2) significantly increased heart rate and depressed diastolic function of the heart in response to isoproterenol. Moreover, pulmonary inhalation of UFTiO2 elevated mean and diastolic blood pressure in response to norepinephrine. Pretreatment of the rats ip with the transient receptor potential (TRP) channel blocker ruthenium red inhibited substance P synthesis in nodose ganglia and associated functional and biological changes in the cardiovascular system. In conclusion, the effects of pulmonary inhalation of UFTiO2 on cardiovascular function are most likely triggered by a lung-nodose ganglia-regulated pathway via the activation of TRP channels in the lung.