Day: 01/15/2012

Energy drinks: health risks and toxicity.

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Objectives:

To describe the epidemiology and toxicity of caffeinated energy drink exposures in Australia.

Design, setting and subjects:

Retrospective observational study analysing data from calls regarding energy drink exposures recorded in the database of an Australian poisons information centre over 7 years to 2010.

Main outcome measures:

Type of exposure; co-ingestants; symptoms reported; and reported hospitalisations.

Results:

Callers reported 297 exposures to energy drinks, which showed an increasing annual trend from 12 in 2004 to 65 in 2010. Median age for the 217 subjects with recreational exposure was 17 years (interquartile ratio [IQR], 15–21; range, 11–60) and 57% were male. One hundred recreational users co-ingested other substances, predominantly alcohol (50) or other caffeinated products (44). The number of energy drinks consumed in one session varied greatly (median, 5 units; IQR, 3–8; range, 1–80). Most subjects who reported recreational use reported experiencing symptoms (87%). The most common symptoms were palpitations, agitation, tremor and gastrointestinal upset. Twenty-one subjects had signs of serious cardiac or neurological toxicity, including hallucinations, seizures, arrhythmias or cardiac ischaemia. At least 128 subjects (57 with no co-ingestants) required hospitalisation.

Conclusions:

Reports of caffeine toxicity from energy drink consumption are increasing, particularly among adolescents, warranting review and regulation of the labelling and sale of these drinks. Educating adolescents and increasing the community’s awareness of the hazards from energy drinks is of paramount importance.

Source:MJA

 

 

Late mortality after severe traumatic brain injury.

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Traumatic brain injury (TBI) continues to be a significant public health issue in Australia. Despite advances in acute medical care and decreases in mortality, those affected experience long-term morbidity and have an increased late mortality rate. TBI is the leading cause of death and disability among young people, and the incidence of severe TBI is higher in men than women at a ratio of 3.5 : 1.The leading causes of TBI include: motor vehicle accidents (50%); falls (21%); violence (12%); and sports and recreation (10%). In Australia in 2008, there were 2493 new cases of TBI (about 1000 of these were severe), and the estimated total cost of care was $8.6 billion. Across Australia, lifetime cost per incident case of severe TBI was estimated at $4.8 million. In 2007, more than 16 000 patients were admitted to hospitals with TBI, with an average length of stay of 6.1 days in acute care, 64.2 days in rehabilitation and 84.1 days in other care. These patients characteristically have multiple disabilities and, in addition to health care services, they frequently receive other disability support services (eg, case management, individual therapy support, life skills development).

Many factors affecting outcomes after TBI are modifiable, and influenced by medical management. Multidisciplinary assessments early in the course of the disease guide medical care and provide predictive information about the potential for recovery. Rehabilitation interventions have documented benefit in patients with TBI. Research into rehabilitation in severe TBI is challenging because of: the heterogenous manifestations of sequelae of severe TBI; the unpredictable course of the disease; the range and variety of rehabilitation services; and inconsistent use of appropriate outcome measures. Few studies tackle long-term outcomes in this population, so evidence is insufficient for establishing optimum integrated care, agreement on a minimum clinical dataset for effective communication between clinicians, and incorporation of patient and caregiver perspectives.

The multicentre study by Baguley and colleagues in this issue of the Journal adds clarity by describing the long-term mortality pattern in adults with severe TBI, and identifies the risk factors associated with mortality. Among their 2545 patients with severe TBI discharged from tertiary rehabilitation units of the New South Wales Brain Injury Rehabilitation Program, with a mean follow-up period of 10 years, there were 258 recorded deaths. The authors report an increased risk of death up to 8 years after discharge from rehabilitation services that was 3.2 times greater than that for the general population, and higher than rates in previous reports (range of long-term mortality estimates, 1.1–3.1). The mortality rates remained higher than for the general population for up to 5 years after discharge from rehabilitation. True mortality rates may be underestimated; similar data for late mortality after TBI in children and Indigenous people are needed. The findings of Baguley and colleagues have implications for health service use and health modelling.

The study by Baguley et al is the first long-term mortality report of Australian data, and shows an increased risk of death among patients with more severe TBI, greater functional dependence, previous drug and alcohol misuse, epilepsy before their TBI and older age at injury; these findings are consistent with those of other studies. Compared with the general population, those with severe TBI had a particularly high risk of death from respiratory disorders, and a high risk of death from nervous system, mental and behavioural, and digestive disorders. Discharge to an aged care facility was identified as a risk factor independent of functional dependency at discharge from rehabilitation, and needs further investigation. Older patients are considered at risk because of an altered pathophysiological response in the ageing central nervous system. Further, health, lifestyle and social deprivation have been linked with survival. Other reports suggest that TBI itself provokes lifestyle and behavioural changes, or defines a subgroup in the population at higher risk of death for other reasons. Future research should target interventions for general preventive measures to maintain health, and social and lifestyle changes in people discharged to the community after a TBI.

The important elements of service provision for patients with TBI are similar to those in other conditions requiring neurorehabilitation:

  • involvement and support of primary health practitioners;
  • education of doctors, patients and caregivers about mortality, declining health and high-risk behaviours for targeted intervention;
  • clinical guidelines to include routine postdischarge follow-up over a longer time, and a flexible health care delivery system that prioritises the rehabilitation needs of patients with TBI; and
  • a clear plan of action and compliance, including indications for referral to specialised multidisciplinary services.

Policy recommendations to establish services for continuity of care (acute to subacute and community care) for patients with TBI include:

  • develop rehabilitation services (including infrastructure and personnel) for patients with severe TBI;
  • provide services to meet the complex needs of those with severe TBI, to identify unmet needs for assistance and reduce reliance on informal assistance;
  • link TBI rehabilitation programs with the existing Australian Rehabilitation Outcomes Centre dataset for long-term collection of clinical data, using standardised common data elements;
  • computerise national monitoring systems in real-time to document mortality and morbidity in TBI, and monitor patterns of recovery;
  • review policy and implement rigorous assessment of the impact of quality care to decrease mortality rates and harm from ineffective or insufficient treatment;
  • expand national insurance schemes to fund non-compensatable TBI rehabilitation; and
  • maintain a sustained public health information campaign to publicise issues and promote strategies for implementation in patients with TBI.

 

Source:MJA

 

 

Childhood obesity and risk of the adult metabolic syndrome: a systematic review

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While many studies have demonstrated positive associations between childhood obesity and adult metabolic risk, important questions remain as to the nature of the relationship. In particular, it is unclear whether the associations reflect the tracking of body mass index (BMI) from childhood to adulthood or an independent level of risk. This systematic review aimed to investigate the relationship between childhood obesity and a range of metabolic risk factors during adult life.

Objective:

To perform an unbiased systematic review to investigate the association between childhood BMI and risk of developing components of metabolic disease in adulthood, and whether the associations observed are independent of adult BMI.

Design:

Electronic databases were searched from inception until July 2010 for studies investigating the association between childhood BMI and adult metabolic risk. Two investigators independently reviewed studies for eligibility according to the inclusion/exclusion criteria, extracted the data and assessed study quality using the Newcastle–Ottawa Scale.

Results:

The search process identified 11 articles that fulfilled the inclusion and exclusion criteria. Although several identified weak positive associations between childhood BMI and adult total cholesterol, low-density lipo protein-cholesterol, triglyceride and insulin concentrations, these associations were ameliorated or inversed when adjusted for adult BMI or body fatness. Of the four papers that considered metabolic syndrome as an end point, none showed evidence of an independent association with childhood obesity.

Conclusions:

Little evidence was found to support the view that childhood obesity is an independent risk factor for adult blood lipid status, insulin levels, metabolic syndrome or type 2 diabetes. The majority of studies failed to adjust for adult BMI and therefore the associations observed may reflect the tracking of BMI across the lifespan. Interestingly, where adult BMI was adjusted for, the data showed a weak negative association between childhood BMI and metabolic variables, with those at the lower end of the BMI range in childhood, but obese during adulthood at particular risk.

Source:International Journal of Obestity Research.

 

 

Should infants and adults sleep in the same bed together?

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Over the past two decades, great advances have been made in identification of hazardous sleeping environments for infants and young children, with significant reductions in numbers of deaths. However, one issue that continues to incite heated debate is whether adult caregivers should sleep on the same surface as infants, referred to as “shared sleeping”.

It is recognised that infants who sleep in the same room as their carers have a reduced risk of sudden infant death syndrome (SIDS), possibly due to an increased level of direct supervision. However, what of infants who sleep in the same bed as their parents or carers?

First, it is important to clarify terminology. Although it is claimed that shared sleeping increases the risk of SIDS, it is perhaps more accurate to state that it is associated with an increased risk of infant death generally. An indication that shared-sleeping deaths may be different to “classical” SIDS deaths that occur among infants sleeping on their own is a finding of an almost equal sex ratio in shared-sleeping deaths, compared with the 2 : 1 male–female ratio among infants who died of SIDS. If some of the risk factors for shared-sleeping death (eg, parental obesity, fatigue, soft sleeping surfaces) are examined in isolation, accidental suffocation appears to be a more likely mechanism of death than subtle processes leading to SIDS.These apply to any shared-sleeping surface, not just to beds.

It is difficult to formulate absolute recommendations on shared sleeping, as the current incidence in most communities is unknown, and the form that it takes varies greatly between families. There are also cultural issues to take into consideration — for example, shared sleeping is very common in South-East Asian communities, but with low incidences of unexpected infant deaths.

However, a study from Avon, United Kingdom, found a disturbing percentage increase in shared-sleeping deaths among two cohorts of infants who died of “SIDS”, from 12% (17/147 in 1984–1988) to 50% (18/36 in 1999–2003) (P < 0.001).7 The authors noted that although the number of shared-sleeping deaths that were not on sofas dropped (from 16 to 14), the decrease was not as great as that among infants who were sleeping on their own, perhaps explaining the increased proportion of unexplained infant deaths found in shared-sleeping situations. This difference may be due to mechanisms of death being different in the two circumstances. A similar effect was noted in South Australia, where the proportion of shared-sleeping deaths increased from 7.5% of “SIDS” deaths (23/306 in 1983–1990) to 32.3% (21/65 in 1991–1993). The percentage of deaths in shared-sleeping situations in the early part of the study also showed an overrepresentation compared with the shared-sleeping rate of 1.5% in the general community in 1988.

As some infants are particularly vulnerable to the effects of airway occlusion, and as there is often no clinical predictor of this vulnerability, all that can be stated is that certain infants may be inherently at increased risk in a shared-sleeping situation. It is generally agreed that in Western cultures, the safest place for an infant is in a cot that meets recommended safety features and is positioned beside the caregiver’s bed.

Supporters of shared sleeping cite advantages that include an increased incidence and longer duration of breastfeeding, enhanced maternal–infant bonding and improved settling.However, it has been reported that 50% or more of infants who are found unexpectedly dead are sleeping with an adult. The suggestion of possible accidental asphyxia by a parent “overlaying” a shared-sleeping child has been criticised, because it has been assumed that a parent would always arouse. However, parents can fail to wake if they are sedated or overly fatigued. There is an increased risk of infant death when caregivers have taken illicit drugs, smoked, or consumed more than two units of alcohol. In addition, it is not necessary for an adult to be lying over an infant completely for respiration to be compromised, as an infant who has rolled into a trough between a parent’s much larger body and a soft mattress may also be at risk. This is exemplified by the dangers of shared sleeping on a sofa.

On occasion, parents state that they successfully slept in the same bed as all of their children without any deaths occurring. While such anecdotes are undoubtedly true, few risks are absolute and so it cannot be used as definitive evidence that shared sleeping is always a safe practice.

The key to assisting with this issue lies in adequately informing caregivers of potential risks. Clinicians should discuss with caregivers the risk factors for accidental asphyxiation in shared-sleeping arrangements, such as sedation, excessive fatigue and hazards predisposing to suffocation. This may help prevent infant deaths in the future.

Source:MJA

 

 

 

Self-reported and measured anthropometric data and risk of colorectal cancer in the EPIC–Norfolk study.

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Epidemiological studies have shown inconsistent results for the association between body size and colorectal cancer (CRC) risk. Inconsistencies may be because of the reliance on self-reported measures of body size.

Objective:

We examined the association of self-reported and directly assessed anthropometric data (body height, weight, body mass index (BMI), waist, hip, waist-to-hip ratio (WHR) and chest circumference) with CRC risk in the EPIC–Norfolk study.

Design:

A total of 20 608 participants with complete self-reported and measured height and weight and without any history of cancer were followed up an average of 11 years, during which 357 incident CRC cases were recorded. Hazard Ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models.

Results:

 

After adjustment for confounders, HRs among women in the highest quintile of the body size measure relative to the lowest quintile showed that measured height (HR=1.98, 95% CI=1.19–3.28, P trend=0.009), measured waist circumference (HR=1.65, 95% CI=0.97–2.86, P trend=0.009) and measured WHR (HR=2.07, 95% CI=1.17–3.67, P trend=0.001) were associated with increased CRC risk. Associations using corresponding self-reported measures were attenuated and not statistically significant. Conversely, the association of BMI with CRC risk in women was weaker using measured BMI (HR=1.57, 95% CI=0.91–2.73, P trend=0.05) compared with self-reported BMI (HR=1.97, 95% CI=1.18–3.30, P trend=0.02). In men no significantly increased CRC risk was observed with any of the anthropometric measures.

Conclusions:

Measured height, waist circumference and WHR were associated with CRC risk in women, whereas any significant associations with those measures were attenuated when self-reported data were used.

Source:International Journal of Obestity.

 

 

 

Relationships of occupational and non-occupational physical activity to abdominal obesity.

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Physically active occupations may protect against the risk of abdominal obesity.

Objectives:

This study assessed the interaction between non-occupational physical activity (NOA) (leisure-time, transport and domestic activity) and occupational activity (OA) in relation to abdominal obesity.

Methods:

 

A total of 3539 adults over the age of 20, with no work limitations, employed in one of the 17 occupations classified as low OA (LOA) or high OA (HOA) were identified in the 1999–2004 National Health and Nutrition Examination Survey. Waist circumference (WC) was used to categorize individuals into either non-obese or abdominally obese (WC>88 cm in women and >102 cm in men) categories. NOA was divided into three categories based upon physical activity guidelines: (1) no NOA; (2) insufficient NOA; and (3) sufficient NOA. Logistic regression was used to examine possible associations between NOA, OA and abdominal obesity.

Results:

In those who are sedentary outside of work, a high-activity occupation reduces the odds risk ratio of being categorized with abdominal obesity to 0.37 in comparison with those who work in low-activity occupations. For people working in low-activity occupations, there was a clear association with activity outside of work and the odds risk ratio of being categorized with abdominal obesity. In these adults, a reduced odds ratio was found only among those who met the physical activity guidelines through NOA (odds ratio=0.55; 95% confidence interval (CI)=0.40–0.75).

Conclusion:

HOA is associated with a reduced risk of abdominal obesity. Thus, it is important to include OA in studies seeking to understand the association between physical activity and abdominal adiposity.

Source:International Journal of Obestity.

 

 

Arterial stiffness, central blood pressure and body size in health and disease.

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Body size is associated with increased brachial systolic blood pressure (SBP) and aortic stiffness. The aims of this study were to determine the relationships between central SBP and body size (determined by body mass index (BMI), waist circumference and waist/hip ratio) in health and disease. We also sought to determine if aortic stiffness was correlated with body size, independent of BP.

Methods:

BMI, brachial BP and estimated central SBP (by SphygmoCor and radial P2) were recorded in controls (n=228), patients with diabetes (n=211), coronary artery disease (n=184) and end-stage kidney disease (n=68). Additional measures of waist circumference and arterial stiffness (aortic and brachial pulse wave velocity (PWV)) were recorded in a subgroup of 75 controls (aged 51±12 years) who were carefully screened for factors affecting vascular function.

Results.

BMI was associated with brachial (r=0.30; P<0.001) and central SBP (r=0.29; P<0.001) in the 228 controls, but not the patient populations (r<0.13; P>0.15 for all comparisons). In the control subgroup, waist circumference was also significantly correlated with brachial SBP (r=0.29; P=0.01), but not central SBP (r=0.22; P=0.07). Independent predictors of aortic PWV in the control subgroup were brachial SBP (β=0.43; P<0.001), age (β=0.37; P<0.001), waist circumference (β=0.39; P=0.02) and female sex (β=−0.24; P=0.03), but not BMI.

Conclusion.

In health, there are parallel increases in central and brachial SBP as BMI increases, but these relationships are not observed in the presence of chronic disease. Moreover, BP is a stronger correlate of arterial stiffness than body size.

Source:International Journal of Obestity.

Impact of sleep, screen time, depression and stress on weight change in the intensive weight loss phase of the LIFE study.

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The LIFE study is a two-phase randomized clinical trial comparing two approaches to maintaining weight loss following guided weight loss. Phase I provided a nonrandomized intensive 6-month behavioral weight loss intervention to 472 obese (body mass index 30–50) adult participants. Phase II is the randomized weight loss maintenance portion of the study. This paper focuses on Phase I measures of sleep, screen time, depression and stress.

Methods:

The Phase I intervention consisted of 22 group sessions led over 26 weeks by behavioral counselors. Recommendations included reducing dietary intake by 500 calories per day, adopting the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and increasing physical exercise to at least 180 min per week. Measures reported here are sleep time, insomnia, screen time, depression and stress at entry and post-weight loss intervention follow-up.

Results:

 

The mean weight loss for all participants over the intensive Phase I weight loss intervention was 6.3 kg (s.d. 7.1). Sixty percent (N=285) of participants lost at least 4.5 kg (10 lbs) and were randomized into Phase II. Participants (N=472) attended a mean of 73.1% (s.d. 26.7) of sessions, completed 5.1 (s.d. 1.9) daily food records/week, and reported 195.1 min (s.d. 123.1) of exercise per week. Using logistic regression, sleep time (quadratic trend, P=0.030) and lower stress (P=0.024) at entry predicted success in the weight loss program, and lower stress predicted greater weight loss during Phase I (P=0.021). In addition, weight loss was significantly correlated with declines in stress (P=0.048) and depression (P=0.035).

Conclusion:

Results suggest that clinicians and investigators might consider targeting sleep, depression and stress as part of a behavioral weight loss intervention.

Source:International Journal of Obestity.

 

 

Effects of Chronic Marijuana Use on Brain Activity During Monetary Decision-Making.

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Marijuana (MJ) acutely acts on cannabinoid receptors that are found in numerous brain regions, including those involved in reward processing and decision-making. However, it remains unclear how long-term, chronic MJ use alters reward-based decision-making. In the present study, using [15O]water PET imaging, we measured brain activity in chronic MJ users, who underwent monitored abstinence from MJ for approximately 24 h before imaging, and control participants, while they took part in the Iowa Gambling Task (IGT), a monetary decision making task that strongly relies on the ventromedial prefrontal cortex (vmPFC). During PET imaging, participants took part in the standard and a variant version of the IGT as well as a control task. Chronic MJ users performed equally well on the standard IGT, but significantly worse than controls on the variant IGT. Chronic MJ users and control subjects showed increased regional cerebral blood flow (rCBF) in the vmPFC on both versions of the IGT compared to the control task. In the two-group comparison, chronic MJ users showed significantly greater rCBF than controls in the vmPFC on the standard IGT and greater activity in the cerebellum on both versions of the IGT. Furthermore, duration of use, but not age of first use, was associated with greater activity in the vmPFC. Thus, chronic MJ users tend to strongly recruit neural circuitry involved in decision-making and reward processing (vmPFC), and probabilistic learning (cerebellum) when performing the IGT.

Source: Neuropsychopharmacology/Nature.

 

The Influence of Bacille Calmette-Guérin Vaccine Strain on the Immune Response against Tuberculosis.

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Approximately 100 million doses of bacille Calmette-Guérin (BCG) vaccine are given each year to protect against tuberculosis (TB). More than 20 genetically distinct BCG vaccine strains are in use worldwide. Previous studies suggest that BCG vaccine strain influences the immune response and protection against TB. Current data on which BCG vaccine strain induces the optimal immune response in humans are insufficient.

Objectives: To compare the immune response to three different BCG vaccine strains given to infants at birth.

Methods: Newborn infants in a tertiary women’s hospital were immunized at birth with one of three BCG vaccine strains. A stratified randomization according to the mother’s region of birth was used.

Measurements and Main Results: The presence of mycobacterial-specific polyfunctional CD4 T cells measured by flow cytometry 10 weeks after immunization. Of the 209 infants immunized, data from 164 infants were included in the final analysis (BCG-Denmark, n = 54; BCG-Japan, n = 54; BCG-Russia, n = 57). The proportion of polyfunctional CD4 T cells was significantly higher in infants immunized with BCG-Denmark (0.013%) or BCG-Japan (0.016%) than with BCG-Russia (0.007%) (P = 0.018 and P = 0.003, respectively). Infants immunized with BCG-Japan had higher concentrations of secreted Th1 cytokines; infants immunized with BCG-Denmark had higher proportions of CD107-expressing cytotoxic CD4 T cells.

Conclusions: There are significant differences in the immune response induced by different BCG vaccine strains in newborn infants. Immunization with BCG-Denmark or BCG-Japan induced higher frequencies of mycobacterial-specific polyfunctional and cytotoxic T cells and higher concentrations of Th1 cytokines. These findings have potentially important implications for global antituberculosis immunization policies and future tuberculosis vaccine trials.

Source:The American Journal of Respiratory medicine and critical care.