Masked hypertension and correlation between body composition and nighttime blood pressure parameters in children and adolescents with obesity

INTRODUCTION

Masked hypertension is defined as having a normal blood pressure (BP) in the office but elevated BP outside the office. This study aimed to determine the prevalence of masked hypertension in participants with obesity and to examine the correlation between body composition, dietary intake and ambulatory blood pressure parameters.

MATERIALS AND METHODS

The cross-sectional study of participants with obesity was conducted in the pediatric nutrition clinic of a University Hospital in Thailand. Demographic and anthropometric data, dietary intake, body composition analysis and ambulatory blood pressure monitoring were assessed in all participants. All parameters were compared between the group with masked hypertension and the normotensive group. Correlations between the parameters were analyzed.

RESULTS

Among 49 children with obesity, 23 (47%, 95% confidence interval 34.7, 59.2%) had masked hypertension. Compared with the normotensive group, the group with masked hypertension had a greater mean BMI z-score (4.7 vs. 3.0, P = 0.003), a greater mean of body fat percentage (45 vs. 40, P = 0.012) and a greater total energy intake percentage of dietary reference intake (115 vs. 93, P = 0.034). Multivariate analysis showed that BMI z-score was significantly associated with masked hypertension. Interestingly, mean nighttime SBP positively correlated with BMI z-score and body fat percentage. Moreover, there were negative correlations between fruit intake portion per week and nighttime and 24-h SBP index. However, multivariate linear regression did not show significant correlation between these parameters.

CONCLUSIONS

Masked hypertension was frequent in participants with obesity. The greater BMI z-score and percentage of body fat mass correlated with higher nighttime SBP.

Nitric Oxide-Dependent Protein Post-Translational Modifications Impair Mitochondrial Function and Metabolism to Contribute to Neurodegenerative Diseases

Significance: Most brains affected by neurodegenerative diseases manifest mitochondrial dysfunction as well as elevated production of reactive oxygen species and reactive nitrogen species (RNS), contributing to synapse loss and neuronal injury. Recent Advances: Excessive production of RNS triggers nitric oxide (NO)-mediated post-translational modifications of proteins, such as S-nitrosylation of cysteine residues and nitration of tyrosine residues. Proteins thus affected impair mitochondrial metabolism, mitochondrial dynamics, and mitophagy in the nervous system. Critical Issues: Identification and better characterization of underlying molecular mechanisms for NO-mediated mitochondrial dysfunction will provide important insights into the pathogenesis of neurodegenerative disorders. In this review, we highlight recent discoveries concerning S-nitrosylation of the tricarboxylic acid cycle enzymes, mitochondrial fission GTPase dynamin-related protein 1, and mitophagy-related proteins Parkin and phosphatase and tensin homolog-induced putative kinase protein 1. We delineate signaling cascades affected by pathologically S-nitrosylated proteins that diminish mitochondrial function in neurodegenerative diseases. Future Directions: Further elucidation of the pathological events resulting from aberrant S-nitrosothiol or nitrotyrosine formation may lead to new therapeutic approaches to ameliorate neurodegenerative disorders.

Low-Fat Diet Designed for Weight Loss But Not Weight Maintenance Improves Nitric Oxide-Dependent Arteriolar Vasodilation in Obese Adults

Obesity is associated with microvascular dysfunction. While low-fat diet improves cardiovascular risk, its contributions on microvascular function, independent of weight loss, is unknown. We tested the hypothesis that nitric oxide (NO)-dependent vasodilation in microvessels is improved by low-fat diets designed for weight loss (LFWL) compared to low-fat weight maintenance (LFWM) diet. Obese adults were randomly assigned to either a LFWL diet (n = 11) or LFWM diet (n = 10) for six weeks. Microvessels were obtained from gluteal subcutaneous fat biopsies before and after the intervention for vascular reactivity measurements to acetylcholine (Ach) and flow, with and without L-NAME or indomethacin. Vascular and serum NO and C-reactive protein (CRP) were also measured. LFWL diet increased flow-induced (FID) and ACh-induced dilation (AChID); an effect that was inhibited by L-NAME. Conversely, LFWM diet did not affect FID or AChID. Indomethacin improved FID and AChID in the baseline and this effect was minimized in response to both diets. Serum NO or CRP did not change in response to either diet. In conclusion, LFWL diet improves microvascular reactivity compared to LFWM diet and increased vascular NO contribution to the improved microvascular dilation. These data suggest that weight reduction on low fat diet is critical for microvascular health.

Age-related cardiovascular disease and the beneficial effects of calorie restriction

Aging is a well-recognized risk factor in the development of cardiovascular disease, which is the primary cause of death and disability in the elderly population. The normal process of aging is associated with progressive deterioration in structure and function of the heart and vasculature. These age-related changes likely act as both a catalyst and accelerator in the development of cardiovascular disease. Since the aging population is one of the fastest growing segments of the population, it is of vital importance that we have a thorough understanding of the physiological changes that occur with aging that contribute to the high incidence of cardiovascular disease in this population. This insight will allow for the development of more targeted therapies that can prevent and treat these conditions. One such anti-aging strategy that has received considerable attention as of late is calorie restriction. Calorie restriction has emerged as one of the most effective and reproducible interventions for extending lifespan, as well as protecting against obesity, metabolic disorders, and cardiovascular disease. Herein, we review the multiple beneficial effects that calorie restriction and resveratrol exert on the cardiovascular system with a particular focus on aging. Although calorie restriction and resveratrol have proven to be very effective in preventing and treating the development of cardiovascular disease in animal models, studies continue as to whether these profound beneficial effects can translate to humans to improve cardiovascular health.

Long-term caloric restriction reduces metabolic rate and heart rate under cool and thermoneutral conditions in FBNF1 rats

The long-term metabolic and cardiovascular responses to caloric restriction (CR) are poorly understood. We examined the responses to one year of CR in FBNF1 rats housed in cool (COOL; T(a)=15 °C) or thermoneutral (TMN; T(a)=30 °C) conditions. Rats were acclimated to COOL or TMN for 2 months, instrumented for cardiovascular telemetry and studied in calorimeters. Baseline caloric intake, oxygen consumption (VO(2)), mean arterial blood pressure (MAP), and heart rate (HR) were determined prior to assignment to ad lib (AL) or CR groups (30-40% CR) within each T(a) (n = 8). Groups of rats were studied after 10 weeks CR, one year CR, and after 4 days of re-feeding. Both 10 weeks and one year of CR reduced HR and VO(2) irrespective of T(a). Evaluation of the relationship between metabolic organ mass (liver, heart, brain, and kidney mass) and energy expenditure revealed a clear shift induced by CR to reduce expenditure per unit metabolic mass in both COOL and TMN groups. Re-feeding resulted in prompt elevations of HR and VO(2) to levels observed in control rats. These findings are consistent with the hypothesis that long term CR produces sustained reductions in metabolic rate and heart rate in rats.

The hydrogen sulfide signaling system: changes during aging and the benefits of caloric restriction

Hydrogen sulfide gas (H(2)S) is a putative signaling molecule that causes diverse effects in mammalian tissues including relaxation of blood vessels and regulation of perfusion in the liver, but the effects of aging on H(2)S signaling are unknown. Aging has negative impacts on the cardiovascular system. However, the liver is more resilient with age. Caloric restriction (CR) attenuates affects of age in many tissues. We hypothesized that the H(2)S signaling system is negatively affected by age in the vasculature but not in the liver, which is typically more resilient to age, and that a CR diet minimizes the age affect in the vasculature. To investigate this, we determined protein and mRNA expression of the H(2)S-producing enzymes cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS), H(2)S production rates in the aorta and liver, and the contractile response of aortic rings to exogenous H(2)S. Tissue was collected from Fisher 344 × Brown Norway rats from 8-38 months of age, which had been maintained on an ad libitum (AL) or CR diet. The results demonstrate that age and diet have differential effects on the H(2)S signaling system in aorta and liver. The aorta showed a sizeable effect of both age and diet, whereas the liver only showed a sizeable effect of diet. Aortic rings showed increased contractile sensitivity to H(2)S and increased protein expression of CSE and CBS with age, consistent with a decrease in H(2)S concentration with age. CR appears to benefit CSE and CBS protein in both aorta and liver, potentially by reducing oxidative stress and ameliorating the negative effect of age on H(2)S concentration. Therefore, CR may help maintain the H(2)S signaling system during aging.

Beneficial impact of exercise and obesity interventions on erectile function and its risk factors

INTRODUCTION

Erectile dysfunction (ED) is a multifaceted disease involving cardiovascular, metabolic, and hormonal factors and affects over 100 million men worldwide. ED has been shown to be a harbinger of underlying cardiovascular diseases (CVD), as there are common risk factors (aging, hypertension, obesity) and mechanistic basis.

AIM

To provide an update on clinical and experimental evidence regarding the impact of lifestyle modifications, such as exercise and diet, with respect to changes in erectile function.

MAIN OUTCOME MEASURES

Published evidence regarding the impact of aging, hypertension, and obesity on ED and CVD, as well as new experimental data linking obesity and diminished erectile responses.

METHODS

We reviewed the literature regarding common risk factors of ED and CVD, particularly involving obesity, as well as performed new analysis on the findings of other experimental studies involving diet and exercise interventions.

RESULTS

Physical inactivity negatively impacts on erectile function, and experimental and clinical exercise interventions have been shown to improve sexual responses and overall cardiovascular health. Mediterranean-style diets and a reduction in caloric intake have been found to improve erectile function in men with the aspects of the metabolic syndrome. In addition, both clinical and experimental studies have confirmed that combining the two interventions provides additional benefit to erectile function, likely via reduced metabolic disturbances (e.g., inflammatory markers, insulin resistance), decreased visceral adipose tissue, and improvement in vascular function (e.g., increased endothelial function).

CONCLUSIONS

Lifestyle modifications provide significant benefits to vascular health and erectile function in a population that is increasingly aged and more obese.