Wednesday, January 31, 2007

Sleep Apnea : Night-time Bradyarrhythmia

Night-time Bradyarrhythmia in a Patient with Mild Obstructive Sleep Apnea Syndrome is Reversed With CPAP Treatment

Rainer Dziewas, M.D.; Tanya Imai, M.D.; Ralf Dittrich, M.D.; Marius Humpert, M.D.; Benjamin Hopmann, M.D.; Matthias Böntert, M.D.; Peter Lüdemann, M.D.; Peter Young, M.D.
Department of Neurology, University Hospital of Münster, Münster, Germany

Nocturnal cardiac arrhythmia is a common clinical feature of obstructive sleep apnea syndrome.
Pathologically relevant rhythm disturbances such as atrioventricular block or ventricular tachycardia are known to occur mainly in patients with a high apnea-hypopnea index and marked oxygen desaturation.
We report on a patient with mild obstructive sleep apnea syndrome who nevertheless showed intermittent second-degree atrioventricular block during stages of rapid eye movement sleep-associated hypopneas.
Cardiac arrhythmia was reversed with the initiation of nasal continuous positive airway pressure treatment.
Based on this case report and taking into account known facts from the literature, the finding of intermittent second-degree atrioventricular block in our patient with mild obstructive sleep apnea syndrome supports careful evaluation of electrocardiogram recording acquired during polysomnography in all patients with suspected obstructive sleep apnea syndrome.

Journal of Clinical Sleep Medicine VOL. 2, №4, 2006, p. 454-457
American Academy of Sleep Medicine

Tuesday, January 30, 2007

Prenatal exposure to cocaine

Prenatal cocaine’s lasting cellular effects

Although the “crack baby” hysteria of the 1980s was greatly exaggerated, cocaine use during pregnancy can cause subtle but disabling cognitive impairments — attention deficits, learning disabilities and emotional problems.A recent study by investigators at the Vanderbilt Kennedy Center for Research on Human Development may help explain the long-term behavioral and neurological problems associated with prenatal exposure to cocaine.

In a recent issue of the Journal of Neuroscience, Gregg Stanwood, Ph.D., and Pat Levitt, Ph.D., report that prenatal cocaine exposure in rabbits causes a long lasting displacement of dopamine receptors in certain brain cells, which alters their ability to function normally.Though this effect has not yet been assessed in cocaine-exposed children, the findings give researchers a place to start looking.
“The hysteria surrounding the ‘crack baby’ was sort of overblown,” said Stanwood, research assistant professor of Pharmacology and lead author on the study.Incredibly high levels of cocaine — usually coupled with the abuse of other drugs — can lead to premature labor, preterm birth and low birth weight, Stanwood said.“But in women who have abused relatively low recreational doses of cocaine, it is actually very hard to distinguish those children at birth from children born to anyone else,” he said. “However, as those children age, they do develop deficits in their cognitive and emotional development.”
These children often exhibit attention and arousal problems, similar to children with attention deficit hyperactivity disorder (ADHD). However, the standard treatments for ADHD — Ritalin and other stimulants — are not always effective in these children.
Studying the effects of prenatal cocaine exposure on the developing brain is difficult in human populations because cocaine abusers often abuse other drugs. Animal models can help determine how prenatal cocaine exposure might influence brain development to cause these subtle cognitive impairments.“We thought that it was important to set up an animal model that recapitulates a key feature of human abuse — that being intravenous exposure to low doses of cocaine,” Stanwood said.
A few years ago, Stanwood and Levitt, professor of Pharmacology and director of the Vanderbilt Kennedy Center, established such a model in rabbits. They found that exposure to low levels of intravenous cocaine during a very short window of time during gestation — equivalent to the late first trimester and early second trimester in humans — caused specific alterations in brain circuits that use the neurotransmitter dopamine. Additionally, these cocaine-exposed offspring showed attention problems as well as insensitivity to stimulants like amphetamine, suggesting that cocaine exposure had altered the development of the dopamine pathways in the brain.
“In collaboration with Dr. Eitan Friedman of the City University of New York, we had previously shown a decrease in signaling of a particular receptor protein, the dopamine D1 receptor,” Stanwood said. “We know that this receptor is involved in regulating the formation of cortical circuitry. It’s also involved in the behavioral effects of amphetamines and cocaine.”
“The current study was an attempt to look at the mechanism of this decrease in D1 receptor signaling,” he said.
Stanwood examined the levels of D1 receptor in brain cells taken from “teenage” rabbits that were exposed to cocaine during that short, sensitive prenatal period.He found that cocaine exposure did not alter the total amount of D1 receptor produced in the brain. However, there was a dramatic alteration in the location of the protein within the cell.
“It’s not where it should be,” he said. D1 receptors are normally found at the cell surface, but neurons from the cocaine-exposed animals showed the receptor was predominantly sequestered inside the cells.
“The fascinating thing is that this effect appears permanent,” said Stanwood. This implies that cocaine exposure during a brief, sensitive period of neural development can lead to long-lasting effects at the cellular level.
This change also altered the growth of neuronal processes, suggesting that the altered D1 receptor trafficking may underlie the changes in neuronal architecture and behavior that Stanwood and others have previously observed.What remains to be determined, he cautioned, is whether D1 receptor localization is affected in humans exposed to cocaine prenatally.
If found in humans, “it gives us a new way to think about helping those children as they continue to mature.” Because cocaine exposure seems to alter the distribution of the D1 receptor, Stanwood suggests that researchers might find a way to “steer” the receptor into the correct cellular location. That could provide new avenues for treating the attention problems in cocaine-exposed children, as well as in children with stimulant-resistant ADHD.
“Neither we nor anyone else has yet identified whether this mechanism occurs in the human population,” Stanwood said, “so that is a critical next step.”
Vanderbilt University Medical Center

Friday, January 19, 2007

Depression women: hormone secretion

The pattern of growth hormone secretion during the menstrual cycle in normal and depressed women

KASA-VUBU Josephine Z. (1) ; DIMARAKI Eleni V. (2); YOUNG Elizabeth A. (3);

1) Department of Pediatrics, University of Michigan, Ann Arbor Michigan, ETATS-UNIS

2) Department of Internal Medicine, University of Michigan, Ann Arbor Michigan, ETATS-UNIS
3) Department of Psychiatry, University of Michigan, Ann Arbor Michigan, ETATS-UNIS

Objective. Major depression is associated to altered hypothalamic-pituitary function. Stress is linked to elevated cortisol as well as menstrual cycle disturbance; however, there is no known relationship between depression and menstrual cycle disruption. The aim of this study was to investigate changes of growth hormone (GH) secretion during the menstrual cycle in normal and depressed women.

Patients and methods. Nineteen women affected with depression and 24 normal controls were included. The two groups had comparable body mass index (BMI), and age (29.4 ± 9.8 vs. 28.6 ± 9.7 years). Nine depressed and 10 controls were studied in the follicular phase, while 10 depressed and 14 controls were studied in the luteal phase of the cycle. GH was sampled every 10 min for 24 h, and the data were analysed by the cluster pulse detection method.

Results. There was no difference in 24-h mean GH concentrations between depressed and control subjects (P = 0.93), even after accounting for menstrual cycle phase (P = 0.38). GH pulse frequency was higher during the follicular phase of the cycle (P = 0.032), and nocturnal GH was higher in the follicular phase of the cycle (P = 0.05, and after adjusting for 24-h GH, P = 0.0138) regardless of whether the subjects were depressed or healthy.

Conclusions. In studies of GH secretion in women with or without depression, it is necessary to control for the phase of menstrual cycle.

Keywords: Adenohypophyseal hormone; Endocrinology; Adult; Female; Human; Menstrual cycle; Secretion; Somatotropin hormone

Clinical endocrinology 2005, vol. 62, №6, pp. 656-660.

Thursday, January 18, 2007

Comorbidity of autism

Tics and Tourette syndrome in autism spectrum disorders

Roberto Canitano, Giacomo Vivanti
University Hospital of Siena, Italy

Autism spectrum disorders (ASDs) are more frequently associated with tic disorders than expected by chance. Variable rates of comorbidity have been reported and common genetic and neurobiological factors are probably involved. The aim of this study was to determine the rate of tic disorders in a clinical sample (n = 105) of children and adolescents with ASDs and to describe the clinical characteristics of a group with comorbid ASDs and tics (n = 24). The overlap between tics and other repetitive movements and behaviors in ASDs was carefully assessed. Among individuals with ASDs, 22 percent presented tic disorders: 11 percent with Tourette disorder (TD), and 11 percent with chronic motor tics. All had various degrees of cognitive impairment. An association between the level of mental retardation and tic severity was found. It is concluded that the occurrence of tics in ASDs should not be overlooked and should be carefully evaluated.
Key Words: autism • pervasive developmental disorders • tics • Tourette syndrome • comorbidity of autism
Autism, Vol. 11, No. 1, 19-28 (2007)
© 2007 The National Autistic Society, SAGE Publications

Wednesday, January 17, 2007

Mental Illness: Religiosity and Psychosocial Adjustment

Religiosity, Psychosocial Adjustment, and Subjective Burden of Persons Who Care for Those With Mental Illness

Aaron B. Murray-Swank, Ph.D., Alicia Lucksted, Ph.D., Deborah R. Medoff, Ph.D., Ye Yang, M.S., Karen Wohlheiter, M.S. and Lisa B. Dixon, M.D., M.P.H.

OBJECTIVE: The purpose of this study was to characterize the nature of religious and spiritual support received by family caregivers of persons with serious mental illness and to test hypotheses that religiosity would be associated with caregiver adjustment.
METHODS: Eighty-three caregivers who participated in a study of the Family to Family Education Program of the National Alliance on Mental Illness were assessed at baseline in terms of their religiosity and receipt of spiritual support in coping. They also completed measures of depression, self-esteem, mastery, self-care, and subjective burden. Hierarchical regression was used to test hypotheses that religiosity would be associated with better adjustment, with confounding variables controlled for.
RESULTS: Thirty-seven percent of participants reported that they had received spiritual support in coping with their relative's illness in the previous three months. When age, race, education, and gender were controlled for, religiosity was associated with less depression and better self-esteem and self-care. Personal religiosity was a stronger predictor of adjustment than religious service attendance.
CONCLUSIONS: Family caregivers of persons with serious mental illness often turn to spirituality for support, and religiosity may be an important contributor to caregiver adjustment. Collaborative partnerships between mental health professionals and religious and spiritual communities represent a powerful and culturally sensitive resource for meeting the support needs of family members of persons with serious mental illness.
Psychiatr Serv 57:361-365, March 2006
© 2006 American Psychiatric Association

Tuesday, January 16, 2007

B vitamin: role in cognitive function

Vitamin B6, B12, and Folic Acid Supplementation and Cognitive Function
A Systematic Review of Randomized Trials

Ethan M. Balk, MD, MPH; Gowri Raman, MD; Athina Tatsioni, MD; Mei Chung, MPH; Joseph Lau, MD; Irwin H. Rosenberg, MD
Tufts-New England Medical Center Evidence-based Practice Center, Institute for Clinical Research and Health Policy Studies, Tufts-New England Medical Center (Drs Balk, Raman, Tatsioni, and Lau and Ms Chung), and Nutrition and Neurocognition Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University (Dr Rosenberg), Boston, Mass.
Background. Despite their important role in cognitive function, the value of B vitamin supplementation is unknown. A systematic review of the effect of pyridoxine hydrochloride (hereinafter "vitamin B6"), cyanocobalamin or hydroxycobalamin (hereinafter "vitamin B12"), and folic acid supplementation on cognitive function was performed.
Methods. Literature search conducted in MEDLINE with supplemental articles from reviews and domain experts. We included English language randomized controlled trials of vitamins B6 and/or B12 and/or folic acid supplementation with cognitive function outcomes.
Results. Fourteen trials met our criteria; most were of low quality and limited applicability. Approximately 50 different cognitive function tests were assessed. Three trials of vitamin B6 and 6 of vitamin B12 found no effect overall in a variety of doses, routes of administration, and populations. One of 3 trials of folic acid found a benefit in cognitive function in people with cognitive impairment and low baseline serum folate levels. Six trials of combinations of the B vitamins all concluded that the interventions had no effect on cognitive function. Among 3 trials, those in the placebo arm had greater improvements in a small number of cognitive tests than participants receiving either folic acid or combination B-vitamin supplements. The evidence was limited by a sparsity of studies, small sample size, heterogeneity in outcomes, and a lack of studies that evaluated symptoms or clinical outcomes.
Conclusion. The evidence does not yet provide adequate evidence of an effect of vitamin B6 or B12 or folic acid supplementation, alone or in combination, on cognitive function testing in people with either normal or impaired cognitive function.
Archives of Internal Medicine 2007, Vol. 167 No. 1, 21-30
© 2006 American Medical Association.

Monday, January 15, 2007

Weight loss: Nonpharmacologic strategy

The Effect of Weight Loss on C-Reactive Protein

Elizabeth Selvin, PhD, MPH; Nina P. Paynter, MHS; Thomas P. Erlinger, MD, MPH

Background. Several studies suggest that weight loss reduces C-reactive protein (CRP) level; however, the consistency and magnitude of this effect has not been well characterized. Our objective was to test the hypothesis that weight loss is directly related to a decline in CRP level.

Data Sources. We searched the Cochrane Controlled Trials Register and MEDLINE databases and conducted hand searches and reviews of bibliographies to identify relevant weight loss intervention studies.
Study Selection We included all weight loss intervention studies that had at least 1 arm that was a surgical, lifestyle, dietary, and/or exercise intervention. Abstracts were independently selected by 2 reviewers.

Data Extraction. Two reviewers independently abstracted data on the characteristics of each study population, weight loss intervention, and change in weight and CRP level from each arm of all included studies.

Data Synthesis. We analyzed the mean change in CRP level (milligrams per liter) and the mean weight change (kilograms), comparing the preintervention and postintervention values from each arm of 33 included studies using graphical displays of these data and weighted regression analyses to quantify the association.

Results. Weight loss was associated with a decline in CRP level. Across all studies (lifestyle and surgical interventions), we found that for each 1 kg of weight loss, the mean change in CRP level was –0.13 mg/L (weighted Pearson correlation, r = 0.85). The weighted correlation for weight and change in CRP level in the lifestyle interventions alone was 0.30 (slope, 0.06). The association appeared roughly linear.

Conclusion. Our results suggest that weight loss may be an effective nonpharmacologic strategy for lowering CRP level.

Author Affiliations: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, and Welch Center for Prevention, Epidemiology, and Clinical Research, The Johns Hopkins University, Baltimore, Md (Dr Selvin and Ms Paynter), and Department of Internal Medicine, University of Texas Medical Research, Austin (Dr Erlinger).
Archives of Internal Medicine. Vol. 167 No. 1, 31-39, 2007.
© 2006 American Medical Association.

Friday, January 12, 2007

High-functioning autism: non-social cognitive tests

Disembedding performance in children and adolescents with Asperger syndrome or high-functioning autism

Nils Kaland Erik Lykke Mortensen Lars Smith
Høgskolen i Lillehammer,Norway

The aim of the present study was to assess the findings, reported in earlier studies, that individuals with autism spectrum disorders process visuo-spatial tasks faster than typically developing control persons. The participants in the present study were children and adolescents with Asperger syndrome (AS) or high-functioning autism (HFA) (N = 13), and a matched group of typically developing children and adolescents (N = 13). The results showed that the participants in the clinical group performed marginally less well than those in the control group on both the Block Design Test and the Embedded Figures Test, but the differences were not statistically significant. Thus, earlier findings suggesting that individuals with autism spectrum disorders solve non-social cognitive tasks faster than typically developing control persons were not replicated. The results are discussed with special reference to the hypothesis of weak central coherence.

Key Words: Asperger syndrome • high-functioning autism • non-social cognitive tests • response times
Autism, Vol. 11, No. 1, 81-92 (2007)
© 2007 The National Autistic Society

Thursday, January 11, 2007

Rotavirus vaccine


Alan R. Shaw­
Vaxinnate, Cranbury, New Jersey 08512; email:

Rotavirus is the single most common cause of acute, dehydrating gastroenteritis worldwide. This is a highly contagious and highly democratic disease. The attack rate in infants and young children is similar regardless of sanitation, socioeconomics or geography. Rotavirus vaccine development began in the early 1980s using a "Jennerian" approach based on rotaviruses that normally infect animals. Although these vaccines were found to be generally safe, protection from disease was inconsistent. The second generation of vaccines was based on the same animal viruses configured to carry the relevant coat proteins of human rotaviruses. An attenuated human rotavirus vaccine has also been developed. After close to 20 years of laboratory and clinical studies, safe and effective rotavirus vaccines are approaching regulatory approval. Full Text

Annual Review of Medicine 2006, Vol. 57: 167-180

Wednesday, January 10, 2007

Depressive disorders: Screening and Risk Factors

There are several tools that are useful for screening children and adolescents for possible depression. They include the Children's Depression Inventory (CDI) for ages 7 to 17; and, for adolescents, the Beck Depression Inventory (BDI) and the Center for Epidemiologic Studies Depression (CES-D) Scale. When a youngster screens positive on any of these instruments, a comprehensive diagnostic evaluation by a mental health professional is warranted. The evaluation should include interviews with the youth, parents, and when possible, other informants such as teachers and social services personnel.
Risk Factors
In childhood, boys and girls appear to be at equal risk for depressive disorders; but during adolescence, girls are twice as likely as boys to develop depression. Children who develop major depression are more likely to have a family history of the disorder, often a parent who experienced depression at an early age, than patients with adolescent- or adult-onset depression. Adolescents with depression are also likely to have a family history of depression, though the correlation is not as high as it is for children.
Other risk factors include:
  • Cigarette smoking
  • Stress
  • A loss of a parent or loved oneBreak-up of a romantic relationship
  • Attentional, conduct or learning disorders
  • Chronic illnesses, such as diabetes
  • Abuse or neglect
  • Other trauma, including natural disasters
  • Treatment
Treatment for depressive disorders in children and adolescents often involves short-term psychotherapy, medication, or the combination, and targeted interventions involving the home or school environment. There remains, however, a pressing need for additional research on the effectiveness of psychosocial and pharmacological treatments for depression in youth. While data from adults indicate the need for maintenance treatment after episode recovery in order to prevent recurrences, the value of such treatment in children and adolescents has yet to be determined through research.
Psychotherapy. Recent research shows that certain types of short-term psychotherapy, particularly cognitive-behavioral therapy (CBT), can help relieve depression in children and adolescents. CBT is based on the premise that people with depression have cognitive distortions in their views of themselves, the world, and the future. CBT, designed to be a time-limited therapy, focuses on changing these distortions. An NIMH-supported study that compared different types of psychotherapy for major depression in adolescents found that CBT led to remission in nearly 65 percent of cases, a higher rate than either supportive therapy or family therapy. CBT also resulted in a more rapid treatment response.

Another specific psychotherapy, interpersonal therapy (IPT), focuses on working through disturbed personal relationships that may contribute to depression. IPT has not been well investigated in youth with depression; however, one controlled study found that IPT led to greater improvement than clinical contact alone.
Continuing psychotherapy for several months after remission of symptoms may help patients and families consolidate the skills learned during the acute phase of depression, cope with the after-effects of the depression, effectively address environmental stressors, and understand how the young person's thoughts and behaviors could contribute to a relapse.
Medication. Research clearly demonstrates that antidepressant medications, especially when combined with psychotherapy, can be very effective treatments for depressive disorders in adults. Using medication to treat mental illness in children and adolescents, however, has caused controversy. Many doctors have been understandably reluctant to treat young people with psychotropic medications because, until fairly recently, little evidence was available about the safety and efficacy of these drugs in youth.

In the last few years, however, researchers have been able to conduct randomized, placebo-controlled studies with children and adolescents. Some of the newer antidepressant medications, specifically the selective serotonin reuptake inhibitors (SSRIs), have been shown to be safe and efficacious for the short-term treatment of severe and persistent depression in young people, although large scale studies in clinical populations are still needed. So far, there are two controlled studies showing efficacy of fluoxetine and paroxetine, respectively. It is important to note that available studies do not support the efficacy of tricyclic antidepressants (TCAs) for depression in youth.

Medication as a first-line course of treatment should be considered for children and adolescents with severe symptoms that would prevent effective psychotherapy, those who are unable to undergo psychotherapy, those with psychosis, and those with chronic or recurrent episodes. Following remission of symptoms, continuation treatment with medication and/or psychotherapy for at least several months may be recommended by the psychiatrist, given the high risk of relapse and recurrence of depression. Discontinuation of medications, as appropriate, should be done gradually over 6 weeks or longer.

Talking With Parents
It is very important for parents to understand their child's depression and the treatments that may be prescribed. Physicians can help by talking with parents about their questions or concerns, reinforcing that depression in youth is not uncommon, and reassuring them that appropriate treatment with psychotherapy, medication, or the combination can lead to improved functioning at school, with peers, and at home with family. In addition, referring the youth and family to a mental health professional and to the information resources listed at the back of this publication can help to enhance recovery.

Tuesday, January 09, 2007

Major depressive disorder: Symptoms and Signs

Depressive disorders to Adults, Children, and Adolescents
Depressive disorders, which include major depressive disorder (unipolar depression), dysthymic disorder (chronic, mild depression), and bipolar disorder (manic-depression), can have far reaching effects on the functioning and adjustment of young people. Among both children and adolescents, depressive disorders confer an increased risk for illness and interpersonal and psychosocial difficulties that persist long after the depressive episode is resolved; in adolescents there is also an increased risk for substance abuse and suicidal behavior. Unfortunately, these disorders often go unrecognized by families and physicians alike. Signs of depressive disorders in young people often are viewed as normal mood swings typical of a particular developmental stage. In addition, health care professionals may be reluctant to prematurely "label" a young person with a mental illness diagnosis. Yet early diagnosis and treatment of depressive disorders are critical to healthy emotional, social, and behavioral development.
A number of epidemiological studies have reported that up to 2.5 percent of children and up to 8.3 percent of adolescents in the U.S. suffer from depression. An NIMH-sponsored study of 9- to 17-year-olds estimates that the prevalence of any depression is more than 6 percent in a 6-month period, with 4.9 percent having major depression. In addition, research indicates that depression onset is occurring earlier in life today than in past decades. A recently published longitudinal prospective study found that early-onset depression often persists, recurs, and continues into adulthood, and indicates that depression in youth may also predict more severe illness in adult life. Depression in young people often co-occurs with other mental disorders, most commonly anxiety, disruptive behavior, or substance abuse disorders, and with physical illnesses, such as diabetes.
Clinical Characteristics
The diagnostic criteria and key defining features of major depressive disorder in children and adolescents are the same as they are for adults. However, recognition and diagnosis of the disorder may be more difficult in youth for several reasons. The way symptoms are expressed varies with the developmental stage of the youngster. In addition, children and young adolescents with depression may have difficulty in properly identifying and describing their internal emotional or mood states. For example, instead of communicating how bad they feel, they may act out and be irritable toward others, which may be interpreted simply as misbehavior or disobedience. Research has found that parents are even less likely to identify major depression in their adolescents than are the adolescents themselves.
Symptoms of Major Depressive Disorder Common to Adults, Children, and Adolescents:
  • Persistent sad or irritable mood
  • Loss of interest in activities once enjoyed
  • Significant change in appetite or body weight
  • Difficulty sleeping or oversleeping
  • Psychomotor agitation or retardation
  • Loss of energy
  • Feelings of worthlessness or inappropriate guilt
  • Difficulty concentrating
  • Recurrent thoughts of death or suicide

Five or more of these symptoms must persist for 2 or more weeks before a diagnosis of major depression is indicated.

Signs That May Be Associated with Depression in Children and Adolescents
  • Frequent vague, non-specific physical complaints such as headaches, muscle aches, stomachaches or tiredness
  • Frequent absences from school or poor performance in school
  • Talk of or efforts to run away from home
  • Outbursts of shouting, complaining, unexplained irritability, or crying
  • Being bored
  • Lack of interest in playing with friends
  • Alcohol or substance abuse
  • Social isolation, poor communication
  • Fear of death
  • Extreme sensitivity to rejection or failure
  • Increased irritability, anger, or hostility
  • Reckless behavior
  • Difficulty with relationships

While the recovery rate from a single episode of major depression in children and adolescents is quite high, episodes are likely to recur. In addition, youth with dysthymic disorder are at risk for developing major depression. Prompt identification and treatment of depression can reduce its duration and severity and associated functional impairment.

National Institute of Mental Health

Sunday, January 07, 2007

Vitamin D: risk of multiple sclerosis

High levels of vitamin D in the body may decrease the risk of multiple sclerosis
The possibility that vitamin D could help protect people from developing multiple sclerosis (MS) has been posited by researchers in recent decades, but evidence to support that link has been scant. In the first large-scale, prospective study to investigate the relationship between vitamin D levels and MS, researchers at the Harvard School of Public Health (HSPH) have found an association between higher levels of vitamin D in the body and a lower risk of MS.

“If confirmed, this finding suggests that many cases of MS could be prevented by increasing vitamin D levels. Although these levels could be increased by taking supplements, before any recommendation is made it is important to establish whether we are seeing a true causal association or whether vitamin D levels are only a marker of MS risk,” said Alberto Ascherio, senior author of the study and associate professor of nutrition and epidemiology at HSPH.
MS is a chronic degenerative disease of the central nervous system. It affects some 350,000 people in the U.S. and 2 million worldwide, and occurs most commonly in young adults. Women, who are affected more than men, have a lifetime risk of about 1 in 200 in the U.S. Vitamin D is a hormone manufactured naturally in the body, and its levels can be increased with exposure to sunlight, consumption of foods rich in vitamin D, such as fatty fish, and by taking supplements.
The researchers, led by Ascherio, worked in collaboration with colleagues in the U.S. Army and Navy to determine whether vitamin D levels measured in healthy young adults predict their future risk of developing MS. The investigation relied on a study population of more than 7 million individuals, whose serum samples are stored in the Department of Defense Serum Repository. Between 1992 and 2004, 257 U.S. Army and Navy personnel with at least two serum samples stored in the repository were diagnosed with MS. A control group, consisting of participants who did not develop MS, was randomly selected from the study population. Serum samples were analyzed for levels of 25-hydroxyvitamin D, a good indicator of vitamin D availability to tissues, and individuals were divided into five groups of equal size according to their average levels. Because vitamin D levels are strongly influenced by skin color, separate analyses were conducted among whites, blacks, and Hispanics.
The results showed that, among whites, MS risk declined with increasing vitamin D levels—the risk was 62% lower among individuals in the top fifth of vitamin D concentration (corresponding approximately to levels above 100 nmol/L or 40 ng/mL) than among those in the bottom fifth (approximately below 63 nmol/L or 25 ng/mL). The association was strongest among individuals who were younger than 20 when they first entered the study. No significant association was found among blacks and Hispanics, possibly because of a smaller sample size and the lower levels of vitamin D found in those groups. The average age of onset of MS cases was 28.5 years old; there was no significant difference in the results between men and women.
“The results of this study converge with a growing body of experimental evidence supporting the importance of vitamin D in regulating the immune system and suppressing autoimmune reactions, which are thought by most experts to play a key role in the development of MS,” said Ascherio. Kassandra Munger, first author and a doctoral candidate in nutrition at HSPH, added, “The amount of vitamin D that is needed to reach levels associated with MS protection is largely considered safe, and in fact higher vitamin D levels could be beneficial to prevent osteoporosis and other chronic diseases.”
The researchers note that there could be other possible explanations for the protective role of vitamin D. For example, it’s possible that exposure to UV light from the sun—the major determinant of serum levels of 25-hydroxyvitamin D—could protect people in other ways than increased vitamin D production.
The authors suggest further studies exploring how vitamin D may protect individuals from developing MS. “Although the results of this study are quite encouraging, reasonable certainty of a protective effect of vitamin D supplements requires direct experimental evidence in a large trial. Meanwhile, we are planning to expand our study to obtain more accurate data on the importance of age and of the vitamin D levels that need to be achieved for optimal protection,” said Ascherio.
Harvard School of Public Healt

Saturday, January 06, 2007

ADHD — Common Questions

Attention-Deficit/Hyperactivity Disorder (ADHD) — Common Questions

As they learn more about Attention-Deficit/Hyperactivity Disorder (ADHD), many parents will have similar questions and concerns. Here are answers to a few of the more frequently asked questions. Also remember that your pediatrician is available to answer your questions and discuss your concerns.

Will My Child Outgrow ADHD?
ADHD continues into adulthood in most cases. However, by developing their strengths, structuring their environments, and using medication when needed, adults with ADHD can lead very productive lives. In some careers, having a high-energy behavior pattern can be an asset.

Why Do so Many Children Have ADHD?
The number of children who are being treated for ADHD has risen. It is not clear whether more children have ADHD or more children are being diagnosed with ADHD. ADHD is now one of the most common and most studied conditions of childhood. Because of more awareness and better ways of diagnosing and treating this disorder, more children are being helped.

Are Schools Putting Children on ADHD Medication?
Teachers are often the first to notice behavior signs of possible ADHD. However, only physicians can prescribe medications to treat ADHD. This follows a careful process of diagnosis.

Are Children Getting High on Stimulant Medications?
There is no evidence that children are getting high on stimulant drugs such as methylphenidate and amphetamine. These drugs also do not sedate or tranquilize children and have no addictive properties.
Stimulants are classified as Schedule II drugs by the US Drug Enforcement Administration. There are some reports of abuse of this class of medication. If your child is on medication, it is always best to supervise the use of the medication closely.

Are Stimulant Medications "Gateway" Drugs Leading to Illegal Drug or Alcohol Abuse?
People with ADHD are naturally impulsive and tend to take risks. But those patients with ADHD who are taking stimulants are actually at lower risk of using other drugs. Children and teenagers who have ADHD and also have coexisting conditions may be at high risk for drug and alcohol abuse, regardless of the medication used.

Excerpted from "Understanding ADHD" from the American Academy of Pediatrics. For more information about this brochure, click here.

Friday, January 05, 2007

Sleep apnea

Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome may be defined as a cessation of breathing characterized by repetitive episodes of airway obstruction caused by collapse of the upper airway during sleep. Classic features of patients with obstructive sleep apnea syndrome include:

  • Excessive daytime sleepiness
  • Loud snoring during sleep
  • Fatigue
  • Obesity or being overweight

Research has suggested that there is a strong association between obstructive sleep apnea syndrome and cardiovascular diseases including:

  • Hypertension - high blood pressure
  • Congestive heart failure - accumulation of fluids in the lungs and other body tissues caused by insufficient pumping of blood by the heart muscles
  • Arrhythmias - irregular heart beats
  • Stroke
  • Angina pectoris - chest pain that occurs in people with underlying coronary artery disease

Polysomnography (overnight sleep test) is considered to be the most accurate test available for establishing the diagnosis of obstructive sleep apnea syndrome in adults. During polysomnography, episodes of apnea (cessation of breathing lasting for 10 seconds or longer) and hypopnea (decreased rate and depth of breathing lasting 10 seconds or longer) are recorded. The number of apnea/hypopnea episodes per hour of sleep is calculated and is expressed as the apnea-hypopnea index (AHI). Most experts agree that an AHI score of 5 or higher in patients with excessive daytime sleepiness is sufficient to establish the diagnosis of obstructive sleep apnea syndrome.

In general, the treatment options for patients with obstructive sleep apnea syndrome include:

  • Lifestyle modifications (e.g., weight loss; smoking cessation; avoiding sleeping in the supine position)
  • Continuous positive airway pressure (CPAP)
  • Oral appliances
  • Surgery

Thursday, January 04, 2007

Mental imagery and autonomic reactivity in children

Effects of self-induced mental imagery on autonomic reactivity in children

Developmental and Behavioral Pediatrics, Case Western Reserve University. Cleveland, Ohio, USA.

The purposes of this research study were: (1) to determine whether changes in cardiac rate, skin temperature, and/or electrodermal activity occur as children change mental imagery and (2) to determine whether such changes are related to age, sex, or other variables.

Children who were evaluated in this study had no previous experience with hypnosis or biofeedback training and were in good health with no learning disabilities. Thirty-eight boys and 38 girls ranging in age from 5 to 15 years were studied in a comfortable setting with a constant room temperature and biofeedback equipment. A Procomp 5DX computer software unit was used to measure autonomic reactivity during baseline and mental processing periods. After baseline monitoring indicated stabilization of autonomic measures, each child was asked to think about being in a quiet, pleasant place for 120 seconds. Pulse rate, skin temperature, and electrodermal activity were recorded. A resting period followed, and each child was then asked to think about an exciting activity, such as a preferred sports activity, for another 120 seconds. At the end of this monitoring, each child was asked to describe what had been his/her mental imagery during the two monitoring periods. Data analysis used paired t tests and repeated measures analysis of variance. For all children, the pulse rates showed significant decreases (p < .001) during quiet and relaxing imagery and significant increases (p < .001) during active imagery. Skin temperatures increased significantly (p < .001) during quiet imagery and active imagery, whereas electrodermal activity decreased (p < .001) during active imagery. Observed changes did not relate to age or sex.

The results confirm our clinical observations that deliberate changing of mental imagery by children results in immediate autonomic changes. Questions evolving from this study and similar studies done in adults are: (1) Do average-thinking processes impact on autonomic changes over long periods of time and (2) do these changes ultimately impact on health, such as cardiovascular status?

J Dev Behav Pediatr. 1996 Oct;17(5):323-7.