Weight of the Nation

A perspective article, NEJM 2012; 367: 389-391, addresses the topic of whether Americans are ready to solve the problem of obesity.  Short answer: No!

The article discusses the Institute of Medicine (IOM) report “Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation” along with the accompanying HBO documentary (HBO: The Weight of the Nation).

“The centerpiece of THE WEIGHT OF THE NATION campaign is the four-part documentary series, each featuring case studies, interviews with our nation’s leading experts, and individuals and their families struggling with obesity. The first film, CONSEQUENCES, examines the scope of the obesity epidemic and explores the serious health consequences of being overweight or obese. The second, CHOICES, offers viewers the skinny on fat, revealing what science has shown about how to lose weight, maintain weight loss and prevent weight gain. The third, CHILDREN IN CRISIS, documents the damage obesity is doing to our nation’s children. Through individual stories, this film describes how the strong forces at work in our society are causing children to consume too many calories and expend too little energy; tackling subjects from school lunches to the decline of physical education, the demise of school recess and the marketing of unhealthy food to children. The fourth film, CHALLENGES, examines the major driving forces causing the obesity epidemic, including agriculture, economics, evolutionary biology, food marketing, racial and socioeconomic disparities, physical inactivity, American food culture, and the strong influence of the food and beverage industry.”

While the IOM report identifies a need for structural changes in our environment, public opinion consistently focuses on personal responsibility.

  • 64% identify overeating, lack of exercise, and watching too much TV as the biggest causes
  • 18% identify external factors as the biggest causes, including exposure to junk food, lack of safe places to play, limited availability of healthy foods

Obstacles for addressing this problem also include the following:

  • Obesity-prevention efforts may further stigmatize individuals. The article specifically cites criticism aimed at ‘ads that aired in Georgia;’ these were pulled after concerns of increasing obesity stigma.
  • “Issue-attention cycle” problem.  “This pattern occurs when initial public alarm over the discovery of a problem and optimism about its quick resolution are replaced by the realization that solving the problem will require some public sacrifice and will displace powerful societal interests.”

Related blog posts:

Is obesity neglect?

NAFLD Guidelines 2012

Treating diabetes with surgery

Lower leptin with physical activity

Staggering cost of obesity

Iron and hepcidin –not just for grownups

As alluded to in a previous post (Help with hepcidin), hepcidin is integral to iron metabolism.  In a recent study (J Pediatr 2012; 160: 949-53), serum and urine hepcidin concentrations in preterm infants were found to correlate well with iron homeostasis markers in preterm infants.

This study examined 31 preterm infants (23-32 weeks gestational age).

Findings:

  • Serum hepcidin was highest in infants with systemic inflammation.
  • Both serum and urine hepcidin correlated strongly with ferritin (Figure 2 in study) and negatively with soluble transferrin receptor/ferritin-ratio.
  • Infants with lower hemoglobin concentrations and higher reticulocyte counts had lower serum hepcidin.
  • There was good correlation between urine and serum hepcidin (Figure 1 in study). As such, urine hepcidin may become useful non-invasive marker for iron status in sick preterm infants

Long-chain polyunsaturated fatty acids, breastmilk, and infant cognition

A lot has been written about improving infant cognition and breastfeeding, even on this blog (More evidence that breastfeeding improves cognitive development).  Formula companies in their efforts to duplicate the nutritional value of breast milk have supplemented with a number of agents, including long-chain polyunsaturated fatty acids (LCPUFA).  But, does this work?

A meta-analysis of LCPUFA supplementation failed to show any significant effect on early infant cognition (Pediatrics 2012; 129: 1141-49).  Twelve trials with 1802 infants met inclusion criteria.  Included trials were randomized clinical studies that measured cognition with Bayley Scales of Infant Development.

LCPUFAs have been hypothesized to be a potential reason for improved cognition.  LCPUFAs are vital for cell membranes and play a critical role in development and growth.  The two main LCPUFAs are docosahexaenoic acid (DHA) and arachidonic acid (AHA). “An estimated 30-fold increase in the amount of DHA and AA in the infant forebrain occurs between the last trimester of pregnancy and the first 2 years of life.”

The authors note that while breastfed babies tend to have higher intelligence, confounding factors have made it difficult to determine whether actual nutritional differences in breast milk are the reason for this difference.  On average, breastfeeding mothers have higher intelligence, larger incomes, and spend more time with their infants.  Thus, bonding/social interactions as well as other breast milk properties (eg antimicrobial, antiinflammatory, and immunomodulatory) may be important factors.

On the same subject, a second article in the same issue (Pediatrics 2012; 129: 1134-40) also showed that breastfed infants had slightly improved cognitive development compared with formula-fed babies (both cow’s milk and soy formula).  This conclusion was based on Bayley Scales of Infant Development and the Preschool Language Scale-3.  In total, this study examined 391 infants at ages 3, 6, 9, and 12 months.  The authors state that “models were used while adjusting for socioeconomic status, mother’s age and IQ, gestational age, gender, birth weight, head circumference, race, age, and diet history”  –that’s a lot of variables to adjust!

More on breast milk from previous blog entries:

Breastfed babies less likely to develop fatty liver

Breastfeeding: protection from asthma

Pediatric NAFLD Position Paper

A previous blog post (NAFLD Guidelines 2012) described comprehensive, up-to-date NAFLD guidelines from AASLD, AGA, and ACG.   Another group of experts from ESPGHAN (European Society for Pediatric Gastroenterology, Hepatology, and Nutrition) has also published a position paper on the diagnosis of NAFLD in children; coincidentally, these were published recently as well (JPGN 2012; 54: 700-13).

While there is some overlap in the information between the two guidelines, there are some notable differences.  The JPGN manuscript does include a nice differential diagnosis list  which can cause fatty liver disease (Table 2), including some rare entities like Dorfman-Chanarin syndrome, Cantu syndrome, Madelung lipomatosis, and numerous medications.  This review has more emphasis on etiology.

Table 3 lists a recommended workup in children with suspected NAFLD:

  • Standard liver function tests/blood counts/coagulation studies
  • Fasting glucose & insulin
  • Lipid profile
  • Glucose tolerance test & glycosylated hemoglobin
  • Calculation of HOMA-IR, markers of insulin resistance

AND Tests to exclude other liver diseases: 

  • Lactate, uric acid, iron, ferritin, pyruvate
  • Copper, ceruloplasmin, 24-hour urinary copper
  • Sweat test
  • Celiac serology (TTG IgA and serum IgA)
  • α-1-antitrypsin levels and phenotype when indicated
  • Amino and organic acids
  • Plasma free fatty acids and acyl carnitine profile
  • Urinary steroid metabolites
  • Other specific tests as suggested by evaluation (eg. viral hepatitis panel, serum immunoglobulins, liver autoantibodies)

When one looks at the recommended diagnostic algorithm (Figure 1) and tests outlined, these guidelines are not nearly as practical as the NAFLD guidelines from AASLD, AGA, and ACG and often contradictory between the tables/figures and the text.  How much would it cost for the recommended testing if/when extrapolated to the vast numbers of individuals with these disorders?  In addition, a much more limited diagnostic approach is suggested in the final section than outlined in Table 3 and Figure 1.

Imaging: these authors advocate LFTs and ultrasonography in all obese children (> 3 years) and adolescents.  If normal LFTS and sonography, the algorithm suggests the use of MRI if clinical signs of insulin resistance.  Later, the authors conclude “MRI is not cost-effective.”

Liver Biopsy: while the authors state that there is “no present consensus or evidence base to formulate guidelines” for liver biopsy, this is not well-reflected in their diagnostic algorithm in which arrows point to liver biopsy in almost everyone –either early liver biopsy or eventual biopsy in patients with persistent disease.  Accepted liver biopsy indications, according to the executive summary, include the following:

  • Exclude other treatable disease
  • Suspected advanced disease
  • Before pharmaceutical/surgical treatment
  • Research purposes

My conclusion about this position paper is it is less helpful than the AASLD/AGA/ACG guidelines.  In fact, when extensive diagnostic testing is recommended by experts, it is fortunate that other expert guidelines are available that support a more cost-effective approach.  In NAFLD cases that seem atypical and especially in the very young patient, this reference may still be helpful.

Is obesity neglect?

Usually not –according to a thoughtful commentary on this controversial topic (J Pediatr 2012; 160: 898-99).

Suggested criteria for child removal:

  • 1. High likelihood for serious and imminent harm
  • 2. Reasonable likelihood that coercive intervention will be effective
  • 3. Absence of alternative options for addressing the problem

However, “allowing a child to lose all opportunity to live into healthy adulthood when effective treatment is available runs contrary to the central mission of child rearing…When this occurs, regardless of the cause, it must be all about the child, and something must be done.”

Related blog posts:

Treating diabetes with surgery

Lower leptin with physical activity

Staggering cost of obesity

Additional references:

Breastfeeding: protection from asthma

Good news for breastfed babies –breastfeeding may reduce risk of wheezing and asthma for several years (J Pediatr 2012; 160: 991-6).

In this prospective birth cohort study of 1105 infants from New Zealand, detailed feeding information was obtained at 3, 6, and 15 months which allowed calculation of breastfeeding duration. This information was correlated with information about wheezing and asthma collected at 2, 3, 4, 5, and 6 years.

Findings (after controlling for confounding variables):

  • Each month of exclusive breastfeeding was associated with significant reductions in asthma at all timepoints.  The effect was most prominent at younger ages.
  • The authors estimate that if every infant in the cohort had been exclusively breastfed for 6 months, that asthma would have been reduced by 50% at 2 years, 42% at 3 years, 30% at 4 years, 42% at 5 years, and 32% at 6 years.
  • In atopic children, the effects of exclusive breastfeeding are more pronounced.  In this study, exclusive breastfeeding for ≥3 months reduced asthma at ages 4, 5, and 6 by 62%, 55%, and 59% respectively.

The authors note that not all studies have found that breastfeeding improves asthma.  However, most of these studies reported outcomes in older children.

Related Posts:

Breastfed babies less likely to develop fatty liver

More evidence that breastfeeding improves cognitive development

Additional references:

  • -NEJM 2011; 364: 701, 769.  Living on a farm decreases risk of childhood asthma.
  • -Thorax 2009; 64: 604-9. Breastfeeding and asthma in children followed for 8 years.
  • -Br Med J 2007; 335: 815-20.  Longer time of breastfeeding does not reduce allergy/asthma. n=17,046 pairs of mother-infant (13,889 followed up at age 6.5yrs)

TODAY is worrisome for a lot of tomorrows

The TODAY study (NEJM 2012; 366: 2247-56 and editorial 2315-16) =Treatment Options for Type 2 Diabetes in Adolescents and Youth.

While the study has a catchy acronym, the findings are disturbing.  Eligible patients (n=699) were 10 to 17 years old were followed on average over 3.86 years; they were divided into three groups:

  • Metformin 1000mg BID –48% achieved primary outcome (glycated hemoglobin <8% for at least 6 months).
  • Metformin with lifestyle changes –53% achieved primary outcome.  The lifestyle counseling that patients received in the study likely exceeded the typical counseling that most patients receive in clinical practice.
  • Metformin with rosiglitazone (4mg BID) –61% achieved primary outcome.  While this group had the best glycemic response, this group also had the greatest increase in BMI.

Other findings:

Comorbid conditions were common:

  • Hypertension: at baseline in 81 (11.6%) and new cases during study 155 (22.2%)
  • Dyslipidemia (LDL): at baseline in 23 (3.3%) and new cases during study 49 (7%)
  • Triglyceridemia: at baseline in 127 (18.2%) and new cases during study 70 (10%)
  • Microalbuminurina: at baseline in 44 (6.3%) and new cases during study 72 (10.3%)

Frequent adverse events noted with medications (Table 2 in study): gastrointestinal symptoms noted in about half of all study participants in each group, rash noted in about 40%, and elevated LFTs in about 40%.

Take home messages (borrowed from editorial):

“Most youth with type 2 diabetes will require multiple oral agents or insulin therapy within a few years after diagnosis”

“Fifty years ago, children did not avoid obesity by making healthy choices; they simply lived in an environment that provided fewer calories and included more physical activity.”

“Public-policy approaches–sufficient economic incentives to produce and purchase healthy foods and to build safe environments that require physical movement…will be necessary to stem the epidemic of type 2 diabetes and its associated morbidity.”

Related posts:

Treating diabetes with surgery

Cardiovascular disease for the entire family

Staggering cost of obesity

Lower leptin with physical activity

Reasons for refeeding syndrome

Refeeding syndrome (RFS) is defined as the potentially fatal shifts in fluid and electrolytes that may occur in malnourished patients who are abruptly refed either enterally or parenterally.  The biochemical hallmark is hypophosphatemia.  Other changes can include hypokalemia, hypomagnesemia, and thiamin deficiency.  RFS can worsen the prognosis of children with celiac crisis as well (JPGN 2012; 54: 522-5).

A chart review from Lucknow, India from Jan-Dec 2010, identified 5 cases of RFS among 35 celiac patients.  All were severely malnourished.  All had anemia, hypoalbuminemia, hypophosphatemia, hypokalemia, and hypomagnesemia.  All improved with initial caloric restriction followed by gradual escalation of caloric intake along with electrolyte supplementation.

This article shows that a variety of causes of malnutrition can lead to refeeding syndrome. Considering refeeding syndrome in any severely malnourished child may help improve the prognosis by altering the nutritional management.

Additional references:

  • Nutr Clin Pract 2012; 27: 34-40. Reviewed refeeding syndrome publications since 2000.  Hypophosphatemia occurred in 96% of cases (26 of 27).
  • Crit Care Med 2010; 14: R172-R178.  Refeeding syndrome with anorexia.
  • Nutrition 2010; 26: 156-67. Review of refeeding syndrome treatment.
  • Nutr Clin Pract 2008; 23: 166-71.  Death due to refeeding syndrome.
  • JPEN 1990: 14.1; 90-97. Refeeding syndrome review.
  • Crit Care Med 1990; 18: 1030-1033. Review.