Excessive Gestational Weight Gain and Risk of Childhood Obesity

I have become increasingly interested in the role that excessive gestational weight gain plays in the childhood obesity epidemic.  Obviously a woman is supposed to gain weight during pregnancy, but nationally about 50% of pregnant women gain more weight than is recommended by the Institute of Medicine for a healthy pregnancy.  In our birth cohort in New York City 64% of the mothers gained more weight during pregnancy than is recommended and excessive gestational weight gain was associated with a three fold increase in the odds of obesity for the child at age 7.  Excessive gestational weight gain was also associated with larger waist circumference and higher percentage body fat for the child at age 7.  The paper is on pubmed [here].

I was also interviewed about our research on New York’s WNBC [see here].


Prenatal Phthalate Exposure and Childhood Obesity


Diethyl phthalate

My team just published a paper assessing the links between prenatal exposures to phthalates and childhood body size at age 5 and 7.  Using data from the Columbia Center for Children’s Environment Health we measured nine metabolites of six phthalates (di-(2-ethylhexyl) phthalate (DEHP), di-n-octyl-, di-iso-butyl-, di-n-butyl-, butylbenzyl-, and diethyl phthalates) in urine samples collected from pregnant women during their third trimester.  Body size and body composition data were collected from their children at ages 5 and 7.

Because the 9 metabolites represent a fairly complex, inter-correlated mixture of chemicals we applied Principal Component Analyses to identify major patterns of metabolite concentrations in the maternal urine samples.  Two prominent patterns of metabolite concentrations were identified: 1) a pattern representing variation in DEHP metabolite concentrations, and, 2) a pattern representing variation in non-DEHP phthalate metabolite concentrations.   In boys, higher concentrations of non-DEHP metabolites in maternal urine were associated with lower BMI z-score, lower fat percentage and smaller waist circumference. Among boys, body size outcomes were not associated with higher DEHP metabolite concentrations and among girls body size outcomes were not associated with either pattern of phthalate metabolites in maternal urine.

These findings were actually contrary to our hypotheses, past cross-sectional studies have suggested that phthalate exposures are associated with higher risk for obesity.


Antibiotic use during pregnancy and childhood obesity

My team working on the Childhood Obesity Project in Columbia Center for Children’s Environmental Health recently published an article showing that a woman’s use of antibiotics during pregnancy is associated with heightened risk of obesity in her child at age 7.  In addition, children born by C-section also had a higher risk of obesity.  The underlying idea is that antibiotic use during pregnancy and birth by C-section alters the normal transmission of bacteria from the mother to the child and that disturbances in the development of the ecosystem of gut bacteria that live within each of us influences our risk of weight gain. A similar idea underlies another recent paper I co-authored that showed that having pets in the home may alter the link between delivery by C-section delivery childhood obesity risk.

Our work on antibiotic use was picked up by the NYTimes, FoxNews.com and USAToday.


CEO.com article: Staying Healthy while on Business Trips

My colleague Dr. Michael Friedman and I recently wrote an op-ed piece for CEO.com on staying healthy while traveling for business.  A couple of years ago my student and I published a research article showing that among those who traveled for business, chronic disease health conditions correlated with the extent of travel, this was particularly true for obesity risk.  Analyses from the World Bank show the same pattern of results for their employees; medical claims for all conditions are higher among those who travel the most on World Bank business.

Now Michael and I are starting to think about concrete recommendations for how business travelers can avoid unhealthy lifestyle choices while they are on the road and how they can maintain their health while they are away from home. Our piece for CEO.com was our first efforts to put some ideas out their.


CartoDB maps of graffiti reports in NYC

I have started working with CartoDB a web based GIS tool that allows you to map and animate spatial data.  I downloaded reports of graffiti over the last several years from the NYC open.gov data site and was able to create this map showing the density of reports across NYC; darker red colors indicate more reports. CartoDB can also create animations of time sequence data.

Graffiti_smOne issue I ran into was that most of the NYC data uses the State Plane Coordinate system for point data while CartoDB and most other GIS tools require Longitude and Latitude data.  I found a program called Corpscon6 from the US Army Corps of Engineers that batch converts State Plan Coordinate data to Long and Lat data.  NYC usually uses the NAD83-feet format and you want to set the zone to “3104 – New York State Long Island”.

Most implementations of WordPress won’t let you embed the CartoDB maps and animations, so you will need to click out of my blog to see it (click here).


Making of our Knight Foundation News Challenge Video

My team recently submitted a project idea to the Knight Foundation News Challenge “How can we harness data and information for the health of communities?”  Out of the 643 entries submitted to the Knight Foundation News Challenge, our project “Open CANVAS: A Web Application Harnessing Google Street View to Collect and Share Data on Neighborhoods” was one of the 40 projects selected as finalists.  Each team was asked to revise their projects for the next round of review and to make a 30 second video explaining the project.

Here is the video we came up with…


How we made the video:

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Obesity and Prostate Cancer Risk

I just published a new paper linking obesity to an increased risk of prostate cancer after an initial benign biopsy that is getting some nice media attention.  Our work shows that among men who have had a prostate biopsy that was negative for cancer, obese men, as compared to normal weight men, had a significantly higher risk of being diagnosed with prostate cancer in the years following that initial biopsy.  This risk was particularly high for a diagnosis occurring in the first four years after biopsy.  We also found that obesity was associated with the presence of pre-cancerous cells in the initial biopsy.

We know that obese men have a higher risk of dying of prostate cancer, but medical science hasn’t determined whether obesity puts men at a higher risk of developing prostate cancer or makes it more difficult to survive prostate cancer (or both).  This new work, particularly the finding that obesity is associated with the presence of pre-cancerous cells in otherwise benign biopsy specimens, suggests that obesity may be involved in the development of prostate cancer.

NYTimes.com, NBC.com and the Huffington Post have reported on the research and the NY Times is scheduled to write about it in the Tuesday Science Times.


Beware the for-profit academic journals and conferences

The NY Times had an interesting article on the rise of pseudo-scientific journals and conference organizations that basically dupe scientists into publishing, speaking at conferences or sitting on editorial boards and charge them a fee for doing so.  These journals have names very similar to well known academic journals but charge ‘page fees’ to scientists for publishing an article online, in an open-access format.  The article singles out the OMICS Publishing group, which publishes ~250 open-access “journals”, as being one of the major purveyors of these journals.  I get endless email from the OMICS journals asking me to submit papers, often from journals that appear to have nothing to do with my research area.  I also get endless emails from conferences in China asking me to give key note speeches on topics I don’t research.

An area the article did not cover, but is a potentially more troubling phenomena I have seen, is when industry groups buy the intellectual property of established but defunct journals and then turn them into mouth pieces for industry interests. A related trick is when industry groups publish a Supplement issue to a journal and use this special issue as a vehicle for industry funded studies.    The Journal presumably takes a fee (1) for publishing the Supplement issue but the editorial stance seems to be controlled by the industry group.   I recently saw a special issue in which the list of guest editors of the special issue almost exactly overlapped with the executive board of the industry group that funded the issue and the findings of the articles supported the stated positions of the industry group.

(1) A couple of years ago I helped organize a conference and when we approached established journals about publishing a special/supplemental issue based on the papers presented at the conference we found the cost was up to $50K.


Making Illustrations with PowerPoint

I have written previously about the value of including graphics in publications, here I show some ways to create your own graphics.  PowerPoint provides some solid vector graphics tools that can be used to create illustrations.  The image below was created entirely in PowerPoint using the Shape, Edit Shape –> Edit Points and the Shape Fill Gradient tools.

Slide1 Continue reading


CNN Editorial

CNN.com just published my editorial on the value of Body Mass Index (BMI) as an indicator of obesity related health risks.  The editorial comments on a recent paper my students and I wrote looking at the relative value of various anthropometric measures (BMI, Fat mass index, Fat-free mass index, Waist circumference, Waist-to-height ratio and Percent body fat) for predicting blood pressure, fasting blood glucose, HDL and LDL-cholesterol levels.