A randomized controlled laboratory study on the long-term effects of methylphenidate on cardiovascular function and structure in rhesus monkeys.

BACKGROUND: Whether long-term methylphenidate (MPH) results in any changes in cardiovascular function or structure can only be properly addressed through a randomized trial using an animal model which permits elevated dosing over an extended period of time. METHODS: We studied 28 male rhesus monkeys (Macaca mulatta) approximately 7 years of age that had been randomly assigned to one of three MPH dosages: vehicle control (0 mg/kg, b.i.d., n = 9), low dose (2.5 mg/kg, b.i.d., n = 9), or high dose (12.5 mg/kg, b.i.d., n = 10). Dosage groups were compared on serum cardiovascular and inflammatory biomarkers, electrocardiograms (ECGs), echocardiograms, myocardial biopsies, and clinical pathology parameters following 5 years of uninterrupted dosing. RESULTS: With the exception of serum myoglobin, there were no statistical differences or apparent dose-response trends in clinical pathology, cardiac inflammatory biomarkers, ECGs, echocardiograms, or myocardial biopsies. The high-dose MPH group had a lower serum myoglobin concentration (979 ng/mL) than either the low-dose group (1882 ng/mL) or the control group (2182 ng/mL). The dose response was inversely proportional to dosage (P = .0006). CONCLUSIONS: Although the findings cannot be directly generalized to humans, chronic MPH exposure is unlikely to be associated with increased cardiovascular risk in healthy children.

Cardiac Effects of Highly Active Antiretroviral Therapy in Perinatally HIV-Infected Children: The CHAART-2 Study.

BACKGROUND: Before the introduction of highly active antiretroviral therapy (HAART), cardiac mortality and morbidity were common in HIV-infected children. OBJECTIVES: This study sought to identify long-term cardiovascular effects of HAART in HIV-infected children. METHODS: The CHAART-2 (HAART-Associated Cardiotoxicity in HIV-Infected Children) study prospectively compared 148 echocardiograms from 74 HAART-exposed children to 860 echocardiograms from 140 HAART-unexposed but HIV-infected children from the Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection (P2C2 HIV) study. Both studies used similar protocol, centralized echocardiographic interpretation, and measures expressed as z-scores referenced to healthy controls. Associations between HAART exposure and echocardiographic measures were evaluated using generalized estimating equations. RESULTS: Comparing the HAART-exposed and HAART-unexposed groups, any HAART exposure was positively associated with left ventricular (LV) fractional shortening (z-score for difference = 1.07; p = 0.02) and HAART exposure duration (z-score difference per year = 0.17; p = 0.003. LV mass was negatively associated with any HAART exposure (z-score difference = -0.64; p = 0.01) as was septal thickness (z-score difference = -0.93; p = 0.001). Duration of HAART exposure was negatively associated with LV end-systolic dimension and heart rate (z-score difference per year= -0.11; p = 0.05; and z-score difference per year = -0.10; p = 0.002, respectively). During 11 years of follow-up, in the HAART-exposed group, LV mass and LV end-diastolic septal thickness were lower whereas LV contractility and LV fractional shortening were higher when compared to the HAART-unexposed group. CONCLUSIONS: Cardiac structure and function were better in perinatally HIV-infected children exposed to HAART than in those of similar children from the pre-HAART era but did decline over time. Evidence-based strategies for cardiovascular monitoring are needed to inform treatment decisions to improve long-term cardiovascular health.

The Safety of Ingested Caffeine: A Comprehensive Review.

Caffeine is the most widely consumed psychoactive drug in the world. Natural sources of caffeine include coffee, tea, and chocolate. Synthetic caffeine is also added to products to promote arousal, alertness, energy, and elevated mood. Over the past decade, the introduction of new caffeine-containing food products, as well as changes in consumption patterns of the more traditional sources of caffeine, has increased scrutiny by health authorities and regulatory bodies about the overall consumption of caffeine and its potential cumulative effects on behavior and physiology. Of particular concern is the rate of caffeine intake among populations potentially vulnerable to the negative effects of caffeine consumption: pregnant and lactating women, children and adolescents, young adults, and people with underlying heart or other health conditions, such as mental illness. Here, we review the research into the safety and safe doses of ingested caffeine in healthy and in vulnerable populations. We report that, for healthy adults, caffeine consumption is relatively safe, but that for some vulnerable populations, caffeine consumption could be harmful, including impairments in cardiovascular function, sleep, and substance use. We also identified several gaps in the literature on which we based recommendations for the future of caffeine research.

Lessons learned from the Pediatric Cardiomyopathy Registry (PCMR) Study Group.

Cardiomyopathy is a rare disorder of the heart muscle, affecting 1.13 cases per 100,000 children, from birth to 18 years of age. Cardiomyopathy is the leading cause of heart transplantation in children over the age of 1. The Pediatric Cardiomyopathy Registry funded in 1994 by the National Heart, Lung, and Blood Institute was established to examine the epidemiology of the disease in children below 18 years of age. More than 3500 children across the United States and Canada have been enrolled in the Pediatric Cardiomyopathy Registry, which has followed-up these patients until death, heart transplantation, or loss to follow-up. The Pediatric Cardiomyopathy Registry has provided the most in-depth illustration of this disease regarding its aetiology, clinical course, associated risk factors, and patient outcomes. Data from the registry have helped in guiding the clinical management of cardiomyopathy in children under 18 years of age; however, questions still remain regarding the most clinically effective diagnostic and treatment approaches for these patients. Future directions of the registry include the use of next-generation whole-exome sequencing and cardiac biomarkers to identify aetiology-specific treatments and improve diagnostic strategies. This article provides a brief synopsis of the work carried out by the Pediatric Cardiomyopathy Registry since its inception, including the current knowledge on the aetiologies, outcomes, and treatments of cardiomyopathy in children.

The joint effects of water and sanitation on diarrhoeal disease: a multicountry analysis of the Demographic and Health Surveys.

OBJECTIVES: To assess whether the joint effects of water and sanitation infrastructure, are acting antagonistically (redundant services preventing the same cases of diarrhoeal disease), independently, or synergistically; and to assess how these effects vary by country and over time. METHODS: We used data from 217 Demographic and Health Surveys conducted in 74 countries between 1986 and 2013. We used modified Poisson regression to assess the impact of water and sanitation infrastructure on the prevalence of diarrhoea among children under 5. RESULTS: The impact of water and sanitation varied across surveys, and adjusting for socio-economic status drove these estimates towards the null. Sanitation had a greater effect than water infrastructure when all 217 surveys were pooled; however, the impact of sanitation diminished over time. Based on survey data from the past 10 years, we saw no evidence for benefits in improving drinking water or sanitation alone, but we estimated a 6% reduction of both combined (prevalence ratio = 0.94, 95% confidence limit 0.91-0.98). CONCLUSIONS: Water and sanitation interventions should be combined to maximise the number of cases of diarrhoeal disease prevented in children under 5. Further research should identify the sources of variability seen between countries and across time. These national surveys likely include substantial measurement error in the categorisation of water and sanitation, making it difficult to interpret the roles of other pathways.